This experiment was conducted to investigate the effects of free range rearing and cage rearing on visceral organ development,reproductive characters and serum biochemical indexes of laying hens.One hundred and eighty 25-week-old laying hens were selected and randomly divided into 2 groups with 6 replicates per group and 15 hens per replicate.One of the two groups was put to the ground for free range rearing,and the another group reared in cage unceasingly.The two groups were fed the same diet.On day 42 of the test,four hens per replicate of each group were randomly selected to collect blood samples,and then slaughtered to determine visceral organ development and reproductive character indexes.The results showed as follows:the body weight of free-range birds was significantly lower than that of cage-reared birds (P ＜ 0.01).The indexes of gizzard,liver,duodenum,jejunum,ileum and cecum of free-range birds were significantly higher than those of cage-reared birds (P ＜0.01),and the indexes of stomach and rectum were significantly higher than those of cage-reared birds (P ＜ 0.05).The laying rate,oviduct weight and follicle weight of free-range birds were significantly lower than those of cage-reared birds (P ＜ 0.01),and oviduct length of free-range birds was significantly lower than that of cage-reared birds (P ＜ 0.05).The serum triglyceride concentration of free-range birds was significantly lower than that of cage-reared birds (P ＜ 0.05),however,the interleukin-2 concentration of free-range birds emerged a trend of increase (P ＞ 0.05).It is concluded that compared with cage rearing,free range rearing can decrease the body weight,increase visceral organ indexes,reduce reproduction performance,and improve the body health in a way.%本试验旨在研究散养与笼养对产蛋鸡内脏器官发育、繁殖性状、血清生化指标的影响.选取25周龄笼养蛋鸡180只,随机分为2组,每组6个重复,每个重复15只,将其中一组放至地面进行散养.试验第42天,每个重复中随机选取4只鸡,翅静脉采血,然后屠宰并测定内脏器官发育及繁殖性状的相关指标.结果表明:散养鸡体重极显著小于笼养鸡(P＜0.01),肌胃指数、肝脏指数、十二指肠指数、空肠指数、回肠指数、盲肠指数极显著大于笼养鸡(P＜0.01),腺胃指数、直肠指数显著大于笼养鸡(P＜0.05)；散养鸡产蛋率、输卵管重量、卵泡重极显著小于笼养鸡(P＜0.01),输卵管长度显著小于笼养鸡(P＜0.05)；散养鸡血清甘油三酯含量显著低于笼养鸡(P＜0.05),但白细胞介素-2含量与笼养鸡相比有提高的趋势(P＞0.05).结果提示,与笼养相比,散养降低了鸡体重,增大了内脏器官指数,降低了繁殖性能,对机体的健康状况有一定改善作用.
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