Wageningen University, Animal Breeding and Genomics Centre, 6700 AG Wageningen, the Netherlands.
Poult Sci. 2012 Mar;91(3):556-64. doi: 10.3382/ps.2011-01794.
Ascites or pulmonary hypertension syndrome is a metabolic disorder in broilers. Male broilers have a higher BW and are therefore expected to be more prone to developing ascites than females. As genetic parameters might be affected by the ascites incidence, genetic parameters might differ between male and female broilers. The aims of this study were to estimate the heritability for the ratio of right ventricular weight to total ventricular weight (RATIO) and BW in male and female broilers, the genetic correlation between RATIO and BW separately for male and female broilers, and the genetic correlations between BW for ascitic and nonascitic broilers. Data were available from 7,856 broilers (3,819 males and 4,037 females). The broilers in the experiment were kept under a cold temperature regimen and increased CO(2) levels. In this study, we showed that the incidence of ascites is higher in male than in female broilers. Heritability estimates for BW at 7 wk of age were higher for male (0.22) than for female (0.17) broilers, and for RATIO heritability, estimates were higher for female (0.44) than for male (0.32) broilers. The genetic correlations between RATIO and BW measured at different ages changed from slightly positive at 2 wk of age to moderately negative at 7 wk. The change in genetic correlation was more extreme for male (from 0.01 to -0.62) than for female (from 0.13 to -0.24) broilers. The difference in ascites incidence between male and female broilers is the most likely reason for the difference in genetic correlations. The genetic correlation between BW traits measured in broilers with fluid in the abdomen and without fluid in the abdomen decreased from 0.91 at 2 wk to 0.69 at 7 wk. We conclude that under circumstances with ascites, data from male and female broilers should be analyzed separately.
腹水或肺动脉高压综合征是肉鸡的一种代谢紊乱。雄性肉鸡体重较大，因此比雌性肉鸡更容易发生腹水。由于遗传参数可能受腹水发病率的影响，雄性和雌性肉鸡的遗传参数可能不同。本研究的目的是估计雄性和雌性肉鸡右心室重量与总心室重量比（RATIO）和体重的遗传力、雄性和雌性肉鸡分别的 RATIO 和 BW 之间的遗传相关性以及腹水和非腹水肉鸡之间 BW 的遗传相关性。数据来自 7856 只肉鸡（3819 只雄性和 4037 只雌性）。实验中的肉鸡处于低温和高二氧化碳水平的环境中。本研究表明，雄性肉鸡的腹水发病率高于雌性肉鸡。7 周龄时雄性肉鸡的 BW 遗传力估计值（0.22）高于雌性肉鸡（0.17），而 RATIO 的遗传力估计值则是雌性肉鸡（0.44）高于雄性肉鸡（0.32）。不同年龄时 RATIO 和 BW 之间的遗传相关性从 2 周龄时的略微正相关变为 7 周龄时的中度负相关。雄性肉鸡的遗传相关性变化更为极端（从 0.01 变为-0.62），而雌性肉鸡的遗传相关性变化相对较小（从 0.13 变为-0.24）。雄性和雌性肉鸡腹水发病率的差异是遗传相关性差异的最可能原因。腹中有液体和没有液体的肉鸡 BW 性状之间的遗传相关性从 2 周龄时的 0.91 下降到 7 周龄时的 0.69。我们得出结论，在有腹水的情况下，应分别分析雄性和雌性肉鸡的数据。
