饲粮色氨酸水平对断奶仔猪器官指数及小肠相关基因表达的影响  

Effects of Dietary Tryptophan Levels on Organ Index and Small Intestine Related Gene Expression in Weaning Pigs(Sus scrofa)

作　　者：马文锋[1,2] 郭亮 王占彬 赵芙蓉[1] MAWen-Feng;GUO Liang;WANG Zhan-Bin;ZHAO Fu-Rong(College of Animal Science and Technology,Henan University of Science and Technology,Luoyang 471023,China;College of Animal Science and Technology,China Agricultural University,Beijing 100193,China;College of Animal Science and Veterinary Medicine,Tianjin Agricultural University,Tianjin 300384,China)

机构地区：[1]河南科技大学动物科技学院,洛阳471023 [2]中国农业大学动物科技学院,北京100193 [3]天津农学院动物科学与动物医学学院,天津300384

出　　处：《农业生物技术学报》2021年第8期1538-1545,共8页Journal of Agricultural Biotechnology

基　　金：国家重点基础研发计划(2018YFD0500603);国家自然科学基金(31702122)。

摘　　要：色氨酸是断奶仔猪(Sus scrofa)的第二或第三限制性氨基酸,在调控采食、生长、免疫及肠道发育等方面发挥重要作用。本研究降低了日粮的粗蛋白含量,设置了4个不同的色氨酸含量,旨在研究饲粮色氨酸水平对断奶仔猪血清生化指标、不同组织吲哚-2,3双加氧酶(indole-2,3 dioxygenase,IDO)和小肠紧密连接蛋白基因表达的影响。实验采用单因子实验设计,选用初始体重为(6.5±0.2)kg的三元(杜×长×大)健康断奶仔猪240头,随机分为4个处理,每个处理6个重复,每个重复10头猪,实验期28 d。饲粮中色氨酸与赖氨酸的比例分别为0.15、0.18、0.21和0.24,其余营养素含量相同。利用生化测定仪检测仔猪血清生化指标,利用qRT-PCR检测肾、脾、胃和小肠IDO的基因表达量以及小肠闭锁蛋白(occludin)和闭合小环蛋白-1(zona occludens-1,ZO-1)的基因表达量。结果表明,与色氨酸与赖氨酸比例为0.15组相比,提高比例至0.18、0.21或者0.24时,断奶仔猪的肾脏、脾脏、胃和回肠的IDO表达量均显著降低(P<0.05),而0.24组空肠IDO表达量显著提高(P<0.05)。饲粮中色氨酸与赖氨酸比例由0.15提高至0.18、0.21和0.24时,断奶仔猪十二指肠和回肠occludin和ZO-1的基因表达量均显著降低(P<0.05),0.18和0.24组空肠ZO-1表达量显著降低(P<0.05),0.21组的仔猪空肠occludin表达量显著升高(P<0.05)。饲粮中色氨酸与赖氨酸比例由0.15提高至0.24时,也可以降低断奶仔猪血清尿素氮水平(P<0.05)。本研究发现,调控饲粮色氨酸与赖氨酸的比例由0.15至0.18时,可以调控机体组织IDO和小肠紧密连接蛋白的mRNA丰度,同时影响机体的氮代谢状态。综合以上指标考虑,断奶仔猪饲粮适宜的色氨酸与赖氨酸比值为0.18。本研究结果为色氨酸在断奶仔猪日粮的合理应用提供了一定的理论依据。Tryptophan is the second or third limiting amino acid for weaning pigs(Sus scrofa),which plays an important role in the regulation of feeding intake,growth,immunity and intestinal development.The 4 different ratio of tryptophan to lysine was conducted to investigate the effects of dietary tryptophan level on serum biochemical index,organ IDO and intestinal tight junction protein gene expression in weaning pigs.A total of 240 weaning pigs(Large White×Landrace×Duroc)with an initial body weight of(6.5±0.2)kg were randomly divided into 4 treatments with 6 repetitions and 10 pigs each repetition and the experiment lasted for 28 d.The dietary ratios of tryptophan to lysine were 0.15,0.18,0.21,and 0.24.The result showed that compared with the group with tryptophan to lysine ratio of 0.15,when the ratio was increased to 0.18,0.21 or 0.24,the expression of IDO gene in the spleen,kidney,stomach and ileum of weaning pigs was significantly reduced(P<0.05),and the expression of jejunum IDO mRNA in the 0.24 group was significantly increased(P<0.05).When the dietary ratios of tryptophan to lysine increased from 0.15 to 0.24,the expression of occludin and ZO-1 in the duodenum and ileum were significantly reduced(P<0.05),the jejunum expression levels of ZO-1 mRNA in the 0.18 and 0.24 groups were significantly decreased(P<0.05),while the jejunum occludin mRNA expression levels in the 0.21 group were significantly increased(P<0.05).When the ratio of dietary tryptophan to lysine increased from 0.15 to 0.24,the level of serum urea nitrogen was influenced in weaning pigs(P<0.05).It was found that when the ratio of tryptophan to lysine was adjusted from 0.15 to 0.24,the gene expression of IDO and small intestinal tight junction protein in the organism could be significantly regulated,and nitrogen metabolism of the organism could be also affected in this study.In conclusion,the optimal ratio of tryptophan to lysine for weaning pigs was 0.18.The results provides a theoretical basis for the application of tryptophan in the diet of wean

关 键 词：色氨酸 断奶仔猪 吲哚-2 3双加氧酶(IDO) 紧密连接蛋白 

分 类 号：S828.91[农业科学—畜牧学]