鸡、鸭消化道pH和消化酶活的比较研究

Comparative Study of the pH in Digestive Tract and Digestive Enzyme between Cock and Drake

为阐明鸡、鸭对营养物质利用率差异的原因,比较了8只公鸡和8只公鸭消化道内容物酸碱性及体内主要蛋白质消化酶、碳水化合物水解酶和脂肪水解酶活性的差异。结果表明:(1)鸭消化道前段除口腔pH比鸡的高(P<0.01),食管膨大部、腺胃和肌胃的pH均比鸡低(P<0.05或P<0.01),而后段消化道从空肠开始到直肠,鸭的pH均比鸡高(P<0.05)。(2)鸡和鸭消化道内主要蛋白酶活性存在差异。鸭肌胃内容物中胃蛋白酶的相对活性和总量都极显著高于鸡的(P<0.01);鸭十二指肠、空回肠和盲肠内容物以及胰腺组织中胰蛋白酶的相对活性和总量高于鸡(P<0.05或P<0.01);鸭空回肠内容物中糜蛋白酶的活性显著高于鸡(P<0.05)。(3)鸭胰腺组织中脂肪酶相对活性极显著高于鸡(P<0.01),脂肪酶总量显著高于鸡(P<0.05);肠道内容物中脂肪酶的活性也大多数高于鸡。(4)鸡和鸭消化道内可溶性碳水化合物水解酶活性差异没有很强的规律性,但鸭空回肠内容物中纤维素酶的相对活性高于鸡(P<0.01),盲肠内容物中纤维素酶的总量显著高于鸡(P<0.05)。消化道中消化酶活性差异是鸡鸭对饲料养分消化利用差异的原因之一。

8 Hy-Line Brown cocks and 8 Peking drakes with the same weight and age （18 weeks） were slaughtered after fasting 8 h to compare the pH in digestive tract and digestive enzyme between cock and drake. The results showed that： （1） The pH value of crop, glandular and stomach gizzard content in drake were lower than those of cock （P〈0.05 or P〈0.01）, but the jejunum-ileum and rectum content pH value of drake were higher than those of cock（P〈0.05）. （2） The relative activity and total of pepsin in stomach gizzard content of drake significantly higher than those of cock （P〈0.01）. The relative activity and total of trypsin in duodenum, jejunum-ileum and caecum content of drake were significantly higher than those of cock （P〈0.05 or P〈 0.01）. The relative activity of chymotrypsin in jejunum-ileum content of drake were significantly higher than those of cock （P〈0.05）. （3） The relative activity of lipase activities in pancreas tissue of drake was significantly higher than those of cock （P〈0.05）, and the total was also higher （P〈0.01）. （4） There was no orderliness for the differences of amylase and maltase activities in digestive tract content and digestive organ tissue between cock and drake, but the relative activi- ties of cellulase in jejunum-ileum content of drake were significantly higher than those of cock （P〈0.01）, and in rectum content the total of cellulase was higher than those of cock （P〈0.05）.