饲粮蛋白水平对宁都黄鸡生长性能、屠宰性能、体蛋白沉积及血液生化指标的影响

Effects of dietary crude protein on growth performance, carcass traits,body protein deposition and blood biochemical indices of Ning-du yellow chickens

试验旨在分析饲粮粗蛋白质(CP)水平对宁都黄鸡生长性能、屠宰性能、体蛋白沉积和血液生化指标的影响,确定其适宜饲粮CP水平。采用单因素完全随机试验设计,分3个阶段,分别选用1、29、57日龄体重相近宁都黄鸡母鸡各600、480和336只,随机分为4个处理,每处理6个重复,每重复分别25、20和14只。不同阶段饲粮CP水平为:1~28日龄17.0%、18.5%、20.0%和21.5%, 29~56日龄15.5%、17.0%、18.5%和20.0%,57~105日龄14.0%、15.5%、17.0%和18.5%。结果表明,1~28日龄,20.0%和21.5%组料重比(F/G)显著低于17.0%组(P<0.05);20.0%组体CP含量和日沉积CP质量极显著高于17.0%和18.5%组(P<0.01),20.0%组日沉积CP质量显著高于其他各组(P<0.05),17.0%和20.0%组体蛋白沉积率极显著高于21.5%组(P<0.01)。29~56日龄,17.0%组末重和平均日增重(ADG)显著高于20.0%组(P<0.05),F/G显著低于18.5%和20.0%组(P<0.05)。18.5%和20.0%组体CP沉积率极显著低于15.5%和17.0%组(P<0.01)。17.0%组血清TC含量显著低于其他各组(P<0.05);17.0%和18.5%组血清TG含量显著低于20.0%组(P<0.05);15.5%、17.0%和18.5%组血清GLU含量极显著低于20.0%组(P<0.01);17.0%组血清TP含量极显著高于15.5%和20.0%组(P<0.01)。57~105日龄,15.5%组末重和ADG显著高于17.0%和18.5%组(P<0.05),14.0%和15.5%组F/G显著低于18.5%组(P<0.05)。15.5%组体CP含量显著高于14.0%和18.5%组(P<0.05),15.5%组体CP沉积率极显著高于18.5%组(P<0.01)。105日龄宁都黄鸡屠宰率随饲粮CP水平升高显著降低(P<0.05),与14.0%和17.0%组相比,18.5%组全净膛率显著升高(P<0.05),腹脂率显著下降(P<0.05)。研究结果建议宁都黄鸡不同生长阶段适宜CP水平分别为,1~28日龄20.0%,29~56日龄17.0%,57~105日龄15.5%。

This experiment was conducted to investigate the effects of dietary crude protein(CP)level on growth performance, carcass traits, body protein deposition and blood biochemical indices of Ningdu yellow chickens in order to determine CP requirements of Ning-du yellow chickens at different growth phases. A single factor complete randomized trial design was adopted. In three separate phases, 600, 480 and 336 female Ning-du yellow chickens with similar body weight at 1, 29 and 57 days of age were randomly assigned into four groups with six replicates of 25, 20 and 14 each, respectively.The CP levels were 17.0%, 18.5%, 20.0%, 21.5% at 1 to 28 days of age;15.5%, 17.0%, 18.5%, 20.0%at 29 to 56 days of age;and 14.0%, 15.5%, 17.0%, 18.5% at 57 to 105 days of age, respectively. The results showed that at 1 to 28 days of age, the ratio of feed to gain(F/G) of 20.0% and 21.5% groups were significantly lower than that of 17.0% group(P<0.05);body protein content and daily protein deposition in 20.0% group were extremely higher than those in 17.0% and 18.5% CP groups(P<0.01),daily protein deposition in 20.0% group was higher than that in other groups(P<0.05), the body CP deposition rate in 17.0% and 20.0% groups were extremely higher than that in 21.5% group(P<0.01). At29 to 56 days of age, the final weight and the average daily gain(ADG) in 17.0% group was significantly higher than those in 20.0% group(P<0.05), the F/G of 17.0% group was significantly lower than that of18.5% and 20.0% groups(P<0.05);the body CP deposition rate in 18.5% and 20.0% groups were extremely higher than that in 15.5% and 17.0% groups(P<0.01);the serum TC in 17.0% CP group was significantly lower than that in other groups(P<0.05);the serum TG in 17.0% and 18.5% groups were significantly lower than that in 20.0% group(P<0.05), serum GLU in 15.5%, 17.0% and 18.5% groups were extremely lower than that in 20.0% group(P<0.01);the serum TP in 17.0% group was extremely higher than that in 15.5% and 20.0% groups(P<0.01). At 57 to 105 days of age, final weight and ADG in15.5% group were significantly higher than those in 17.0% and 18.5% groups(P<0.05), the F/G of14.0% and 15.5% groups were significantly lower than that of 18.5% groups(P<0.05);body protein content in 15.5% CP group was higher than that in 14.0% and 18.5% CP groups(P<0.05), and daily protein deposition in 15.5% CP group was extremely higher than that in 18.5% CP group(P<0.01);with dietary CP level increasing, the dressing percentage at 105 days of age showed a decreasing trend(P<0.05);compared with 14.0% and 17.0% groups, eviscerated yield percentage in 18.5% group was significantly increased(P<0.05), abdominal fat percentage was significantly decreased(P<0.05). Based on the results, 20.0%, 17.0% and 15.5% dietary CP levels were recommended for Ningdu chickens at 1 to 28 days of age, 29 to 56 days of age and 57 to 105 days of age, respectively.