Department of Animal Nutrition, Faculty of Animal Production and Technology, University of Veterinary and Animal Sciences, Lahore, 54000, Pakistan.
Department of Poultry Production, Faculty of Animal Production and Technology, University of Veterinary and Animal Sciences, Lahore, 54000, Pakistan.
Trop Anim Health Prod. 2022 May 11;54(3):186. doi: 10.1007/s11250-022-03184-w.
This study evaluated the effect of amino acids balanced at a specific lysine ratio with exogenous protease supplementation and reduced CP levels in the broiler diet. In total, 480 straight-run broiler chicks (Ross-308) were used for the study. A completely randomized design in the factorial arrangement was applied, with 4 treatments of 6 replicates with 20 birds each. Treatments consisted of 2 lysine ratios (100% and 110%; factor 1) without or with exogenous protease supplementation (200 g/ton; factor 2). Twenty percent reduction of CP from standard requirements of Ross-308 (18.4% vs 23% in starter and 17.2% vs 21.5% in grower phase) was made in all the treatment diets. Growth performance (feed intake, weight gain, feed conversion ratio, livability), carcass traits (live and carcass weight, carcass yield, heart, liver, gizzard, leg quarter, breast weight, and abdominal fat percentage), gut morphology (villus height, crypt depth, and villus height and crypt depth ratio), and serum metabolites (total protein, albumin, and uric acid) were evaluated. A significant interaction (p ≤ 0.05) for lysine ratio and protease was noted in body weight gain, feed conversion ratio, carcass traits, and gut morphology throughout the experimental period yet a non-significant (p > 0.05) influence was observed on serum metabolites. It was concluded that the broiler diet with a net reduction of 20% CP from Ross-308 standards, balanced for amino acids at lysine ratio 110% and supplemented with exogenous protease, could be used to improve growth performance, intestinal health, and carcass traits.
本研究评估了在肉鸡日粮中降低 CP 水平并添加特定赖氨酸比例平衡氨基酸和外源性蛋白酶对肉鸡的影响。共使用 480 只罗斯 308 直线型肉鸡进行研究。采用完全随机设计的析因安排，设 4 个处理，每个处理 6 个重复，每个重复 20 只鸡。处理包括 2 个赖氨酸比例（100%和 110%；因子 1）和添加或不添加外源性蛋白酶（200 g/吨；因子 2）。所有处理日粮均降低了 20%的 CP，低于罗斯 308 的标准要求（育雏期为 18.4%比 23%，生长期为 17.2%比 21.5%）。评估了生长性能（采食量、体重增加、饲料转化率、成活率）、胴体特性（活重、屠体重、胴体产肉率、心脏、肝脏、肌胃、腿肉、胸肉和腹脂率）、肠道形态（绒毛高度、隐窝深度、绒毛高度与隐窝深度比）和血清代谢物（总蛋白、白蛋白和尿酸）。在整个实验期间，赖氨酸比例和蛋白酶的交互作用（p≤0.05）对体重增加、饲料转化率、胴体特性和肠道形态有显著影响，但对血清代谢物无显著影响（p＞0.05）。结论是，用降低 20%CP 的罗斯 308 标准日粮，平衡赖氨酸比例为 110%并添加外源性蛋白酶，可改善生长性能、肠道健康和胴体特性。
