Effects of Bacillus Subtilis Preparations on Performance,Ruminal Fermentation,Blood Biochemical and Immune Indices of Beef Cattle
The aim of this experiment was to study the effects of Bacillus subtilis preparation on rumen fermentation,performance,blood biochemistry,immune indicators,and meat quality in beef cattle.A completely randomized design was employed,involving 48 Simmental beef cattle in similar physical condition during the fattening period.The cattle were randomly divided into four groups:control group(fed with basic diet,CON),low-dose group(Bacillus subtilis preparation added to the basic diet at 0.3 g·kg-1 DM,LAL),medium-dose group(Bacillus subtilis prepara-tion added to the basic diet at 0.45 g·kg-1 DM,LAM),and high-dose group(Bacillus subtilis preparation added to the basic diet at 0.6 g·kg-1 DM,LAH).Each group had 4 replicates,with 3 cattle in each replicate.The pre-trial period lasted for 10 days,and the formal period lasted for 90 days.The results showed as follows:1)Adding Bacillus subtilis preparation to the diet did not significantly affect rumen fluid pH,rumen fluid ammonia nitrogen(NH3-N),dry matter in-take(DMI),body measurements,slaughter performance,and meat quality of the experimental cattle(P＞0.05).2)The serum total antioxidant capacity(T-AOC)in the LAL group was signif-icantly higher than that in the CON group(P＜0.05).3)Compared to the CON group,the molar concentration of butyrate in rumen fluid was significantly lower in LAL and LAM groups(P＜0.05).Additionally,compared to CON group,the ratio of acetate/propionate in rumen flu-id in the LAL and LAM groups,total protein(TP)and globulin(GLB)content in blood of the LAM and LAH groups,as well as the activity of alanine transaminase(ALT)and aspartate transaminase(AST)in blood of the LAM and LAH groups,were significantly higher(P＜0.05).4)Compared to the CON group,the LAH group showed a significant decrease in feed/gain ratio(F/G)(P＜0.05),and the LAH group exhibited significantly higher average daily gain(ADG),triglyceride(TG)levels in blood,haptoglobin(Hp),and serum amyloid A(SAA)compared to the CON group(P＜0.05).In conclusion,Bacillus subtilis preparation can improve the rumen environment,blood antioxidant function,and immune function in beef cattle to var-ying degrees.The highest weight gain efficiency in cattle was observed when the addition rate was 0.6 g·kg-1DM.
万方数据
维普
