肠道健康程度对断奶仔猪生长性能、养分表观消化率、体组成和肠道菌群的影响

Effects of Intestinal Health Degree on Growth Performance,Nutrient Apparent Digestibility,Body Composition and Intestinal Microbiota of Weaned Piglets

本试验旨在探究不同肠道健康程度对21~28日龄断奶仔猪生长性能、养分表观消化率、体组成和肠道菌群的影响。试验1选取180头平均体重为(6.03±0.04)kg的21日龄健康“杜×长×大”断奶仔猪,随机分配到60个栏舍中(公母各占1/2),根据试验前7 d的腹泻率,进一步分为T1-T2组(腹泻率小于15%,共31栏)和T3-T4组(腹泻率大于15%,共29栏),并继续饲喂到仔猪平均体重达到25 kg,测定生长性能和血清免疫指标。试验2采用比较屠宰法,选取72头平均体重为(6.13±0.04)kg的21日龄健康“杜×长×大”断奶仔猪,其中12头(公母各占1/2)作为初始屠宰组,以测定初始体成分含量;剩余60头随机分为20栏(公母各占1/2),根据7 d的腹泻率,随机选定6栏(公母各占1/2)腹泻率小于15%的仔猪(T1-T2组)和6栏(公母各占1/2)腹泻率大于15%的仔猪(T3-T4组),并在此基础上每栏挑选1头猪进行屠宰,以测定终末体成分含量,同时测定生长性能、养分表观消化率、结肠内容物短链脂肪酸含量及结肠菌群。试验1和试验2饲喂相同的基础饲粮。结果表明:1)与T1-T2组相比,T3-T4组断奶仔猪21~28日龄终末体重和平均日增重显著降低(P<0.05),腹泻率显著提高(P<0.05);T3-T4组各养分表观消化率均无显著差异(P>0.05)。2)与T1-T2组相比,T3-T4组断奶仔猪空体粗脂肪含量、粗脂肪沉积速率和总能均显著降低(P<0.05)。3)与T1-T2组相比,T3-T4组断奶仔猪血清免疫球蛋白G含量显著降低(P<0.05),血清白细胞介素-6(P=0.075)和肿瘤坏死因子-α(P=0.092)含量有升高趋势。4)与T1-T2组相比,T3-T4组断奶仔猪结肠内容物戊酸含量显著提高(P<0.05),异戊酸含量有提高趋势(P=0.071);T3-T4组断奶仔猪结肠放线菌门(Actinobacteriota)和罕见小球菌属(Subdoligranulum)相对丰度显著提高(P<0.05)。5)在仔猪29日龄至25 kg阶段,T1-T2组和T3-T4组间仔猪生长性能无显著差异(P>0.05)。综上所述,基于本研究的肠道健康程度等级划分体系,与腹泻率大于15%的仔猪相比,腹泻率小于15%的仔猪在21日龄断奶后的1周内平均日增重显著提高,空体粗脂肪含量和粗脂肪沉积速率显著提高,免疫功能有所提高,炎症反应有所降低;同时,结肠有害菌相对丰度显著降低。此外,断奶过渡期的肠道健康程度不会对仔猪生长至25 kg的生长性能产生影响。

This experiment was conducted to investigate the effects of different intestinal health degrees on growth performance,nutrient apparent digestibility,body composition and intestinal microbiota of weaned piglets from 21 to 28 days of age.In experiment 1,a total of 180 healthy“Duroc×Landrace×Yorkshire”weaned piglets of 21-day-old with an average body weight of(6.03±0.04)kg were randomly assigned to 60 pens(half male and half female),and further divided into T1-T2 group(diarrhea rate was less than 15%,total 31 pens)and T3-T4 group(diarrhea rate was greater than 15%,total 29 pens)according to the diarrhea rate of 7-day experiment,then continued feeding until the average body weight of piglets reached 25 kg,and growth performance and serum immune indices were measured.In experiment 2,using comparative slaughter method,a total of 72 healthy“Duroc×Landrace×Yorkshire”weaned piglets of 21-day-old with an average body weight of(6.13±0.04)kg were selected.Among them,12 piglets(half male and half female)were selected as the initial slaughter group to determine the initial body composition content.The remaining 60 piglets were randomly divided into 20 pens(half male and half female).According to the diarrhea rate of 7-day experiment,6 pens(half male and half female)with diarrhea rate less than 15%(T1-T2 group)and 6 pens(half male and half female)with diarrhea rate greater than 15%(T3-T4 group)were randomly selected,and on this basis,1 pig in each pen was selected for slaughter to determine the body composition content,and growth performance,nutrient apparent digestibility,short-chain fatty acid contents in colon content and colon microbiota were measured.The pigs in experiment 1 and experiment 2 were fed the same basal diet.The results showed as follows:1)compared with T1-T2 group,the final body weight and average daily gain of weaned piglets from 21 to 28 days of age in T3-T4 group were significantly decreased(P<0.05),and the diarrhea rate was significantly increased(P<0.05);there were no significant differences in apparent digestibility of nutrients in T3-T4 groups(P>0.05).2)Compared with T1-T2 group,the empty body ether extract content,ether extract deposition rate and total energy of weaned piglets in T3-T4 group were significantly decreased(P<0.05).3)Compared with T1-T2 group,the serum immunoglobulin G content of weaned piglets in T3-T4 group was significantly decreased(P<0.05),and the serum interleukin-6(P=0.075)and tumor necrosis factor-α(P=0.092)contents were tented to be increased.4)Compared with T1-T2 group,the valeric acid content in colon content of weaned piglets in T3-T4 group was significantly increased(P<0.05),and the isovaleric acid content had an increasing trend(P=0.071);the relative abundances of Actinobacteriota and Subdoligranulum in colon of weaned piglets in T3-T4 group was significantly increased(P<0.05).5)There was no significant difference in growth performance between T1-T2 group and T3-T4 group from 29 days of age to 25 kg(P>0.05).In conclusion,based on the intestinal health grading system of this study,compared with piglets with diarrhea rate greater than 15%,piglets with diarrhea rate less than 15%have significantly higher average daily gain,significantly higher empty body ether extract content and ether extract deposition rate,higher immune function and lower inflammatory response within 1 week after weaning at 21 days of age;at the same time,the relative abundances of harmful bacteria in colon were significantly decreased.In addition,the intestinal health degree during the weaning transition does not affect the growth performance of piglets growing up to 25 kg.