饲粮能量水平和来源对肉鸡腹水症的影响及其机理

Effects of Dietary Energy Levels and Sources on Ascites Syndrome and Its Mechanism in Broilers

本试验采用2×2×2因子设计,研究不同饲粮能量水平、来源,不同生理应激状态对肉鸡腹水症的影响及其机理。饲粮能量水平为13.79和11.70 MJ/kg,能量来源为高脂和低脂,肉鸡生理状态为正常和3,3′,5-三碘甲腺原氨酸(3,3′,5-triiodothyronine,T3)诱导的应激状态。320只1日龄健康爱拔益加(AA)肉鸡随机分配到8个处理中,每个处理4个重复。试验鸡自由采食和饮水,试验期为21 d。结果表明:1)高能饲粮(13.79 MJ/kg)极显著提高了肉鸡的心脏指数(P<0.01)、全期增重(P<0.01)和单位代谢体重耗氧量(P<0.01),显著降低了肝脏超氧化物歧化酶(SOD)活性(P<0.05),肉鸡肝脏丙二醛(MDA)含量增加了25.6%(P>0.05);2)饲粮能量来源对上述指标均无显著影响(P>0.05),但高脂使肝脏MDA含量增加了35.5%;3)在T3诱导下,肉鸡心脏指数极显著增加(P<0.01),全期增重极显著降低(P<0.01),肝脏MDA含量增加了17.8%(P>0.05);4)饲粮能量水平和T3对肉鸡心脏指数具有极显著的互作效应(P<0.01)。以上结果提示:高能饲粮可促使肉鸡腹水症的发生,其机理是高能饲粮条件下,肉鸡生长速度快,单位体重耗氧量高,肝脏抗氧化能力降低,脂质过氧化程度增加,且高能饲粮效应在T3诱导下作用更为显著。

A 2×2×2 factorial design was used to investigate the effects of dietary energy levels,energy sources and different physiological stress on ascites syndrome（AS）,and its mechanism in broilers.Two dietary energy levels were 13.79 and 11.70 MJ/kg,two dietary energy sources were high and low fat,and two kinds of physiological stress were normal and 3,3′,5-triiodothyronine（T3） induced stress.Three hundred and twenty Arbor Acres chicks of 1-day-old were randomly allotted into 8 treatments with 4 replicates per treatment of 10 birds per replicate.Water and feed were provided ad libitum for 21 days.Results were showed as follows： 1） high dietary energy levels could significantly increase heart indexes（P0.01）,body weight gain（P0.01）,and oxygen consumption per metabolic body weight（P0.01）,and significantly decrease SOD activity in liver（P0.05）,while MDA content in liver was increased by 25.6%（P0.05）;2） dietary energy sources had no significant effects on the parameters above（P0.05）,but high fat increased the MDA content in liver by 35.5%;3） T3 inducement could significantly increase heart indexes（P0.01）,decrease body weight gain（P0.01）,and MDA content in liver was increased by 17.8%（P0.05）;4） a significant interaction between dietary energy level and T3 supplementation was found on the heart indexes of broilers（P0.01）.It is concluded that high dietary energy level leads to a higher incidence of AS because of the increase of growth rate,oxygen consumption and lower antioxidant ability in liver,which causes lipid peroxidation to be increased.Meanwhile,more significant effects are found with T3 inducement.