Effects Of Rumen-Protected Fat And Rumen-Protected Glucose On Growth Performance,Nutrient Apparent Digestibility And Meat Quality Of Dumengsa Sheep

Energy is one of the main factors affecting the growth properties and meat quality of ruminants,and dietary energy levels in particular play an essential role in regulating the deposition of animal fats.In this study,two rumen additives,rumen-protected fat(RPF)and rumen-protected glucose(RPG),were supplemented on the basis of conventional sheep diet to study the effects of RPG and RPF on digestion and metabolism of sheep.Effect of production performance and quality of meat.A total of 24 8-month-old Dumengsa ewe were divided into four treatment groups,including control group(CON group),1%rumen-protected glucose group(RPG group),2%rumen-protected fat group(RPF group)and 1%rumen-protected glucose+2%rumen-protected fat group(RPG+RPF group).The pre-experiment lasted 14 days and the trial lasted 100 days,with digestion and metabolism tests performed for a week at the end of the 90-day period.At the end of 100 days,test samples were taken for slaughter.The results of this experiment were as follows:(1)Compared with CON group,other treatment groups had no significant effects on daily gain,daily feed intake and feed to gain ratio of Dumengsa sheep,but RPG+RPF group had further advantages in feed to gain ratio.RPG and RPF had no significant effects on serum GLU,TC and TG(P>0.05),but had significant effects on AST and ALT concentrations(P<0.05).In addition,compared with CON group,RPG and RPF supplementation had no significant effects on serum TAOC,MDA,GSH-Px,SOD and CAT(P>0.05),but POD activity was significantly decreased(P<0.05).(2)The apparent digestibility of dry matter(DM),neutral detergent fiber(NDF),acid detergent fiber(ADF),crude fat(EE)and crude protein(CP)of Dumengsa sheep in RPF group and RPG+RPF group was significantly increased(P<0.05);the apparent digestibility of EE and CP of Dumengsa sheep in RPG group was significantly decreased(P<0.05).Therefore,the addition of RPF is more beneficial to effectively increase the apparent digestibility of nutrients in Dumengsa sheep.(3)The addition of RPG and RPF can reduce the water loss rate and the yellowness value(P<0.05),and effectively prolong the fresh-keeping time of mutton,in which the RPG+RPF group has the most significant effect on improving the yellowness value.RPG and RPG+RPF supplementation significantly increased the content of crude fatty in back muscle(P<0.05);RPF and RPG+RPF supplementation significantly increased the contents of saturated fatty acid(SFA)and unsaturated fatty acid(UFA)in dorsal muscle(P<0.05).The MUFA/SFA ratio of meat in RPG group was significantly higher than that in other groups(P<0.05).The PUFA/SFA ratio of meat in RPG+RPF group was significantly higher than that in other groups(P<0.05),the ratio of PUFA/SFA in meat in RPG and RPF groups was significantly higher than that in the CON group(P<0.05).RPF increases the amount of unsaturated fatty acids in meat,and the addition of RPG and RPF increases the ratio of MUFA/SFA and PUFA/SFA in meat,effectively increasing the fatty acid composition.in summary,the addition of RPG and RPF promotes efficient absorption of nutrients from Dumengsa,effectively improving the fatty acid composition of meat and increasing the ratio of beneficial fatty acids such as oleic,linoleic and organic acids.Among them,the RPG+RPF group achieved the best results in improving the quality of Dumengsa sheep.