肉鸭生长期饲粮养分适宜浓度范围的研究

A STUDY ON DIEIARY NUTRIENTS DENSITY FOR DUCKLINGS

选用６４０只（公母各半）1日龄天府内鸭（平均体重５７.０±３．０ｇ），按性别随机分成３２组，采用５因素部分实施的二次回归通用旋转组合设计，估测了为最大增重和最大胸腿肌率时肉鸭生长期饲粮ＭＥ、Ｃａ、ＴＰ、ＡＰ和ＣＰ的适宜浓度范围和Ｎａ的适宜添加水平。试验结果表明：最大增重时，肉鸭饲粮ＭＥ适宜水平为：０～３周１２．７５ＭＪ／ｋｇ，４～７周１２．６６ＭＪ／ｋｇ，养分适宜浓度为：０～３周，ＣＰ１７．７０％或１３．９９／ＭＪＭＥ，Ｎａ０．１２％（适宜添加水平，下同），Ｃａ０．８２％，ＴＰ０．６９％，ＡＰ０．４８％；４～７周，ＣＰ１６．９７％或１３．４ｇ／ＭＪＭＥ，Ｎａ０．１０％，Ｃａ０．７５％，ＴＰ０．６４％，ＡＰ０．４５％。最大胸腿肌率时，饲粮ＭＥ适宜水平为１１．８２ＭＪ／ｋｇ，养分适宜浓度为：ＣＰ前期为２１．２３％或１８．０ｇ／ＭＪＭＥ，后期为１６．２３％或１３．７ｇ／ＭＪＭＥ，Ｎａ０．１６％，Ｃａ０．５０％，ＴＰ０．６４％，ＡＰ０．４５％。本次试验还观察到饲粮钙磷不平衡导致肉鸭生长下降、腿骨发育不良等症状，试验鸭采食低磷饲粮（含ＴＰ０．４０％，ＡＰ０．１６％）时于８日龄出现缺磷症状。

The second order regression current rotation design(5 factors,half done)was usedto inquire the optimum dietary metabolizable energy(ME),crude protein(CP),sodium(Na),calcium(Ca),total phosphorus(TP),available phosphorus(AP)density formaximum weight gain and maximum percentage of breast and thigh musclar in netcarcass of ducklings.640 Tianfu ducklings of l day old were selected and allottedrandomly to 32 groups according to sex. The results showed that the optimum dietarynutrient density of ducklings for maximum weight gain were ME 12.75 MJ/kg,CP17.70%or l3.9g/MJME Na(addition leve1)0.12%, Ca 0.82%,TP 0.69%,AP0.48%for the starter period(0～3week),and the corresponding density for thegrower period(4～7week)were l2.66MJ/kg,16.97%or 13.4g/MJME,0.15%,0.75%0.64%,0.45%。The optimum ratio between Ca and AP for weight gain was l :0.60.The optimum dietary nutrient density for the maximum percentage of thigh and breastmusclar were ME 11.82MJ/kg,CP 2l.23%or l8.0g/MJME for starter and l6.23%or13.7g/MJME for grower, Na 0.16%,Ca 0.50%, TP 0.64%,AP 0.45%;The optimumratio between Ca and AP was l :0.90.Phosphorus deficiency syndroms were ohservedamong ducklings fed a low phosphorus diet(containing TP 0.40%,AP 0.16%)。