中文摘要：

本试验研究了鱼油对断奶仔猪生产性能、炎性介质和下丘脑-垂体-肾上腺轴激素的影响。选用32头（28±3）日龄、体重（8．91±0．74）蝇的杜洛克×长白×大白仔猪，随机分为4组，每组4个重复，每个重复2头猪，1公1母。采用双因子设计，主因子包括：1）饲粮处理（5％鱼油或5％玉米油）；2）免疫应激[注射脂多糖（LPS）或生理盐水]。试验期19d。在试验第19天，每个饲粮组中1／2的猪注射150μg／kg BW的LPS，另1／2注射生理盐水作为对照。分别在注射前（0h）、注射后2和4h，采血测定血浆肿瘤坏死因子-α（TNF-α）、前列腺素E2（PGE2）、皮质醇、促肾上腺皮质激素（ACTH）和促肾上腺皮质激素释放激素（CRH）含量。结果表明：1）鱼油对仔猪生产性能无显著影响（P〉0．05）。2）在注射后2h，LPS刺激显著提高了TNF-α、PGE2、ACTH和皮质醇的含量（P〈0．01）。鱼油对TNF-α、PGE2和皮质醇含量的影响与LPS刺激存在显著的互作关系（P〈0．05），即鱼油缓解了LPS刺激导致的TNF-α、PGE2和皮质醇含量的上升（P〈0．05），而对注射生理盐水的猪则不存在这种效应。鱼油显著降低了ACTH的含量（P〈0．01）。在4h，LPS刺激显著提高了TNF-α、PGE2和皮质醇的含量（P〈0．05）。鱼油对TNF-α含量的影响与LPS刺激存在显著的互作关系（P〈0．05），即鱼油降低了LPS刺激的猪血浆中TNF-α的含量（P〈0．05），而对注射生理盐水的猪则不存在这种效应。鱼油降低了PGE2（P〈0．01）和ACTH（P〈0．05）含量，而对皮质醇的含量无显著影响（P〉0．05）。在注射后2和4h，LPS刺激与鱼油对CRH均无显著影响（P〉0．05）。结果提示，鱼油缓解了免疫应激引起的仔猪下丘脑-垂体-肾上腺轴激素的改变，其机制可能与其降低了炎性细胞因子的含量有关。

英文摘要：

This experiment was conducted to investigate the effects of fish oil supplementation on production performance,inflammatory parameters and hypothalamus-pituitary-adrenal axis in piglets.Thirty-two crossbred（Duroc×Large White×Landrace） piglets with（8.91±0.74） kg BW weaned at（28±3） d of age were randomly allocated into 4 group with 4 replicates per group and 2 pigs（male∶female was 1∶1） in each replicate in a two-factorial design.The main factors consisted of diet（5% fish oil or 5% corn oil） and immunological challenge [lipopolysaccharide（LPS） or physiological saline].The experiment lasted for 19 days.On day 19,pigs were injected intraperitoneally with either 150 μg/kg BW of LPS or an equivalent amount of sterile saline.Blood samples were collected at pre-injection（0 h）,or 2,4 h post-injection for analysis of tumor necrosis factor-α（TNF-α）,prostaglandin E2（PGE2）,cortisol,adrenocorticotropic hormone（ACTH） and corticotrophin releasing hormone（CRH）.The results showed that fish oil had no effects on production performance of piglets compared to corn oil（P〈0.05）.At 2 h post-injection, LPS challenge significantly increased contents of TNF-α,PGE2,ACTH and cortisol（P〈0.01）,LPS challenge×diet interactions were observed for TNF-α,PGE2,cortisol such as these measurements responded to the LPS challenge to a lesser extent in pigs receiving the fish oil diet than in pigs fed the corn oil diet（P〈0.05）.Pigs fed fish oil had lower ACTH level compared with those fed corn oil（P〈0.01）.At 4 h post-injection,LPS challenge significantly increased contents of TNF-α,PGE2,and cortisol（P〈0.05）.Among LPS-treated pigs,pigs fed fish oil had lower TNF-α than those fed corn oil（P〈0.05）.Pigs fed fish oil had lower PGE2（P〈0.01） and ACTH levels（P〈0.05） compared with those fed corn oil,but fish oil had no effects on cortisol content（P〈0.05）.Both LPS and fish oil had no effect on CRH.These results suggest that fish oil alters hypothalamus-p