Department of Animal Nutrition, Veterinary College and Research Institute, Tamil Nadu Veterinary and Animal Sciences University (TANUVAS), Namakkal, Tamil Nadu, India.
Trop Anim Health Prod. 2023 Feb 16;55(2):82. doi: 10.1007/s11250-023-03505-7.
A study was conducted to assess the effect of feeding different crude protein (CP) levels with isocaloric metabolizable energy (ME) diets on growth performance, carcass traits, and myostatin (MSTN) gene expression of Aseel chicken during 0 to 16 weeks of age. A total of two hundred and ten day-old Aseel chickens were randomly allotted to seven dietary treatment groups. Each group had thirty chicks distributed into three replicates of ten chicks in each. Experimental diets were formulated to have varying levels of CP, viz. 18.5, 19.0, 19.5, 20.0, 20.5, 21.0, and 21.5%, with isocaloric energy of 2800 kcal ME/kg diets of mash feed fed to birds in a completely randomized design. Different CP levels had a significant effect (P < 0.05) on the body weight gain (BWG) of Aseel chicken. At the end of 16 weeks of age, the group fed 21% CP gained 223.53 g more than the lowest CP (18.5%)-fed group. The different CP levels did not significantly (P > 0.05) influenced the feed intake of all treatment groups, but numerically highest feed intake was observed in the lowest CP (18.5%)-fed group. However, significant differences in feed efficiency (FE) appeared from the 13th week only with the 21.0% CP-fed group showing the best FE until the 16th week (3.86 to 4.06). The maximum dressing % (70.61) was observed by the 21% CP-fed group. The CP 21% diet down-regulated the MSTN gene expression in breast muscle tissue to 0.07 folds when compared to the diet of CP 20%. The best economical coordinates for maximum performance for Aseel chicken appeared to be CP of 21% and ME of 2800 kcal/kg to achieve the best FE of 3.86 at the earliest age of 13 weeks. In conclusion, 21% CP in an isocaloric diet of 2800 kcal ME/kg, in Aseel chickens, would be optimum to improve the growth performance at maximum in terms of BWG and FE up to 16 weeks of age.
这项研究旨在评估在等能代谢能 (ME) 日粮下，不同粗蛋白 (CP) 水平对 0 至 16 周龄阿塞尔鸡生长性能、胴体特性和肌肉生长抑制素 (MSTN) 基因表达的影响。总共 210 只 1 日龄的阿塞尔鸡被随机分配到 7 个日粮处理组。每个处理组有 30 只小鸡，每个处理组分为 3 个重复，每个重复 10 只小鸡。实验日粮的 CP 水平分别为 18.5、19.0、19.5、20.0、20.5、21.0 和 21.5%，能量为 2800kcal ME/kg，以颗粒料形式饲喂鸡，采用完全随机设计。不同 CP 水平对阿塞尔鸡的体重增重 (BWG) 有显著影响 (P<0.05)。16 周龄时，21%CP 组比最低 CP(18.5%)组多增重 223.53g。不同 CP 水平对所有处理组的采食量均无显著影响 (P>0.05)，但最低 CP(18.5%)组的采食量最高。然而，仅从第 13 周开始，饲料效率 (FE) 才出现显著差异，21.0% CP 组的 FE 一直保持最佳，直到第 16 周 (3.86 至 4.06)。21% CP 组的最大出肉率 (70.61%)。与 20% CP 日粮相比，21% CP 日粮下调了胸肌组织 MSTN 基因的表达，至 0.07 倍。对于阿塞尔鸡来说，最大性能的最佳经济坐标似乎是 CP 21%和 ME 2800kcal/kg，以在最早的 13 周达到最佳的 3.86 FE。总之，在等能 2800kcal ME/kg 日粮中，CP 为 21%，对于阿塞尔鸡来说，在 16 周龄之前，以最大的 BW 和 FE 提高生长性能将是最佳的。
