González-Cerón F, Rekaya R, Anthony N B, Aggrey S E
NutriGenomics Laboratory, Department of Poultry Science, University of Georgia, Athens 30602.
Department of Animal and Dairy Science, University of Georgia, Athens 30602.
Poult Sci. 2015 Feb;94(2):162-8. doi: 10.3382/ps/peu052. Epub 2015 Jan 14.
Improvement in growth has been widely reported as the cause of increased incidence of leg problems in broiler chickens. We report herein the genetic relationship between growth and leg problems in a random mating broiler control population. The traits studied were valgus (VL), varus (VR), and tibial dyschondroplasia (TD), which were expressed on a binary scale of 0 (normal) and 1 (abnormal); growth rates from 0 to 4 wk (BWG 0-4) and from 0 to 6 wk of age (BWG 0-6); and residual feed intake from 5 to 6 wk of age (RFI 5-6). A threshold-linear mixed model was employed for the joint analysis of the categorical and linear traits. Incidences of VL, VR, and TD were 26, 4, and 2%, respectively. Heritability of leg problems ranged from 0.11 to 0.13. Phenotypic correlations alluded to an unfavorable relationship between growth and leg problems; however, the genetic relationship between growth and leg problems was extremely weak, ranging from 0.01 to 0.08. There is, therefore, a basis for genetic improvement in leg problems. However, improved management practices would also be important to reduce incidence of leg problems in broiler chickens.
生长性能的改善被广泛报道为肉鸡腿部问题发病率增加的原因。我们在此报告一个随机交配的肉鸡对照群体中生长与腿部问题之间的遗传关系。所研究的性状包括外翻（VL）、内翻（VR）和胫骨软骨发育不良（TD），这些性状以二元尺度表示，0表示正常，1表示异常；0至4周龄的生长速率（BWG 0 - 4）和0至6周龄的生长速率（BWG 0 - 6）；以及5至6周龄的剩余采食量（RFI 5 - 6）。采用阈值线性混合模型对分类性状和线性性状进行联合分析。VL、VR和TD的发病率分别为26%、4%和2%。腿部问题的遗传力范围为0.11至0.13。表型相关性表明生长与腿部问题之间存在不利关系；然而，生长与腿部问题之间的遗传关系极其微弱，范围为0.01至0.08。因此，腿部问题存在遗传改良的基础。然而，改进管理措施对于降低肉鸡腿部问题的发病率也很重要。
