Effects of various supplemental levels of multi-enzyme on amino acid profiles in yolk, antioxidant capacity, cecal microbial community and metabolism of laying hens

This study was conducted to determine the impacts of multi-enzyme on antioxidant capacity, egg quality, amino acid profiles in yolk, cecal microflora and metabolites in laying hens. A total of 384 Jingfen No.6 laying hens aged 65-weeks were randomly divided into 4 treatments groups (6 replicates per group) and fed diets containing 0, 150, 300, or 600 g/t multi-enzyme in an 8-week feeding duration. Our study found that supplementation with 600 g/t multi-enzyme resulted significantly increased the albumen height (P < 0.05) and haugh unit (P < 0.05). With increasing levels of multi-enzyme supplementation in the diet, the total antioxidant capacity (T-AOC) in the serum was significantly (P = 0.005) increased and the activity of glutathione peroxidase (GSH-Px) in the liver was also notably enhanced (P = 0.010). Dietary supplementation with different levels of multi-enzyme significantly effects on the composition of amino acid profiles in yolk. The results of 16s rRNA sequencing and untargeted metabolomics analysis of cecal content reveal that the multi-enzyme altered the cecal microflora and metabolites profiles. Correlation analysis unveiled notable relationships between distinct microbes and metabolites with T-AOC in serum, the activity of GSH-Px in liver, amino acids in yolk, albumen height and haugh units. This study suggested the multi-enzyme supplementation regulated cecal microbial community and metabolism, which may be in turn altered the composition of amino acid profiles in yolk, antioxidant capacity and egg quality.

本研究旨在探究复合酶制剂（multi-enzyme）对65周龄京粉6号蛋鸡的抗氧化能力、鸡蛋品质、蛋黄氨基酸组成、盲肠微生物区系及代谢产物的影响。本研究共选取384只65周龄的京粉6号蛋鸡，随机分为4个处理组（每组6个重复），饲喂添加0、150、300、600 g/t复合酶制剂的日粮，试验周期为8周。研究发现，日粮添加600 g/t复合酶制剂可显著提高蛋清高度（P < 0.05）与哈氏单位（Haugh unit）；随着日粮中复合酶制剂添加水平的提升，血清总抗氧化能力（total antioxidant capacity, T-AOC）显著升高（P=0.005），肝脏谷胱甘肽过氧化物酶（glutathione peroxidase, GSH-Px）活性也显著增强（P=0.010）。日粮添加不同水平的复合酶制剂可显著改变蛋黄氨基酸组成。对盲肠内容物进行16S rRNA测序与非靶向代谢组学（untargeted metabolomics）分析的结果显示，复合酶制剂可改变盲肠微生物区系与代谢产物谱。相关性分析揭示，特定微生物与代谢产物分别与血清总抗氧化能力、肝脏谷胱甘肽过氧化物酶活性、蛋黄氨基酸组成、蛋清高度及哈氏单位存在显著关联。本研究表明，日粮添加复合酶制剂可调控盲肠微生物群落与代谢过程，进而可能改善蛋黄氨基酸组成、机体抗氧化能力及鸡蛋品质。