22～42日龄黄羽肉鸡钙需要量研究

Calcium Requirement of Yellow-Feathered Broilers Aged 22 to 42 Days

本试验旨在研究不同饲粮钙水平对22～42日龄黄羽肉鸡生长性能、胫骨性能和血清生化指标的影响,探讨22～42日龄黄羽肉鸡的钙需要量。试验选用22日龄岭南黄羽肉公鸡1 200只,分为6个处理,每个处理5个重复,每个重复40只鸡。处理1(对照组)肉鸡饲喂玉米-豆粕型基础饲粮(钙水平为0.45%),处理2～6(试验组)肉鸡饲喂在基础饲粮中添加不同水平石粉的试验饲粮,饲粮钙水平分别为0.60%、0.75%、0.90%、1.05%和1.20%,其他营养水平各处理基本一致。试鸡自由采食与饮水。试验期21 d。结果表明:1)在基础饲粮中添加钙显著提高了试鸡42日龄体重和平均日增重(P<0.05),显著降低了料重比(P<0.05),0.75%、0.90%、1.05%和1.20%钙水平组平均日采食量显著低于对照组和0.60%钙水平组(P<0.05)。2)不同饲粮钙水平对试鸡胫骨鲜重无显著影响(P>0.05),而对胫骨折断力、脱脂胫骨干重、胫骨灰分含量、脱脂胫骨灰分含量、脱脂胫骨中钙和磷含量、胫骨灰分中钙和磷含量影响显著(P<0.05),0.90%和1.05%钙水平组胫骨性能指标均显著优于对照组(P<0.05)。3)不同饲粮钙水平对试鸡血清钙、磷含量无显著影响(P>0.05)。综合得出,以生长性能和胫骨性能为评定指标,22～42日龄黄羽肉鸡钙需要量分别为0.60%和0.90%。

This experiment was conducted to investigate the effects of dietary calcium level on growth performance,tibia quality and serum biochemical indices of yellow-feathered broilers aged 22 to 42 days,and then to estimate the dietary calcium requirement of yellow-feathered broilers.One thousand and two hundred 22-day-old male Lingnan broilers were randomly assigned to six dietary treatments.Each treatment consisted of five replicates with 40 birds per replicate.Dietary treatments included the corn-soybean meal based diet supplemented with different levels of limestone to ensure dietary calcium levels up to 0.45%(control),0.60%,0.75%,0.90%,1.05% and 1.20%,respectively.The contents of other nutrients in diets were consistent.Feed and water were provided ad libitum during the experimental period of 21 days.Results showed as follows: 1) compared with the control group,higher dietary calcium significantly increased the final weight and the average daily gain of broilers(P<0.05),and significantly decreased the ratio of feed to gain(P<0.05).The average daily feed intake of broilers in 0.75%,0.90%,1.05% and 1.20% calcium groups was significantly lower than that in the control group and 0.60% calcium group(P<0.05).2) Different dietary calcium levels did not significantly affect the fresh weight of tibia(P>0.05),but significantly affected the broking strength and ash content of tibia,the contents of calcium and phosphorus in tibia ash,the dry weight of defatted tibia,and the contents of tibia ash,calcium and phosphorus in defatted tibia(P<0.05).At all above indices,0.90% and 1.05% groups were better than the control group(P<0.05).3) Different dietary calcium levels did not affect the contents of calcium and phosphorus in serum of broilers(P>0.05).In conclusion,based on the growth performance and tibia quality,the calcium requirements of yellow-feathered broilers aged 22 to 42 days are 0.60% and 0.90%,respectively.