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 4227% (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］
LIU Mei
. Effects of Acute Heat Stress on Growth Performance and
Lipid Metabolism of Broilers[J]. Chinese Journal of Animal Nutrition, 2011
, 23(05)
: 862
-868
.
DOI: 10.3969/j.issn.1006-267x.2011.05.022
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