Effects Of Fermented Wheat Bran Polysaccharides On Growth And Rumen Microbiota Of Lambs

To investigate the effect of fermented wheat bran polysaccharides on growth and rumen microbiota of lambs.This thesis included three experiments and the main research contents and results are as follows:Experiment 1:Effects of FWBPs on rumen fermentation parameters of Lamb in vitro.This study adopted a single-factor completely randomized experimental design,Four lambs（Dorper×Small-tailed Han Sheep）with the same body condition were selected as rumen fluid donors,The experiment was divided into one control group and four experimental groups.The fermentation substrate of the control group was the basal diet,and the experimental groups was supplemented with 0.5‰,1‰,2‰and 4‰FWBPs in the basal diet.Five fermentation time points of 3,6,9,12 and 24 h were set in each group,and three replicates were set at each time point.By measuring rumen fermentation parameters at different concentrations and time points to screen the optimal addition concentration.The results showed that:（1）At 3 h,the p H of 1‰and 4‰groups was significantly lower than 0 and 0.5‰groups（P<0.05）,at 6,9,12 and 24 h,the p H of 1‰,2‰and 4‰groups was significantly lower than 0 and 0.5‰groups（P<0.05）.（2）At 3 h,the NH₃-N concentration in 1‰and 4‰groups was significantly lower than 0.5‰group（P<0.05）,at 12 h,the concentration of NH₃-N in 1‰group was significantly lower than0.5‰and 4‰groups（P<0.05）,at 24 h,the concentration of NH₃-N in 0.5‰and 1‰groups was significantly higher than 0 group（P<0.05）.（3）At 3 and 6 h,the concentration of BCP in 1‰and 2‰groups was significantly higher than that in 0,0.5‰and 4‰groups（P<0.05）,at 24 h,the concentration of BCP in 1‰group was significantly lower than that in 0 and 0.5‰groups（P<0.05）.（4）At 3 h,gas production in 1‰group was significantly higher than 0,0.5‰and 4‰groups（P<0.05）,at 6h,gas production in 2‰group was significantly higher than 0,0.5‰and 4‰groups（P<0.05）.At 9 and 12 h,gas production in 1‰and 2‰groups was significantly higher than that in the other three groups（P<0.05）,and at 24 h,gas production in 2‰group was significantly higher than that in the other four groups（P<0.05）.（5）Combined with multiple combination effect index（MFAEI）,FWBPs supplementation level was 2‰,which had a better promotion effect on rumen fermentation in vitro.Experiment 2:Effects of FWBPs on growth performance,blood biochemical and immune indices of lambs.Adopt a single-factor completely randomized experimental design,twelve crossbred lambs（Dorper×Small-tailed Han Sheep）of 1.5-month-old in good condition and similar body weight（11.38±0.19 kg）were selected,they randomly divided into 2 groups,included the control group and the FWBPs group,each group was 6replicates,and they were reared in a single pen.Lambs in the control group were fed milk replacer,Lambs in the FWBPs group were fed milk replacer with 2‰fermented wheat bran polysaccharides,The dietary supplement of the control group was free feeding,and the dietary supplement of the FWBPs group was based on the feed intake of the control group,the experimental period was 28 d.The results showed that:compare with the control group,（1）1-28d the average daily gain（ADG）had significantly increased（P<0.05）,F:G had significantly decreased（P<0.05）,the final body weight and carcass body weight tended to improve（P=0.08）in the FWBPs group of lambs.（2）The concentration of total protein（TP）had significantly increased（P<0.05）,the concentration of aspartate aminotransferase（AST）（P=0.08）and interleukin-1β（IL-1β）（P=0.07）tended to decrease in the FWBPs group of lambs.Experiment 3:Effects of FWBPs on gastrointestinal development and rumen microbiota of lambs.Experiment design is the same as experiment 2,The results showed that:compare with the control group,（1）Heart weight/body weight（P=0.07）,kidney weight/body weight（P=0.08）,and spleen weight（P=0.09）had a increased trend,the length of small intestine tended to decrease（P=0.06）,The width of ruminal papillae had significantly increased（P<0.05）,the epithelial cell thickness had an increased trend（P=0.08）,the duodenal villus height of lambs was significantly increased（P<0.05）in the FWBPs group of lambs.（2）The concentration of NH₃-N had significantly decreased（P<0.05）,the butyrate proportion had an increased trend（P=0.05）,but,the isobutyrate and isovalerate proportion had significantly decreased（P<0.05）in rumen,at the family level,the relative abundance of Lachnospiraceae had significantly increased（P<0.05）,at the genera level,the relative abundance of Lachnospiraceae＿NK3A20＿groupand Solobacterium had significantly increased（P<0.05）,the relative abundance of NK4A214＿group（P=0.07）,Megasphaera（P=0.05）,and Treponema（P=0.08）had an increased trend in FWBPs group,LEf Se result displayed that Clostridia,Clostridia＿UCG＿014,Lachnospirales,Lachnospiraceae,NK4A214＿group,Lachnospiraceae＿NK3A20＿group,Fibrobacter＿succinogenes,Lachnospiraceae＿bacterium＿TF01＿11,DNF00809,and Erysipelotrichaceae＿UCG＿007were enriched in the FWBPs group,Spearman correlation analysis results showed that the relativeabundancesofTreponema,NK4A214＿group,and Lachnospiraceae＿NK3A20＿group were in positive correlation to the butyrate proportion（P<0.10）,the relative abundances of Treponema was also in positive to the isovalerate proportion（P<0.10）.In summary,FWBPs can promote rumen fermentation of lambs in vitro,adding 2‰FWBPs in milk replacer can lowers levels of inflammatory cytokines in the blood,promote gastrointestinal development,optimize rumen fermentation parameters,and improve the rumen microflora structure,improve the growth performance of lambs.