早期限饲对肉鸡肌肉生长及生产性能的长期影响

本研究旨在比较不同生长阶段隔日限饲(早期限饲:1~14日龄限饲,后期限饲:50~63日龄限饲)对肉鸡肌肉生长及相关激素水平的影响,并探讨早期限饲对肉鸡肌肉生长的程序化作用。试验结果:1)早期限饲组整个试验阶段体重均极显著低于对照组,后期限饲组限饲一周后体重显著低于对照组并于63日龄实现完全补偿生长;2)早期限饲组14日龄和63日龄胸肌、腓肠肌重均显著低于对照组;后期限饲组63日龄胸肌、腓肠肌重均显著低于对照组,且二者与早期限饲组均差异不显著;3)早期限饲显著降低了14日龄肉鸡肌肉中DNA、RNA和蛋白含量,63日龄恢复至正常水平,且核酸、蛋白水平在胸肌和腓肠肌内的趋势表现不一致;4)早期限饲组14日龄血清中T3、T4水平均显著低于对照组,63日龄血清T3水平仍显著低于对照组;后期限饲组63日龄血清T3水平显著低于对照组,T4水平与对照组差异不显著。结果表明:1)限饲可显著阻碍肉鸡肌肉的生长;2)不同部位的肌肉对限饲的敏感度不同;3)早期营养因子对肉鸡肌肉的生长具有"程序化"作用,甲状腺激素可能参与这些过程的调节。

Long-term effect of early feed restriction on muscle growth and production performance of broilers

The present experiment was carried out to investigate the effect of intermittent feed restriction on muscle growth and hormone levels in different stages(ERG: early feed restriction group;LRG: later feed restriction group)of broilers,and to examine the long effect of early feed restriction on muscle growth.The results showed: 1) body weight of ERG was significantly lower throughout the whole experimental period,and body weight of LRG was significantly lower after feed restricting for 1 week whereas no difference on 63 d compare with the control group;2) in ERG group the lateral gastrocnemius muscle weight and pectoral muscle weight were significantly lower on 14 d and 63 d,and the pectoral and lateral gastrocnemius muscle weight were significantly lower on 63d in the LRG;3) the DNA,RNA and protein contents in ERG decreased significantly on 14 d whereas no difference on 63 d,and no consistent trend was observed on nucleic acid and protein contents in pectoral and lateral gastrocnemius muscle;4)the T3,T4 levels was significantly lower on 14 d while only T3 level was still lower on 63 d,and in the LRG,T3 level,not T4,was also significantly lower on 63 d.These results implied: 1)feed restriction could markedly delay the muscle growth of broiler,and the effect has long lasting;2) different response to early feed restriction was observed between pectoral and lateral gastrocnemius muscle;3) thyoxine hormones might be included in this process.