Effects of Bacillus on Growth Performance,Nutrient Apparent Digestibility,Serum Indices and Diarrhea Rate of Pre-Weaned Holstein Calves
This experiment aimed to investigate the effects of Bacillus(Bacillus subtilis and Bacillus lichenifor-mis)on growth performance,nutrient apparent digestibility,serum indices and diarrhea rate of pre-weaned Holstein calves,to provide a theoretical basis for the application of Bacillus subtilis and Bacillus licheniformis for better breeding of healthy calves.A completely randomized compartmentalized experimental design was used in this experiment,24 newborn Holstein female calves with body wight of(38.09±1.35)kg were divide into 6 blocks,each block contained 4 calves,which contained 2 calves in control group(feeding milk+starter)and Bacillus group(feeding milk+1 g/d Bacillus+starter).Calves were weaned at 56 days of age and the ex-periment ended.The results showed that compared with the control group,on 56 days of age,the body height of calves of Bacillus group was tended to decrease(P=0.06),the apparent digestibility of dry matter(P=0.08)and crude protein(P=0.05)was tended to increase,the serum immunoglobulin G content was signifi-cantly increased(P<0.05),the serum total antioxidant capacity(P=0.08)and albumin content(P=0.09)were tended to increase;during 28 to 56 days of age,the Fecal abnormality days were tended to decrease(P=0.09).In conclusion,feeding Bacillus has no significant effect on growth performance of calves,but increase the immunity level and antioxidant capacity of calves before weaning and the apparent digestibility of dry matter and crude protein of diet for calves to a certain extent,and reduce the diarrhea days of calves.[Chinese Jour-nal of Animal Nutrition,2024,36(9):5805-5816]