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

Abstract Text: The effects of Bacillus subtilis spores and spray-dried yeast cell wall (YCW) on health 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, after the 2^nd day of live and a 20% pellet ration fed “ad libtum”, in treatment 2 the 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 (Alltech of Brazil, Brazil). The Bacillus subtilis spores and YCW were mixed with milk and fed directly to the calves. The animals were housed in individual pens, with free access to water, starter feed  and milk (give three times a day) until weaning that occurs on 9^th week of life. Fecal consistency (FC) was scored as 1 when firm, 2 when soft or of 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.

Keywords: dairy calves, probiotic, immune function

Table 1.

	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	33.20	27.80	-	0.08
FC < 3 (%)	61.76	75.22	68.61	-	0.34
IgG  20 d (mg mL-1)	25.50	21.00	24.38	-	0.51
Average IgG 20- 60 d (mg mL -1)	17.48	15.61	17.06	1.274	0.55
Weight weaning (kg)	77.55	81.60	78.20	3.102	0.61

¹ Rectal temperature, number of observation; ²Fecal consistency