The overall cost of feed is influenced largely by the nutritional requirements that are specified in its formulation and the ingredients that are used to meet those nutrient specifications. To meet the demand for breast meat and further processed products, heavy broiler chickens are grown to body weights exceeding 3.5 kg. In this study, we evaluated the effects of altering AA density and AME content of the diets over the last 3 feeding phases (grower: 12–26 D, finisher: 26–36 D, and withdrawal: 36–49 D) on the growth performance and processing yield of mixed-sex Cobb 700 × MV broilers. Broilers were fed a common starter diet followed by a 3 × 2 factorial arrangement of diets with 3 levels of AA density (low, medium, and high) and 2 levels of energy (low and high) beginning with the grower period. Broilers fed the high AA diet were heavier as compared with those fed the low AA diet, and FCR was observed to decrease incrementally when AA density and energy level were increased independently. Skinless-boneless breast yield increased incrementally with AA density, whereas fat pad yield increased as AA density of the diet decreased. Overall, our results demonstrate that the performance and meat yield of mixed-sex Cobb 700 × MV broilers responded positively to a higher density of AA and energy.

饲料的总成本在很大程度上受饲料配方中规定的营养要求以及用于满足这些营养要求的成分的影响。为了满足对胸肉和深加工产品的需求，将重的肉鸡生长到体重超过3.5千克。在这项研究中，我们评估了在最后三个喂养阶段（生长：12–26 D，肥育：26–36 D和戒断：36–49 D）改变日粮中AA浓度和AME含量对生长的影响型Cobb 700×MV肉鸡的性能和加工产量。肉鸡饲喂普通的起子日粮，然后从成长期开始，按3×2的日粮安排3种AA密度（低，中和高）和2种能量（低和高）的日粮。饲喂高AA日粮的肉鸡比饲喂低AA日粮的肉鸡重，观察到当AA密度和能量水平独立增加时，FCR会逐渐降低。随着AA密度的增加，去皮去骨的乳房的产量逐渐增加，而随着日粮的AA密度的降低，脂肪垫的产量则增加。总体而言，我们的结果表明，混合性别的Cobb 700×MV肉鸡的性能和肉产量对较高的AA和能量密度有积极的反应。