Want A More Profitable Dairy? Take Care Of Your Calves!

Three key factors can reduce calf mortalities and boost milk yield: correct hygienic practice in calf cages, control of Cryptosporidium parvum, and implementing a colostrum programme. Specialist veterinarian Dr Chris van Dijk and feed specialist Kenneth Botha explain these. 

- Gerhard Uys

Many dairy producers struggle with calf mortality and slow growth. Dr Chris van Dijk, veterinarian and CEO of the Milk Producers’ Organisation, (MPO) and Kenneth Botha, feed specialist and technical director at Barnlab Feed, stress that good calf cage hygiene and a colostrum programme are essential for addressing this problem and raising a healthy herd.

CRYPTOSPORIDIUM PARVUM

Speaking at an MPO training day in Lichtenburg, North West, Van Dijk explained that incorrect hygiene and management practices were the main cause of Cryptosporidium parvum infection.

The tiny, two- to six-micron coccidian protozoa organism infects mainly the small intestine and leads to diarrhoea. It damages the gut villi, leading to poor absorption of nutrients.

“This is often lethal in newborn calves, or puts their growth at risk, which in turn affects their eventual production.”

C. parvum is particularly difficult to control as it forms oocysts with a protective outer layer. It is resistant to disinfection, but it can be destroyed by ozone, chlorine dioxide or desiccation.

“In a milking parlour, there are always liquids, and calves with a C. parvum infection are also susceptible to Escherichia coli, salmonella, and the coronavirus or rotavirus. Some farmers have lost many calves to it.”

Cryptosporidium is prevalent throughout South Africa; a sign is chronic diarrhoea, especially in young calves. Although mortality may not always be high, morbidity is, and other infections abound as the calves’ immunity levels are low.

TRANSMISSION

C. parvum in the gut is passed on via dung, water, milk and food. It then infects new hosts via the faecal-oral route, and can infect humans.