Department of Nutrition, Liuhe Feed Comp. Qingdao, Shandong, People's Republic of China.
Poult Sci. 2011 Jul;90(7):1406-15. doi: 10.3382/ps.2010-01230.
The effects of stocking density, sex, and dietary ME concentration on live performance, footpad burns, and leg weakness of broilers were investigated. A total of 876 male and 1,020 female 1-d-old chicks were placed in 24 pens to simulate final stocking density treatments of 26 kg (LSD; 10 males or 12 females/m(2)) and 42 kg (HSD; 16 males or 18 females/m(2)) of BW/m(2) floor space. Two series of experimental diets with a 150 kcal/kg difference in ME concentration (2,800, 2,900, and 3,000 or 2,950, 3,050, and 3,150 kcal of ME/kg) were compared in a 3-phase feeding program. The HSD treatment significantly decreased BW gain and feed conversion ratio (FCR). The HSD chickens consumed less feed by 35 d of age; thereafter, the reverse was true. Male chickens had significantly higher feed intake (FI), BW gain, and FCR compared with females. A significant interaction was found of stocking density and age for FI, BW gain, and FCR. Compared with LSD treatment, HSD broilers had a higher FI and a lower FCR from 36 to 42 d of age. Stocking density, sex, and age had a significant interaction for BW gain and FCR. Female broilers had worse BW gain and FCR when stocked at high density from 36 to 42 d of age. Stocking density had no significant influence on breast, thigh, or abdominal fat yield. Female broilers had significantly higher breast yield and abdominal fat. Male broilers and HSD treatment had high footpad burn and gait scores. A low ME diet increased footpad burn score but had no effect on gait score. The result indicated that stocking density had a more severe effect on the growth of male broilers before 35 d of age. Female broilers need more space than males at similar BW per square meter near marketing age. The incidence and severity of leg weakness are associated with sex, diet, and stocking density. This result suggests that the deteriorated effect of high stocking density is sex and age dependent.
本研究旨在探讨饲养密度、性别和日粮代谢能浓度对肉鸡生产性能、脚垫烧伤和腿部疾病的影响。试验选用 1 日龄雄性和雌性肉鸡各 876 只和 1020 只，饲养于 24 个栏位中，以模拟最终的饲养密度处理，即体重为 26kg（低密度，每平方米饲养 10 只雄性或 12 只雌性）和 42kg（高密度，每平方米饲养 16 只雄性或 18 只雌性）。采用 3 阶段饲养方案，比较了代谢能浓度相差 150kcal/kg 的 2 个系列试验日粮（2800、2900 和 3000kcal/kg 或 2950、3050 和 3150kcal/kg 的 ME/kg）。高密度饲养组肉鸡的体重增重和饲料转化率显著降低。高密度饲养组肉鸡在 35 日龄前采食量较低，之后则相反。雄性肉鸡的采食量、体重增重和饲料转化率显著高于雌性肉鸡。饲养密度和日龄对采食量、体重增重和饲料转化率有显著的互作影响。与低密度饲养组相比，高密度饲养组肉鸡在 36-42 日龄时采食量较高，饲料转化率较低。饲养密度、性别和日龄对体重增重和饲料转化率有显著的互作影响。雌性肉鸡在 36-42 日龄高密度饲养时，体重增重和饲料转化率较差。饲养密度对胸肌、大腿肌和腹脂产量没有显著影响。雌性肉鸡的胸肌产量和腹脂产量显著高于雄性肉鸡。雄性肉鸡和高密度饲养组的脚垫烧伤和跛行评分较高。低 ME 日粮增加了脚垫烧伤评分，但对跛行评分没有影响。结果表明，在 35 日龄前，饲养密度对雄性肉鸡的生长影响更严重。接近上市体重时，雌性肉鸡比雄性肉鸡每平方米需要更多的空间。腿部疾病的发生率和严重程度与性别、日粮和饲养密度有关。这些结果表明，高密度饲养的恶化效应与性别和日龄有关。
