Cravener T L, Roush W B, Mashaly M M
Department of Poultry Science, Pennsylvania State University, University Park 16802.
Poult Sci. 1992 Mar;71(3):427-33. doi: 10.3382/ps.0710427.
The influence of population density on the growth performance and stress level of Hubbard x Hubbard chicks of equally mixed sex was studied. Six hundred and sixteen birds were housed under .05, .07, .09, or .11 m2 per bird (four replicates per density) from 0 to 7 wk. There were no treatment effects on feed conversion at 6 or 7 wk. Birds housed at .07, .09, and .11 m2 per bird had similar 7-wk BW and carcass weights, all significantly higher than birds housed at .05 m2 per bird. Under .05 m2 per bird, a higher percentage of breast blisters and ammonia burns (30%) was observed than at other densities. The 7-wk heterophil to lymphocyte ratios of birds raised at .09 and .11 m2 per bird (.42 and .45) were significantly higher than those at .05 and .07 m2 per bird (.28 and .30). Lowered BW and decreased carcass quality of birds raised at .05 m2 per bird suggested that these birds were stressed. However, decision analysis of economic potential indicated that the optimum profit potential per square meter was .05 m2 per bird for Maximax and Equally Likely decisions and .07 m2 per bird for the Maximin decision.
研究了饲养密度对性别均匀混合的哈伯德×哈伯德雏鸡生长性能和应激水平的影响。616只雏鸡从0至7周龄期间分别饲养在每只鸡占有0.05、0.07、0.09或0.11平方米的空间中（每个密度设置4个重复）。在6周龄或7周龄时，各处理组间的饲料转化率没有差异。每只鸡饲养在0.07、0.09和0.11平方米空间中的雏鸡，7周龄时的体重和胴体重量相近，且均显著高于每只鸡饲养在0.05平方米空间中的雏鸡。每只鸡饲养在0.05平方米空间时，胸部水泡和氨气灼伤的发生率（30%）高于其他饲养密度。每只鸡饲养在0.09和0.11平方米空间中的雏鸡，7周龄时的异嗜性粒细胞与淋巴细胞比例（分别为0.42和0.45）显著高于每只鸡饲养在0.05和0.07平方米空间中的雏鸡（分别为0.28和0.30）。每只鸡饲养在0.05平方米空间中的雏鸡体重降低、胴体品质下降，表明这些雏鸡受到了应激。然而，经济潜力的决策分析表明，对于乐观决策和等可能决策，每平方米的最佳盈利潜力是每只鸡占有0.05平方米空间；对于悲观决策，每平方米的最佳盈利潜力是每只鸡占有0.07平方米空间。
