中型褐壳产蛋鸡饲粮非植酸磷适宜水平的研究

Study on an Optimum Level of Dietary Non-Phytate Phosphorus for Heavy-typed Brown-Eggshell Layers

用 2 0周龄的商品代北京红开产蛋鸡 15 0只进行饲养试验和磷代谢试验 ,研究饲粮非植酸磷水平对 2 0～ 40周龄阶段蛋鸡产蛋性能、蛋及蛋壳品质、血清生化特性和饲粮植酸磷表观消化利用率的影响 ,进而从多方面综合评价中型褐壳产蛋鸡的饲粮非植酸磷适宜水平 ,同时测定产蛋鸡对饲粮植酸磷的消化能力。试鸡按完全随机设计以体重随机分为 5个处理组 ,分别喂以含非植酸磷 0 2 0 %、0 2 5 %、0 30 %、0 35 %和 0 40 %及含钙量均为 3 5 %的玉米—豆粕型饲粮。饲粮非植酸磷水平对鸡的产蛋率、蛋重、产蛋量、采食量、饲料效率、蛋壳强度、蛋品哈氏单位、蛋形指数、血清白蛋白、球蛋白和碱性磷酸酶 (AKP)活性无明显影响 (P >0 18) ,而对蛋壳厚 (P <0 0 4)、蛋壳重 (P<0 0 7)及植酸磷表观消化率 (P <0 0 5 )有显著影响。蛋壳厚、蛋壳强度及蛋壳重均以 0 2 0 %非植酸磷水平组最大 ,此时鸡对饲粮植酸磷的表观消化率高达 70 5 % ,但随饲粮非植酸磷水平的增加 ,上述 4项指标均恒定降低 ,在0 30 %～ 0 40 %非植酸磷水平 ,蛋壳厚 (P <0 0 4)和蛋壳重 (P <0 0 7)明显降低 ,在 0 2 5 %和 0 40 %时植酸磷表观消化率分别比 0 2 0 %水平组降低 17 7和 2 1 4个百分点 (P <0 0 5 )。结果表明 ,北京红中型褐壳?

A feeding trial and phosphorus balance trial were carried out using a total of 150 20 week old commercial Beijing Red layers to study the optimum level of dietary nonphytate phosphorus for those layers during a phase of 20～40 weeks,and evaluate the ability of the layers to digest dietary phytate phosphorus.Layers were randomly allotted to one of five treatments according to bodyweight in a completely randomized design,and fed the corn soybean meal diets containing 0 20,0 25,0 30,0 35 or 0 40% nonphytate phosphorus at 3 50% calcium,respectively for 20 weeks.Dietary nonphytate phosphorus level did not affect (P>0 18) egg production rate,egg weight,egg yield,feed intake,feed conversion efficiency,eggshell strength,Haugh unit,egg shape index,serum albumin,serum globulin,and serum alkaline phosphatase (AKP) activity,but influenced eggshell thickness (P<0 04),eggshell weight (P<0 07) and apparent digestibility of phytate phosphorus (P<0 05).Layers had the greatest values of eggshell thickness,eggshell strength,eggshell weight,and apparent digestibility (70 5%) of phytate phosphorus at 0 20% nonphytate phosphorus,but had consistently decreased values of the above four indices with increasing nonphytate phosphorus levels.Layers had decreased eggshell thickness (P<0 04) and eggshell weight (P<0 07) at 0 30% 0 40% nonphytate phosphorus levels as well as decreased (P<0 05) apparent digestibility of phytate phosphorus (52 8% and 49 1% at 0 25% and 0 40% nonphytate phosphorus levels,respectively).The results from this study suggest that 0 20% (the analyzed value was 0 23%) nonphytate phosphorus in a basal corn soybean diet would be an optimum level for 20～40 week old commercial Beijing Red layers;And this type of layers have a strong ability to digest dietary phytate phosphorus.