8~18周龄如皋黄鸡粗蛋白质和代谢能需要量的研究

Dietary Crude Protein and Metabolic Energy Requirements of Rugao Yellow Chickens Aged from 8 to 18 Weeks

本试验通过研究饲粮粗蛋白质(CP)和代谢能(ME)水平对8~18周龄如皋黄鸡生长性能、均匀度以及跖骨和鸡冠发育的影响,旨在确定8~18周龄如皋黄鸡CP和ME需要量。试验选用8周龄体况良好、体重接近的如皋黄鸡1800只,随机分成15组,每组8个重复,每个重复15只鸡。采用5×3双因子完全随机试验设计,因子1为饲粮CP水平,设14.00%、14.75%、15.50%、16.25%和17.00%5个水平;因子2为饲粮ME水平,设10.88、11.30和11.72 MJ/kg 3个水平。试验期10周(8~18周龄)。结果表明:1)饲粮CP水平显著影响蛋鸡18周龄体重(P<0.05),饲粮ME水平显著影响蛋鸡15、16、17和18周龄体重(P<0.05)。2)饲粮CP和ME水平均显著影响蛋鸡8~18周龄平均日增重(ADG)、平均日采食量(ADFI)和料重比(F/G,P<0.05);此外,饲粮ME水平显著影响蛋鸡8~15周龄ADG和F/G以及16~18周龄ADFI(P<0.05)。3)饲粮CP水平显著影响蛋鸡8~15周龄、16~18周龄和8~18周龄平均日粗蛋白质摄入量(ADCPI)和粗蛋白质转化比(CPCR)以及8~18周龄代谢能转化比(MECR,P<0.05)。饲粮ME水平显著影响蛋鸡16~18周龄和8~18周龄ADCPI,8~15周龄、16~18周龄和8~18周龄的平均日代谢能摄入量(ADMEI)以及8~15周龄和8~18周龄CPCR和MECR(P<0.05)。4)饲粮ME水平显著影响蛋鸡15、16、17和18周龄体重变异系数(P<0.05)。5)饲粮CP和ME水平对15和18周龄蛋鸡跖长、冠长和冠高均无显著影响(P>0.05)。6)饲粮CP和ME水平对8~18周龄蛋鸡生长性能、均匀度以及跖骨和鸡冠发育的影响均不存在显著交互作用(P>0.05)。综合考虑生长性能、均匀度以及跖骨和鸡冠发育等指标,如皋黄鸡8~18周龄饲粮适宜CP水平为14.75%,适宜ME水平为11.72 MJ/kg。

This experiment was conducted to evaluate the effects of dietary crude protein(CP)and metabolic energy(ME)levels on growth performance,flock uniformity and shank and comb development of Rugao yellow chickens aged from 8 to 18 weeks,to determine the CP and ME requirements of Rugao yellow chickens aged from 8 to 18 weeks.One thousand and eight hundred 8-week-old healthy Rugao yellow chickens with similar body weight were assigned to 15 groups with 8 replicates per group and 15 hens per replicate.This experiment took a 5×3 factorial design with 5 dietary CP levels(14.00%,14.75%,15.50%,16.25%and 17.00%)and 3 dietary ME levels(10.88,11.30 and 11.72 MJ/kg).The trial period lasted for 10 weeks(8 to 18 weeks of age).The results showed as follows:1)the body weight of laying hens at 18 weeks of age was significantly affected by dietary CP level(P<0.05),and the body weight of laying hens at 15,16,17 and 18 weeks of age was significantly affected by dietary ME level(P<0.05).2)The average daily weight gain(ADG),average daily feed intake(ADFI)and the ratio of feed to gain(F/G)of laying hens aged from 8 to 18 weeks were significantly affected by dietary CP and ME levels(P<0.05);besides,the ADG and F/G of laying hens aged from 8 to 15 weeks and the ADFI of laying hens aged from 16 to 18 weeks were significantly affected by dietary ME level(P<0.05).3)The average daily crude protein intake(ADCPI)and the ratio of crude protein to gain(CPCR)of laying hens aged from 8 to 15 weeks,16 to 18 weeks and 8 to 18 weeks,and the ratio of metabolic energy to gain(MECR)of laying hens aged from 8 to 18 weeks were significantly affected by dietary CP level(P<0.05).The ADCPI of laying hens aged from 16 to 18 weeks and 8 to 18 weeks,the average daily metabolic energy intake(ADMEI)of laying hens aged from 8 to 15 weeks,16 to 18 weeks and 8 to 18 weeks,and the CPCR and MECR of laying hens aged from 8 to 15 weeks and 8 to 18 weeks were significantly affected by dietary ME level(P<0.05).4)The body weight coefficient of variation of laying hens at 15,16,17,and 18 weeks of age was significantly affected by dietary ME level(P<0.05).5)The shank length,comb length and comb height of laying hens at 15 and 18 weeks of age were not affected by dietary CP or ME levels(P>0.05).6)Dietary CP and ME levels had no significant interaction in growth performance,flock uniformity and shank and comb development of laying hens aged from 8 to 18 weeks(P>0.05).In conclusion,comprehensive considering the indexes of growth performance,flock uniformity and shank and comb development,the appropriate dietary CP and ME levels for Rugao yellow chickens aged from 8 to 18 weeks are 14.75%and 11.72 MJ/kg,respectively.