Abstract Context Gelatin, presently a waste material from animal tissues and bones, may be suitable as a partial dietary replacement for soybean meal. In combination with protease, it may enhance growth performances of broiler chickens. However, limitations when introducing gelatin, are its unusual amino acid profile and digesta viscosity. Aim An experiment was conducted to elucidate effects on growth performance, blood biochemistry, carcass and meat characteristics, and feed costs of partial replacement of soybean meal with gelatin and protease in broilers diets. Methods The experimental design was a factorial arrangement of two levels of mono-component protease (0 and 200 g/t diet) and four levels of gelatin (0%, 2.82%, 4.23% and 5.64% of the diet) with six replicates and 15 male broiler chickens in each pen. Key results The higher levels of gelatin inclusion decreased bodyweight and increased feed conversion ratio (P < 0.001), whereas addition of enzyme improved both parameters (P < 0.001). Higher gelatin inclusion levels decreased abdominal fat, and enzyme addition resulted in greater carcass yield (P < 0.001). European performance efficiency factor reduced with incremental gelatin levels but increased with enzyme inclusion (P < 0.001). Feed cost per bird was reduced at higher gelatin inclusion levels, more so in the protease-treated diets up to 4.23% inclusion level. Lipid peroxidation values for breast and thigh meat decreased significantly with gelatin inclusion in the absence of protease but increased in the presence of protease. Breast and thigh lipid peroxidation was reduced (P < 0.001) by supplementation of protease in the control diet. Conclusions The results suggest that the performance-depressing effects of gelatin can be overcome to some extent by inclusion of a protease. Implications The use of gelatin may reduce dependence on soybean meal and reduce costs by using what is at present a waste material. Consideration is needed of the digestible amino acid profile of gelatin, and choice of more effective enzymes to reduce deleterious effects of gelatin.

中文翻译：

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明胶和单组分蛋白酶部分替代肉鸡日粮中豆粕对生长性能、胴体和血液生化特性、肉类脂质氧化和经济性的影响

摘要背景明胶目前是一种来自动物组织和骨骼的废料，可能适合作为豆粕的部分膳食替代品。与蛋白酶结合使用，可提高肉鸡的生长性能。然而，引入明胶时的局限性在于其不寻常的氨基酸谱和消化物粘度。目的 进行了一项试验，以阐明肉鸡日粮中用明胶和蛋白酶部分替代豆粕对生长性能、血液生化、胴体和肉类特性以及饲料成本的影响。方法 实验设计是两个水平的单组分蛋白酶（0 和 200 g/t 日粮）和四个水平的明胶（日粮的 0%、2.82%、4.23% 和 5.64%）的因子排列，六次重复和每个围栏中 15 只雄性肉鸡。主要结果 较高水平的明胶含量降低了体重并提高了饲料转化率 (P < 0.001)，而添加酶则改善了这两个参数 (P < 0.001)。较高的明胶含量会降低腹部脂肪，添加酶会导致更高的屠体产量（P < 0.001）。欧洲性能效率因子随着明胶水平的增加而降低，但随着酶的加入而增加（P < 0.001）。每只鸡的饲料成本在较高的明胶含量下降低，在蛋白酶处理的日粮中，含量高达 4.23%。在没有蛋白酶的情况下，加入明胶的胸肉和大腿肉的脂质过氧化值显着降低，但在蛋白酶存在时增加。乳房和大腿脂质过氧化减少（P < 0. 001) 通过在对照饮食中补充蛋白酶。结论 结果表明，通过包含蛋白酶，可以在一定程度上克服明胶的性能抑制作用。影响 明胶的使用可以减少对豆粕的依赖，并通过使用目前的废料来降低成本。需要考虑明胶的可消化氨基酸谱，并选择更有效的酶来减少明胶的有害影响。