Effects Of Fermented Rice Straw On Production Performance,and Meat Quality And Fatty Acid-related Gene Expression In Angus Cattle

Microbial fermentation can enhance the nutritional value of feeds,improve the palatability of feeds,and in turn improve the production performance and meat quality of ruminants.In this experiment,we investigated the effects of fermented rice straw on the production performance,slaughter performance and meat quality of Angus cattle through feeding tests,slaughter tests and meat quality identification and analysis,and compared the relative expression of PPAR γ,FABP4,SREBP-1,HSL,SCD and LPL genes in the longest dorsal muscle,liver,subcutaneous fat and tail fat by RT-PCR.HSL,SCD and LPL genes in the longest dorsal muscle,liver,subcutaneous fat and tail fat by RT-PCR,to lay the foundation for subsequent studies on meat quality,with a view to providing a theoretical basis for the efficient use of rice straw resources and the safe and efficient breeding of Angus cattle.The main findings of the study are as follows.1.There were no significant differences in gas production and pH values between the groups(P>0.05),and the NH3-H content of test group I and test group II was significantly higher than that of the control group(P<0.05),while the NH3-H content of test group II was significantly higher than that of test group I(P<0.05).Compared with the control group,the proportion of propionic acid was significantly higher(P<0.05),the ethylene propionate ratio was significantly lower(P<0.05)and the total volatile fatty acid was significantly higher(P<0.05)in the test group,while the differences in other indicators were not significant(P>0.05);the apparent digestibility of dry matter,crude protein and neutral detergent fibre were significantly higher(P<0.05)in test group Ⅰ and test group Ⅱ than in the control group,while the differences in other digestibility The mean daily weight gain,mean feed intake and final abdominal girth of test group Ⅰ and test group Ⅱ were significantly higher than those of the control group(P<0.05),and the feed-to-weight ratio was significantly low er than that of the control group(P<0.05).Compared with the control group,the breeding efficiency of test group Ⅰ and test group Ⅱincreased by 7.60%and 14.94%respectively;the serum globulin and total protein content of test groupⅠ and test group Ⅱ were significantly higher than the control group(P<0.05).2.The differences in slaughter performance indexes between the groups were not significant(P>0.05);the muscle meat yellowing(b*)value and crude fat content of test group Ⅰ and test group Ⅱwere significantly higher than those of the control group(P<0.05),and the muscle shear force was significantly lower than that of the control group(P<0.05).The muscle saturated fatty acid(SFA)content was lower(P>0.05),the monounsaturated fatty acid(MUFA)and polyunsaturated fatty acid(PUFA)content was higher(P>0.05),and the muscle essential amino acid(EAA),non-essential amino acid(NEAA)and total amino acid(TAA)contents were higher(P>0.05).3.PPAR γ,FABP4 and SREBP-1 gene expression were significantly up-regulated in dorsal longest muscle and caudal fat(P<0.05);PPAR γ gene expression was significantly up-regulated in liver tissue and subcutaneous fat,while SREBP-1 and FABP4 gene expression were up-regulated respectively(P<0.05);HSL,LPL and SCD gene expression were significantly down-regulated in liver and dorsal longest muscle(P<0.05)The expression of HSL and LPL genes was significantly down-regulated in subcutaneous and caudal fat,respectively(P<0.05).Under the conditions of this experiment,fermented rice straw could improve the rumen fermentation environment,increase the apparent digestibility of nutrients,enhance production performance,improve meat quality and affect the expression of fatty acid-related genes.The analysis of the above studies concluded that 20%was the relatively suitable amount of fermented rice straw to be added.