Effects of Bacillus subtilis and yeast cell wall on diarrhea incidence and immune function of dairy calves

Abstract - The effects of Bacillus subtilis spores and spray-dried yeast cell wall (YCW) on heath of dairy calves in the first 60 d of age were evaluated using 30 animals in three treatments. In control treatment, dairy calves received 8 liter of milk/day and a 20% pellet ration, in treatment 2 calves received the same ration of treatment 1 plus 3x10⁹  viable spores/calf/d of Bacillus subtilis (Calpis Co. Ltda, Tokyo, Japan), in  treatment 3 it was offered treatment 2 + 4 g/calves/d of YCW). Bacillus subtilis spores and YCW were mixed with milk and fed to calves. The animals were housed in individual pens, with free access to water, starter feed and milk (8 L, three times a day) until weaning. Fecal consistency (FC) was scored as 1 when firm, 2 when soft or  moderate consistency, 3 when runny or mild diarrhea, and 4 when watery and profuse diarrhea. The FC 1 and 2 were considered no diarrhea. The supplementation with Bacillus subtilis tended (P=0.08) to increased number of calves without diarrhea (Table 1). Dairy calves feeding with probiotic and YCW showed higher rectal temperature. However, there is no difference (P > 0.05) in the levels of serum immunoglobulin G (IgG). The use of Bacillus subtilis reduced diarrhea incidence of pre-weaning calves without effects on serum immunoglobulin levels.

Table 1.Retal temperature (RT), feces consistence (FC), serum imunoglobulin at 20 day (mg mL^-1), average of serum IgG (20-60 day) and weaning weight (kg) for Holstein calves receiving B.subtilis and yeast.

 

	Control	B. subtilis	B. subtilis+EPL	SEM	P Treat
RT mean1	38.71	38.75	38.87	0.039	0.02
RT % >= 39ºC	26.58	28.44	36.81	3.7	0.14
FC < 3 (no diarrhea)1	25.3	33.2	27.8	-	0.08
FC < 3 (%)	61.76	75.22	68.61	-	0.34
IgG  20 d (mg mL-1)	25.5	21	24.38	-	0.51
Average IgG 20- 60 d (mg mL -1)	17.48	15.61	17.06	1.274	0.55
Weaning weight (kg)	77.55	81.6	78.2	3.102	0.61

Key words: dairy calves, immune function, probiotic.