Effects Of Different Roughage On Production Performance,Meat Quality And Rumen Micro Flora Of Hu Lambs

This experiment was aimed to study the impacts of various roughage（wheat straw,alfalfa and peanut seedlings）on the production performance and meat quality,rumen fermentation and microbial flora of Hu lambs.In the experiment,60 Hu lambs with good health,normal appetite,about 3 months of age,and weighing between 24 and 28 kg were selected.They were divided into 3 groups according to the principle of similar body weight,and they were fed by the Wheat Straw group（Wheat Straw group WG）.The roughage was wheat straw,the Alfalfa Hay group（Alfalfa Hay group,AG）was fed alfalfa hay,and lambs in the Peanut vine group（Peanut vine group,PG）were fed peanut vine as roughage.Three replicates per group,five lambs per replicate.The preliminary trial period of the test is 7 days,while the formal experiment period is 60 days.Exp.1:At the end of the fattening experiment,one Hu lambs was repeatedly selected from each of WG,PG and AG for fasting,weighing,and slaughter.The production performance and economic benefits of Hu lambs were tested and analyzed.The results showed that:（1）During 97-127 days,mean daily intake mass and average daily weight gain were higher in alfalfa group and the PG than in WG（P<0.05）;during 127-157 d,the mean daily weight gain and mean daily dry matter intake of Hu lambs in the peanut seedling group were expressively exceed those of WG（P<0.05）,and there was no significant difference from the alfalfa group（P>0.05）;throughout the experiment,the main daily food consumption and daily gain of the test lambs in the peanut seedling and alfalfa groups were meaningfully higher than those in the WG（P<0.05）;however,their feed-to-meat ratio was obviously higher than that of the test lambs in the WG（P<0.05）;（2）Immunoproteins Ig A,Ig G and Ig M were expressively（P<0.05）higher in the alfalfa group than in the WG,and immunoprotein Ig A was obviously（P<0.05）higher in the peanut seedling group than in the WG.The interleukin-1β,interleukin-6 and interleukin-8 of the WG meaningfully exceeded those in the alfalfa group（P<0.05）.Serum CD4 and CD8 levels in the alfalfa group were expressively higher than lambs in the peanut seedling and WG（P<0.05）,and the CD4/CD8 values of the AG group and the peanut seedling group distinctly went beyond those in the WG（P<0.05）.（3）Profit between alfalfa group and peanut seedling group evidently exceeded that in the WG（P<0.05）.Exp 2:The Hu lambs slaughter performance,muscle physical properties,muscle nutrient content and muscle amino acid were measured and analyzed.The results showed that:（1）The pre-slaughter fresh weight of Hu lambs in the peanut seedling group was prominently higher than that in the alfalfa and WG（P<0.05）,the slaughter rate and net meat rate of lambs in the peanut seedling and alfalfa groups were conspicuously higher than those in the WG（P<0.05）,and the bone to meat ratio of test lambs in the wheat straw and alfalfa groups was prominently higher than that in the peanut seedling group（P<0.05）,also in the wheat straw and alfalfa groups,the lambs bone to meat ratio conspicuously exceed that in the peanut seedling group（P<0.05）.（2）In contrast to the alfalfa group,there was significant drip loss reduction of Hu lambs muscle in the WG and the PG（P<0.05）,and the shear force was significantly increased（P<0.05）.Compared with the PG,the redness of the AG was significantly reduced（P<0.05）,the brightness and yellowness of the Hu lambs muscle in the WG group and the AG group were significantly reduced（P<0.05）,also the muscle yellowness of Hu lambs in the alfalfa group was prominently lower than that of the WG（P<0.05）.（3）The dry matter and crude protein content in the muscles of Hu lambs in the alfalfa and peanut seedling groups meaningfully exceeded those in the WG（P<0.05）,while the crude fat and crude ash content in the three treatment groups were not significantly different（P>0.05）.（4）Compared with PG group and WG group,diet alfalfa can reduce palmitic acid content in Hu lambs muscle（P<0.05）,and significantly increase linolenic acid content（P<0.05）.In comparison with the WG,the oleic and erucic acid contents of Hu lambs in the peanut seedling group were prominently increased（P<0.05）.Exp 3:The experimental results of rumen fermentation and rumen tissue morphometric analysis of Hu lambs showed that:（1）the rumen weight of Hu lambs in alfalfa group and peanut seedling group significantly exceeded that of Hu lambs in WG（P<0.05）,and the reticulorumen weight of Hu lambs in peanut seedling group was significantly more than that of lake lambs in WG and alfalfa group（P<0.05）.The proportion of flap stomach to compound stomach was expressively higher in the alfalfa group than in the peanut seedling group（P<0.05）.（2）The content of ammoniacal nitrogen was expressively lower in the alfalfa group than in the WG（P<0.05）.The contents of total volatile fatty acids,acetic acid,ethyl acetic acid and pentanoic acid in the rumen liquid of the peanut seedling group were prominently higher than those of the wheat straw and alfalfa groups（P<0.05）,propionic acid contents in the peanut seedling and alfalfa groups expressively exceeded those of the WG（P<0.05）,also the ratio of acetic acid to propionic acid in the peanut seedling group expressively exceeded that in the alfalfa and WG（P<0.05）.（3）The rumen papilla length and papilla surface area in the peanut seedling group were prominently higher than those in the alfalfa and WG（P<0.05）,while the papilla width was expressively lower than those in the alfalfa and WG（P<0.05）.The thickness of cuticle and muscle layer of rumen in alfalfa group meaningfully exceeded that in WG and peanut seedling group（P<0.05）,while the thickness of epithelium in WG was expressively exceeded that in alfalfa group and peanut seedling group（P<0.05）.Exp 4:At the end of the fattening test,adoption of 16S rDNA technology was to test the diversity index and variation of the bacterial communities of rumen and investigate the effect of various roughage on farding-bag fermentation parameters and rumen liquid colony.The test results showed that:（1）At day 60 of the trial,tenericute number was expressively higher in the peanut seedling group than in the wheat straw and alfalfa groups（P=0.026）at the phylum level.（2）At the genus level,the content of Prevotellaceae_UCG-001 in the WG and the AG was significantly higher than that in the PG（P=0.025）.Compared with WG,Succiniclasticum in the PG was significantly reduced（P=0.023）.（3）Ruminococcaceae UCG-001 had prominently and positive relationship with the content among acetic acid,metacetonic acid,ethyl acetic acid,pentanoic acid and total volatile fatty acid,and the unassorted Prevotellaceae had prominently and positive relationship with the content between butyric acid and valeric acid content.Lachnospiraceae_NK3A20_group has a significant positive correlation with pH,and Prevotella₇（Prevotella₇）has a significant negative correlation with pH.Quinella,Succiniclasticum,unclassified_oClostridiales and Veillonellaceae_UCG-001 were significantly negatively correlated with feed intake.Prevotellaceae_UCG-001,Succiniclasticum and unclassified_oClostridiales were significantly negatively correlated with daily weight gain.In summary:adding peanut seedlings or alfalfa to the Hu diet can improve its production performance,slaughter performance and economic benefits.Improve intramuscular fat and improve the quality of lamb.In particular,adding alfalfa can improve biochemical indicators such as serum immunity,and improve the immunity of Hu lambs.The addition of Peanut vines or alfalfa not only accelerates the development of rumen papillae,but also improves the rumen fermentation function.Three kinds of roughage can affect the abundance of some functional flora at the level of certain phyla and genus of Hu lambs’s rumen microflora,and have significant correlation with different environmental factors.This work will help to change the structure of rumen flora and its metabolism by adding different roughages,thereby improving its production performance and meat quality.