Romero L F, Zuidhof M J, Renema R A, Naeima A N, Robinson F
University of Alberta, Agricultural, Food and Nutritional Science, Agriculture/Forestry Centre, Edmonton, Alberta T6G 2P5, Canada.
Poult Sci. 2009 Jan;88(1):236-45. doi: 10.3382/ps.2008-00151.
This study assessed egg traits, chick traits, growth, yield, and meat quality characteristics of the offspring from broiler breeders classified by 2 measurements of energetic efficiency: residual feed intake (RFI), defined as the difference between observed and expected ME intake, and residual maintenance requirement (RME(m)), defined as the residual of the relationship between hen maintenance requirement and feed intake. A group of 72 pullets were placed in laying cages from 16 to 60 wk of age. Individual hen-based feed allocation was provided following a standard BW target. At 41wk, eggs from 8 d of production were collected and pedigree hatched. Chicks were assigned to 1 of 3 maternal RFI (RFI(mat)) categories: low, average, and high. A total of 366 chicks were placed in 36 floor pens, 6 per sex x RFI(mat) interaction, and raised to 38 d. At the end of the breeder experiment (60 wk), broilers were retrospectively assigned to a low or high maternal RME(m) (RME(mmat)) category. Low RFI(mat) broilers had greater 38-d BW than average and high RFI(mat) broilers. That was achieved through a greater BW gain and feed intake of low RFI(mat) broilers from 21 to 28 d. It was found that RFI(mat) had no effect on feed conversion, yield, or meat quality characteristics. Low RME(m) hens produced heavier eggs (62.3 g) and chicks (42.5 g) than high RME(m) hens (60.0 g; 41.0 g), but RME(mmat) did not affect broiler 38-d BW. High RME(mmat) broilers had greater breast yield (29.5%) and lower breast shear force (4.7 kg of force/g) than low RME(mmat) broilers (28.5%; 5.6 kg of force/g). The low RFI(mat) x high RME(mmat) broilers had the greatest growth to 38 d. It was found that RFI(mat) was inversely related to broiler growth, particularly when RME(mmat) was high. Although low maintenance requirements may be desirable for egg and chick production, hens with a high maintenance requirement produced broilers with greater breast yield and tenderness. Minimizing maintenance requirements may not be compatible with maximizing broiler performance and meat yield.
本研究评估了通过两种能量效率测量方法分类的肉种鸡后代的蛋性状、雏鸡性状、生长性能、产量和肉质特征：剩余采食量（RFI），定义为观察到的与预期代谢能摄入量之间的差异；以及剩余维持需要量（RME(m)），定义为母鸡维持需要量与采食量之间关系的残差。一组72只小母鸡从16周龄至60周龄饲养在产蛋笼中。按照标准体重目标提供基于个体母鸡的饲料分配。在41周龄时，收集8天生产期的鸡蛋并进行系谱孵化。雏鸡被分配到3个母体RFI（RFI(mat)）类别中的1个：低、中、高。总共366只雏鸡被放置在36个地面围栏中，按性别×RFI(mat)相互作用每组6只，并饲养至38日龄。在种鸡实验结束时（60周龄），肉鸡被追溯性地分配到低或高母体RME(m)（RME(mmat)）类别。低RFI(mat)肉鸡在38日龄时的体重比中、高RFI(mat)肉鸡更大。这是通过低RFI(mat)肉鸡在21至28日龄期间更大的体重增加和采食量实现的。研究发现，RFI(mat)对饲料转化率、产量或肉质特征没有影响。低RME(m)母鸡产的蛋（62.3克）和雏鸡（42.5克）比高RME(m)母鸡产的蛋（60.0克；41.0克）更重，但RME(mmat)对肉鸡38日龄体重没有影响。高RME(mmat)肉鸡的胸肉产量（29.5%）高于低RME(mmat)肉鸡（28.5%），胸肉剪切力（4.7千克力/克）低于低RME(mmat)肉鸡（5.6千克力/克）。低RFI(mat)×高RME(mmat)肉鸡在38日龄时生长最快。研究发现，RFI(mat)与肉鸡生长呈负相关，特别是当RME(mmat)较高时。虽然低维持需要量可能有利于蛋和雏鸡生产，但维持需要量高的母鸡生产的肉鸡胸肉产量更高且更嫩。将维持需要量降至最低可能与最大化肉鸡性能和肉产量不相容。
