PDF(Pubmed)
Abstract：
Broiler breeders are subjected to feed restriction programs to control excessive growth. However, current levels of feed restriction and concomitant growth restriction are becoming severe, raising welfare and suboptimal reproductive performance concerns in underfed breeders. To circumvent the issue, our previous studies investigated the effects of new strategic growth curves, with various degrees of relaxed growth restrictions, on broiler breeders and their progeny\'s performance. The broiler breeder study was conducted with 40 Ross 708 broiler breeder pullets reared on 1 of 10 target growth trajectories using a precision feeding (PF) system. The growth trajectories were designed with 2 levels of the amount of prepubertal BW gain and 5 levels of pubertal growth timing. The prepubertal BW gain (g1) was estimated from the breeder-recommended standard BW gain (Standard g1) target, or 10% higher (High g1). The pubertal growth timing (I2) was advanced such that it happened at I2-0% = 22.29 wk, I2-5% = 21.16 wk, I2-10% = 20.05 wk, I2-15% = 18.94 wk, I2-20% = 17.82 wk of age. Two broiler experiments with different maternal ages (35 and 42 wk) were conducted as the extension of the breeder experiment to evaluate the intergenerational effects of a reduced degree of maternal prepubertal phase growth restriction and earlier maternal pubertal phase growth on offspring growth and development. The current paper investigated the economic aspects of implementing the growth curves using the partial budget analysis. Increasing prepubertal BW gain by 10% and advancing the pubertal growth phase by 20% (scenario 10) could increase margin over feed and chick cost for the hatching egg producers by CDN$1.97/hen. For broiler chicken supply chain as a whole, the highest differential margin over feed and chick cost was for maternal growth scenario 10 from 42-wk-old hens. The latter margin over feed and chick cost was greater than that of breeder-recommended maternal growth (from 35-wk-old hens) by $0.1053/kg live chicken under the current economic situation.
摘要：
对肉鸡饲养员进行饲料限制程序以控制过度生长。然而,当前的饲料限制和伴随的生长限制水平变得越来越严重，提高营养不良育种者的福利和次优生殖性能问题。为了规避这个问题，我们以前的研究调查了新的战略增长曲线的影响，随着不同程度的放松增长限制，关于肉鸡育种者及其后代的表现。肉鸡饲养员研究是使用精确饲喂（PF）系统在10个目标生长轨迹中的1个上饲养的40个Ross708肉鸡饲养员母鸡。生长轨迹设计为2个水平的青春期前BW增加量和5个水平的青春期生长时间。根据饲养员推荐的标准BW增益（标准g1）目标估计青春期前BW增益（g1），或高10%（高g1）。青春期生长时间（I2）提前，因此发生在I2-0％=22.29周，I2-5%=21.16周，I2-10%=20.05周，I2-15%=18.94周，I2-20%=17.82周龄。作为饲养员实验的延伸，进行了两个不同母亲年龄（35和42周）的肉鸡实验，以评估降低程度的母亲青春期前生长限制和较早的母亲青春期生长对后代生长发育的代际影响。本文使用部分预算分析研究了实施增长曲线的经济方面。将青春期前BW增加10％，并将青春期生长期提前20％（方案10），可以将孵化卵生产者的饲料和小鸡成本的利润率提高CDN$1.97/hen。对于整个肉鸡供应链来说，与42周龄母鸡相比，在母鸡生长情景10中，饲料和小鸡成本的差异最大。在当前的经济形势下，后者在饲料和小鸡成本上的利润率比饲养员建议的母体生长（从35周龄母鸡开始）高0.1053美元/公斤活鸡。
