蝽防御素应用于断奶仔猪饲粮中的耐受性及影响

Corresponding author, associate professor, E-mail: xiaohao@gdaas.cnTolerance and Impact of Bug Defensin in Weaned Piglets’ Diet

本试验通过对断奶仔猪生长性能、脏器指数、血清生化指标、抗氧化能力、机体免疫、肠道健康等指标的检测,探究蝽防御素(THA)在断奶仔猪饲粮中的耐受性及影响。选取平均初始体重为(6.05±0.03)kg的21日龄杜×长×大断奶仔猪108头,采用完全随机分组试验设计,根据体重随机分为3组,每组6个重复,每个重复6头猪,公母各占1/2。对照组饲喂玉米-豆粕型基础饲粮,试验组饲喂在基础饲粮中分别添加400、4000 mg/kg THA的试验饲粮,试验期28 d。试验期间每2周称重,观察试验猪临床症状,记录每个重复的采食量。试验结束后,挑选每个重复中最接近该重复平均体重的猪进行屠宰采样。结果表明:1)与对照组相比,饲粮中添加400 mg/kg THA能显著提高断奶仔猪平均日采食量(P<0.05),并显著降低腹泻率(P<0.05);添加4000 mg/kg THA对仔猪生长性能指标无显著影响(P>0.05)。2)与对照组相比,饲粮中添加400和4000 mg/kg THA对断奶仔猪的心脏、肝脏、脾脏、肺脏、肾脏指数均无显著影响(P>0.05)。3)与对照组相比,饲粮中添加400和4000 mg/kg THA对血常规指标均无显著影响(P>0.05)。4)与对照组相比,饲粮中添加400 mg/kg THA可显著降低血清中白蛋白的含量(P<0.05);饲粮中添加4000 mg/kg THA可显著降低血清中肌酐的含量(P<0.05)。5)与对照组相比,饲粮中添加400和4000 mg/kg THA对仔猪的血清抗氧化指标均无显著影响(P>0.05)。6)与对照组相比,饲粮中添加4000 mg/kg THA可显著提高血清中白细胞介素-8(IL-8)的含量(P<0.05)。7)与对照组相比,饲粮中添加400和4000 mg/kg THA对仔猪空肠黏膜中紧密连接蛋白基因相对表达量均无显著影响(P>0.05)。8)与对照组相比,饲粮中添加400 mg/kg THA可显著提高仔猪回肠中淀粉酶的活性(P<0.05)。9)与对照组相比,饲粮中添加400 mg/kg THA可显著增加空肠绒毛高度(P<0.05)。饲粮中添加4000 mg/kg THA对断奶仔猪肠道形态无不利影响,同时对肾脏和肝脏没有损伤。添加THA可提高断奶仔猪免疫力,改善肠道形态,提高小肠消化吸收能力。综上所述,饲粮中添加400 mg/kg THA能降低断奶仔猪腹泻,改善肠道健康,而饲粮中添加4000 mg/kg THA对断奶仔猪属于安全水平。

In this experiment,we determined the appropriate additive amount of bug defensin(THA)in the diet of weaned piglets by testing the growth performance,organ indexes,serum biochemical indexes,antioxidant ability,body immunity and intestinal health of weaned piglets.A total of 108 piglets weaned at 21 days of age with the average intial body weight of(6.05±0.03)kg were used in a completely randomized grouping trial design,and randomly divided into 3 groups according to body weight,with 6 replicates of 6 pigs in each group and half of the male and half of the female.The control group(CON)was fed a corn-soybean meal basal diet and the experimental groups were fed the basal diet with 400 and 4000 mg/kg THA for 28 days.The pigs were weighed every two weeks during the trial period,clinical signs were observed,and feed intake was recorded for each replicate.At the end of the trial,the pigs in each replicate that were closest to the average weight of that replicate were selected for slaughter sampling.The results showed as follows:1)the addition of 400 mg/kg THA to the diet significantly increased the average daily feed intake(P<0.05)and significantly reduced the diarrhea rate(P<0.05)compared with the control group;the addition of 4000 mg/kg THA had no significant effect on the growth performance of piglets(P>0.05).2)Dietary THA supplementation at 400 and 4000 mg/kg had no significant effect on the heart,liver,spleen,lung,and kidney indexes of weaned piglets compared with the control group(P>0.05).3)Compared with the control group,400 and 4000 mg/kg THA had no significant effect on blood routine indexes(P>0.05).4)Compared with the control group,when the THA content in the diet was 400 mg/kg,it significantly decreased the serum albumin content(P<0.05);dietary addition of 4000 mg/kg THA could significantly reduce the content of serum creatinine(P<0.05).5)Compared with the control group,dietary supplementation of 400 and 4000 mg/kg THA had no significant effect on serum antioxidant indexes of piglets(P>0.05).6)Compared with the control group,dietary supplementation of 4000 mg/kg THA significantly increased the content of serum interleukin-8(IL-8)(P<0.05).7)Compared with the control group,dietary supplementation of 400 and 4000 mg/kg THA had no significant effect on the relative expression of tight junction protein genes in the jejunal mucosa of piglets(P>0.05).8)Compared with the control group,400 mg/kg THA significantly increased the activity of amylase in the ileum of piglets(P<0.05).9)Compared with the control group,dietary supplementation of 400 mg/kg THA significantly increased the activity of amylase in the ileum of piglets(P<0.05).Compared with the control group,dietary supplementation of 400 mg/kg THA significantly increased jejunal villus height(P<0.05).The addition of 4000 mg/kg THA to the diet had no adverse effect on the intestinal morphology of weanled piglets,and at the same time there was no damage to kidney and liver.THA supplementation can improve the immunity,intestinal morphology,and small intestinal digestion ability of weaned piglets.In conclusion,dietary supplementation of 400 mg/kg THA can reduce diarrhea and improve intestinal health in weaned piglets,while dietary supplementation of 4000 mg/kg THA is safe for weaned piglets.