Effects Of Adding Oat Hay In Diet On Production Performance,Metabolism And Rumen Microflora Of Sheep

In order to investigate the Effects of adding oat hay in diet on growth performance,ruminal fermentation,metabolism and microflora of sheep,select appropriate feeding amount of oat hay,9 cross breed sheep?Merino×Mongolian?with similar body weight?70.32±2.14?kg and body condition were selected and randomly divided into 3 groups averagely,There were three set of diets,base on ratio of oat hay and corn silage in the roughage?dry matter basis?,i.e.,C1?100%whole corn silage?,C2?50%oat hay+50%whole corn silage?and C3?100%oat hay?.The ratio of the concentrate to roughage was 35:65.A 3×3 Latin square design was used.Three trial periods were conducted with 22 days for each period?15 days for pretest and 7 days for formal?.Samples were taken at the last 3 days of the formal test.Daily body weight gain of sheep,DM intake,nutrient apparent digestibility,rumen pH,rumen N metabolism,VFA,gas production,methane production,IVDMD,IVCPD and relative content of microflora were determined.The results are as follows:1.Adding oat hay in diet had no remarkable influence on dry matter intake?P>0.05?,but significantly increased daily body weight gain and feed conversion rate?P<0.05?;The apparent digestibility of DM?OM?NDF?ADF and N,as well as retention rate of N markedly improved?P<0.05?.2.Adding oat hay in diet significantly affected ruminal fermentation.Compared with C1,C2 or C3 had no remarkable influence on pH and total nitrogen concentration,but significantly reduced rumen urea nitrogen,NH₃-N,and serum urea nitrogen concentration?P<0.05?;C2 also increased?16.58%and 9.03%?rumen protein nitrogen concentration?131.06 mg/dL?,compared with C1and C3.C2 also had slightly higher rumen pH and total nitrogen concentration,but significantly lower NH₃-N?11.54 mg/dL?than C1?15.86 mg/dL?or C3?12.96 mg/dL?.Adding oat hay in diet did not change the concentration of rumen TVFA and proportion of propionic acid,but significantly increased the proportion of acetate acid,butyric acid and acetate/propionate.3.Adding oat hay in diets significantly increased gas production and methane production,NH₃-N,TVFA,acetate acid,butyric acid and acetate/propionate?P<0.05?,but did affect pH and propionic acid.The gas production of C2 and C3were 36.23%and 12.54%higher than C1.Adding oat hay in diet also significantly increased the IVDMD and IVCPD.C2 group had the highest MFAEI,while C1had the lowest.4.Adding oat hay in diets significantly influenced the relative content of fungus and cellulolytic bacteria.The relative contents of fungus in rumen fluid of C2?2.95?and C3?2.65?were remarkably higher than C1 before feeding,but reduced 1h after feeding and down further at 3h,then increased.The relative content of protozoa in rumen fluid of C2 was significantly lower than control and C3 before feeding,but 3h after feeding,a remarkable increase was observed in C2 and C3,then droped at 5h.The relative content of Ruminococcus flavefaciens fluctuated significantly.C3had the greatest variations in 7h after feeding,while C2 kept its contents among0.81-1.25 times of the control.The relative content of Ruminococcus albus before feeding was 0.85-3.07 times of the control.Within 7h after feeding,C2 and C3 had significantly higher values than C1,a mild fluctuation was obtained in C2.The relative content of Fibrobacter succinogenes showed different trend.C2 had up-down-up-down changes,while C3 showed down-up-down.5.In conclusion,adding oat hay in sheep diet increased feed conversion rate and nutrient apparent digestibility,promoted NH₃ utilization and rumen protein nitrogen,increased gas production,the proportion of rumen TVFA and the relative contents of cellulolytic bacteria,reduced the relative content of protozoa in rumen.So under the same level of concentrates,feeding sheep with 50%oat hay+50%whole corn silage as roughage had the best performance...