本试验旨在探讨急性热应激对肉仔鸡生长性能及脂肪代谢的影响。试验选用了体重相近的健康的28日龄爱拔益加（AA）雄性肉仔鸡120只，随机分成3组：急性热应激组、对照组和饲粮配对组，每组4个重复，每个重复10只鸡。试验期为7 d。结果表明：与对照组比较，急性热应激组AA肉仔鸡的平均日采食量和平均日增重分别显著下降33.84%、6501%（P<0.05），料重比增加8914%（P<0.05）。同时，与饲粮配对组相比，急性热应激组的平均日增重降低2829%（P>0.05），料重比增加4227%（P>0.05）。急性热应激显著增加了肝脏、腹脂和颈皮下脂肪的相对重量（P<0.05），同时有增加腿皮下脂肪相对重量的趋势（P>0.05）。急性热应激对血清中游离脂肪酸和总胆固醇含量均无显著影响（P>0.05），但显著增加了甘油三酯、高密度脂蛋白胆固醇和低密度脂蛋白胆固醇的含量（P<0.05），对照组与饲粮配对组相比以上血清生化指标均无显著差异（P>0.05）。急性热应激显著增加了肝脏乙酰辅酶A羧化酶和脂肪酸合成酶及腹脂脂肪酸合成酶基因的mRNA相对表达水平（P<005），同时显著降低了肝脏脂蛋白脂酶基因的mRNA相对表达水平（P<0.05）。由此可知，急性热应激可使AA肉仔鸡生长性能下降，营养成分重分配，脂肪沉积增加。

The experiment was conducted to study the effects of heat stress on growth performance and lipid metabolism of broilers. One hundred and twenty 28-day-old healthy male AA broilers with similar body weight were randomly allotted to three treatments (4 replicates per treatment with 10 birds per replicate): constant heat stress at 34 ℃ with ad libitum feeding (acute heat stress group), constant optimal ambient temperature at 21 ℃ with ab libitum feeding (control group), and constant optimal ambient temperature at 21 ℃ but pair-fed with the amount consumed by the acute heat stress group (pair-fed group). The experiment period was 7 d. The results showed as follows: compared with the control group, average daily feed intake （ADFI） in acute heat stress group was decreased by 33.84% (P<0.05), average daily gain (ADG) was decreased by 65.01% (P<0.05), and the ratio of feed to gain (F/G) was decreased by 89.14% (P<0.05). Compared with pair-fed group, ADG in acute heat stress group was decreased by 28.29% (P>0.05), and F/G was increased by 4227% (P>0.05). The fat deposition of acute heat stressed AA broilers were increased in hepatic fat (P<0.05), abdominal fat (P<0.05), cervical subcutaneous fat (P<0.05), and thigh subcutaneous fat (P>0.05). The contents of free fatty acid (FFA) and total cholesterol (TC) in serum of acute heat stressed AA broilers had no significant change (P<0.05), but the contents of triglyceride (TG), high density lipoprotein-cholesterol (HDL-C) and low density lipoprotein-cholesterol (LDL-C) were significantly increased (P<0.05), but there was no significant difference in serum biochemical indices between control group and pair-fed group (P>0.05). Acute heat stress significantly increased acetylcoa carboxylase (ACC) and fatty acid synthase (FAS) in liver and FAS in abdominal fat (P<0.05), and significantly decreased lipoprotein lipase (LPL) gene mRNA expression (P<0.05). These results indicate that acute heat stress decreases growth performance of AA broilers, redistributes nutrient constituents, and increases fat deposition.［Chinese Journal of Animal Nutrition, 2011, 23（5）：862 -868］