Effects Of Buckwheat Straw Diet Supplemented With Mannose Oligosaccharides On Performance,Immunity And Antioxidant Function Of Tan Sheep

In the past few decades,due to the widespread application of antibiotics,the animal husbandry industry has developed rapidly.While the diseases of livestock and poultry have been controlled,antibiotics have also brought a series of negative effects,such as the emergence of antibiotic resistance,the emergence of super bacteria,environmental pollution.Many research results indicate that mannose-oligosaccharides(MOS)are one of the effective alternatives to antibiotics and have a positive effect on animals.In this experiment,the effect of adding MOS in diet on growth performance,slaughter performance,meat quality,digestion and metabolism,immune and antioxidant functions and rumen fermentation parameters of Ningxia Tan sheep was studied to provide scientific basis for the green and efficient breeding of Tan sheep and straw feeding technology including feeding experiment,slaughter experiment,digestion and metabolism experiment.20 healthy Tan sheep with an average weight of 30.5 kg were randomly divided into 4 groups,5 in each group,and raised respectively in a single cage.The control group and test groups I,II,and III were fed with basal diet,basal diet+1%MOS,basal diet+2%MOS,and basal diet+3%MOS.The buckwheat straw was treated with cellulase and then mixed with corn silage at 40:60 as the experimental roughage.The basic dietary ratio of concentrate to forage was 30:70.The results showed that:(1)The addition of MOS in the diet had no significant effect on the rumen pH and ammonia nitrogen concentration of Tan sheep at Od,30d,and 60d(P>0.05).The content of TVFA,acetic acid,butyric acid,isobutyric acid,valeric acid,isovaleric acid and the ratio of acetic acid to propionic acid showed a trend of "increasing first and then decreasing" with the increase of MOS(P>0.05),which was the lowest in the control group,and highest in the test group II(except isovaleric acid).The content of acetic acid in group I and group II was significantly higher than that in group III(P<0.05).It has no significant effect on the ADF apparent digestibility,dietary nitrogen,fecal nitrogen,urine nitrogen,digested nitrogen,deposited nitrogen,apparent nitrogen digestibility and energy metabolism(P>0.05);After adding MOS,the apparent digestibility of DM and NDF was significantly higher than that in the control group(P<0.05).The apparent digestibility of DM(60.37%)and NDF(59.32%)was the highest in test group I;compared with the control group,the total nitrogen output of the experimental groups was significantly reduced,and the nitrogen utilization rate and biological value of nitrogen were significantly improved.The total nitrogen output(P<0.01)of the group I was the lowest,and the nitrogen utilization rate(P<0.01)and the biological value of nitrogen were the highest.The values were 6.71g/d,55.43%,and 85.4%respectively;fecal energy and urine energy were the lowest in the group I,and metabolic energy and total energy metabolic rates were the highest(P>0.05).(2)The addition of MOS in the diet had no significant effect on the content of serum urea,triglycerides,total cholesterol and free fatty acids of Tan sheep at 0d,30d and 60d(P>0.05);the contents of serum glucose and protein were increased.Compared with the control group,the content of total protein,albumin,and globulin in the group ? and ? increased significantly at 60 days(P<0.01),and the ratio of globulin to albumin and glucose content increased significantly(P<0.05).(3)MOS supplement in the diet could improve the immunity and antioxidant capacity of sheep.The serum immunoglobulin content(IgA,IgG,IgM)and antioxidant enzyme activity(T-AOC,T-SOD)showed a trend of "increasing first and then decreasing" with the increasing addition of MOS;when the supplemental amount of MOS was 2%,the IgA and IgM concentrations at 30 days,and the IgG concentration and the T-SOD activity at 60 days were significantly higher than the control group(P<0.05).And the MDA content was the lowest at 30 and 60 days(P>0.05).(4)The addition of MOS in the diet had no significant effect on the average daily weight gain,feed weight ratio,body length growth,body height growth,meat water loss rate,meat pH and slaughter performance indicators.(P>0.05);The chest circumference and eye muscle area of Tan sheep in the group I was significantly higher than that in the control group(P<0.05).Besides,the total weight gain,average daily weight gain,net meat weight,and carcass net meat rate(49.03%))and pure profit was the highest,while the feed-weight ratio and the bone-to-meat ratio was the lowest,but the difference was not significant(P>0.05);the shear force,drip loss,meat color yellowness and brightness values of the group Ilwere significantly lower than those in the control group(P<0.05 or P<0.01),while the marbling score and cooked meat rate(60.28%)was the highest(P>0.05).In summary,adding 1-2%MOS to the diet under this test condition can improve Tan sheep's production performance,slaughter performance,immunity and antioxidant capacity,and rumen fermentation parameters,and can promote nutrients,nitrogen and energy digestion and metabolism to improve the quality of lamb.