磷酸对肉鸡消化道pH值、消化酶活性和蛋白消化率的影响

Effects of Dietary Phosphoric Acid on pH,Enzymatic Activity of Digestive Tract and Protein Digestibility in Broilers

试验旨在研究日粮添加不同剂量磷酸对肉鸡消化道p H值、消化酶活性及蛋白消化率的影响,以确定肉鸡日粮适宜磷酸添加量。将720只1日龄AA肉公鸡分成6组(1个对照组和5个处理组),每组6个重复,每个重复20只鸡,对照组饲喂基础饲粮,处理组分别在基础日粮中添加0.05%、0.10%、0.15%、0.20%、0.25%磷酸。结果表明:磷酸浓度显著影响肉鸡42日龄嗉囊、肌胃+腺胃和回肠的p H(P<0.05),且呈显著二次曲线关系(P<0.05);显著影响肉鸡42日龄腺胃和肌胃胃蛋白酶的总酶、酶原、酶活和激活度(P<0.05),除了肌胃酶原呈一次线性关系(P<0.05),其他均呈显著二次曲线关系(P<0.05);显著影响肉鸡42日龄十二指肠、空肠和回肠内胰蛋白酶及十二指肠糜蛋白酶的活性(P<0.05),且十二指肠、空肠胰蛋白酶与磷酸浓度呈一次线性关系(P<0.05),回肠胰蛋白酶和十二指肠糜蛋白酶与磷酸浓度呈显著二次曲线关系(P<0.05);显著影响肉鸡蛋白质和干物质消化率(P<0.05),且呈显著一次线性关系(P<0.05)。由此可知,日粮添加不同剂量磷酸对肉鸡消化道p H值、消化酶活性及蛋白消化率都有显著影响,达到最佳消化道p H值、消化酶活性及蛋白消化率的磷酸浓度为0.15%。

This experiment was conducted to evaluate the effects of diet with different phosphoric acid concentration on p H,enzymatic activity of digestive tract and protein digestibility in broiler and confirm phosphoric acid propriate dosage of broiler diet. 720 1-day-age AA broilers were randomly assigned to 6 groups with 6 replicates and 20 birds per replicate.Birds were fed basal diets supplemented with 0（control）,0.05%,0.10%,0.15%,0.20%,0.25% phosphoric acid for 42 days,respectively. The results showed as follows：phosphoric acid concentration had significant effects on p H of crop,muscular stomach plus glandular stomach and ileum of broilers at 42 days of age（P〈0.05）,and showed a quantitative representation（P〈0.05）. Phosphoric acid concentration had significant effects on total enzyme,proenzyme,enzyme activity and activity of pepsase in muscular stomach and glandular stomach of 42-day-age broiler（P〈0.05）,and showed a quantitative representation except that muscular stomach proenzyme showed a linear correlation（P〈0.05）.Phosphoric acid concentration had significant effects on trypsase in duodenum,jejunum and ileum of 42-day-age broiler,and chymotrypsin in duodenum of 42-day-age broiler（P〈0.05）,there was significant linear correlation between trypsase of duodenum,jejunum and phosphoric acid concentration（P〈0.05）,and there was significant quantitative representation between trypsase of ileum,chymotrypsin of duodenum and phosphoric acid concentration（P〈0.05）.Phosphoric acid concentration had significant effects on protein and dry matter digestibility（P〈0.05）,and showed a liner correlation（P〈0.05）. It was indicated that phosphoric acid concentration had significant effects on p H,enzymatic activity of digestive tract and protein digestibility in broiler,propriate dosage of phosphoric acid in broiler diet for p H,enzymatic activity of digestive tract and protein digestibility was 0.15%.