小麦日粮中木聚糖酶和植酸酶对肉仔鸡生长和养分消化率的影响

432只艾维因肉仔鸡用于研究小麦基础日粮中添加木聚糖酶(320FXU/kg)或添加750U/kg植酸酶降低日粮中0.08％的非植酸磷后,对生长性能、日粮表观代谢能、粗蛋白和植酸磷表观消化率的影响。试验结果表明:无论是单一添加木聚糖酶或植酸酶,还是同时添加这两种酶,都能提高1-6周龄肉仔鸡的增重和饲料转化率,降低死亡率。添加木聚糖酶可提高肉仔鸡小麦日粮的表观代谢能2.14％,增加氮的存留量2.58％。750U/kg的植酸酶完全可以降低肉仔鸡小麦日粮中0.08％非植酸磷。添加植酸酶的处理组可提高植酸磷的表观消化率43.25％,减少植酸磷排泄量55.0％。植酸酶和木聚糖酶对全期饲料转化率和植酸磷的表观消化率表现有明显的正互作效应(P<0.05)。

EFFECTS OF XYLANASE AND PHYTASE ON THE GROWTH AND NUTRIENT DIGESTIBILITY IN BROILERS FED WHEAT- BASED DIETS

An experiment was conducted with 432 Avian chicks to investigate the effects of xylanase supplementation(320 FTU/kg) alone or in combination with 750 U/kg phytase, replaced 0.08% dietary available P,in wheat - based diets on the growth performance of broilers and utilization of nutrients. The results indicated that addition of xylanase alone or in combination with phytase increased body weight gain and feed efficiency in broilers fed wheat - rapeseed meal - soybean meal diet during week 1 to 6 and decreased the overall mortality. In the groups of birds receiving 320 FTU/ kg of xylanase, a marked elevation of the dietary AME and retained nitrogen were observed. Addition of phytase effectively increased the digestibility of phytic P by 43.25% , dramatically decreased the excretion of phytic P by 55.0% (P <0.01) .It seems feasible to completely replace 0.08% inorganic phosphorus supplementation with 750 U/ kg microbial phytase to wheat- based diets for broilers. Addition of phytase, instead of 0.08% available P, simultaneously with xylanase exhibited positive interaction on the overall feed:gain ration and the apparent diggestibility of dietary phytic P(P<0.05).