Xu M, Du S, Wang J, Yu Z P, Harmon D L, Yao J H
College of Animal Science, Northwest A&F University, Shaanxi, Yangling 712100, P. R. China.
J Anim Physiol Anim Nutr (Berl). 2009 Feb;93(1):122-9. doi: 10.1111/j.1439-0396.2007.00792.x.
The objective of the experiment was to evaluate the effect of rumen escape starch (RES), accomplished by altering dietary starch concentrations on pancreatic exocrine secretion of goats. Four goats (36.8 +/- 3.2 kg) with common bile duct re-entrant and duodenal catheters were used in a 4 x 4 Latin square. Goats were fed diets containing 20%, 30%, 40% and 50% starch. Periods consisted of 10 day adaptation followed by 3 day of sample collection. Juice was collected in 1-h fractions continuously for 72 h. Total juice secreted was recorded, and 3% sub samples were retained to form a composite sample. The remaining fluid was returned to the duodenum. Juice composite samples were analyzed for activities of alpha-amylase, trypsin, chymotrypsin and lipase. Secretion of pancreatic alpha-amylase was lower (p < 0.05) when comparing lambs fed 20% starch diet with 30%, 40% and 50% starch diets. Lipase secretion was greater (p < 0.05) in lambs fed 40% starch diet compared with the other diets. Total secretion of juice, trypsin and chymotrypin was not affected (p > 0.05) by dietary starch concentration. Rumen escape starch increased with increasing dietary starch concentration (p < 0.05). Regression analysis showed that increasing RES results in a quadratic increase (p < 0.05) in pancreatic alpha-amylase and lipase secretion, and the secretion of alpha-amylase and lipase is maximum when RES is 113 and 83 g/day respectively. These results suggest that optimal RES for pancreatic secretion of alpha-amylase and lipase is 80-110 g/day in adult goats.
该实验的目的是通过改变日粮淀粉浓度来评估瘤胃逸出淀粉（RES）对山羊胰腺外分泌的影响。选用4只（体重36.8±3.2千克）安装了胆总管再入式导管和十二指肠导管的山羊，采用4×4拉丁方设计。给山羊饲喂淀粉含量分别为20%、30%、40%和50%的日粮。每期包括10天的适应期，随后是3天的样本采集期。连续72小时每1小时采集一次胰液。记录胰液的总分泌量，并保留3%的子样本以形成混合样本。其余液体返回十二指肠。对胰液混合样本进行α-淀粉酶、胰蛋白酶、糜蛋白酶和脂肪酶活性分析。与饲喂30%、40%和50%淀粉日粮的羔羊相比，饲喂20%淀粉日粮的羔羊胰腺α-淀粉酶分泌量较低（p<0.05）。与其他日粮相比，饲喂40%淀粉日粮的羔羊脂肪酶分泌量较高（p<0.05）。日粮淀粉浓度对胰液、胰蛋白酶和糜蛋白酶的总分泌量没有影响（p>0.05）。瘤胃逸出淀粉随日粮淀粉浓度的增加而增加（p<0.05）。回归分析表明，RES增加会导致胰腺α-淀粉酶和脂肪酶分泌呈二次增加（p<0.05），当RES分别为113克/天和83克/天时，α-淀粉酶和脂肪酶的分泌量最大。这些结果表明，成年山羊胰腺分泌α-淀粉酶和脂肪酶的最佳RES为80-110克/天。
