Xin Xiangqi, Han Miaomiao, Wu Yuan, Dong Yuanyang, Miao Zhiqiang, Zhang Junzhen, Song Xianyi, Jia Ru, Su Yuan, Liu Ci, Bai Rui, Li Jianhui
College of Animal Sciences, Shanxi Agricultural University, Taigu, Jinzhong 030801, China.
Animals (Basel). 2022 Aug 28;12(17):2216. doi: 10.3390/ani12172216.
This study was conducted to investigate the effects of different levels of yeast chromium on growth performance, organ index, antioxidant capacity, immune performance and liver health of broilers under high stocking density. A total of 684 1-day-old Arbor Acres broilers were selected and fed a common diet from 1 to 22 days of age. At the end of 22 days, broilers with similar weight were randomly divided into six treatments, with six replications in each treatment. The broilers in control groups were fed with a control diet and raised at low stocking density of broilers (14 broilers/m2, LSD) and high stocking density (20 broilers/m2, HSD). The broilers in treatment groups were fed with diets supplemented with 200, 400, 800 and 1600 µg Cr/kg chromium yeast (Cr-yeast) under HSD, respectively. The experimental period was 23~42 days. Compared with the LSD group, the HSD group significantly decreased the liver index (ratio of liver weight to live weight of broilers) of broilers (p < 0.05), the HSD group significantly increased the content of corticosterone (CORT) and the activities of alanine aminotransferase (ALT) and alkaline phosphatase (ALP) and decreased the prealbumin (PA) level in the serum (p < 0.05). HSD decreased the total antioxidant capacity (T-AOC) contents in the serum, liver and breast, serum glutathione peroxidase (GSH-Px) activities, breast total superoxide dismutase (T-SOD) activities and liver catalase (CAT) activities of broilers (p < 0.05). The HSD group significantly increased the total histopathological score (p < 0.05). Compared with the HSD group, adding 200, 400, and 1600 Cr-yeast significantly increased the liver index of broilers (p < 0.05), all HSD + Cr-yeast groups decreased the ALT activities (p < 0.05), and the HSD + 800 group significantly decreased the CORT contents and the ALP activities of the serum (p < 0.05); the HSD + 400, 800 and 1600 groups increased the PA contents of the serum (p < 0.05); HSD + 800 group significantly reduced the tumor necrosis factor-α (TNF-α) and Interleukin-1β (IL-1β) contents of the serum (p < 0.05); moreover, the HSD + 400 group increased the GSH-Px activities of the serum (p < 0.05), the T-AOC and the T-SOD activities of the breast (p < 0.05) and the T-AOC and CAT activities of the liver (p < 0.05). Adding 800 Cr-yeast significantly decreased the total histopathological score (degree of hepatocyte edema and inflammatory cell infiltration) under HSD (p < 0.05). In summary, Cr-yeast can improve the antioxidant capacity and immune traits, and liver health of broilers under HSD. Based on the results of the linear regression analysis, the optimal supplementation of Cr-yeast in antioxidant capacity, immunity ability and liver health were at the range of 425.00−665.00, 319.30−961.00, and 800.00−1531.60 µg Cr/kg, respectively.
本研究旨在探讨不同水平的酵母铬对高饲养密度下肉鸡生长性能、器官指数、抗氧化能力、免疫性能及肝脏健康的影响。选取684只1日龄爱拔益加肉鸡，在1至22日龄期间饲喂普通日粮。22日龄末，将体重相近的肉鸡随机分为6个处理组，每个处理组6个重复。对照组肉鸡饲喂基础日粮，分别在低饲养密度（14只/m²，LSD）和高饲养密度（20只/m²，HSD）条件下饲养。处理组肉鸡在HSD条件下分别饲喂添加200、400、800和1600 μg Cr/kg铬酵母（Cr-yeast）的日粮。试验期为23至42天。与LSD组相比，HSD组显著降低了肉鸡的肝脏指数（肝脏重量与肉鸡体重之比）（p < 0.05），HSD组显著提高了血清中皮质酮（CORT）含量、丙氨酸氨基转移酶（ALT）和碱性磷酸酶（ALP）活性，并降低了血清中前白蛋白（PA）水平（p < 0.05）。HSD降低了肉鸡血清、肝脏和胸肌中的总抗氧化能力（T-AOC）含量、血清谷胱甘肽过氧化物酶（GSH-Px）活性、胸肌总超氧化物歧化酶（T-SOD）活性及肝脏过氧化氢酶（CAT）活性（p < 0.05）。HSD组显著提高了总组织病理学评分（p < 0.05）。与HSD组相比，添加200、400和1600 μg Cr/kg Cr-yeast显著提高了肉鸡的肝脏指数（p < 0.05），所有HSD + Cr-yeast组均降低了ALT活性（p < 0.05），HSD + 800 μg Cr/kg组显著降低了血清中CORT含量和ALP活性（p < 0.05）；HSD + 400、800和1600 μg Cr/kg组提高了血清中PA含量（p < 0.05）；HSD + 800 μg Cr/kg组显著降低了血清中肿瘤坏死因子-α（TNF-α）和白细胞介素-1β（IL-1β）含量（p < 0.05）；此外，HSD + 400 μg Cr/kg组提高了血清中GSH-Px活性（p < 0.05）、胸肌中T-AOC和T-SOD活性（p < 0.05）以及肝脏中T-AOC和CAT活性（p < 0.05）。添加800 μg Cr/kg Cr-yeast显著降低了HSD条件下的总组织病理学评分（肝细胞水肿和炎性细胞浸润程度）（p < 0.05）。综上所述，铬酵母可提高HSD条件下肉鸡的抗氧化能力、免疫性能及肝脏健康。基于线性回归分析结果，铬酵母在抗氧化能力、免疫能力及肝脏健康方面的最佳添加量分别为425.00−665.00、319.30−961.00和800.00−1531.60 μg Cr/kg。
