| 摘要: |
| [目的]研究不同无机磷水平日粮中添加植酸酶对肉鸡生长性能及骨骼的影响,以确定适宜的无机磷和植酸酶用量。[方法] 选取1日龄肉鸡1500只,随机分为5个处理,对照组日粮中添加16。3 g/kg磷酸氢钙,其余4组分别添加12。3,8。2,4。1和0 g/kg磷酸氢钙后再添加500 FTU/kg植酸酶,各组钙磷比为1。2～1。4,测定各组鸡的生长性能、胫骨鲜重、胫骨脱脂重、胫骨灰分和矿物质元素含量以及胫骨折断强度。[结果] 未添加磷酸氢钙组肉鸡的日平均采食量、日增重均显著低于对照组(P＜0。05)；添加8。2 g/kg磷酸氢钙组肉鸡日增重最高,料重比最低；肉鸡胫骨鲜重、脱脂率在各处理间差异不显著(P＞0。05),脱脂率随日粮中添加无机磷水平的降低而升高；胫骨脱脂重随日粮中无机磷水平下降而降低,28日龄未添加磷酸氢钙组肉鸡的胫骨脱脂重显著低于其他组(P＜0。05)。28日龄肉鸡胫骨灰分含量以未添加磷酸氢钙组显著低于其他各组(P＜0。05)；胫骨钙、磷含量以未添加磷酸氢钙组低于其他各组,但各组差异不显著(P＞0。05)；28日龄肉鸡胫骨镁、锰、铜、铁、锌含量随日粮中无机磷添加水平的降低而逐渐升高,42日龄肉鸡胫骨镁、锰、铁含量在添加植酸酶组也有同样变化。肉鸡胫骨折断强度以未添加磷酸氢钙组低于其他各组,其中28日龄肉鸡该组胫骨折断强度显著低于其他组(P＜0。05)。[结论] 日粮中添加植酸酶能提高肉鸡生长性能及矿物质元素的利用率,但不能完全替代磷酸氢钙,以添加8。2 g/kg磷酸氢钙组(0～4周龄:Ca 7。6 g/kg,总磷(TP) 5。4 g/kg；5～7周龄:Ca 7。0 g/kg,TP 5。3 g/kg)后再添加植酸酶对肉鸡的饲养效果较好,鉴于植酸酶对矿物元素的释放作用,有必要重新评定日粮配方中矿物元素的需要量。 |
| 关键词: 肉鸡 无机磷 植酸酶 生长性能 骨骼 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项目(30471261) |
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| Effects of phytase and inorganic phosphorus supplementation on growth performance and bone in broiler chicks diets |
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| Abstract: |
| 【Objective】 An experiment was conducted to study the effect of phytase supplementation in broilers fed on different dietary levels of inorganic phosphorus on growth performance and bone in order to determine reasonable inorganic P and phytase level.【Method】 A total of 1500 broilers were chosen and grouped randomly into five experimental treatments.A control group with 16.3 g/kg dicalcium phosphate in diet was used,and the other four dicalcium phosphate groups were performed by 12.3,8.2,4.1 and 0 addition with phytase supplementation by 500 FTU/kg respectively.Dietary Ca:Tp ratio between 1.2 to 1.4 was controlled in all treatments.The tibia fresh weight,fat-free weight,tibia ash,mineral elements contents and tibia breaking strength were monitored.【Result】 The results demonstrated that feed intake and ADG of no dicalcium phosphorus addition group was significantly lower than that of the control P＜0.05).ADG of 8.2 g/kg calcium phosphate dibasic group was the highest and feed gain ratio was the lowest among groups.Tibia fresh weight and tibia fat-free rate were not significantly different of all treatments(P＞0.05),and tibia fat-free rate was increased in response to decreasing inorganic P levels;Tibia fat-free weight was decreased in response to decreasing inorganic P,and it was significantly lower than that of the other groups on 28 d of the age(P＜0.05).Tibia ash content of no dicalcium phosphorus addition group was lower than that of the other groups on 28 d of the age(P＜0.05).Tibia Ca,tibia P contents of no dicalcium phosphorus addition group were lower than that of the other groups,but they did not show significant difference (P＞0.05) among all treatments.Tibia Mg,tibia Mn,tibia Cu,tibia Fe,tibia Zn contents increased in response to decreasing dietary inorganic P on 28 d of age,Tibia Mg,tibia Mn,tibia Fe contents with phytase addition groups had the same variation on 42 d of age.Tibia breaking strength of no dicalcium phosphorus addition group was lower than that of the other groups,and it was lower significantly than that of the other groups on 28 d of the age(P＜0.05).【Conclusion】 The study indicated that the growth performance and utilization of the mineral elements were improved with phytase addition in diet,but it can not replace calcium phosphate dibasic completely and 8.2 g/kg dicalcium phosphorus group(0-4 W,Ca 7.6 g/kg,TP 5.4 g/kg;5-7 W,Ca 7.0 g/kg,TP 5.3 g/kg) with phytase addition appears to provide better efficacy in broiler breeding.In view of contribution of phytase on releasing binding minerals,it is necessary to reevaluate dietary requirements of mineral elements. |
| Key words: broiler phosphorus phytase growth performance bone |
