低磷日粮中添加植酸酶对蛋鸡产蛋性能、内源消化酶及养分消化率的影响

摘要

To evaluate the effects of low-available phosphorus (AP) diet supplemented with phytase on the laying performance, the activity of digestive enzyme and nutrient utilization in laying hens, 18-week-old laying hens (n = 840)were randomly allocated into 7 groups.Group Ⅰ , as the positive control, was fed with the basal diet.Group Ⅱ, as the negative control, was fed with low-AP diet.Groups Ⅲ, Ⅳ and Ⅴ were fed with low-AP diet adding coated dosage-form phytase at three levels (300 U/kg, 1 000 U/kg and 10 000 U/kg, respectively).Groups Ⅵ and Ⅶ were supplemented with 300 U/kg phytase of powdery dosage-form and granular dosage-form, respectively.The results indicated that compared with the negative control, the addition of phytase to the low-AP diet did not significantly affect egg weight, broken eggshell rate, the indexes of egg quality,the activity of amylase, the activity of disaccharidase and the apparent digestibility of dry matter, ash and energy (P＞0.05), but significantly enhanced the egg preduction, laying rate, the activity of trypsin in group Ⅳ and the apparent digestibility of Ca, P and protein ( P＜0.05 ).It was concluded that low-AP diet supplemented with phytase could increase laying performance, the activity of digestive enzyme and nutrient utilization in laying hens.The 300 U/kg coated phytase was enough to meet the nutrient requirement of laying hens for growth and production.%为探明在低磷的玉米一豆粕型日粮中添加植酸酶对蛋鸡产蛋性能、内源消化酶及养分消化率的影响,该研究选用18周龄体重、产蛋周龄相近的伊莎褐蛋鸡840羽,随机分成7组:对照1( Ⅰ组,基础日粮,未添加植酸酶)、对照2(Ⅱ组,有效磷水平降低0.12个百分点)及在对照2基础上分别添加300 U/kg、1 000 U/kg和10 000U/kg的包衣状植酸酶、300 U/kg的粉状植酸酶及300 U/kg的微丸状植酸酶(试验Ⅲ、Ⅳ、Ⅴ、Ⅵ和Ⅶ组).结果表明:与对照2相比,除Ⅴ组外,各试验组的产蛋量和产蛋率显著提高(P0.05);蛋品质的各项指标无显著差异(P>0.05);各试验组的淀粉酶、二糖酶活性无显著差异(P>0.05),Ⅳ组的胰蛋白酶活性得到了显著提高(P<0.05);各试验组的干物质、灰分、能量及氨基酸的表观消化率无显著差异,Ⅳ组的钙、磷及蛋白质的利用率得到了显著提高(P<0.05).由此可见,在低磷日粮中添加适量的植酸酶可改善蛋鸡的产蛋性能,增强蛋鸡肠道消化酶活性并能提高饲料的养分消化率.