饲粮添加酶解蛋白肽对断奶仔猪生长性能、血清免疫指标和肠道菌群的影响

Effects of Dietary Enzymatic Protein Peptide on Growth Performance,Serum Immune Indices and Intestinal Flora of Weaned Piglets

本试验旨在探究饲粮添加酶解蛋白肽对断奶仔猪生长性能、血清免疫指标和肠道菌群的影响,以确定断奶仔猪饲粮中酶解蛋白肽的适宜添加水平。试验选取150头21日龄体重为(7.01±0.17) kg的健康"杜×长×大"三元杂交断奶仔猪,随机分为5个组,每组5个重复,每个重复6头(公母各占1/2)。各组断奶仔猪分别饲喂在基础饲粮中添加0(对照组)、2%、4%、6%和8%酶解蛋白肽的等氮等能饲粮。试验共35 d,其中预试期7 d、正试期28 d。结果表明:1)与对照组相比,饲粮添加6%和8%酶解蛋白肽极显著提高各阶段断奶仔猪平均日采食量和平均日增重(P<0.01),极显著降低第1~14天和第1~28天腹泻率(P<0.01),显著降低第15~28天料重比(P<0.05);饲粮添加6%酶解蛋白肽极显著降低断奶仔猪第15~28天腹泻率(P<0.01),显著降低第1~14天和第1~28天料重比(P<0.05)。2)试验第14天,与对照组相比,饲粮添加2%~6%酶解蛋白肽极显著提高断奶仔猪血清免疫球蛋白G(IgG)含量(P<0.01),饲粮添加2%、4%和8%酶解蛋白肽极显著提高血清免疫球蛋白M(IgM)含量(P<0.01);试验第28天,与对照组相比,饲粮添加2%和4%酶解蛋白肽显著或极显著提高断奶仔猪血清IgG含量(P<0.05或P<0.01),饲粮添加2%~8%酶解蛋白肽显著或极显著提高血清IgM含量(P<0.05或P<0.01)。3)与对照组相比,饲粮添加2%和4%酶解蛋白肽显著提高断奶仔猪肠道菌群Chao1指数(P<0.05)。在门水平上,与对照组相比,饲粮添加6%酶解蛋白肽显著提高断奶仔猪肠道菌群拟杆菌门相对丰度(P<0.05)。在属水平上,与对照组相比,饲粮添加4%和8%酶解蛋白肽极显著提高断奶仔猪肠道菌群乳酸菌属相对丰度(P<0.01),饲粮添加2%~8%酶解蛋白肽显著降低肠道菌群Intestinimonas相对丰度(P<0.05),饲粮添加4%~8%酶解蛋白肽显著降低肠道菌群狭义梭菌属相对丰度(P<0.05);此外,饲粮添加8%酶解蛋白肽极显著提高肠道菌群优杆菌属相对丰度(P<0.01),显著提高Lachnospiracea_ncertae_edis相对丰度(P<0.05);饲粮添加6%和8%酶解蛋白肽显著或极显著降低肠道菌群衣原体属相对丰度(P<0.05或P<0.01)。4)与对照组相比,饲粮添加2%~8%酶解蛋白肽均极显著提高断奶仔猪粪便中乳酸、乙酸和丙酸含量(P<0.01)。综上所述,饲粮添加酶解蛋白肽能够降低断奶仔猪腹泻率,提高免疫性能,从而提高生长性能,且以添加水平为6%~8%时效果较优;这种对断奶仔猪的改善效果与丰富肠道菌群多样性,改善肠道菌群结构,即增加有益菌数量、降低有害菌数量有关。

The purpose of this experiment was to explore the effects of enzymatic protein peptide on growth performance,serum immune indices and intestinal flora of weaned piglets,so as to determine the appropriate supplemental level of enzymatic protein peptide in diet for weaned piglets. A total of 150“Duroc×Landrace×Yorkshine”three-way crossbred weaned piglets at 21 days of age with initial body weight of(7.01±0.17)kg were randomly divided into 5 groups with 5 replicates in each group and 6 piglets(half male and half female)in each replicate. The weaned piglets in each group were fed isonitrogenous and isoenergetic diets supplemented with 0(control group),2%,4%,6% and 8% enzymatic protein peptide,respectively. The experiment lasted for 35 days,including 7 days of pre-experiment and 28 days of formal experiment. The results showed as follows:1)compared with the control group,dietary 6% and 8% enzymatic protein peptide extremely significantly increased the average daily feed intake and average daily gain of weaned piglets in every stage(P <0.01),extremely significantly decreased the diarrhea rate in days 1 to 14 and 1 to 28(P<0.01),and significantly decreased the feed to gain ratio in days 15 to 28(P<0.05). Dietary 6% enzymatic protein peptide significantly extremely decreased the diarrhea rate of weaned piglets in days 15 to 28(P<0.01),and significantly decreased the feed to gain ratio in days 1 to 14 and 1 to 28(P<0.05). 2)On day 14 of the experiment,compared with the control group,dietary 2% to 6% enzymatic protein peptide extremely significantly increased the immunoglobulin G(IgG)content in serum of weaned piglets(P<0.01),and dietary 2%,4% and 8% enzymatic protein peptide extremely significantly increased the immunoglobulin M(IgM)content in serum(P <0.01). On day 28 of the experiment,compared with the control group,dietary 2% and 4% enzymatic protein peptide significantly or extremely significantly increased the serum IgG content(P<0.05 or P<0.01),and dietary 2% to 8% enzymatic protein peptide significantly or extremely significantly increased the serum IgM content(P<0.05 or P<0.01). 3)Compared with the control group,dietary 2% and 4% enzymatic protein peptide significantly increased the Chao1 index of intestinal flora of weaned piglets(P<0.05). At the phylum level,compared with the control group,dietary 6% enzymatic protein peptide significantly increased the relative abundance of Bacteroidetes in intestinal flora of weaned piglets(P<0.05). At the genus level,compared with the control group,dietary 4% and 8% enzymatic protein peptide extremely significantly increased the relative abundance of Lactobacillus in intestinal flora of weaned piglets(P<0.01),dietary 2% to 8% enzymatic protein peptide significantly reduced the relative abundance of Intestinimonas in intestinal flora(P<0.05),and dietary4% to 8% enzymatic protein peptide also significantly reduced the relative abundance of Clostridium_sensu_stricto in intestinal flora(P<0.05);in addition,dietary 8% enzymatic protein peptide extremely significantly increased the relative abundance of Eubacterium(P<0.01)and significantly increased the relative abundance of Lachnospiracea_incertae_sedis in intestinal flora(P<0.05);dietary 6% and 8% enzymatic protein peptide significantly or extremely significantly reduced the relative abundance of Chlamydia in intestinal flora(P<0.05 or P<0.01). 4)Compared with the control group,dietary 2% to 8% enzymatic protein peptide extremely significantly increased the contents of lactic acid,acetic acid and propionic acid in feces of weaned piglets(P<0.01). In conclusion,dietary enzymatic protein peptide can reduce the diarrhea rate,improve the immune performance,and improve the growth performance of weaned piglets,and the supplemental level of 6% to 8%has the best effects. The improvement effects on weaned piglets are related to the enrichment of intestinal flora diversity and the improvement of intestinal flora structure,that is,increasing the number of beneficial bacteria and decreasing the number of harmful bacteria.[Chinese Journal of Animal Nutrition,2022,34(2):839-851]