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Saccharomyces cerevisiae boulardii improves acute phase response and phagocytosis during weaning in dairy calves
The use of direct fed microbials (DFM) as alternatives to antibiotic growth promoters in farm animal production continues to stimulate research and commercial interest. During the early period of life, inadequate immune development and weaning stress contributes to increase susceptibility to infectious diseases in calves. Currently, it is less clear how DFM elicit acute phase immune response in calves. This study aimed to investigate the effect of Saccharomyces cerevisiae and Lactobacillus acidophilus on acute phase response and phagocytosis during the early period of calf growth.
Forty eight Holstein calves(2-7 days old) were grouped according to body weight and circulating IgG and randomly assigned to four treatments as follows; Control (CTRL)- fed milk replacer with starter diet introduced gradually in the third week of the experiment; CTRL supplemented with Saccharomyces cerevisiae boulardii CNCM I-1079 (7.5x109 cfu/L milk replacer+ 3x109 cfu/kg feed) (SCB); CTRL supplemented with Lactobacillus acidophilus BT1386 (2.5x108 cfu/L milk replacer+ 1x109cfu/kg feed) (LA); and CTRL supplemented with tetracycline (528mg/L milk) and neomycin (357mg/L milk) before weaning and chlortetracyclin (55 mg/kg) after weaning (ATB). After weaning calves received hay in addition to starter diet and their respective treatments. Serum samples on experiment days 29 and 43 (pre-weaning), 46, 49, 51 and 54 (weaning) and 58 and 65 (post-weaning) were used for measurements of C-reactive protein and haptoglobin. Likewise, polymorphonuclear neutrophils (PMN) were isolated from plasma on days 15 and 43 (pre-weaning), 47 and 54 (weaning), 59, 66 and 87 (post-weaning), stimulated with lipopolysaccharide and phagocytosis beads pH rhodo Green E. coli bio particles. Phagocytosis was then measured using flow cytometry. The effects of treatments were analyzed using a complete randomized block design with repeated measures and PROC MIXED of SAS with Tukey adjustments for multiple comparisons.
Serum concentrations of C-reactive protein and haptoglobin in SCB-treated calves increased during weaning (day 54; P<0.05) when compared to CTRL, LA and ATB-treated calves. Concentrations of C-reactive protein tended to increase on day 65 (post weaning; P<0.10) with SCB compared with CTRL or ATB. The PMN from calves on SCB increased (P<0.05) phagocytosis during weaning (day 47) as compared to CTRL.
Data show that SCB has immunomodulatory effects in calves and a possible role in enhancing innate immune and inflammatory responses of calves during the critical stress period of weaning. Direct fed SCB might play a role in innate immunity as an early defense system against infections in calves.
Keywords: Calf, Saccharomyces cerevisiae, C-reactive proteins, haptoglobin, innate immunity