Fontana E A, Weaver W D, Denbow D M, Watkins B A
Department of Poultry Science, Virginia Polytechnic Institute and State University, Blacksburg 24061-0332.
Poult Sci. 1993 Feb;72(2):243-50. doi: 10.3382/ps.0720243.
A total of five experiments were conducted to investigate the effects of early feed restriction on organ weights, fat deposition, and carcass composition in broilers. In Experiments 1 and 2, broiler chicks were reared in litter pens for 49 days, whereas Experiments 3, 4, and 5 were conducted in battery cages for 28 days. Feed restriction in all experiments was accomplished by providing male broiler chicks 40 kcal per bird per day for 7 (Experiments 1 and 2) or 6 (Experiments 3, 4, and 5) days, starting at 4 days of age. Feed restriction of broiler pullets in Experiment 1 was imposed from 4 to 9 days of age. Furthermore, the starter and grower diets in Experiment 2 contained either 1 or 4% added fat and the starter diets in Experiments 3, 4, and 5 contained either 21 or 26% protein. No significant differences were observed for abdominal fat pad and gizzard weights, liver and carcass fat, or carcass protein between early restricted birds and ad libitum controls at 49 days of age in Experiments 1 and 2. Furthermore, with the exception of Experiment 4, no differences in abdominal fat pad weights were observed among the different feeding regimens. Significant increases in abdominal fat pad weights, percentage liver, and percentage carcass fat were noted for females at 49 days of age when compared with male broilers. Carcass fat was significantly higher and carcass protein was significantly lower in broilers fed commercial versus reduced fat diets. Broilers fed a 21% protein diet had significantly heavier abdominal fat pad weights at 28 days of age than birds fed a 26% protein diet.
总共进行了五项实验，以研究早期限饲对肉鸡器官重量、脂肪沉积和胴体组成的影响。在实验1和实验2中，肉鸡雏鸡在垫料饲养栏中饲养49天，而实验3、实验4和实验5在层叠式笼中进行28天。在所有实验中，从4日龄开始，通过给雄性肉鸡雏鸡每天每只提供40千卡热量，持续7天（实验1和实验2）或6天（实验3、实验4和实验5）来实现限饲。实验1中对肉用小母鸡的限饲从4日龄至9日龄。此外，实验2中的开食料和生长料含有1%或4%的添加脂肪，实验3、实验4和实验5中的开食料含有21%或26%的蛋白质。在实验1和实验2中，49日龄时，早期限饲的鸡与自由采食的对照鸡相比，腹部脂肪垫和砂囊重量、肝脏和胴体脂肪或胴体蛋白质方面未观察到显著差异。此外，除实验4外，不同饲养方案之间未观察到腹部脂肪垫重量的差异。与雄性肉鸡相比，49日龄时雌性的腹部脂肪垫重量、肝脏百分比和胴体脂肪百分比显著增加。与低脂日粮相比，采食商品日粮的肉鸡胴体脂肪显著更高，胴体蛋白质显著更低。28日龄时，采食21%蛋白质日粮的肉鸡腹部脂肪垫重量显著高于采食26%蛋白质日粮的肉鸡。
