高纤维日粮对生长育肥猪生长性能、肉品质及肠道微生物的影响

Effects of High Fiber Diet on Growth Performance,Meat Quality and Intestinal Microbiome of Growing-finishing Pigs

旨在研究高纤维日粮对生长育肥猪生长性能、肉品质及肠道健康的影响。选取健康、平均体重(48.83±0.49)kg的杜×长×大三元杂交猪72头,随机均分为对照组和高纤维组,每个处理组4个重复,每个重复9头猪,试验期共84 d。对照组饲喂基础日粮,高纤维组饲喂麦麸含量为15%的高纤维日粮,后期(6周后)统一饲喂高纤维日粮。测定每头猪初始体重、每3周体重、终末体重及耗料量。试验结束时,取背最长肌用于检测肉品质、肌纤维特性,取回肠样品检测肠道形态及肠道屏障相关指标,取盲肠和结肠内容物用于检测肠道微生物及其代谢产物。结果表明:与对照组相比,试验第1~3周,高纤维组3周末重(BW)、平均日增重(ADG)显著降低(P<0.05),料肉比(F/G)显著升高(P<0.05);在试验第7~9周,高纤维组第9周末重显著高于对照组(P<0.05),ADG有增加的趋势(P=0.055);在整个试验过程中,与对照组相比高纤维组ADG显著增加(P<0.05)。与对照组相比,高纤维组屠宰后24小时肉样pH(pH_(24 h))显著提高(P<0.05),肌纤维横截面积显著降低(P<0.05),决定肌纤维类型的MyHC I基因表达水平显著提高(P<0.05)。与对照组相比,高纤维组回肠绒毛高度和绒毛高度与隐窝深度比值(V/C)极显著升高(P<0.01),隐窝深度显著降低(P<0.05);紧密连接蛋白Claudin-1、Occludin的mRNA表达水平显著提高(P<0.05);与对照组相比,高纤维组杯状细胞的数量极显著增加(P<0.01),显著上调了Muc-2的mRNA表达水平(P<0.05)。与对照组相比,高纤维组盲肠厚壁菌门和变形菌门的相对丰度显著提高(P<0.05),拟杆菌门的相对丰度极显著降低(P<0.01),梭菌属的相对丰度显著增加(P<0.05),而链球菌属显著减少(P<0.05);在结肠中,高纤维组芽孢杆菌属的相对丰度极显著增加(P<0.01),而螺旋菌门和链球菌属的相对丰度极显著降低(P<0.01)。在盲肠中,和对照组相比,高纤维组显著提高了乙酸(P<0.05)、丙酸(P<0.05)、丁酸(P<0.05)的浓度;在结肠中,显著提高了乙酸(P<0.05)、丙酸(P<0.05)、丁酸(P<0.05)、戊酸(P<0.05)和异戊酸(P<0.05)的浓度。综上所述,在生长育肥猪日粮中添加15%麦麸,可提高育肥猪的生长性能,显著提高育肥猪背最长肌pH_(24h),降低肌纤维横截面积,促进慢肌纤维相关基因的表达,改善肠道形态、肠道屏障和肠道微生物组成,增加短链脂肪酸的产生,有利于机体健康,降低饲养成本。

The study was aimed to investigate the effects of high fiber diet on growth performance,meat quality and intestinal health of growing-finishing pigs.A total of 72 healthy cross-bred(Duroc×Landrace×Large White)pigs with an average body weight of(48.83±0.49)kg were randomly divided into control group and high-fiber group with four replicates in each group and nine pigs per replicate.The trial lasted for 84 days.Pigs in the control group were fed with basal diet,pigs in the high fiber group were fed with the high fiber diet with 15%wheat bran,and the late stage(six weeks later)the two groups were both fed with the high fiber diet.Determine The initial body weight,body weight every three weeks,final weight and feed consumption of each pig were determined.At the end of the experiment,the longissimus dorsi was taken to detect meat quality and muscle fiber characteristics,ileum sample was taken to detect intestinal morphology and intestinal barrier related indexes,cecum and colon contents were taken to detect intestinal microbiome and their metabolites.The results showed that compared with the control group,at 1-3 weeks of the experiment,the body weight(BW)at the third week and average daily gain(ADG)in high fiber group were significantly decreased(P<0.05)and the ratio of feed intake to gain(F/G)was significantly increased(P<0.05).At 7-9 weeks of the experiment,the weight of the high fiber group at the 9th week was significantly higher than that of the control group(P<0.05),and ADG had an increasing trend(P=0.055).During the whole experiment,ADG in the high fiber group increased significantly compared with the control group(P<0.05).In the high fiber group,the 24 hours after slaughter pH(pH_(24 h))of meat samples increased significantly(P<0.05),the cross-sectional area of muscle fibers was significantly decreased(P<0.05)and the mRNA expression level of MyHC I,which determines the type of muscle fiber was significantly increased(P<0.05)compared with the control group.Compared with the control group,villus height and villus height to crypt depth ratio(V/C)of ileum were extremely significantly increased in the high fiber group(P<0.01),the crypt depth was significantly decreased(P<0.05),while the mRNA expression levels of tight junction protein Claudin-1 and Occludin were significantly increased(P<0.05).Compared with the control group,the number of goblet cells in the high fiber group was extremely significantly increased(P<0.01),and the mRNA expression level of Muc-2 was significantly increased(P<0.05).Compared with the control group,the relative abundance of Firmicutes and Proteobacteria in cecum of the high fiber group were extremely significantly increased(P<0.05),whereas the relative abundance of Bacteroidetes was extremely significantly decreased(P<0.01),the relative abundance of Clostridium was significantly increased(P<0.05),while that of Streptococcus was significantly decreased(P<0.05).In the colon,the relative abundance of Bacillus was extremely significantly increased(P<0.01),while that of Spirochaetes and Streptococcus was extremely significantly decreased(P<0.01)in the high-fiber group.In the cecum,compared with the control group,the concentrations of acetic acid(P<0.05),propionic acid(P<0.05)and butyric acid(P<0.05)were significantly increased in high fiber group.In the colon,the concentrations of acetic acid(P<0.05),propionic acid(P<0.05),butyric acid(P<0.05),valerate acid(P<0.05)and isovalerate acid(P<0.05)were significantly increased.In conclusion,adding 15%wheat bran to the diet of growing-finishing pigs can improve the growth performance,significantly increase the longissimus dorsi pH 24 h of finishing pigs,reduce the cross-sectional area of muscle fiber,promote the expression of slow muscle fiber related genes,improve intestinal morphology,intestinal barrier and intestinal microbial composition,increase the production of short chain fatty acids,which is beneficial to the body health and reduction of feeding cost.