The effects of supplementing prickly pear (<i>Opuntia ficus-indica</i>) powder on dairy calves’ health and growth performance

This study aimed to evaluate the effects of dietary prickly pear (Opuntia ficus-indica) powderand Lactobacillus supplements on calf growth and faecal pathogen counts. Prickly pear leaves were harvested, sun-dried for 14 days, and oven-dried at 105 °C, before grinding into a powder. Twenty-four female Holstein dairy calves (39.03 ± 0.75 kg live weight) were randomly assigned to each of the four treatment groups. The four treatments were: T1: the control group, calves fed a basal diet (milk plus calf meal), without supplementation; T2: calves fed the basal diet plus Lactobacillus at 5 g/day; T3: calves fed the basal diet plus prickly pear powder at 2.5 g/day; and T4: calves fed the basal diet plus prickly pear powder at 5 g/day. These treatments were applied from four days of age until weaning. Calf starter feed and clean water were provided ad libitum for the entire study period. The dietary treatments affected the feed dry matter intake, feed conversion ratio, average daily gain, weaning weight, faecal total coliform count, faecal Escherichia coli count, and faecal Enterobacteriaceae count, compared to the control group. It was concluded that the dietary supplementation of Lactobacillus or prickly pear powder improves feed efficiency and body weight gain, as well as reducing faecal pathogen counts in Holstein dairy calves.