Effect Of Yeast Hydrolysate On Growth Performance,Rumen Fermentation And Meat Quality Of Holstein Steers

This experiment was designed to investigate the effects of different dosages of yeast hydrolysate on growth performance,Growth Performance,Blood Index,Rumen Fermentation,Slaughter Performance and Meat Quality of Holstein steers.A total of 33 Holstein steer with good health condition and similar body weight(542.07±9.18kg)were randomly divided into 3 groups,with 11 steer in each group.Steers in groupD(control group)were fed a basal diet.The yeast hydrolysate were supplemented at 50 g(group Y1)and 100 g(group Y2)per day per head.The experiment lasted for 111 d.(1)The average daily gain of steers in group Y2 was significantly higher than that of groupD(P<0.05);The feed-to-weight ratio of the steers has a decreasing trend compared to group I(P=0.09).The dry matter intake of steers was no significant difference among groups(P>0.05).The apparent digestibility of crude protein of steers,calcium in groups Y1 and Y2 was significantly higher than that of group D(P<0.05).Serum total protein content,glutathione enzyme content and total antioxidant capacity of steers in groups Y1 and Y2was significantly higher than that in the group I(P<0.05);ALT content,AST content,serum malonaldehyde content of steers in groups Y1,Y2 were significantly lower than those in group D(P<0.05).(2)Propionic acid,MCP concentrationof steers in groups Y1,Y2 were significantly higher than those in group Ⅰ(P<0.05),Ethylene-propylene ratio,NH3-N concentration of steers in groups Y1,Y2 were significantly lower than those in group D(P<0.05),Butyric acid,TVFA concentration and pH of steers was no significant difference among groups(P>0.05).In phylum level,The relative abundance of Bacteroides group Y2 increased compared with group D and Y1(P>0.05).In genus level,Desulfobulbus,Mycoplasma_girerdii of steers in groups Y1,Y2 were significantly higher than those in group D(P<0.05).The relative abundance of Oribacterium group III was higher than that of groups Ⅰ and Ⅱ(P>0.05).In genus level,Brevundimonas_terrae of steers in groups Y2 were significantly higher than those in group D(P<0.05).Desulfovibrio_sp of steers in groups Y2 were significantly lower than those in group D(P<0.05).(3)Longissimus muscle area of steers in groups Y1,Y2 were significantly higher than those in group D(P<0.05).Slaughter rate,Bone weight,Meat/Bone,Net meat percentage,Carcass yield,Back fat thickness,Fat color,Marbling grade of steers was no significant difference among groups(P>0.05).(4)Shear force of steers in groups Y1,Y2 were significantly lower than those in group D(P<0.05).Dehydration rate,Drop loss,Meat colorof steers was no significant difference among groups(P>0.05).The crude fat of steer beef in groups Y1 and Y2 was significantly higher than that in group D(P<0.05).Water content,crude protein,and crude ash content of steers was no significant difference among groups(P>0.05).MUFA,PUFA,P/S of steers in groups Y1,Y2 were significantly higher than those in group I(P<0.05).(5)Flavor substances(sodium glutamate,thiamine,inosine,inosinic acid)content were significantly higher than those in group I(P<0.05).Umami fatty acid,sweet amino acid content were significantly higher than those in group I(P<0.05).Bitter amino acid content were significantly lower than those in group I(P<0.05).MDA,Protein carbonyl value content were significantly lower than those in group I(P<0.05).Under the conditions of this experiment and comprehensive consideration,the appropriate amount of yeast hydrolysate added to Holstein steers is 100 g/head·d...