Effects of Cage Density on Growth Performance,Immune Organ Development,Antioxidant Capacity,Intestinal Tissue Morphology and mRNA Expression of Immune-Related Genes of Male and Female Separately-Fed Yellow-Feathered Broilers
The aim of this experiment was to investigate the effects of cage density on growth performance,immune organ development,antioxidant capacity,intestinal tissue morphology and mRNA expression of im-mune-related genes of male and female separately-fed yellow-feathered broilers.A total of 720 twenty-one-day-old yellow-footed hemp chickens were selected and raised in three layers of cascading cage(length ×width × height=1.2 m×0.8 m×0.4 m),and male and female broilers were reared separately and randomly divided into 4 groups(5 replicates in each group),which were 15(low density group),17(medium density group),19(medium-high density group)and 21 birds/m2(high density group),respectively.The experimental period was 42 days.The results showed as follows:1)for male broilers,during 21 to 42 days of age,the average daily feed intake of high density group was significantly lower than that of low density group and medium den-sity group(P＜0.05);during 43 to 63 days of age,the average daily feed intake of medium-high density group and high density group was significantly lower than that of low density group and medium density group(P＜0.05),and the average daily gain of medium-high density group and high density group was significantly lower than that of low density group(P＜0.05).For female broilers,during 21 to 42 days of age,the average daily feed intake of medium-high density group and high density group was significantly lower than that of low density group(P＜0.05),and the average daily gain of high density group was significantly lower than that of low density group(P＜0.05);during 43 to 63 days of age,the average daily feed intake of high density group was significantly lower than that of low density group and medium density group(P＜0.05),and the average daily gain of medium-high density group was significantly lower than that of low density group(P＜0.05).2)For male broilers,the liver weight of low density group was significantly lower than that of other groups(P＜0.05),and the liver index was significantly lower than that of high density group(P＜0.05).3)For female broilers,the serum superoxide dismutase activity of medium density group was significantly higher than that of high density group(P＜0.05),and the serum malondialdehyde content of medium-high density group was sig-nificantly higher than that of high density group(P＜0.05).4)For male broilers,the jejunal villus height/crypt depth of medium density group was significantly higher than that of high density group(P＜0.05).For female broilers,the duodenal crypt depth of high density group was significantly higher than that of medium-high density group(P＜0.05),the duodenal villus height/crypt depth of medium-high density group was sig-nificantly higher than that of high density group(P＜0.05);the jejunal villus height of high density group was significantly lower than that of medium density group and medium-high density group(P＜0.05),and the jeju-nal villus height/crypt depth of high density group was significantly lower than that of low density group(P＜0.05);the ileal crypt depth of high density group was significantly higher than that of other groups(P＜0.05).5)For male broilers,the mRNA expression level of tumor necrosis factor-a(TNF-a)in jejunum of medium-high density group was significantly higher than that of other groups(P＜0.05).For female broilers,the mR-NA expression levels of nuclear factor erythroid2-related factor 2(Nrf2)and Toll-like receptor 4(TLR4)in jejunum of medium-high density group were significantly higher than those of low density group(P＜0.05).In conclusion,high cage density can affect the growth performance,antioxidant capacity and intestinal tissue mor-phology related indicators of yellow-feathered broilers.Cage density may affect intestinal immune function of yellow-feathered broilers by influencing gene expression of intestinal antioxidant and immune-related genes.[Chinese Journal of Animal Nutrition,2024,36(4):2277-2291]
万方数据
维普
