饲粮添加苏氨酸对伪狂犬病毒诱导的免疫应激仔猪生长性能和肠道健康的影响

本研究旨在观察饲粮中添加苏氨酸对伪狂犬病毒(Pseudorabies virus,PRV)诱导的免疫应激仔猪生长性能和肠道健康的影响。试验选用30头平均体重为(6.94±1.26)kg健康的"杜×长×大"断奶仔猪,采用3×2因子试验设计,饲粮中真可消化苏氨酸水平为0.74%、0.89%和1.11%;仔猪接受免疫应激(注射PRV弱毒苗)或不应激(注射灭菌生理盐水)处理。免疫应激仔猪于试验第8天早上注射PRV弱毒疫苗。试验期为21 d。结果表明:PRV的注射极显著提高了试验第21天血清PRV特异性抗体水平(P<0.01),表明PRV疫苗攻毒诱导免疫应激模型构建成功。PRV诱导的免疫应激有提高仔猪7～21 d的料重比的趋势(P<0.10),且显著提高了1～21 d的料重比(P<0.05),极显著提高了空肠隐窝深度(P<0.01),极显著降低了空肠绒毛高度/隐窝深度(P<0.01),并引起十二指肠黏膜变性坏死脱落等形态学病变。饲粮添加苏氨酸能在一定程度上影响仔猪7～21 d和1～21 d的料重比(P<0.10),并有提高仔猪十二指肠绒毛高度的趋势(P<0.10),对十二指肠绒毛高度/隐窝深度的影响与PRV诱导的免疫应激存在显著的互作效应(P<0.05),且能够缓解PRV诱导的免疫应激产生的肠道形态学病变。由以上的试验结果可知,饲粮添加苏氨酸能在一定程度上减缓PRV诱导的免疫应激带来的断奶仔猪生长性能下降和肠道损伤。

Effects of Threonine Supplementation on Growth Performance and Intestinal Health of Weaner Piglets Challenged with Pseudorabies Virus

This experiment was conducted to investigate the effects of threonine supplementation on growth performance and intestinal health of weaner piglets challenged with Pseudorabies virus(PRV).A total of 30 healthy DLY weaner piglets with an average body weight of(6.94±1.26) kg were used in this experiment.A 3×2 factorial design was used.Dietary true ileal digestible threonine(TIDT) levels were 0.74%,0.89% and 1.11%,respectively.Piglets were injected with live swine PRV or sterilized saline water.The injection was carried out on day 8,and the whole experiment lasted for 21 days.The results showed that the injection of PRV significantly increased serum PRV-specific antibody level(P<0.01),which showed that stress pattern had been successfully established.Under immune stress condition challenged by PRV,the feed︰gain ratio(F/G) of piglets at 1 to 21 days(P<0.10) and 7 to 21 days of the experiment(P<0.05) and the crypt depth in jejunum of piglets(P<0.01) were increased.The ratio of villus height to crypt depth in jejunum of piglets was significantly decreased(P<0.01) in such an immune stress condition and pathological changes such as degeneration,necrosis and exfoliation occurred in duodenal mucosal epithelium of the villus.As the dietary TIDT level increased,the villus height in duodenum of piglets experienced an upward trends(P<0.10).Threonine supplementation,to a certain extent,could affect the feed︰gain ratio of piglets at 1 to 21 days and 7 to 21 days of the experiment(P<0.10).At the same time,there was a significant interaction between dietary TIDT level and immune stress on the ratio of villus height to crypt depth in duodenum(P<0.05),and the pathological changes which were induced by PRV could be alleviated at a relative high dietary TIDT level.In conclusion,supplementation of dietary threonine,to a certain extent,can improve growth performance and alleviate intestinal injury which is induced by PRV injection.