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Development of an in vitro protein digestibility assay mimicking the chicken digestive tract 被引量:9
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作者 Dervan D.S.L.Bryan Dawn A.Abbott henry l.classen 《Animal Nutrition》 2018年第4期401-409,共9页
It is difficult to obtain in vivo digestion kinetics data of high protein ingredients using chickens. Collecting kinetics data requires repeated sampling of digesta from the small intestine during the digestion proces... It is difficult to obtain in vivo digestion kinetics data of high protein ingredients using chickens. Collecting kinetics data requires repeated sampling of digesta from the small intestine during the digestion process,which is not easily accomplished due to the anatomical structure of chicken digestive tract. An in vitro technique is proposed for measuring the digestion kinetics of protein sources fed to chickens. The method has a 30 min gastric and 3 h intestinal phase. Five hundred milligram crude protein(CP)equivalent of each meal sample(CP = % N × 6.25) was digested with pepsin(28,260 units) in 50 m L polyethylene centrifuge tubes for 30 min in a shaking water bath(150 strokes/min; 30 mm stroke length)at 41C. The 6.5 mL pancreatin was selected as the enzyme concentration for the intestinal phase, during which time 500 m L aliquots were collected at 0, 15, 30, 45, 60, 90, 120, 150, 180 and 240 min. Samples were diluted 1:820 with HCl and sodium acetate buffer, and then mixed with ninhydrin reagent(2:1) at100 ± 2C for 15 min and spectrometric readings taken at 568 nm. To validate the assay, 5 replications of soybean meal(SBM), corn gluten meal(CGM), corn distillers dried grains with solubles(CDDGS), porcine meal(PCM), fish meal(FM) and casein(CA) were digested. The digestion data were modeled with PROC NLIN procedure, and the intra coefficient of variation(CV) assessed using PROC MEANS of SAS 9.4. The digestion values at 180 min were SBM 95 ± 4, FM 93 ± 3, PCM 68 ± 4, CGM 82 ± 3 and CDDGS 70 ± 2.Intra CV for SBM, CGM, CDDGS, PCM and FM were 5%, 5%, 12%, 10% and 2%, respectively. The estimated fractional digestion rates for SBM, CGM, CDDGS, FM and PCM were 0.023, 0.013, 0.009, 0.024 and 0.013,respectively. In conclusion, the proposed in vitro technique estimated the rate and extent of the digestion of CP for the meals with low intra CV. 展开更多
关键词 Protein DIGESTION rate Soybean MEAL CORN GLUTEN MEAL CORN distillers DRIED grains with solubles Fish MEAL Porcine MEAL
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Hulless barley and β-glucanase affect ileal digesta soluble β-glucan molecular weight and digestive tract characteristics of coccidiosis-vaccinated broilers 被引量:2
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作者 Namalika D.Karunaratne Rex W.Newkirk +3 位作者 Nancy P.Ames Andrew G.Van Kessel Michael R.Bedford henry l.classen 《Animal Nutrition》 SCIE CSCD 2021年第3期595-608,共14页
Exogenousβ-glucanase(BGase)in barley-based feed has been shown to reduce digesta viscosity in chickens,and thereby improve performance.Less well studied is the potential for BGase to convert barleyβ-glucan into low ... Exogenousβ-glucanase(BGase)in barley-based feed has been shown to reduce digesta viscosity in chickens,and thereby improve performance.Less well studied is the potential for BGase to convert barleyβ-glucan into low molecular weight carbohydrates,which might influence digestive tract function and enteric disease.Coccidiosis-vaccinated broiler chickens were fed graded levels of hulless barley(HB)and BGase to determine their effects onβ-glucan depolymerization and digestive tract characteristics.Broilers were fed highβ-glucan HB(0%,30%and 60%replacing wheat)and BGase(0%,0.01%and 0.1%)in a 3×3 factorial arrangement.A total of 5,346 broilers were raised in litter floor pens and vaccinated for coccidiosis on d 5.Each treatment was assigned to 1 pen in each of 9 rooms.The significance level was set at P≤0.05.At both 11 and 33 d of broiler ages,peak molecular weight ofβ-glucan in ileal digesta decreased with increasing BGase for 30%and 60%HB.The maximum molecular weight for the smallest 10%β-glucan molecules(MW-10%)decreased with BGase at both ages for 30%and 60%HB;for birds fed 0%HB,only 0.1%BGase decreased MW-10%.The 0.1%BGase increased caecal short chain fatty acids(SCFA)compared to the 0.01%BGase at d 11 only for the 60%HB.Ileal pH increased with increasing HB and BGase at d 11 and 33.Caecal pH was lower for 0.1%BGase than 0%BGase for 60%HB at d 11.Relative mRNA expression of interleukin 6(IL-6)and IL-8 in the ileum increased with 0.1%BGase at d 11 and 33,respectively,whereas expression of ileal mucin 2(MUC2)decreased with 0.1%BGase at d 33.In the caeca,interactions between HB and BGase were significant for monocarboxylate transporter 1(MCT1)and mucin 5AC(MUC5AC)on d 11,but no treatment effects were found at d 33.In conclusion,BGase depolymerized high molecular weightβ-glucan in HB in a dose-dependent manner.Hulless barley and BGase did not increase SCFA concentrations(except for 60%HB with 0.1%BGase at d 11)and caused minor effects on digestive tract histomorphological measurements and relative mRNA gene expression. 展开更多
关键词 Prebiotic Non-starch polysaccharide Fermentation Short-chain fatty acid Feed enzyme
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Effect of protein sources on performance characteristics of turkeys in the first three weeks of life 被引量:1
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作者 Megan L.Ross Dervan D.S.L.Bryan +1 位作者 Dawn A.Abbott henry l.classen 《Animal Nutrition》 SCIE 2019年第4期396-406,共11页
The effect of nutrition during the early life of turkey poults has a long-lasting impact on bird performance.This study assessed the digestibility of 5 high protein feed ingredients(soybean meal [SBM],corn gluten meal... The effect of nutrition during the early life of turkey poults has a long-lasting impact on bird performance.This study assessed the digestibility of 5 high protein feed ingredients(soybean meal [SBM],corn gluten meal [CGM],canola protein concentrate [CPC],fish meal [FM],and porcine meal [PCM]) in broiler chickens,as well as their use in turkey pre-starter diets fed to 21 d of age.The first experiment(5 × 2 factorial arrangement) determined nitrogen corrected apparent metabolizable energy(AMEn) and apparent ileal amino acid digestibility(AIAAD) of each ingredient in broiler chickens at 5 and 21 d of age,using 6 replications of 30 and 8 chicks,respectively.In the second experiment(completely randomized design),4 replication pens,containing 23 d-old poults,were randomly assigned to one of 5 dietary treatments.The diets were formulated based on the AMEn and AIAAD values derived in the first experiment,and consisted of a high SBM control diet,and 4 additional diets with either CPC,FM,PCM or CGM replacing 25% of the protein supplied by SBM in the control diet.Statistical analysis was completed using Proc Mixed in SAS 9.3.Planned contrasts were used to compare treatments in the second experiment.Trends were identified at P <0.10 and significant differences identified at P≤0.05.Bird age did not affect CPC,FM,CGM,and SBM AMEn,but the PCM value at d 5 was higher than that at d 21.Apparent ileal amino acid digestibility increased with age for most amino acids(AA),but the response was AA and protein source dependent.The largest average increase in AIAAD between 5 and 21 d of age was observed for CGM.Inclusion of CPC,FM,PCM,or CGM increased body weight up to 14 d,in comparison to poults fed the SBM diet,but feed efficiency and water consumption were not affected.Terminal ileum digesta moisture values were higher for birds fed SBM when compared to those fed PCM.These results demonstrate that combining SBM with CPC,FM,PCM,or CGM improves poult performance during the first 14 d of life in comparison to feeding SBM alone. 展开更多
关键词 Soybean MEAL CORN GLUTEN MEAL CANOLA MEAL Fish MEAL PORCINE MEAL TURKEYS
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Diet medication and beta-glucanase affect ileal digesta soluble betaglucan molecular weight,carbohydrate fermentation,and performance of coccidiosis vaccinated broiler chickens given wheatbased diets 被引量:1
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作者 Namalika D.Karunaratne henry l.classen +3 位作者 Andrew Gvan Kessel Michael R.Bedford Nancy P.Ames Rex W.Newkirk 《Animal Nutrition》 SCIE CAS CSCD 2023年第4期288-296,共9页
Exogenous enzymes as alternatives to feed antibiotics in poultry has become an emerging research area with the emergence of antibiotic resistance.The objective was to evaluate the effects of diet medication(antibiotic... Exogenous enzymes as alternatives to feed antibiotics in poultry has become an emerging research area with the emergence of antibiotic resistance.The objective was to evaluate the effects of diet medication(antibiotics)andβ-glucanase(BGase)on digesta solubleβ-glucan depolymerization,carbohydrate fermentation,and performance of coccidiosis-vaccinated broiler chickens fed wheat-based diets.A total of 1,782 broilers were raised on litter floor pens,and each treatment was assigned to 1 pen in each of the9 rooms.The 3 dietary treatments were based on wheat as the sole grain(control,control+medication and control+0.1%BGase),and the birds were fed the respective treatments ad libitum from 0 to 33 d.Treatments were arranged in a randomized complete block design and analyzed as a one-way ANOVA.Beta-glucanase reduced the peak molecular weight,weight average molecular weight(Mw)and maximum molecular weight for the smallest 10%β-glucan molecules(MW-10%)in ileal digesta at d 11and 33,whereas diet medication reduced Mw and MW-10%at d 33 compared to the control(P<0.01).Beta-glucanase and medication reduced the ileal viscosity at d 11 compared to the control(P=0.010).Ileal propionic acid concentration at d 11 and caecal total SCFA,acetic,and butyric acid concentrations at d 33 were lower in the BGase-supplemented diet than in the control(P<0.05).The BGase-added diet had higher duodenal p H compared to the control at d 33(P=0.026).The effect of medication on carbohydrate fermentation was minimal.Diet medication increased weight gain after d 11,whereas BGase increased the gain for the total trial period compared to the control(P<0.001).Feed intake was not affected by the dietary treatment.Medication and BGase improved feed efficiency after d 11 compared to the control(P<0.001).The response to diet medication was larger than BGase,considering weight gain and feed efficiency after d 11(P<0.001).In conclusion,diet medication and BGase depolymerized high molecular weight ileal solubleβ-glucan and increased overall bird performance.Dietary BGase may benefit bird health in broilers fed wheat-based diets without medication. 展开更多
关键词 BETA-GLUCAN Prebiotic Non-starch polysaccharide Soluble fiber Feed antibiotic
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