Effects Of Different Roughage On Production Performance,Meat Ouality And Rumen Microflora Of Simmental Crossbred Cattle

The purpose of this experiment was to study the effects of different kinds of hay added to the diet of Simmental hybrid cattle on the performance,meat quality and rumen flora of Simmental hybrid cattle.75 Simmental crossbred cattle of similar weight（395～405kg）from 12 to 14 months old were randomly divided into three treatment groups（5 repeats per treatment group,5 beef cattle per repetition）:wheat straw group（Wheat Straw group,WG）was fed with wheat straw.Peanut seedling group（Peanut vine,PG）was fed with peanut seedling and dry Medicago sativa.The forage group（Alfalfa Hay,AG）was fed with Medicago sativa hay,the pre-trial period was 7 days,the positive trial period was 90 days,and the digestion test and slaughtering sampling were 7 days for a total of 104 days.Exp.1:At the end of the fattening experiment,one cattle was selected on per replicate pens for fasting,weighing,slaughter.And analysis of the growth performance,serum biochemical,tissue antioxidant indexes,economic benefits of the cattles.The results showed that:（1）Compared with WG,the PG ADFI significantly higher（P<0.05）,the AG ADG significantly higher（P<0.05）,F/G significantly reduced（P<0.05）.（2）the PG and the AG serum ALT levels significantly reduced（P<0.05）,the AG serum HDL-C significantly higher（P<0.05）,the PG and the AG serum LDL-C significantly reduced（P<0.05）.（3）The AG serum T-AOC significantly higher（P<0.05）,the AG liver T-AOC and SOD activity significantly higher（P<0.05）,the AG spleen GSH-PX activity significantly higher（P<0.05）.（4）the AG gross margin significantly higher（P<0.05）.Exp.2:At the end of the fattening experiment,one cattle was selected on per replicate pens for fasting,weighing,slaughter.And analysis of the carcass indicators,meat quality.The results showed that:（1）Compared with WG,the AG meat weighs significantly higher（P<0.05）,the AG meat bone than the highest,and significantly higher the PG（P<0.05）.（2）The AG muscle marbling score score has reached 3.0 points,significantly higher than the WG and the PG（P<0.05）,the PG and the AG muscle shear force were significantly higher than WG（P<0.05）;three groups of muscle pH were within the normal range,the AG was significantly lower than the other two groups（P<0.05）.（3）The AG dry matter of muscle and crude fat significantly higher than WG（P<0.05）,the PG muscle crude protein content increased significantly（P<0.05）.Exp.3:At the end of the fattening experiment,one cattle was selected on per replicate pens for fasting,weighing,slaughter.The content of amino acids and fatty acids in the carcass 6-7 intercostal dorsal longest muscle was determined.The results showed that:（1）The PG and the AG muscle total amino acids is significantly higher than WG（P<0.05）;the AG Glu is significantly higher than the WG and the the PG（P<0.05）,the PG and the AG Asp is significantly higher than that of WG（P<0.05）;The PG Phe was significantly higher than that of WG（P<0.05）,the PG and AG of lys is significantly higher than the WG（P<0.05）.（2）The AG palm oleic acid content is significantly higher than the PG（P<0.05）,the AG linoleic acid content is significantly higher than WG（P<0.05）,the PG and AG alpha linolenic acid content is significantly higher than WG（P<0.05）;the AG total saturated fatty acids content was significantly lower than the WG and PG（P<0.05）,single unsaturated fatty acid content is significantly higher than the WG（P<0.05）,the PG and AG ω-3 content significantly higher than the WG（P<0.05）,the AG co-6/co-3 significantly reduced（P<0.05）.Exp.4:At the end of the fattening experiment,one cattle was selected on per replicate pens for fasting,weighing,slaughter.2-4 hours after feeding collect rumen fluid of cattle,to determination of rumen fermentation indexes（pH,NH3-N,MCP,VFAs）.The richness and diversity of bacterial community in the rumen were detected by 16S rDNA.To explore the effects of different roughage on rumen fermentation parameters and gastric juice flora.The results showed that:（1）The NH3-N of rumen fluid increases in turn in WG,PG,AG,and significant differences among the three groups（P<0.05）;The AG MCP of rumen fluid is significantly higher than the WG（P<0.05）;About VFAs content of rumen fluid,the AG AA was significantly lower than WG（P<0.05）,PA of The PG and AG content is significantly higher than WG（P<0.05）,AA/PA of The PG and AG was significantly lower than WG（P<0.05）.（2）Tenericute of The PG quantity is significantly higher than the WG and AG in phylum classification level（P=0.002,P=0.022）.（3）In genus classification level,compared with the WG,the Ruminococcaceae_UCG-001 of the AG significantly reduced（P=0.018）,the Prevotella₁ of the AG is on a downward trend（P=0.067）,the norank_fBacteroidales_BS11_gut_group of AG is on the rise（P=0.079）.（4）The results of correlation analysis between rumen environmental factors and rumen flora showed that:Ruminococcaceae_ucg-001 and norank f Bacteroidales RF16 group were negatively correlated with CP intake.Ruminococcaceae_ucg-001 was positively correlated with the intake of ADF and NDF.Ruminococcus₂,succinivibrionaceae_ucg-002,norank_oMollicutes_RF9 were positively correlated with rumen pH.Ruminococcaceae_ucg-001 was negatively correlated with NH3-N of rumen fluid.Prevotella₁,Prevotellaceae_UCG-003,norank_pSR1_Absconditabacteria_are positively correlated with AA content.Weissella was positively correlated with PA content while ruminococcaceae_UCG-001 was negatively correlated with PA content.Butyrivibrio₂,Christensenellaceae_R-7_group,Pseudobutyrivibrio,Ruminococcaceae_NK4A214_group are positively correlated with BA content while Lactobacillus,Succiniclasticum are negatively correlated with BA content.These findings indicated that different roughage could improve rumen fermentation types to some extent,that different fiber sources in the diet could change the richness of related rumen bacteria,and that rumen environmental factors were correlated with rumen bacteria.