Livestock Science - Articles in Press

The validity of n-alkanes to estimate intake and digestibility in Nellore beef cattle fed a tropical grass (Brachiaria brizantha cv. Marandu) - Corrected Proof

2010-08-27

Abstract: The objective of the present experiment was to evaluate the ability of n-alkanes to estimate dry matter (DM) intake (DMI) and digestibility (DMD) in Nellore beef cattle fed a tropical grass cut at two growth stages (30 or 60days). The effect of two different faecal sampling procedures (daily pool–Total- or rectal spot–Spot–samples) was also tested. Differences in faecal concentration between sampling methods were lower than 2% and 0.7% for 30-d and 60-d old grass, respectively, with slightly higher values in Spot samples. Faecal recoveries were not affected by the grass growth stage, except in the cases of C31, C33, and C35 (P<0.05), which were lower for 30-d compared to 60-d. There was lower ratio (P<0.05) between internal and external recovery alkane pairs C31/C32, C33/C32 and C35/C36 in treating 30-d treatment than in 60-d old grass. Faecal recovery of natural alkanes increased with chain length, recoveries up to 77.0% (C35), whereas dosed alkanes C28, C32 and C36 showed average recoveries of 94.2%, 97.2% and 86.8%, respectively. Estimates of DMI were different from current values (P<0.05) when used C31/C32, C33/C32 and C35/C36 natural/dosed alkane pairs, regardless of the sampling procedure. An exception was the DMI estimated using the C35/C36 alkane pair of the samples of total sampling, which does not differ from the actual values (P>0.05). However, using recovery-corrected faecal concentrations reduced the differences between observed and estimated values (P>0.05). Similarly, the DMD was underestimated with the alkanes C31, C33 and C35, regardless of the method of sampling. Observed effect of forage development stage in the estimates of DMD (P<0.05), (lower values for 30-d treatment were observed than in the 60-d), due to lower faecal recovery of alkanes in the 30-d treatment. By correcting the concentrations of alkanes with the faecal recovery of the individual alkane, the differences between the estimated and actual values were canceled (P>0.05), regardless of age of forage, the alkane used or the sampling method.

Principal components analysis applied to genetic evaluation of racing performance of Thoroughbred race horses in Korea - Corrected Proof

Jong-Eun Park, Jeong-Ran Lee, Seungyoon Oh, Jin Woo Lee, Hee-Seok Oh, Heebal Kim — 2010-08-23

Abstract: Selection of proper phenotypic trait among various traits related with interesting performance plays an important role in genetic evaluation. In this study, principal components analysis (PCA) was adapted to generate a new index as a measure of racing performance of 12,279 horses. This method allows us to reduce the number of variables considered in the evaluation of the horses' racing performance, which may facilitate modeling genetic programs. The resulted racing time, earning prize and rank were selected for generating new indices as the representation of racing performance of the horses. Three indices used in this study were: 1) PCA1 generated from the modified values of racing time, earning prize and rank, 2) PCA2 generated from the modified racing time and rank, and 3) the adjusted racing time. The first principal components (PCs), elements in the eigenvector corresponding to the largest eigenvalue of PCA, of PCA1 and PCA2 explained the variance of the selected variables about 75.6% and 75.4% respectively. Linear combinations of the first PCs and adjusted variables were used as new performance indices. Those animal models were composed of significant explanatory variables selected by Akaike information criterion (AIC). Heritability and repeatability were 0.324 (±0.026) and 0.334 (±0.034) for adjusted racing time, 0.319 (±0.014) and 0.326 (±0.018) for PCA1, and 0.324 (±0.010) and 0.332 (±0.012) for PCA2 respectively. Estimated heritabilities and repeatabilities for three indices showed similar values for domestic racing records. However, models using PCA showed better fitting for data than model using racing time as a performance index. The proposed methodology is efficient to evaluate the total variance in this group of correlated traits, allowing reduction in the number of variables for genetic evaluation and construction of better fitting model.

A meta-analysis of the effects of supplemental dietary fat on protein and fibre digestibility in the horse - Corrected Proof

J. Sales, P. Homolka — 2010-08-23

Abstract: Any associative effects between supplemental dietary fat and nutrient digestibility would have an influence in the calculation of digestible energy and nutrient values of horse diets. However, these effects are inconsistently reported in the literature. The use of meta-analysis, which accounts for variation among studies, could quantify differences in nutrient digestibility caused by fat supplementation. Too few studies have presented data on intake to evaluate the relation between dietary fat intake and nutrient digestibility through a modelling approach. Consequently, unitless standardised effect sizes (Hedges' g) were calculated within studies for differences in digestibility between supplemented and non-supplemented diets. Twenty-two studies were identified that provided 43 comparisons for apparent total tract digestibility of crude protein (CPD), 44 for neutral detergent fibre digestibility (NDFD), and 30 for acid detergent fibre digestibility (ADFD). The calculation of mean effect sizes across studies by fixed effects models presented significant (P<0.001) heterogeneity with all outcomes. Given that the causes of heterogeneity could not effectively be identified by meta-regression and subgroup analyses, random effects models, which include between-study and within-study variation, were used to summarise effect sizes. Compared to no supplementation, added fat had no effect (mean effect size=0.204; 95% confidence intervals=−0.101 to 0.509; P=0.191) on CPD. Dietary fat supplementation did not affect NDFD (mean effect size=−0.126; 95% confidence intervals=−0.429 to 0.176; P=0.413); however, it caused a significant (P=0.008) decrease in ADFD (mean effect size=−0.430; 95% confidence intervals=−0.749 to −0.111). With the limited value of acid detergent fibre in practical feed formulation, current results indicate that the calculations of digestible energy values of fat supplemented horse diets will not be influenced by associative fibre effects.

Future of NSP-degrading enzymes to improve nutrient utilization of co-products and gut health in pigs - Corrected Proof

R.T. Zijlstra, A. Owusu-Asiedu, P.H. Simmins — 2010-08-20

Abstract: Globally, the amount of co-products in swine diets is expected to continue to increase, resulting in the feeding of diets with a higher content of non-starch polysaccharides (NSP) than traditional cereal-based diets. Such diets may open up opportunities for NSP-degrading enzyme to improve nutrient digestibility and voluntary feed intake and thereby reduce the risk of feeding diets high in co-products. The link between supplemental enzymes and nutrient digestibility is understood; however, links to other underlying mechanisms in digestive physiology, e.g., intestinal microbial populations and physical characteristics of digesta to benefit gut health and voluntary feed intake are not well understood. Seven presenters highlighted unique components of these links between NSP, enzymes, and digestive physiology. Suggested critical gaps in knowledge were: a better understanding of the changes in enzyme substrates during processing, feedstuff components other than nutrients and NSP (antibiotic residues, mycotoxins), and the impact that co-products may play on altering gut health and feed intake. In conclusion, supplemental enzymes in the correct combination and proportions may play an important role in efficient and effective nutrient use of co-products in swine diets, but their effects on gut health warrant further investigation.

Estimation of genetic parameters for milk urea nitrogen and its relationship with milk constituents in Iranian Holsteins - Corrected Proof

Navid Ghavi Hossein-Zadeh, Mehrnaz Ardalan — 2010-08-20

Abstract: The objectives of this study were to estimate the heritability of milk urea nitrogen (MUN) concentration in the first three parities and describe the genetic and phenotypic relationship between MUN and other milk constituents in Iranian Holstein dairy cows. Test-day records including MUN data obtained from 57,301 dairy cows on 20 large dairy herds in Iran between January 2005 and June 2009. Genetic parameters for MUN and productive traits were estimated using random regression test-day models. Regression curves were modeled using Legendre polynomials of order 3. Coefficient of variation for MUN was 38.76%. Average estimated heritabilities for MUN were from 0.14 to 0.21 over the parities. Phenotypic trend of MUN increased significantly over the years. Also, average phenotypic correlations of MUN with milk production traits were low and generally close to zero. The average genetic correlation was close to zero for MUN and lactose percentage (−0.01); was moderately positive for MUN and net energy concentration of milk (0.31), fat percentage (0.21), protein percentage (0.30), total solids (0.29), solids-not-fat (0.26), and milk yield (0.24), and was negative for MUN and somatic cell score (−0.04). Herd-test day explained 46% to 52% of the variation in MUN across the parities, which suggests that management adjustments at herd-level can reduce MUN. This study shows that it is possible to influence MUN by herd practice and by genetic selection.

Effects of feeding whole crop rice combined with soybean oil on growth performance, carcass quality characteristics, and fatty acids profile of Longissimus muscle and adipose tissue of pigs - Corrected Proof

H.F. Wang, J.A. Ye, C.Y. Li, J.X. Liu, Y.M. Wu — 2010-08-20

Abstract: This study was conducted to determine the effects of soybean oil supplementation on growth performance, carcass characteristics and fatty acids composition in muscle and adipose tissue of pigs fed on whole crop rice (WCR, variety bc1). Forty-eight pigs (Duroc × Landrace × Yorkshire, 36kg) were randomly assigned to four treatments with three replications each. The diets included the ground WCR at levels of 0, 8, 12 or 16% and supplemented with soybean-oil at levels of 0, 2, 3 and 4 %, accordingly replacing the maize, and designated as control C, T1, T2 and T3, respectively. All pigs at about 90kg were slaughtered to determine carcass quality and fatty acid composition. In growing period, the daily feed intake was significantly lower for pigs fed the diets containing WCR than for those on the control diets. The pigs on T3 diet had significantly lower average daily gain (735g/day) than those on C (806g/day), T1 (808g/day) or T2 (827g/day) diets (P<0.05). The feed conversion ratio was significantly lower in pigs on T1 (2.79) or T2 (2.72) diets than on the control (2.98) (P<0.05). No significant difference was found in daily feed intake, average daily gain and feed conversion ratio among pigs on different diets in finishing period (P>0.05). The carcass characteristics did not differ among different treatments (P>0.05). The water holding capacity of loin muscle was significantly lower for pigs fed diets containing WCR than for those on the control (P<0.05). There were no significant differences in meat color, marbling, pH and cooking loss among pigs on different diets. The concentration of saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) in back fat decreased significantly with the inclusion of soybean oil in the diet (P<0.05). The same trend was showed in Longissimus muscle, and SFA in T1 and MUFA in T3 were significantly lower than those in the control (P<0.05), respectively. The polyunsaturated fatty acid (PUFA), n-6 PUFA and n-3 PUFA were significantly higher in the Longissimus muscle and backfat of pigs fed diet with soybean oil and WCR than those in the control (P<0.05). The Longissimus muscle and back fat of pigs fed the diet with soybean oil and WCR were significantly higher in PUFA/SFA and lower in n-6/n-3 ratio than those of the control (P<0.05), with exception of the ratio of n-6/n-3 in muscle for T1. The study suggests that whole crop rice could be used as a feed ingredient for growing-finishing pigs with soybean-oil supplementation and that the treatment including soybean oil would improve the fatty acid profile of the carcass as food for humans.

Polymorphisms identification and associations of KLF7 gene with cattle growth traits - Corrected Proof

2010-08-19

Abstract: The Kruppel-like factor KLF7 gene was studied as a candidate for genetic markers of growth traits. We investigated the growth traits at different ages of 1002 Chinese cattles belonging to four breeds and applied artificially created restriction site (ACRS)-PCR-RFLP and DNA sequencing methods to reveal three SNPs: NC_007300:g.41401C>T (p.F54F), 42025T>C and 42075A>G. The statistical results indicated there was a strong linkage not only between C41401T and T42025C in Jiaxian, but also between T42025C and A42075G in Qinchuan, Nanyang and Chinese Holstein respectively (r2>0.33). Significant statistical differences in genotypic frequencies at the three loci displayed that the polymorphisms were remarkably correlated with cattle breeds by χ2 test (P<0.001). In addition, the cattle with genotype T2T2, C2C2 (T42025C), A3A3 (A42075G), haplotype C1C1C2C2A3A3 and C1T1T2C2A3G3 showed better growth traits (P<0.01). The biochemical and physiological functions, together with the results obtained in our investigation, suggest that the KLF7 gene might play important roles affecting growth traits in cattle.

Mineral digestibility and environmental issues. Efficacy and interactions of phytases - Corrected Proof

Rainer Mosenthin, Jiri Broz — 2010-08-19

Abstract: Means to reduce excretion of both P and trace elements such as Cu and Zn in pig manure include better agreement between supply and requirement and development of comprehensive strategies to improve biological availability of these elements, e.g. by using organic rather than inorganic mineral sources. However, comparison of results between studies is often confounded by the response criteria used for measuring the efficiency of different mineral sources. Low digestibility of P in feed ingredients remains the main problem, although it can be partly alleviated by supplementing pig diets with microbial phytases, and by using highly digestible mineral phosphates. More recently, research has focused on ways to manipulate pig's gut environment by adding organic acids or prebiotic substances (e.g. ß-glucans) to the diet in order to improve P digestibility. Eventually, cross reactions of feed enzymes such as exogenous microbial phytases and non-starch polysaccharide (NSP) degrading enzymes with microbial fermentation processes through changes in intestinal pH may affect both enzyme activity and efficiency.

Risk factors and rates of perinatal and postnatal mortality in cattle in Switzerland - Corrected Proof

U. Bleul — 2010-08-17

Abstract: There have been many studies on perinatal and postnatal mortality in calves, but most are limited to small numbers of breeds or herds. The goal of this study was to determine the perinatal (first 24h) and postnatal mortality rates during the first four months in 22 breeds and cross-breeds commonly occurring in Switzerland and to identify possible risk factors. From 2005 to 2007, 2,122,184 calvings were analysed, which yielded an overall perinatal mortality rate of 2.4%. There was a significant yearly increase in the mortality rate. The postnatal mortality rates from days 2 to 7, 8 to 28 and 29 to 120 were 0.5%, 1.3% and 0.7%, respectively. Dystocia was associated with a relative risk of perinatal mortality of 12.2, and significantly affected the postnatal mortality rates in all time periods investigated. The overall dystocia rate associated with bull calves was more than twice that of heifers, but there was no sex-related difference in Dexter, Hereford, Highland cattle, Hinterwälder, Jersey und Normande breeds. There were significant correlations between the mean birth weights of the different breeds and the dystocia rate (r=0.6), and between the mean difference in male and female birth weights of the different breeds and the dystocia rate (r=0.6). Perinatal mortality was also significantly affected by age of dam, gestation length, sex and weight of calf, season and herd size. Breed had a significant effect on perinatal and postnatal mortality rates, and there were significant interactions between breed and other risk factors of mortality. The identification of breed-specific risk factors of perinatal and postnatal mortality could help to develop strategies to alleviate the problem.

Influence of phytase and carbohydrase enzymes on apparent ileal nutrient and standardized ileal amino acid digestibility in growing pigs fed wheat and barley-based diets - Corrected Proof

E. Kiarie, A. Owusu-Asiedu, P.H. Simmins, C.M. Nyachoti — 2010-08-16

Abstract: Effects of phytase with or without carbohydrases on utilization of nutrients other than P are not well understood in diets adequate in P. Thus, we investigated the effects of Phyzyme XP® (PX) and carbohydrase enzymes (Porzyme®: xylanase and β-glucanase; C) on coefficients of ileal nutrient digestibility (CAID) in growing pigs fed wheat/barley-based diets. The diets were: 1) basal (B, 8% less DE than NRC, 1998, with no enzymes), 2) B+PX, 3) B+PX+50g C/MT (B+PX+50C) and 4) B+PX+100g C/MT (B+PX+100C). The PX was added at 100g/MT to all phytase containing feed, and C was added at 50 and 100g/MT to diets 3 and 4, respectively. Acid insoluble ash was used as an indigestible marker. Diets were fed to 4 barrows (BW 35.9±1.4kg) fitted with a T-cannula at the distal ileum, according to a 4×4 Latin square design. Experimental periods lasted 7d and ileal digesta were collected in 12-h periods on d-6 and d-7. At the end of the 4-wk period, pigs were fed a 5% casein diet to estimate basal endogenous AA losses. Data were subjected to pre-planned contrasts. Overall, diets containing PX had higher (P<0.05) CAID of energy (0.60 vs. 0.58), AA (0.72 vs. 0.69) and phytate (0.56 vs. 0.33) compared with the B diet. When corrected for basal endogenous losses, PX-containing diets had higher (P<0.05) coefficients of standardized ileal digestibility (CSID) of Met and Thr than the B diet. In the presence of PX, the highest response to C for CAID of energy (0.59 vs. 0.62) was achieved at 50g/MT; the AID of DM and energy increased (P<0.05) by 7.2 and 7.0%, respectively, with 50g/MT of C compared to B diet. In conclusion, phytase and carbohydrase combined increased CAID of energy, and that PX-containing diets not only increased CAID of AA but resulted in lower diet-specific endogenous losses in a practical diet.

Gastro-intestinal digesta pH, pepsin activity and soluble mineral concentration responses to supplemental phytic acid and phytase in piglets - Corrected Proof

T.A. Woyengo, O. Adeola, C.C. Udenigwe, C.M. Nyachoti — 2010-08-16

Abstract: Effect of phytic acid (PA) and phytase on gastro-intestinal digesta pH, soluble mineral concentration and pepsin activity in piglets was investigated. Twenty four piglets (initial body weight=7.60±0.73kg; mean±SD) were randomly assigned to 3 experimental diets to give 8 piglets per diet. The diets consisted of a casein-cornstarch-based diet with 0, 2% PA (as sodium phytate), or 2% PA plus phytase at 500FTU/kg. The basal diet was formulated to meet NRC (1998) amino acids requirements for piglets. After consuming experimental diets for 10days, the piglets were killed and digesta sampled from the stomach and jejunum for pH, pepsin activity, and soluble mineral determination. Phytic acid decreased (P<0.01) jejunal digesta pH from 7.13 to 6.61. Phytic acid also decreased (P<0.05) stomach digesta pepsin activity by 46%; jejunal Ca2+ and Mg2+ concentrations by 60 and 85%, respectively; but increased (P<0.0001) jejunal Na+ concentration by 57%. Phytase did not influence (P>0.05) any of the response criteria measured in this study. It is concluded that supplemented PA reduces pepsin activity in the stomach, pH in jejunum, and concentrations of soluble Ca and Mg in the jejunum; and increases Na secretion in the jejunum of piglets. Thus, it appears that PA reduces nutrient utilization in pigs partly through reduced stomach pepsin activity and altered mineral solubility in the small intestine.

Current genetic profile of sheep breeds/populations from Northwestern semi arid zone of India - Corrected Proof

R. Arora, S. Bhatia, D.K. Yadav, B.P. Mishra — 2010-08-16

Abstract: This study examines the genetic profiles of seven sheep breeds/populations of the Northwestern semi arid zone of India based on microsatellite markers. The coarse wooled sheep viz., Jalauni, Sonadi, Muzzafarnagri, Patanwadi, Kheri, Malpura and Munjal were analyzed with 25 microsatellite markers to determine within breed variability, genetic differentiation and relationships among them. The mean number of alleles across all the populations ranged from 6.8 to 8.7, whereas the gene diversity varied from 0.657 to 0.744. These observations reveal a considerable amount of genetic diversity available within these seven breeds/populations. Significant positive within population inbreeding estimates (FIS) were observed for all the breeds/populations which suggested a deficiency in the number of heterozygotes. The relative magnitude of global genetic differentiation was 7.9% thereby implying moderate levels of discrimination among all populations. The pair-wise genetic distance (DA) and genetic differentiation (FST) between these breeds/populations revealed Kheri and Malpura to be the closest, whilst the highest degree of genetic differentiation was found between Muzzafarnagri and Sonadi which was also supported by the tree topology. The generated information sheds light into the current genetic status and relationship between these sheep and can be utilized for their effective conservation and management.

Free-stall cleanliness is affected by stall design - Corrected Proof

L.E. Ruud, C. Kielland, O. Østerås, K.E. Bøe — 2010-08-16

Abstract: The objective of this study was to describe free-stall design and free-stall contamination in a cross sectional field study and to evaluate the effect of free-stall design on free-stall cleanliness. Five trained observers recorded cleanliness and use of bedding in 7 different sectors in 15 random selected free-stalls in each of 232 dairy herds. Of these, 8 herds were excluded from the statistical analyses due to stalls recently being cleaned out despite instructions not to do so. The observers also recorded the position of head and neck rails as well as stall width and construction of a possible brisket locator. The free-stall base was divided into seven sectors and the cleanliness of each sector was scored using a five grade scale reflecting the degree of contamination of each section. Two types of contamination were registered; faeces fallen on stall base (FAECES) and wet footprints (FOOT). Mean stall base length was 2.39 (±0.21) m when placed against wall and 2.23 (±0.11) m in a double row. Mean height of the neck rail was 1.07 (±0.05) m, upper head rail 0.90 (±0.15) m and lower head rail 0.37 (±0.18) m. Contamination was mainly observed in the three rear sectors of the stalls. The most important factors in improving stall cleanliness on the basis of FAECES, in ranked order, were found to be: amount of bedding >1.0L, diagonal stall length≤1.96m, absence of lower head rail, stall length<2.30m, brisket locator distance≤1.83m, stall width>1.13m and upper head rail >0.70m. Regarding FOOT contamination, the most important preventive factors were, in ranked order: amount of bedding >0.5L, soft stall base with >0.5L of bedding, brisket locator height≤0.10m, upper head rail >1.0m, concrete stall base and stall width≤1.13m.

Analysis of water, feed intake and performance of lactating sows - Corrected Proof

S. Kruse, I. Traulsen, J. Krieter — 2010-08-13

Abstract: The aim of the present study was to investigate the relationship between water, feed intake, relative body weight loss, and the weaning weight of piglets of lactating sows and to analyse the curves of water and feed intake. Data recording was performed on the Hohenschulen research farm of the Institute of Animal Breeding and Husbandry of the University of Kiel between April 2007 and June 2008. The sow herd had a size of 105 productive sows. The average water and feed intake, relative body weight loss of sows and the weaning weight of the piglets were 27.5lday−1, 5.9kgday−1, 0.5% and 8.7kg, respectively. Average lactation length was 26days. Water intake increased from day 1 to day 16 of lactation and remained constant until weaning. Second parity class sows had an increased water intake over the lactation period compared to younger and older sows. They also consumed more feed than older sows (6.1kgday−1 versus 5.7kgday−1). The water-to-feed ratio decreased at the beginning until day eight of lactation. After a slight increase the water-to-feed ratio remained constant. The lactation period was divided into three stages (Stage 1: days 1 to 8 of lactation, Stage 2: days 9 to 16 and Stage 3: days 17 to 26). The correlation of water intake between adjacent stages was high 0.76 and 0.80. The relation of feed intake between Stages 1 and 2 and between Stages 1 and 3 was low. The correlation of the water and feed intake within the stages increased more than between these traits and different stages. But the negative values indicated that an increased water intake decreased the relative body weight loss. The relation between the second and third stages of feed intake of lactation and relative body weight loss showed that an increased feed intake decreased relative body weight simultaneously with an increase in the weaning weight of the piglets.

Evaluation of different microbial phytases on phosphorus digestibility in pigs fed a wheat and barley based diet - Corrected Proof

H.D. Poulsen, K. Blaabjerg, A. Strathe, P. Ader, D. Feuerstein — 2010-08-12

Abstract: Phytase increases the availability of phytate phosphorus (P) in plant feedstuffs resulting in a reduced need for inorganic P addition and therefore minimized P excretion. Thus, the majority of pig feed is supplemented with microbial phytases. The present study aimed to examine three commercial phytases: one fungal 3-phytase from Aspergillus ficuum and two formulations of a bacterial 6-phytase from E. coli. The basal diet was composed of wheat, barley, soybean and rapeseed meal supplemented with vitamins and minerals without any added inorganic phosphate. Calcium was adjusted to 6.3g/kg in the basal diet which was heat-treated at 90°C. Phytase was then added at 250, 500 and 750FTU/kg diet. A negative control without added phytase was included (plant phytase <100FTU/kg DM). The experiment comprised 10 treatments of 6 pigs (45kg) kept in metabolism crates and fed one of the 10 diets for 12days, 5days for adaptation and 7days for total collection of faeces. The P digestibility of the negative control was 31%, which increased significantly to 45, 50 and 53% when phytases were added at 250, 500 or 750FTU/kg, respectively. The study showed the same efficacy for the fungal 3-phytase and the two bacterial 6-phytases on P digestibility at all three tested levels. The increase in P digestibility was greatest in the dosage range from 0 to 250FTU/kg, while the increase was linear in the range between 250 and 750FTU/kg.

Genetic associations of conformation, finishing precocity and muscling visual scores with mature weight in Nelore cattle - Corrected Proof

A.A. Boligon, M.E.Z. Mercadante, L.G. Albuquerque — 2010-08-11

Abstract: Were estimate (co)variance and genetic associations between conformation, finishing precocity and muscling visual scores measured at weaning (SCW, SFW and SMW, respectively) and yearling (SCY, SFY and SMY, respectively) with mature weight (MW) in Nelore cows, in order to predict the possible changes that inclusion of visual scores in beef cattle selection indices would bring to female mature weight. The data set contained records of 36,757 females, born between 1993 and 2006, belonging to the Jacarezinho cattle raising farm. (Co)variance components were estimated by bivariate animal models using Bayesian inference method through Gibbs sampling, assuming a linear model for MW and a nonlinear (threshold) model for conformation, finishing precocity and muscling visual scores. The first 10,000 rounds were considered as the burn-in period and discarded. The posterior means of direct heritability distributions were: 0.16±0.02 (SCW); 0.20±0.02 (SFW); 0.19±0.02 (SMW); 0.24±0.02 (SCY); 0.31±0.02 (SFY); 0.32±0.02 (SMY) and 0.46±0.04 (MW). Estimates of genetic correlations between visual scores and MW were positive and moderate, ranging from 0.27±0.06 to 0.36±0.04. Visual scores and MW should respond favorably to direct selection. Mature weight can be used in Nelore breeding programs designed to monitor the cows' size. Selection of animals with higher conformation, finishing precocity and muscling scores, especially at yearling, should promote an increase in cows' mature weight.

Shiga toxin-producing Escherichia coli isolated from human and pig origin induce different gene expression profiles in human Caco-2 epithelial cells - Corrected Proof

2010-08-09

Abstract: Porcine oedema disease is caused by Escherichia coli serotypes that produce potent Shiga toxins. Our aim was to compare the pathogenic potential of porcine and human Shiga toxin-producing E. coli (STEC) isolates harbouring the same panel of clinically important virulence genes in a Caco-2 epithelial cell culture system. The response of Caco-2 cells to STEC infection was investigated by trans-epithelial-electrical-resistance and microarray analysis. Porcine isolates induced a greater reduction in barrier function at 4hours compared to human isolates. A total of 44 genes were differentially expressed in Caco-2 cells exposed to porcine and human isolates. We concluded that while porcine STEC strains had the potential to affect human epithelial cells, they demonstrated host specific mechanisms of virulence that were different to the human isolates.

Dried chicory root has minor effects on the digestibility of nutrients and the composition of the microflora at the terminal ileum and in faeces of growing pigs - Corrected Proof

Mette Skou Hedemann, Knud Erik Bach Knudsen — 2010-08-09

Abstract: The present investigation aimed to study digestibility of nutrient at the terminal ileum and the total tract, and the impact on microbial composition at the two sites. Four experimental diets based on wheat with increasing amounts of dried chicory root (0, 8.6, 17.2 or 25.8%) were formulated. The diets were fed to four pigs fitted with a T-canula at the terminal ileum according to a Latin square design. The digestibility of nutrients, except non-starch polysaccharides, was not affected by the experimental diets at the terminal ileum. The concentration of short chain fatty acids (SCFA) and lactic acid in ileal digesta was unaltered. The digestibility of organic matter and energy in faeces was not affected by the amount of fructan in the diets but the digestibility of protein decreased with increasing content of fructan and surprisingly the digestibility of fat increased. The concentration of SCFA in faeces was unaffected by the dietary composition and it was only the molar proportion of the iso-acids that was influenced by diet. The proportion of iso-acids decreased with increasing amount of fructan in the diets. The composition of the microflora in ileal digesta and faeces was not influenced by the diets as shown by T-RFLP. In conclusion, diets containing high amount of fructan only induced minor changes in nutrient digestibility whereas no alterations of the composition of microflora could be detected. This indicates that growing pigs are well adapted for consumption of high amounts of fructan.

Strategic use of feed ingredients and feed additives to stimulate gut health and development in young pigs - Corrected Proof

C.F.M. de Lange, J. Pluske, J. Gong, C.M. Nyachoti — 2010-08-09

Abstract: There is a wide interest in developing management and feeding strategies to stimulate gut development and health in newly-weaned pigs, in order to improve growth performance while minimizing the use of antibiotics and rather expensive feed ingredients, such as milk products. A better understanding of the mechanisms whereby antibiotics influence animal physiology, as well as appropriate use of disease models and in vitro techniques, will lead to the development of alternatives to in-feed antibiotic. Given the considerable advances made in the understanding of intestinal nutrient utilization and metabolism, a complimentary goal in nutrition might be to formulate young pig diets with the specific task of optimizing the growth, function and health of the gut. Important aspects of gut health-promoting pig diets are: reduced content of protein that is fermented in the pigs' gut, minimal buffering capacity, minimal content of anti-nutritional factors, and supply of beneficial compounds such as immunoglobulins. The optimum dietary level and type of fibre will vary with the nature of enteric disease challenges and production objectives. These diet characteristics are influenced by feed ingredient composition and feed processing, including feed fermentation and application of enzymes. A large number of feed additives have been evaluated that are aimed at (1) enhancing the pig's immune response (e.g. immunoglobulin; ω-3 fatty acids, yeast derived ß-glucans), (2) reducing pathogen load in the pig's gut (e.g. organic and inorganic acids, high levels of zinc oxide, essential oils, herbs and spices, some types of prebiotics, bacteriophages, and anti-microbial peptides), (3) stimulate establishment of beneficial gut microbes (probiotics and some types of prebiotics), and (4) stimulate digestive function (e.g. butyric acid, gluconic acid, lactic acid, glutamine, threonine, cysteine, and nucleotides). When manipulating gut microbiota the positive effects of gut health-promoting microbes should be weighed against the increased energy and nutrient costs to support these microbes. In some instances feed additives have been proven effective in vitro but not effective in vivo. The latter applies in particular to essential oils that have strong anti-microbial activity but appear not to be effective in controlling bacterial pathogens when fed to pigs. A combination of different approaches may provide the most effective alternative to in-feed antibiotics.

Genetic parameters for piglet survival, litter size and birth weight or its variation within litter in sire and dam lines using Bayesian analysis - Corrected Proof

Dagmar N.R.G. Kapell, Cheryl J. Ashworth, Pieter W. Knap, Rainer Roehe — 2010-08-09

Abstract: Genetic parameters for survival at birth, litter size, birth weight and its variation within litter have been estimated in dam (D1, D2 and D3) and sire lines (S1 and S2) and genetic associations among these traits were examined. Genetic parameters, calculated as posterior means, were estimated at piglet (D1 and D2; 23,565 piglets) and litter level (all lines; 3497 litters) using a Bayesian approach. Posterior means of heritabilities for survival at piglet level (SVBP) were consistently low at 0.01, 0.06 to 0.07 and 0.04 to 0.06 for direct (h2d), maternal (h2m) and total (h2t) genetic effects, respectively, with positive posterior means of correlations between the direct and maternal effect (rg-dm). For survival at litter level (SVBL) heritabilities were between 0.05 and 0.20, with highest estimates in lines with lowest birth weight. For individual piglet birth weight (IBW) heritabilities were substantially higher than for SVBP, ranging from 0.13 to 0.19 (h2d), 0.16 to 0.28 (h2m) and 0.08 to 0.28 (h2t). Heritabilities for average litter birth weight (ALBW) ranged from 0.23 to 0.34, while heritabilities for variation of birth weight within litter (STD) ranged from 0.10 to 0.27. Heritabilities for number born in total (NBT) ranged from 0.11 to 0.16. Genetic associations between SVBL and NBT varied from favourable at 0.39 (D1) to unfavourable at −0.22 (D2). Genetic correlations of SVBL with ALBW and STD were mostly favourable (0.22 to 0.55 and −0.18 to −0.52, respectively) except for SVBL-ALBW in D1 (−0.50) and SVBL–STD in S2 (0.48). In D1 favourable genetic correlations were estimated between direct or maternal effects of SVBP and IBW whereas those for D2 were unfavourable. Consistently negative correlations were estimated between direct effects of SVBP and maternal effects of IBW. Adjustment for NBT resulted in slightly higher h2d and h2m for SVBP, with unfavourable rg-dm.Selection for survival is expected to be successful because all lines showed considerable variation for this trait and relatively high heritabilities, in particular in lines with low ALBW. Maternal heritabilities of IBW were mostly at moderate magnitude and thus of interest for selection. For most lines, the correlations between traits indicate that selection on either IBW or ALBW is indirectly increasing survival at birth. The variation in heritabilities among lines indicates that the strategy of selection for an optimal birth weight with lowest variation within litter should be considered per line individually to maximise overall genetic improvement in piglet survival and growth.

Effect of concentrate supplementation at pasture and inclusion of condensed tannins (Quebracho) in concentrates on lamb performance and faecal egg and worm counts - Corrected Proof

L.E.R. Dawson, M.A. McCoy, H.W.J. Edgar, A.F. Carson — 2010-08-09

Abstract: Two studies were undertaken to evaluate the effect of concentrate supplementation at pasture and inclusion of Quebracho on the performance and faecal egg counts of lambs grazing a perennial ryegrass sward from six weeks of age until 5months of age or slaughter. In experiment 1, from six weeks of age until weaning, lambs were offered no concentrate (NC), low protein (130g metabolisable protein (MP)/kg dry matter (DM)) concentrate (LP) or high protein (160g MP/kg DM) concentrate (HP). From weaning until slaughter, lambs were offered 500g/day of LP or HP concentrate containing either zero Quebracho (T0) or 80g Quebracho/kg fresh (T80). Prior to weaning, lambs offered LP or HP concentrate had significantly greater weaning live weights (LW), liveweight gains (LWG) from birth to weaning and reduced age at slaughtered compared to those offered NC (P<0.001). Protein level had no effect on lamb performance. Lambs offered NC in the pre-weaning period had higher LWG from weaning to the end of the study relative to lambs offered LP and HP concentrate. In the post-weaning period, protein content of the concentrate had no significant effect on age at the end of the study, LWG from birth to the end of the study or carcass characteristics. There was a significant interaction between protein content and level of tannin inclusion on LWG from weaning to the end of the study. Lambs offered LP/T0 concentrate had lower LWG than those offered LP/T80, HP/T0 or HP/T80 concentrates (P<0.01). Pre and post-weaning treatment had no significant effect on Strongyle faecal egg counts or total worm counts in the abomasum or small intestine. In experiment 2, from six weeks of age until slaughter, lambs were offered no concentrate (NC), concentrates containing zero Quebracho (LP/T0), concentrate plus 80g Quebracho/kg fresh (LP/T80) and concentrate plus 100g Quebracho/kg fresh (LP/T100). The concentrate contained 130g MP/kg DM. Relative to NC treatment, concentrate supplementation increased lamb LWG from birth to weaning and from birth to the end of the study and reduced age at slaughter (P<0.01). Increasing level of tannin inclusion had no significant effect on lamb performance, faecal egg counts or total worm counts in the abomasum and small intestine. Overall in the study faecal egg counts were low and worm counts taken from slaughtered animals were less than 3000 worms per animal. The results of this work indicate that supplementing lambs with concentrates at pasture improved animal performance, but concentrate supplementation and inclusion of Quebracho had no effect on faecal egg counts.

Impacts of heat stress on baseline immune measures and a subset of T cells in Bama miniature pigs - Corrected Proof

Ju Xiang-hong, Yong Yan-hong, Xu Han-jin, An Li-long, Xu Yingmei — 2010-08-09

Abstract: Understanding the stress-associated mechanisms of immune system function and the increased susceptibility of livestock to disease is now more important than ever because the majority of emerging animal diseases have proven to be zoonotic diseases and, therefore, threaten public health. The objective of the present study was to explore the effect of a 21-day heat stress on total white blood cell (WBC) counts, differential counts, a subset of T cells, NK cytotoxicity and neutrophil phagocytosis in Bama miniature pigs aged approximately 3 to 4months. Pigs were assigned to one of two treatment groups: stress (heat, n=10) or control (no stress treatment, n=10). The results showed that the number of total WBCs was decreased in heat stressed pigs at day 7 (P≤0.05). The percentages of eosinophils and monocytes were significantly higher in stressed pigs than in control pigs at day 1 (P≤0.05). The number of CD8 T cells, unlike the CD3 and CD4 T cell, was significantly increased in heat stressed pigs compared to control pigs at day 1 and day 14 (P≤0.05). Consequently, the ratio of CD4 and CD8 T cells was reduced in stressed pigs compared to control pigs at day 14 (P≤0.05). Neither neutrophil phagocytosis nor natural killer cytotoxicity differed between the treated and control pigs at any time. The results indicate that heat stress influences CD8 T cells and the ratio of CD4 and CD8 cells. This change may play an important role in immune suppression induced by high air temperature.

Seasonal variation in time spent foraging by indigenous goat genotypes in a semi-arid rangeland in South Africa - Corrected Proof

Archibold G. Bakare, Michael Chimonyo — 2010-08-09

Abstract: The feeding behaviour of Xhosa lop-eared (XLE), Nguni (NGN) and Nguni×Boer crossbred (NBC) goat genotypes was compared in a False Thornveld rangeland by recording time spent on browsing, grazing and other non-foraging activities in four seasons; cool-dry (June to August); hot-dry (September to October), hot-wet (November to February) and post-rainy (March to May). The False Thornveld rangeland consists of diverse plant species dominated by Acacia karroo, Grewia occidentalis, Scurtia myrtina Themeda triandra, Panicum maximum, Digitaria eriantha, Eragrostis spp., Cynodon dactylon and Pennisetum clandestinum, and receives an annual rainfall of not more than 490mm. Four observers monitored 8 goats per genotype at 15-minute intervals for 4h (0800–1200h) in the morning and 4h (1200–1600h) in the afternoon. Genotype, season and time of day had an effect on the feeding behaviour of goats on the rangeland (P<0.05). Xhosa lop-eared goats spent more time browsing (P<0.05) in the cool-dry and hot-wet seasons compared to NGN and NBC goats. Nguni goats spent more time browsing (P<0.05) in the hot-dry season. Time spent grazing varied among the goat genotypes with the NBC cross spending more time grazing (P<0.05) in hot-dry, cool-dry and post-rainy seasons. Generally, season and time of day had no effect on time spent on non-foraging activities for the three goat genotypes. It was concluded that NBC goats spent more time grazing compared to other genotypes across all seasons. Conversely, XLE and NGN goat genotypes spent more time feeding on browse species across seasons. Xhosa lop-eared and NGN goat genotypes are thus adapted to the surrounding environment for they may utilise resources more efficiently.

Effect of leptin, DGAT1 and TG gene polymorphisms on the intramuscular fat of Angus cattle in Hungary - Corrected Proof

I. Anton, K. Kovács, G. Holló, V. Farkas, L. Lehel, Z. Hajda, A. Zsolnai — 2010-08-09

Abstract: The objective of this study was to estimate the effect of leptin, thyroglobulin (TG) and acylCoA-diacylglycerol-acyltransferase 1 (DGAT1) loci and linoleic acid supplemented diet on the marbling of meat in the Hungarian Angus population. All genotypes were determined by PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) assay. At leptin and TG loci TT bulls showed the highest fat percentage values in the musculus longissimus dorsi (LD) and musculus semitendinosus (ST), the difference between CC and TT genotypes was significant (p<0.05). DGAT1 AA/AA bulls had significantly higher (p<0.05) intramuscular fat content values than other genotypes. The sunflower supplemented group of bulls presented significantly higher (p<0.05) fat percentage values for LD, than the control group.

Associations between LEP, DGAT1 and FABP4 gene polymorphisms and carcass and meat traits in Nelore and crossbred beef cattle - Corrected Proof

R.A. Curi, L.A.L. Chardulo, M.D.B. Arrigoni, A.C. Silveira, H.N. de Oliveira — 2010-08-09

Abstract: The aim of this study was to estimate the segregation of leptin (LEP), diacylglycerol O-acyltransferase (DGAT1) and fatty acid-binding protein 4 (FABP4) gene polymorphisms in Nelore (Bos indicus) and Nelore×Bos taurus beef cattle, and to evaluate their effects on carcass and meat traits. A total of 300 animals were genotyped for the LEP/BsaAI (Y_11369.1:g.1620G>A), DGAT1-VNTR (18-bp repeat element in the promoter region) and FABP4/MspA1I (AAFC_01136716.1:g.7516G>C) polymorphisms and phenotyped for rib eye area, backfat thickness (BT), intramuscular fat, shear force, and myofibrillar fragmentation index. The allele substitution effects for each of the polymorphisms on the traits of interest were estimated by regression on the number of copies of a particular allele using the General Linear Model procedure. To keep the experiment wise error rate to the specified level, the Bonferroni adjustment was applied. Although the LEP/BsaAI polymorphism has shown segregation for association studies in Nelore cattle [f(A)=0.351], no associations were observed between its alleles and the traits analyzed. The DGAT1-VNTR was found to be polymorphic in Nelore cattle, as well as a potential association with BT. In addition to being non-informative in Nelore animals (allele C was found to be fixed), the FABP4/MspA1I polymorphism showed no association with the studied traits in crossbred animals.

Effect of prepartum administration of monensin on metabolism of pregnant ewes - Corrected Proof

2010-08-09

Abstract: A prospective study involving 18 pregnant ewes of Baloochi breed were conducted to measure the effect of monensin administered 40days pre-lambing on metabolic function pre-parturition and post-parturition. The pregnant ewes were randomly assigned to one of the 4 treatments: 1) were received monensin and fed an ordinary ration, 2) received monensin and fed restricted ration, 3) fed restricted ration without monensin and 4) control group which fed an ordinary ration without monensin administration. Blood was sampled from each sheep at days 60, 45, 30, 20, 15, 10, 5, 1 prior to parturition, and hour 12 and days 1, 2, 3, 4, 7, 13, 19 and 21 postpartum. The BHB concentrations significantly decreased in animals which received monensin and fed a restricted or an ordinary ration in comparison to the group which not received monensin and fed a restricted ration at prepartum period. The sheep which received monensin showed lower concentrations of NEFA in comparison to animals which were not received monensin. There was no significant effect of monensin on energy, protein indicators and electrolytes in postpartum period. However, feed restriction significantly decreased the concentrations of cholesterol, urea, albumin and Mg at post-parturition period. The results of this study indicate that administration of monensin to pregnant ewes during prepartum period had a markedly positive influence on energy indicators in late pregnancy.

Temporal expression pattern of insulin-like growth factors (IGF-1 and IGF-2) ligands and their receptors (IGF-1R and IGF-2R) in buffalo (Bubalus bubalis) embryos produced in vitro - Corrected Proof

Vikash Chandra, G. Sai Kumar, G. Taru Sharma — 2010-08-09

Abstract: The objective of the study was to assess the temporal expression of genes for IGF-1, IGF-2 and their receptors in different pre-implantation stage buffalo embryos (from oocytes to blastocyst) and to evaluate the effect of IGF-1 on culture media during in vitro buffalo embryo development. Buffalo oocytes were retrieved from slaughterhouse derived ovaries. In vitro matured oocytes were fertilized with frozen buffalo bull semen. Presumptive zygotes were cultured in modified synthetic oviductal fluid (mSOF supplemented with β-mercaptoethanol (100μM) and without (control) or with IGF-1 (100ng/ml) till blastocyst stage. For each treatment five replicates were taken. Supplementation of IGF-1 to embryo culture media resulted in significantly higher blastocyst formation rate (29.7% versus 25.6%; p<0.05) than the control group. In vitro produced embryos of different stages were stored in small amount of PBS at −70°C till used for RNA isolation. Total RNA isolated from oocytes and pre-implantation embryos was reverse transcribed to cDNA in total volume of 25μl reaction mixture using Moloney-Murine Leukemia Virus Reverse Transcriptase (MMLV-RT). Polymerase chain reaction (PCR) was performed using cDNA from different pools of oocytes and embryos. RT-PCR revealed that IGF-1 mRNA was neither expressed in oocytes (immature, matured and matured vitrified oocytes) nor at any pre-implantation stage embryos while mRNA for IGF-1R, IGF-2 and IGF-2R were detected in all oocytes as well as in all pre-implantation stage embryos. It can be concluded that supplementation of IGF-1 is useful for in vitro oocyte maturation and embryo development in buffalo.

Genetic diversity and differentiation of Ankole cattle populations in Uganda inferred from microsatellite data - Corrected Proof

2010-08-06

Abstract: A total of 304 individuals from eight Ankole cattle populations of Uganda were analysed based on 19 microsatellite markers to investigate genetic diversity, relationships and population structure. Across all loci, 200 alleles were observed. A high mean number of alleles (MNA) per locus, ranging from 5.89 to 6.79 per population, was observed. Polymorphic information content (PIC) ranged from 0.403 (ILSTS013) to 0.817 (ILSTS036), with an overall mean over all loci of 0.688. The average observed heterozygosity (Ho) was highest in Kaibanda (0.727) and lowest in Kituuha (0.648), while the expected heterozygosity (He) ranged from 0.722 (Nshaara) to 0.664 (Kituuha), though for all populations the differences were not significant. Significant deviations from Hardy–Weinberg proportions were observed over eight loci, however, all 152 loci–population combination tests were in equilibrium after Bonferroni correction. FST estimates for all loci and between all populations were highly significant (P<0.001), suggesting little if any gene flow between the populations. F-statistics at respective loci among all populations were significant, with the exception of the FIT. For all population pairs, FST values were generally low, with an overall mean of 0.041±0.08. Significant (P<0.01) inbreeding effect (FIS) was detected in only the Nasasira population. The mean number of migrants per generation (Nm) across all populations was 3.82. Relationship analysis showed populations from the same geographical counties group together. These results illustrate at the molecular level the fairly wide genetic variation found within the Ankole breed and therefore the potential for genetic improvement.

Selection of stable reference genes for quantitative real-time PCR in porcine gastrointestinal tissues - Corrected Proof

M.T. Ryan, C.B. Collins, J.V. O'Doherty, T. Sweeney — 2010-08-02

Abstract: The selection of stable reference genes is an essential aspect of controlling for the many technical variables that influence the final outcome in quantitative real-time PCR (qPCR). In this study, we evaluated the suitability of 8 commonly used reference genes based on their efficiency and dynamic range in porcine gastrointestinal tissues. The genes included ACTB, B2M, GAPDH, HMBS, HPRT, PPIA, 18S rRNA, and YWHAZ. We then sub-selected four reference genes (ACTB, B2M, GAPDH, PPIA) of ‘medium’ abundance, and evaluated their stability using the geNorm algorithm across three unchallenged and immunologically challenged (bacterial lipopolysaccharide (LPS) and concanavalin A (ConA)) tissue types (liver, ileum, colon) of porcine origin. Normalisation factors were generated for each group using the most stable reference pairs for each group. The most stable reference pairs based on their M values are summarised as follows: 1) liver (B2M, GAPDH), 2) ileum (B2M, PPIA), 3) colon (B2M, PPIA), 4) all treatment groups (B2M, GAPDH), and 5) entire data set (B2M, GAPDH). ACTB was the least stable gene in all groups. The stability of selected reference genes for the ileum and colon differed from the liver but was not significantly altered by immunological challenges with LPS and ConA.

How to assess particle size distribution in diets for pigs? - Corrected Proof

P. Wolf, P. Rust, J. Kamphues — 2010-08-02

Abstract: It is well known that finely ground diets pose the risk of gastric ulcers, whereas coarsely ground diets reduce Salmonella prevalence in pigs as observed in epidemiological, experimental and field studies with piglets or fattening pigs. Therefore, grinding intensity of components in pig diets came on debate again. The aim of this study was to standardize the measurement of grinding intensity, to recognize influences on particle size distribution in diets, and to monitor the “structure” (particle size) in commercial diets for piglets, fattening pigs and sows (in total n=350). Complete diets of different physical forms (ground, pelleted, crumbled) were analysed by dry and/or wet sieve analysis. The distribution of particle sizes was affected by the type of corn (with or without spelt), post-grinding treatment as well as the method of sieving (dry/wet). While monitoring commercial feeds the highest grinding intensity could be observed in complete diets for piglets and fattening pigs, whereas feeds for sows contained more coarsely ground particles.

The effect of cereal type and exogenous enzyme supplementation on intestinal microbiota and nutrient digestibility in finisher pigs - Corrected Proof

2010-08-02

Abstract: A 2×2 factorial experiment was conducted to investigate the interaction between cereal type (oats vs. barley) and exogenous enzyme supplementation (with or without) on intestinal microbiota and nutrient digestibility in finisher pigs. Twenty eight boars (59kg live weight) were randomly assigned to one of four dietary treatments: T1) barley-based diet; T2) barley-based diet plus an enzyme supplement; T3) oat-based diet and T4) oat-based diet plus an enzyme supplement. The enzyme supplement used contained β-glucanase and β-xylanase. Oat-based diets were associated with an increase in the population of Bifidobacteria in the ileum (P<0.05), and colon (P<0.01), increase Lactobacilli population in the caecum (P<0.01) and colon (P<0.05), as well as increased Enterobacteria (P<0.001) population in the colon compared to barley-based diets. However, pigs offered oat-based diets also demonstrated a lower apparent gross energy digestibility (P<0.001) and a higher nitrogen digestibility (P<0.05) compared to barley-based diets. Enzyme-supplemented diets demonstrated a significant negative effect on Lactobacilli population (P<0.01) in the ileum and an increased faecal nitrogen digestibility. In conclusion, un-supplemented oat-based diets increased the population of Bifidobacteria and Lactobacilli in the large intestine compared to barley-based diets but had a negative effect on the nutrient digestibility of the diets.

Effects of nutrient supplementation with laminarin derived from Laminaria hyperborea and Laminaria digitata on mucin gene expression in the porcine ileum - Corrected Proof

M.T. Ryan, A.G. Smith, J.V. O'Doherty, B. Bahar, P. Reilly, T. Sweeney — 2010-08-02

Abstract: Mucins play an important role in protecting the mucosal epithelium from both enzymatic and microbial damage and act as a selective barrier for absorption in the small intestine. The aim of this study was to investigate the effects of nutrient supplementation with laminarin derived from the macroalgal species Laminara hyperborea and Laminara digitata on mucin gene expression in the porcine ileum. Total RNA was extracted from ileal tissues of euthanised pigs (n=7 per group); offered one of five dietary treatments: T1 basal (control) diet, T2 and T3 — basal diets with L. hyperborea at 300ppm or 600ppm, respectively, T4 and T5 — basal diets with L. digitata at 300ppm or 600ppm, respectively. Quantitative real-time PCR was used to quantify 7 mucin genes MUC1, 2, 4, 5AC, 12, 13 and 20. Five (MUC2, 4, 12, 13 and 20) of the 7 mucin genes examined were expressed in the porcine ileum. Dietary supplementation with extracts from L. hyperborea had no effect on any of the mucin genes investigated in this study. Dietary supplementation with extracts from L. digitata had a significant effect on only one mucin gene (MUC2; P=0.05). We conclude that nutrient supplementation with L. digitata derived laminarin had significant effects on expression of the predominant mucin (MUC2) in the porcine ileum.

The growth of exocrine pancreatic insufficient young pigs fed an elemental diet is dependent on enteral pancreatin supplementation - Corrected Proof

2010-08-02

Abstract: Young exocrine pancreas insufficient (EPI) pigs given a commercial feed (polymeric diet) show growth retardation that can be reversed by dietary supplementation with pancreatic enzymes. Our aim was to investigate if providing an elemental diet, mimicking a pre-digested diet, can support body growth in EPI-pigs. Thus, EPI-pigs, pancreatic duct-ligated at 12.2±2.6weeks of age (15.3±4.8kg), were fed for 6days either a commercial polymeric pig feed or infused i.v. with an elemental diet, with or without oral supplementation with a porcine enzyme preparation (Creon®). The body weight (BW) gain was then compared at day 7.Control pigs (with intact pancreata) showed a 14.0±1.3% increase in BW independent of the diet, while EPI-pigs given the same diets either lost (polymeric diet) or slightly increased (elemental diet) their BW. In contrast, EPI-pigs fed the polymeric feed with Creon supplementation showed a normalised growth and EPI-pigs given the elemental diet with Creon supplementation gained 8.5±0.7% in BW.In conclusion, control pigs maintained a normal growth, independently of the diet being given in polymeric or elemental form, while EPI-pigs showed an impaired growth when receiving the same diets without oral enzyme supplementation. This suggests that pancreatic juice or enzyme preparations, in addition to their digestive properties, stimulate nutrient assimilation and anabolic processes in young fast-growing pigs.

Effect of xylanase and β-glucanase on growth performance and nutrient digestibility in piglets fed wheat–barley-based diets - Corrected Proof

A. Owusu-Asiedu, P.H. Simmins, J. Brufau, R. Lizardo, A. Péron — 2010-08-02

Abstract: There is increasing interest in the use of exogenous enzymes to improve diet digestibility and performance of pigs fed mixed grain-based diets. The potential of combination of carbohydrase (xylanase and β-glucanase) to enhance nutrient digestibility and performance was examined in the present study using 160 crossbred pigs (Landrace×Large White) of initial mean BW of 7.4kg. Pigs were randomly assigned to four dietary treatments with 4 pigs per pen and 10 pens per diet for a 42-d feeding period. The diets were: Control (T1, 92% of DE requirement of NRC, 1998, with no enzymes), and control plus carbohydrase combination. The enzyme was added at 50 (T2), 100 (T3) and 200g/MT (T4). Celite was used as an indigestible marker and feed was available to pigs ad libitum. Pigs were weighed at 0, 3 and 6weeks of the experiment and fecal samples were collected for 3days at the end of week 5. On average, piglets grew 525g/d, consumed 845g/d, and exhibited mean FCR of 1.59. Weight gain and feed intake did not differ (P>0.05) among treatments, however, FCR for the overall period was better (P<0.05) for pigs fed diets supplemented with 200g/MT enzyme compared with those fed the control diet. The FCR for the overall period were 1.66, 1.59, 1.60 and 1.57 (SE=0.07) for T1, T2, T3 and T4, respectively. Faecal digestibility of energy and protein did not differ (P>0.05) among treatments, however improvement in performance was observed, suggesting improved nutrient absorption in the ileum. Digestibility of NSP and of some individual sugars (arabinose, xylose, mannose and glucose) numerically increased (P>0.05) with enzyme supplemented diets relative to the control. The digestibility of NSP improved by 2.7 to 5.6% in the carbohydrase-supplemented compared to the control diet. It can be concluded that adding a specific proportions of blend of exogenous xylanase and β-glucanase enzymes to mixed grain-based diets improved performance in weaned pigs.

Apparent nutrient and mineral digestibility in growing–finishing pigs fed phosphorus reduced diets supplemented with benzoic acid and phytase - Corrected Proof

Kathrin Bühler, Benjamin Bucher, Caspar Wenk — 2010-08-02

Abstract: In a study with 32 growing–finishing crossbred gilts (26–109kg BW) the effects of benzoic acid and phytase (Peniophora lycii) on nutrient digestibility in P reduced diets was examined. All animals were restrictively fed one of four experimental diets: control diet (CC) without any supplementation, control diet with 0.5% benzoic acid (CB), phytase diet (750IU/kg,) without benzoic acid (PhyC) and phytase diet with 0.5% benzoic acid (PhyB). Total P (digestible P) content of the control diets was 4g/kg (1.43g/kg). In the grower period a negative interaction of benzoic acid×phytase (p<0.01) on apparent crude protein and energy digestibility was observed. In the finisher period both additives increased digestibility of P by 12% (p<0.02). Phytase improved Ca digestibility in both fattening periods (+13%, p<0.05). In the finisher period an interaction of benzoic acid×phytase (p<0.01) reduced Ca digestibility from 0.62 in diet PhyC to 0.54 in diet PhyB. The results of this study indicate that the combination of benzoic acid and phytase in P reduced diets can adversely affect apparent nutrient and mineral digestibility. So far, the underlying mechanisms remain unclear.

Effect of hydrothermally processed cereals on the performance of weaned piglets - Corrected Proof

C. Ulgheri, E. Grilli, F. Rossi, G. Piva — 2010-08-02

Abstract: Antisecretory factor (AF) is an endogenous protein that has shown to be a potent inhibitor of intestinal fluid secretion and inflammation. AF content in sows' milk is important for protection against neonatal diarrhoea in suckling piglets. Feeding specific hydrothermally processed cereals (HPC) has proven to increase the plasma level of AF and to be helpful in counteracting diarrhoea in domestic animals. The aim of the study was to investigate the effects of an AF-inducing diet on piglets' growth performance and intestinal mucosa.144 weaned piglets with a body weight (BW) of 6.35±0.52kg were randomized for sex and weight and allotted to 3 groups fed ad libitum: (C) control diet; (T1) control diet with 3% supplemental HPC; (T2) control diet with 6% supplemental HPC. On days 0, 14, and 42, animals were weighted, feed consumption and feed:gain ratio (FCR) were determined. Blood samples were collected (n=6 animals per treatment group) to determine the effect of HPC on the intestinal enterocytes. None of the piglet showed diarrhoea during the study.Piglets fed the diet supplemented with 6% of HPC had higher (P<0.05) final BW compared to piglets fed the control diet.ADG was higher for the piglets fed the diet supplemented with 6% HPC 14days after weaning (P<0.05) and during the whole experimental period (P<0.05). Animals fed 6% HPC grew more than piglets receiving 3% HPC supplemented diet during 14–42days.Piglets fed T2 had a lower FCR (P=0.05) than piglets fed C. No difference was detected on feed intake and blood parameters. Intestinal health status and assessed monitoring the plasma level of I-FABP were low for all animals and did not significantly differ between treatment groups. The results of this experiment support the use of HPC as a natural alternative to AGP.

Effect of soy processing on performance of piglets and microbial shedding after an oral challenge with Escherichia coli - Corrected Proof

J.M.A.J. Verdonk, M. Habets, L.S. Andersen — 2010-08-02

Abstract: The aim of this study was to evaluate the effect of soy processing on the performance of piglets orally inoculated with Escherichia coli 0149K91K88LT+(E. coli K88) in a period from 0 to 14d after weaning. Two groups of 18 piglets were fed a wheat–barley–corn diet supplemented with either extracted/toasted (ET) soy bean meal or with enzymatically processed (ENZ) soy bean meal. The piglets were housed individually and given ad libitum access to feed and water. Feed intake (FI), body weight (BW), faecal and body condition score were assessed daily from day 1 to 14 post weaning. Rectal faecal samples were collected at days 2, 7, 9, 12 and 14 to analyse the colony forming units (CFU) for E. coli K88. ENZ soy bean meal resulted in significantly better body condition and only numerically improved feed intake, growth and faecal shedding of E. coli K88 compared to ET soy in piglets before and/or after the oral challenge.

The effects of lactose inclusion and seaweed extract on performance, nutrient digestibility and microbial populations in newly weaned piglets - Corrected Proof

S. Dillon, T. Sweeney, S. Figat, J.J. Callan, J.V. O'Doherty — 2010-08-02

Abstract: A 2×2 factorial experiment was conducted to investigate the interactions between 2 different lactose levels (150g/kg vs 250g/kg) and the addition of seaweed extract (2.8g/kg, containing laminarin and fucoidan) derived from Laminaria spp. on growth performance, nutrient digestibility and faecal microbial population in the weanling pig. Two hundred and forty piglets were selected after weaning (24days of age, 7.6kg (s.d 0.9kg) live weight) and blocked on the basis of live weight and within each block assigned to one of four dietary treatments. Piglets offered diets supplemented with seaweed extract had a higher average daily gain (ADG) (0.322 vs 0.281kg, s.e. ±0.009) (P<0.01) and gain to feed ratio (0.669 vs 0.611kg/kg, s.e. ±0.019) (P<0.05) during the entire experimental period (days 0–25) compared with piglets offered un-supplemented seaweed extract diets. Piglets offered high lactose diets had a higher ADG (0.319 vs 0.283kg, s.e. ±0.009) (P<0.05) and average daily feed intake between days 0 and 25 (0.480 vs 0.447kg, s.e. ±0.011) (P<0.05) compared with piglets offered the low lactose diets. The inclusion of seaweed extract increased (P<0.001) the apparent digestibility of nitrogen (N Dig) and gross energy (GE Dig) and decreased (P<0.05) faecal E. coli populations compared with un-supplemented seaweed extract diets. Piglets offered the high lactose diets had increased GE dig (P<0.001), N dig (P<0.05) and decreased (P<0.05) faecal E. coli populations compared with piglets offered low lactose diets. In conclusion, the inclusion of either a high dietary concentration of lactose or a laminarin–fucoidan extract increased daily gain and gain to feed ratio of post weaned piglets through an increase in nutrient digestibility and decreased E. coli populations in the gut.

Growth, carcass and meat quality characteristics of Small East African goats fed straw based diets - Corrected Proof

J. Safari, D.E. Mushi, L.A. Mtenga, G.C. Kifaro, L.O. Eik — 2010-08-02

Abstract: Thirty-two castrated male goats of Small East African breed (13.8kg BW, 12–18months of age) were used to evaluate the potential of using treated-wheat straw alone or in combination with grass hay as dry season feeds. Animals were allotted into four dietary treatments with eight animals per treatment for 84days. The dietary treatments were either ad libitum amount of untreated wheat straw (UTS), wheat straw treated with urea and lime (TS), untreated wheat straw with hay (UTSH) or treated wheat straw with hay (TSH). In addition, each animal received 220g/day (on as fed basis) of a concentrate diet. Dry matter intake from wheat straws was highest (438.1g/day, P<0.05) for goats on TS. Daily body weight gain for goats fed TS was nearly two-fold higher than for those fed UTS. Meanwhile, goats fed TSH were more (P<0.05) efficient in converting feeds to body tissue as they required 9kg less feed for one kg body weight gain compared to those fed TS. Goats on TS had the highest commercial dressing percentage (DP), which was about 5% higher than the DP of the other dietary groups. Compared to goats fed UTS, those fed TS had 0.70 and 0.32kg heavier muscles and fat, respectively. Goats on diets including hay (TSH and UTSH) produced carcasses with higher proportion of fat than those without access to hay (TS and UTS). There was muscle-specific response to straw treatment with respect to cooking loss notably for M. gluteobiceps and M. triceps brachii. Chemical treatment of straws improved potentials for crop residues to sustain goats in the dry season with a minimum level of fattening. However, straw treatment had limited effect on the quality of goat meat. Grass hay complemented the effects of chemical treatment in increased intake and growth performance of goats.

Assessing diversity losses due to selection for coat colour in the endangered bay-Asturcón pony using microsatellites - Corrected Proof

I. Álvarez, L.J. Royo, L. Pérez-Pardal, I. Fernández, L. Lorenzo, F. Goyache — 2010-08-02

Abstract: The bay-Asturcón pony (A21) population recovery started recently. A total of 297 samples (180 from founder individuals) belonging to the A21 population were genotyped for: a) a set of 15 microsatellites; and b) the presence of the two recessive chestnut alleles reported in the literature (e and ea) on the MC1r gene (locus Extension) and the deletion on the ASIP gene (locus Agouti) associated with recessive black coat in horses. The extent to which the genetic variability of the A21 population could be affected by selection strategies aimed at decreasing the frequency of the chestnut allele was quantified in terms of gene diversity and allelic richness. The possible genetic impact of a controlled introgression of A21 offspring into the black-coated Asturcón (A20) population was also assessed using 261 available A20 genotypes. The wild alleles for the Extension and Agouti loci (E and A, respectively) were the most frequent (77.8% and 59.4%) in the A21 population. Both the e and ea recessive chestnut alleles were identified with frequencies of 21.2% and 1.0%. As expected, the contribution to overall diversity of the founder subpopulation was always higher than that of the A21 offspring subpopulation. Total contribution of the offspring subpopulation to overall allelic richness was negative (−1.84%), showing that all their alleles were present in the founder subpopulation. Although favourable, the chestnut carrier individuals had poor contributions to overall gene diversity and tended to have negative contributions to allelic richness. The elimination of the chestnut carrier A21 individuals would not affect genetic variability to a significant extent. Therefore, efforts for preserving the genetic variability in the A21 population could focus on a careful planning of matings between individuals free of the recessive chestnut alleles. The expected influence of a controlled introgression of A21 offspring on the genetic variability of the A20 population was always favourable. The gene diversity of the introgressed population was higher than that of the original A20 population for both gene diversity (GDT=−1.2%±0.04%) and, particularly, allelic richness (CT=4.9%±0.27%). Very limited gene flow may increase the number of alleles of the A20 population but also would yield a balance of the allelic frequencies at a population level. Therefore, a common breeding policy for the two Asturcón pony populations may ensure the viability of this prominent genetic resource.

Differentially expressed genes in skeletal muscle tissues from castrated Qinchuan cattle males compared with those from intact males - Corrected Proof

2010-07-28

Abstract: In order to study the molecular mechanism involved in meat quality differences especially tenderness variance caused by castration in Qinchuan cattle males, this study investigated the gene expression profile of Longissimus thoracis (LT) muscle and screened differentially expressed genes in LT muscle from both intact male and castrated male Qinchuan cattle at 36months of age utilising Bovine Genome Array. Significance Analysis of Microarrays (SAM) was used to identify the differentially expressed genes, Go (Gene Ontology) and pathway analyses were conducted on which by a free Web-based Molecular Annotation System 2.0 (MAS 2.0). Approximately 11,000 probe sets representing 10,000 genes were detected in LT muscle of 36-month-old Qinchuan cattle. After SAM analysis of the microarray data, 142 genes were shown to be differentially expressed. These genes were predominantly involved in collagen fibril organization and synthesis, regulation of cell growth and development and striated muscle contraction. The significant pathways involved mainly included ECM–receptor (extracellular matrix-receptor) interaction, cell communication and focal adhesion. Quantitative real-time PCR (qRT-PCR) was performed to validate some differentially expressed genes identified by microarray. These patterns of gene expression may contribute to understanding the molecular mechanism of better meat quality of beef derived from castrates than from intact males.

Fatty acid profiles, including CLA isomers and long chain PUFA, in ileal digesta of growing gilts fed flaxseed or tallow containing diets - Corrected Proof

H.R. Martínez-Ramírez, J.K.G. Kramer, C.F.M. de Lange — 2010-07-28

Abstract: The objective of this study was to characterize fatty acid (FA) profiles in digesta collected from distal ileum in growing gilts slaughtered at 50 (n=5) or 110kg BW (n=20) fed either a flaxseed (FS) or beef tallow (BT) supplement, between 25 and 50 or 85 and 110kg BW. The FA contents were expressed as proportions of total analyzed FA contents. The results showed that at both slaughter BW 18:0 and the cis-monounsaturated FA in ileal digesta were similar among fat sources. At both BW, total trans-18:1 FA content was higher in digesta for BT than FS (0.52 vs. 0.18% and 0.43 vs. 0.19% at 50 and 110kg BW, respectively, P<0.05). At 50kg BW, total conjugated linoleic acid (CLA; 0.16 vs. 0.13%) and 22:6n−3 (0.24 vs. 0.16%) contents were not affected by dietary fat source, whereas at 110kg BW total CLA (0.25 vs. 0.16%) and 22:6n−3 (0.26 vs. 0.11%) were higher for BT than FS (P<0.05). Calculations showed that the dietary content of CLA and 22:6n−3 was lower than that found in the ileal digesta suggesting possible synthesis of both FA in pig's gut. The extent of their synthesis and absorption needs further investigation.

Castor bean meal for cattle finishing: 1—Nutritional parameters - Corrected Proof

2010-07-28

Abstract: This study was carried out to evaluate the effects of replacing soybean meal (SM) with castor bean meal supplemented (CBT) or not (CBNT) with calcium oxide on the intake, total, ruminal and intestinal apparent digestibility of dietary contituents, ruminal pH, and nitrogen ammonia concentration (NH3-N), ruminal degradation parameters, and on the ruminal microbial protein synthesis based on urinary purine derivatives excretion or purine bases in the abomasum. Were used 5 Bos indicus crossbreed castrated male cattle were used with average initial body weight of 360±30kg, fistulated in the rumen and the abomasum, in a 5×5 Latin square experimental design. The duration of each experimental period was 14d, with 8d of adaptation and 6d of sampling. The 5 treatments consisted of 4 levels of replacement of SM with CBT (0, 33, 67 and 100% on the DM basis) and one treatment with 100% replacement of SM with CBNT. The diet consisted of 35 and 65% of concentrate and corn silage on the DM basis, respectively. It was verified that DM digestibility was reduced (P<0.05) by alkaline treatment of the castor bean meal. With the exception to ruminal apparent digestibility of crude protein (RDCP), there was no effect of calcium oxide (P>0.05) on the digestibility of other constituents. We observed an increase in RDCP of 24.2% (P<0.05) for the CBNT treatment compared to the CBT. The intestinal digestibility of the dietary constituents was not affected by the percentage of SM replaced with CBT. However, alkaline treatment of the CBNT decreased (P<0.05) the intestinal apparent digestibility of ether extract. There was no interaction (P>0.05) between treatment and time for ruminal pH; however, ruminal pH was influenced (P<0.05) by collection time, with a minimum value of 6.23 estimated at 5.8h after food delivery. However there was an interaction (P<0.05) between treatment and collection time for NH3-N concentration. There were no observed differences (P>0.05) in excretion of nitrogenous compounds in the urine among the different castor bean meal treatments. The N-RNA to total microbial N ratio was not affected by the percentage of CBT, presenting an average of 0.138. No differences were detected (P>0.05) between the two methods used to estimate the ruminal microbial protein synthesis. We conclude that castor bean meal supplemented with 60gkg−1 of calcium oxide can fully replace soybean meal in crossbreed finishing cattle diets.

Weaning and post-weaning performance by fall-born beef calves weaned on different dates in the spring from Neotyphodium coenophialum-infected tall fescue pastures - Corrected Proof

2010-07-26

Abstract: Fall-born calves grazing Neotyphodium coenophialum-infected tall fescue [E+; Lolium arundinaceum (Schreb.) Darbysh.] pastures should benefit from early weaning because of reduced exposure to fungal toxins. However, fall-born calves that grazed E+ and were weaned in mid-April had reduced post-weaning performance compared with calves managed similarly but weaned in early June. Gelbvieh×Angus calves (n=238) were used in a 3-year study to determine the optimal time to wean fall-born calves grazing E+. Cow/calf pairs were allocated randomly to one of four weaning date treatments: 1) March 16 (177±4.7days of age; MarW), 2) April 13 (204±4.7days of age; AprW), 3) May 11 (236±4.7days of age; MayW), and 4) June 8 (264±4.8days of age; JuneW). On their assigned weaning date, calves were weighed, vaccinated, blood samples were collected, and calves were moved to 3.2-ha pastures adjacent to their dams for 14days. After the weaning period, calves were weighed, blood samples were collected, and then calves were moved to pastures containing non-toxic forages. Birth weight and calf weights on MarW, AprW, and MayW weaning dates did not differ (P≥0.21) across weaning date treatments. However, calf weaning weights on their respective weaning dates, weight on JuneW and on June 22 (14days following the JuneW), daily gain between birth and June 22, and weight change between MarW and JuneW increased linearly (P<0.05) across weaning dates. Linear decreases (P<0.05) across weaning dates were noted for antibody titers to bovine virus diarrhea (BVD) and infectious bovine rhinotracheitis (IBR), serum Cu, and platelets at the time of actual weaning. Linear increases (P<0.05) across weaning dates were noted for: i) total antioxidant potential and eosinophils at weaning; ii) changes in antibody titers to BVD and IBR, total antioxidant potential, and serum Zn during the 14-day post-weaning period; and iii) and changes in BVD and BRSV titers and serum Cu between actual weaning date and June 22. Heifer weight at breeding increased (P<0.05) and steer weight at shipping, hot carcass weight and backfat thickness tended (P≤0.10) to increase linearly across weaning dates. Final feedlot weight and gain did not differ (P≥0.18) among weaning dates. Therefore, delaying weaning of fall-born calves grazing E+ pastures until early June may be beneficial for calf weight and immune function at weaning, and heifer weight at breeding, but those benefits in steers may be mitigated through the feedlot period.

The metabolic impact of zinc oxide on porcine intestinal cells and enterotoxigenic Escherichia coli K88 - Corrected Proof

2010-07-26

Abstract: Pharmacological levels of zinc oxide (ZnO) incorporated into the post-weaning piglet diet reduce the incidence of diarrhoea caused by enterotoxigenic Escherichia coli (ETEC) K88. The mechanism for this is not understood. Here, Intestinal Porcine Epithelial Cells (IPEC) J2 were used as an in vitro model of the porcine intestine. ZnO reduced IPEC J2 viability at concentrations ≥200μM, and ETEC adhesion to the host cell was unaffected by ZnO. Characterisation of the metabolism of IPEC J2 cells and ETEC established the effects of ZnO treatment on the metabolic profile of both. Although 100μM ZnO did not inhibit growth of either host or pathogen in fully supplemented media, metabolic profiles were significantly altered. Glucose and mannose were essential energy sources for IPEC J2 cells in the presence of ZnO, as the ability to utilise other sources was compromised. The increase in specificity of requirements to support respiration in ETEC was more pronounced, in particular the need for cysteine as a nitrogen source. These findings indicate that ZnO impacts on both host cell and pathogen metabolism and may provide insight into the mechanism for diarrhoea reduction.

The effects of plant polyphenols on enterotoxigenic Escherichia coli adhesion and toxin binding - Corrected Proof

R. Verhelst, M. Schroyen, N. Buys, T. Niewold — 2010-07-26

Abstract: Pigs frequently encounter bacterial infections like enterotoxigenic Escherichia coli (ETEC). Due to rising concerns about antibiotic resistance of bacteria, there is a large demand for natural alternatives to combat these ETEC infections. Plant polyphenols have been suggested to reduce both the binding of cholera toxin to the GM1 ganglioside and the adhesion of uropathogenic E. coli to F1 fimbriae. In this study different commercial natural polyphenol extracts were evaluated for their possible effect on ETEC. Out of the three polyphenol extracts tested two exert inhibitory effects on the heat-labile toxin binding and all three extracts reduced the binding of ETEC to brush borders. The presence of protein abolished labile toxin binding properties of polyphenols. This makes it unlikely that these polyphenols could be used as an actual feed additive to combat ETEC caused diarrhea.

Estimating fermentative amino acid losses in the upper gut of pigs - Corrected Proof

D. Columbus, J.P. Cant, C.F.M. de Lange — 2010-07-26

Abstract: Fermentative catabolism of dietary and endogenous amino acids (AA) in the upper gut of pigs (FAAC) can result in significant loss of AA available for protein synthesis and body maintenance functions. A continuous infusion trial was performed using isotope tracers to determine ammonia flux in the upper gut, whole body urea flux, urea recycling (urea flux−urinary urea excretion), and FAAC (ammonia flux in the upper gut−urea recycling) in ileal-cannulated growing pigs fed a control diet (C, 19.3% CP), the control diet with added fibre (F, 12% pectin added at expense of cornstarch), or a diet low in protein (LP, 13.6% CP). 15N-ammonium chloride and 13C-urea were infused intragastrically and intravenously, respectively, for a period of 4days. In samples obtained on days 3 and 4 of infusion, 15N-enrichments in blood urea (6.21±1.65, 8.93±2.01, and 9.78±1.40 atoms percent excess (APE) for C, F and LP, respectively) were higher than those in ileal ammonia (0.44±0.12, 0.37±0.14, and 0.71±0.10 APE). This suggests a rapid absorption of ammonia prior to the distal ileum and lack of uniformity for enrichment in the digesta ammonia pool. Simple isotope dilution calculations are, therefore, inadequate for calculating FAAC and ammonia flux in the upper gut of pigs. A two compartment (ileal ammonia and plasma urea) model was developed to determine possible value ranges for FAAC in the upper gut (0.0 to 13.3±1.42, 15.5±1.65, and 10.7±1.20mmolN/kg/d for the three treatments), but this model also has limitations. Quantifying FAAC in the upper gut of pigs offers a number of challenges, but warrants further investigation.

Immune system stimulation of growing pigs does not alter apparent ileal amino acid digestibility but reduces the ratio between whole body nitrogen and sulfur retention - Corrected Proof

A. Rakhshandeh, J.K. Htoo, C.F.M. de Lange — 2010-07-26

Abstract: Immune system stimulation (ISS) can cause morphological and physiological changes in the gastrointestinal tract and impact nutrient utilization in pigs. Apparent ileal digestibility (AID) of sulfur amino acids (SAA) and whole body nitrogen (N) to sulfur (S) balance ratios (N/S-balance) were measured to investigate the impact of ISS and SAA intake on SAA digestibility and utilization in growing pigs. Thirty-six barrows (initial BW 21.5±3.5kg) were fed 800g/day of SAA-limiting diets that supplied 1.1, 2.1 or 3.2g/day of SAA (L1, L2 and L3, respectively). Following adaptation, pigs were injected intramuscularly, with either saline (ISS−; 4 pigs at each SAA intake level) or increasing amounts of Escherichia coli lipopolysaccharide (LPS) (ISS+; 8 pigs at each SAA intake level), while measuring whole body N and S balances. At the end of the balance period, pigs were euthanized and digesta were collected from the distal 1.5m of small intestine for measuring AID (%) of amino acids and energy. The AID of energy and amino acids were not affected by ISS. Whole body N and S retention increased with SAA intake (P<0.01), while only N retention was reduced by ISS (P<0.05). Whole body N/S-balance was reduced as SAA intake decreased; ISS further reduced the N/S-balance (P<0.03), indicating an increase in whole body non-protein SAA pool size due to ISS. In conclusion, ISS per se does not change the AID of amino acids and energy but alters the partitioning of SAA in favor of non-protein body stores in growing pigs.

Relationships between glycaemic index and digesta passage of cereal-based diets in pigs - Corrected Proof

D. Solà-Oriol, T. van Kempen, D. Torrallardona — 2010-07-26

Abstract: Changes in the rate of passage of digesta may affect feed digestibility and glycaemia, but at the same time glycaemia may also regulate stomach emptying and as a consequence digesta passage rate. The correlations between the glycaemic index (GI) of 12 cereals, the ileal and total tract, dry matter (DM) and organic matter (OM) digestibilities and the ileal digesta flow characteristics of pig feeds containing them were studied. GI for each cereal was calculated as the maximal glucose release rate per minute using an in vitro digestibility system. Pigs fitted with an ileal T-cannula were used to measure the DM and OM digestibilities (ileal and total tract) of the corresponding cereal-based diets, and their ileal digesta flow rate, lag time to initial flow of digesta (Tlag) and mean retention time (MRT). Titanium dioxide (TiO2) was used as indigestible marker. The Spearman's correlations between the GI, the parameters of digesta flow and the digestibility values were estimated. GI was significantly correlated with ileal digestibility of OM (r=0.58; P<0.05), ileal digesta flow rate (r=0.79; P<0.01), Tlag (r=−0.76; P<0.01) and MRT (r=−0.87; P<0.01). DM and OM ileal digestibility and the digesta flow parameters were also correlated (P<0.05). Positive significant correlations between cereal GI, feed digestibility and digesta flow rate have been found.

Effect of a gel-based nutritional supplement on growth performance of weaned pigs - Corrected Proof

B. de Rodas — 2010-07-26

Abstract: The abrupt change from a liquid to a dry diet affects feed intake of the pig during the first few days after weaning making them more susceptible to weight loss and diarrhea. A gel-based nutritional supplement may ease the weaning transition to dry feed. Three experiments were conducted to evaluate the effect of gel supplementation (GS) during the first week after weaning and at vaccination (VAC) on performance of weanling pigs. In Exp. 1, two treatments (TRT) were evaluated: 1) control pelleted diet vs. 2) as 1 plus a gel supplement containing plasma protein fed separately. In Exp. 2, TRT 1 and 2 were as described in Exp. 1, and TRT 3 was as 1 plus a gel devoid of plasma protein. Pigs receiving GS had greater (P<0.05) ADG and ADFI during days 0 to 4 and days 0 to 7 postweaning, and pigs fed the two types of gel had similar performance. At the end of the 36-day experiment, pigs receiving GS were heavier (P<0.1) than pigs not receiving GS. In Exp. 3, dietary TRT were arranged as a 2×2 factorial with one factor being VAC and the other being GS. Pigs in the VAC group received Mycoplasma and Circovirus vaccines at days 0 and 14 postweaning, and pigs in the GS group received gel from days 0 to 7 and days 13 to15 postweaning. Pigs receiving GS had greater ADG (P<0.05) during days 0 to 7 and ADFI (P<0.05) during days 0 to 7 and days 14 to 22 postweaning than pigs not receiving GS. VAC pigs had lower (P<0.05) ADG and ADFI than non-VAC pigs during days 14 to 22 postweaning. These data indicate that GS during the first 7days after weaning improves growth performance of nursery pigs and it is beneficial to both VAC and non-VAC pigs.