The effects of yeast cell wall (YCW) supplementation on growth performance, cell-mediated immune response, blood metabolites, and health scores in early-weaned male buffalo (Bubalus bubalis) calves were evaluated. Forty Nili Ravi buffalo calves were randomly divided into four groups and supplemented with four dietary treatments, namely control (animals without prebiotics), YCW-2 (yeast cell wall fed at 2 g/calf/day), YCW-4 (yeast cell wall fed at 4 g/calf/day), and cMOS-4 (commercial mannan-oligosaccharide fed at 4 g/calf/day). Milk intake, dry matter intake (DMI), and health scores were recorded daily, whereas body weight (body weight) and structural developments (hip height, wither height, heart girth, and body length) were recorded weekly. Feed efficiency and average daily gain (ADG) were calculated at the end of the experiment. Blood samples were collected fortnightly to determine glucose, non-esterified fatty acids, beta-hydroxybutyric acid (βHBA), blood urea nitrogen (BUN), catalase, malondialdehyde, creatinine, hepatic enzymes, cholesterol, triglycerides, and total serum protein profile. The cell-mediated immune response was determined by the application of dinitrochlorobenzene directly to the skin. The results of the study revealed that supplementation of YCW and cMOS increased DMI, body weight, feed efficiency, ADG, and structural growth in buffalo calves, whereas faecal scores were significantly improved in supplemented groups compared to the control. Glucose, BUN, and βHBA improved in supplemented animals more than in the control group, indicating bioactivity that contributed to the improvement of gut health. Supplementation with YCW improved the growth performance, physiological responses, and gut health of early-weaned male buffalo calves.
