早期限饲对肉鸡屠宰性能和免疫器官指数的影响

为研究早期限饲对肉鸡屠宰性能和免疫器官指数的影响,选用250只1日龄Ross 308肉仔鸡,随机分为10组,限饲起始日龄(5、7和10日龄)、持续时间(7、10和14 d)和强度(90％、80％和70％)3因素3水平按L9(34)正交试验设计.结果表明:对肉鸡42日龄活体、屠体、全净膛、胸肌和腿肌重的影响:限饲持续时间...

Effects of early feed-restriction on slaughter production and index of immune organs of broilers

The experiment was conducted to determine the effects of early feed-restriction on slaughter production and index of immune organs.250 ROSS 308 broiler chickens were randomly allocated to ten groups divided by orthogonal L9(34) experiment including three factors each for three levels,starting time(5,7 and 10 days of age),duration(7,10 and 14 days) and intensity(90%,80% and 70%) of feed restriction.Slaughter production of restriction showed a sequence of duration>intensity>starting time.With the longer of duration and the stronger of intensity,there was a significant decrease of the weight of body,carcass,whole eviscerated,breast and leg.The index of spleen of 23 days about the three feed-restriction factors was all lower,and the index of 42 days all higher than the control group.The index of thymus of broilers of 23 days in feed-restriction groups was all lower and the index of bursa of fabricius of 42 days was also lower than the control group.Thyroxine T3 and growth hormone of feed-restriction broilers of group 1 and 3 at 23 and 42 days were both lower than the control group,while the ratio of T4/T3 was all higher than the control group.The broilers,feed-restricted at 5 days for 90% and 7 days,had a higher slaughter production than the control group,while the broilers restricted at 5 days for 70% and 14 days was stunned and did not have a compensatory growth at 42 days of age.Feed restriction weakened the tendency of immune organs with the days of age,inhibited the increase of spleen and the decrease of thymus and bursa of fabricius.Feed restriction decreased the basal metabolic rate,increased the deposit of fat with the decrease of thyroxine T3 and the ratio of T4/T3