益生菌制剂对犊牛生长性能、血清生化指标及养分消化率的影响OA

This study aimed to investigate the effects of PP on growth performance,serum biochemical parameters,and nutrient digestibility in calves.The experiment selected 75 healthy 1-day-old Holstein calves.The calves were randomly assigned to 5 groups×3 replicates×5 calves.The control group(CON)received milk replacer+starter feed,while the 4 experiment groups received milk replacer+starter feed+500,1000,1500,2000 mg/kg PP,designated as PP500,PP1000,PP1500,PP2000 groups.The trial lasted 60 days.Results:1)During 31-60 days old,compared with CON group,the calves'ADG of PP1500,PP2000 groups significantly increased by 9.81％,10.28％(P<0.05),and the calves'FCR of PP1500,PP2000 group significantly decreased by 7.79％,8.41％(P<0.05).During 31-60 day-old,the calves ADG of PP500,PP1000 group was lower than PP1500,PP2000 group(P>0.05),and the calves'FCR was higher than PP1500,PP2000 groups(P>0.05).2)Compared with CON group,the calves'serum total protein,albumin in the PP500,PP1000,PP1500,PP2000 groups significantly increased(P<0.05),and the calves'serum urea nitrogen in the PP2000 group significantly decreased(P<0.05).There were no significant differences in the calves serum total protein,albumin,urea nitrogen of PP500,PP1000,PP1500,PP2000 group(P>0.05).The calves'serum glucose of PP1500,PP2000 groups was significantly higher than CON,PP500 groups(P<0.05).There were no significant differences in the calves serum glucose of PP1500,PP2000 group(P>0.05).3)Compared with CON group,the dry matter digestibility of PP1500,PP2000 groups was significantly increased(P<0.05),and the crude protein digestibility of PP500,PP1000,PP1500,PP2000 groups was significantly increased(P<0.05).There were no significant differences in the calves dry matter,crude protein digestibility of PP500,PP1000,PP1500,PP2000 group(P>0.05).In conclusion,PP can improve growth performance,metabolic function,and nutrient digestibility in calves.Under the conditions of this experiment,the recommended supplemental dosage of PP is 1500 mg/kg.