【作者】 王诵涛；

【导师】 谢鹏；

【作者基本信息】 中国农业科学院 ， 动物营养与饲料科学， 2010， 硕士

【摘要】 热应激是一个复杂的生理过程,热应激条件下,引起一些细胞因子如IL-6和激素如糖皮质激素的变化。研究发现其中许多因素的变化都可以诱导MT的合成。但是,热应激时,肉仔鸡MT和IL-6的变化规律还不清楚。因此本研究通过研究在热应激条件下肉仔鸡肝脏中MT、IL-6及相关氧化指标的变化,阐明热应激对肉仔鸡肝脏金属硫蛋白和IL-6的影响。试验以急性热应激和持续热应激两种模式研究MT和IL-6的变化规律。1.急性热应激对肉仔鸡肝脏MT、IL-6分泌规律的影响1.1 35日龄AA肉仔公鸡108只。随机分为2组,每组6个重复,每个重复9只鸡,试验24h。对照组,23℃。应激组,35℃热处理3h,然后温度迅速下降到23℃。通过测定24h内肉仔鸡肝脏中MT、IL-6及相关氧化指标的变化,研究急性热应激条件下MT和IL-6的变化规律,阐明急性热应激对MT和IL-6变化的影响。1.2 35日龄AA肉仔公鸡48只。随机分为2组,每组4个重复,每个重复6只鸡,试验3h,对照组,23℃。应激组,35℃热处理3h。通过密集采样,测定MT和IL-6在高温持续的3h内的变化。试验发现急性热应激可使肉仔鸡肝脏MT水平在1h左右发生显著升高,其后迅速下降,18h以后降低显著。急性热应激开始0.5h后肝脏IL-6含量显著升高;1.5h-2h达到最高点;随后迅速降低,到4.5h降低显著;9h-12h逐渐恢复正常。2.持续热应激对肉仔鸡肝脏MT、IL-6分泌规律的影响35日龄AA肉仔公鸡90只。随机分为3组,每组6个重复,每个重复5只鸡,试验7天,对照组,23℃。配对组,23℃,限制提供日粮,使其日采食量与应激组相同。应激组,23℃-33℃-23℃,采用日变高温模式:1:00-7:00,由23℃均匀升至33℃;7:00-9:00,为33℃恒温;9:00-13:00,由33℃均匀降至23℃;13:00到第二日1:00,为23℃恒温,持续7天。通过测定一周内固定时刻肉仔鸡肝脏中MT、IL-6及相关氧化指标的变化,研究持续热应激条件下MT和IL-6的变化规律,阐明持续热应激对MT和IL-6变化的影响。研究发现,持续热应激条件下,肉仔鸡肝脏MT含量前5天显著降低,第7天时恢复正常。持续热应激条件下,肉仔鸡肝脏IL-6水平第1天至第三天显著升高,然后回落,到第五天时恢复正常。更多还原

【Abstract】 Heat stress is a complex physiological process, including a series of cytokines such as IL-6 and hormones such as glucocorticoids changes.Many of those factors was found to induce MT in some research results.However, on heat stress conditions, the changes of broilers MT and IL-6 is uncleare. Therefore, to clarify the effects of heat stress on broiler hepatic MT and IL-6, hepati MT, IL-6 and some oxidation indicators was determined.We study the changes of MT and IL-6 by two models: acute heat stress and constant heat stress.1.Effects of an acute heat stress on broiler liver MT and IL-6One hundred and eight 35 days old broilers were randomly divided into two groups. Each group had six treatments which had nine broilers.The control group was exposed to 23℃,24h; the stress group was exposed to 35℃, 3h heat temperature,then suddenly declined temperature to 23℃. By determining the changes of MT, IL-6 and related oxidation indicators in broiler liver within 24 hours, we observed the changes of MT, IL-6 and clarified the effects of an acute heat stress on MT and IL-6.2. Effects of an short-term acute heat stress on broiler liver MT and IL-6Forty-eight 35 days old broilers were randomly divided into two groups. Each group had four treatments which had six broilers.The control group was exposed to 23℃,3h; the stress group was exposed to 35℃, 3h heat temperature.By determining the changes of MT, IL-6 and related oxidation indicators in broiler liver within the three hours, we observed the changes of MT, IL-6 and clarified the effects of an acute heat stress on MT and IL-6 in short-term.The results illustrated on actue heat stress conditions, the secretion of MT had significant differernce in 1h,then the level of MT rapid declined. And 18h later the reduction was significant.On actue heat stress conditions, the secretion of IL-6 had significant differernce in 0.5h, and reached the peak between 1.5h-2h; then the level of IL-6 reduced significantly on 4.5h until it came to recover between 9h-12h.3. Effects of constant heat stress on broiler liver MT and IL-6Ninety 35 days old broilers were randomly divided into three groups. Each group had six treatments which had five broilers. The control group was exposed to was exposed to 23℃,7d; the matched group wae exposed to23℃,7d; the stress group was exposed to 23℃-33℃-23℃cycling heat stress daily within a week. By determining the changes of MT, IL-6 and related oxidation indicators in broiler liver within the fixed sampling point, we observed the changes of MT, IL-6 and clarified the effects of the cycling heat stress on MT and IL-6 in seven days.The results illustrated on cycling heat stress conditions, the secretion of MT had significant differernce in 5 days,then the level of MT gradually came to recover in two days.On cycling heat stress conditions, the secretion of IL-6 had significant differernce in 3 days, then the level of IL-6 gradually came to recover on the fifth day.更多还原