Scientists in Japan have developed and tested a novel probiotic formulation to control severe diarrhoea in calves, ensuring their health and reducing mortality, and in turn reducing economic loss.
Diarrhoea in calves (bovine diarrhoea) is caused by a variety of pathogens, including bacteria, viruses and protists. Antibiotics are an extremely effective means of treating bacterial diarrhoea, but they are ineffective when the cause is a virus, a protist or an antibiotic-resistant bacteria.
Thus there is a need for a novel treatment to prevent bovine diarrhoea.
Fermented milks (FMs) have been used as probiotics in animal husbandry as far back as the 1970s; however, the efficacy of these FMs has been inconsistent due to the wide variations in the manufacturing process. Furthermore, there have been cases where FMs themselves have been the source of diarrhoea-causing pathogens.
So the scientists proposed that fermented milk replacers (FMRs) could be an ideal candidate for high-quality and safe probiotics in calves.
In their study, they tested the efficacy of a novel FMR and a lactic acid-based milk replacer (LAB-MR) on newborn calves, compared to commercially milk replacers. In clinical studies, the calves were fed with the milk replacers throughout the experiment. The calves were then exposed to bovine rotavirus (BRV) on the fifth day; the efficacy of each treatment was evaluated 10 days after infection with BRV.
The milk replacers were also subjected to field trials, on farms with a history of high prevalence of BRV and bovine cryptosporidiosis over the previous three years.
Their results showed that bovine diarrhoea due to BRV was much less severe in calves fed with FMR or with LAB-MR. Further, tissue damage to the intestine was reduced, and milk intake during diarrhoea was increased compared to calves on the commercial milk replacer.
In the field trials, FMR feeding reduced the incidence of diarrhoea in a dairy farm with a high incidence of enteritis as a result of mixed infection with BRV and bovine cryptosporidiosis.
Interestingly, the lactobacillus strains in the LAB-MR did not ferment the milk replacer, indicating this strain can protect against diarrhoea in calves without fermentation—suggesting there may be another mechanism by which LAB-MR protects against diarrhoea.