Effects Of Rumen-protected Glucose And Choline On Performance And Meat Quality Of Beef Cattle

Rumen choline(RPC)and ruminal glucose(RPG)can improve the feed utilization of ruminants and improve the health of animals while improving the quality of meat.This trial was conducted in a completely randomized trial design to study two RPC addition levels and two RPG addition levels.Thirty Simmental crossbred bulls with similar body weight(456.32±14.06kg)and lyrics were selected as experimental animals and randomly divided into 5groups,group A(control),group B(20g/d RPC +100g/d RPG),group C(40g/d RPC+100g/d RPG),group D(20g/d RPC+200g/d RPG)and group E(40g /d RPC+200g/d RPG).The RPC and RPG were mixed and fed to the different group of beef cattle in the limit bar feeding mode.The effects on beef growth performance,blood biochemical parameters,carcass quality and meat quality were studied in this research.The results of the research are as follow:(1)RPC and RPG had no significant effect on average daily feed intake of beef cattle(P>0.05),but had significant effect on average daily gain and feed-to-weight ratio(P<0.05).The ADG increased as the addition of RPG,and the average daily gain of group E was significantly higher than that in group A and C(P<0.05),and the feed-to-weight ratio of group D and E were significantly higher than that in group A.RPC and RPG also had no significant effect on the apparent digestibility of nutrients such as CP,ADF,NDF,Ca and TP(P>0.05).But the body's fat utilization rate could be effectively regulated by RPC and RPG,when the dietary RPC supplement was 40g/d,the apparent digestibility of EE was significantly higher than that of the control group(P<0.05),and also had an increasing trend.than group RPC 20g/d.(2)The GLU content in the serum of beef cattle was significantly effected by RPG and RPC(P<0.05).The concentrations of GLU in serum of group D and E were significantly higher than those of group A(P<0.05).RPC and RPG had no significant effect on serum AST and ALT activities(P>0.05),and serum AST and ALT activities in group B and C were slightly higher than group D and E,but it was maintained in the normal range to ensure the health of beef cattle liver;RPC and RPG had significant effect on serum TG content(P>0.05),the serum TG content of the group that RPC addition amount was 40 gram every day and the RPG addition amount was 200 gram every day was significantly lower than the control group(P<0.05),and there was no significant difference with the other three groups(P>0.05);the addition of RPC and RPG had a tendency to lower serum TC content.(3)RPC and RPG had no significant effect on the slaughter rate of beef cattle(P>0.05),but the 40 gram RPC addition every day could significantly increase the net meat rate.The net meat yield of D and E groups was significantly higher than that of the control group(P<0.05).Theenergy efficiency of 40g/d RPC in the diet reduced the weight of perirenal fat(P<0.01).It was found that the slaughter performance of beef cattle in RPC 40g/d+RPG 200g/d group was better,and it could promote the increase of backfat thickness(P>0.05).RPC and RPG had no significant difference in the weight of high-grade meat in the production of ribeye,striploin and tenderloin in beef cattle(P>0.05);and had significant effect on the weight of high rib meat(P>0.05),and the weight of meat in the D and E groups significantly higher than the control group(P<0.05),but had no significant difference with the B and C groups(P>0.05).There was no significant effect on the production of high-quality meat pieces(P>0.05),but the production of beef cattle,outside flat and eye round were higher than that of the control group and the low RPG addition group.The same trend wasn't seen in the other meat.(4)The drip loss and cooking loss of beef were not affected by the change of RPC and RPG(P>0.05),but the beef yellowness value decreased(P>0.05).The intramuscular fat content of beef in group B,C,D and E was significantly higher than that in the control group(P<0.05).Among them,fat content of beef in the group RPC 40g/d and RPG 200g/d is the most especially.(5)RPC and RPG can effectively regulate the diameter of fat cells under the meat cowhide(P<0.05),and the effect on the regulation of perirenal fat and abdominal fat cell diameter is more significant(P<0.01).Compared with the control group,the subcutaneous cell fat diameter of group B and D decreased by 1.79% and 3.14% respectively,while the C and E groups decreased by 1.79% and 3.14% respectively.The group B,C,D,and E of beef cattle were significantly decreased by 8.02%,23.90 %,7.33% and 18.4% than the control group respectively;and perirenal fat cell diameter decreased by 26.08%,39.39%,25.23% and 37.85% respectively.The cell diameter increased slightly under the same conditions of RPC addition.In conclusion,the addition of RPG and RPC to the diet can improve the feed utilization rate of the beef cattle,improve the carcass quality,and promote the health of the fattening cattle and produce high-quality beef.