Coccidiosis is an intestinal disease caused by unicellular parasites that usually occurs in young dairy or beef calves between 3 weeks and 6 months of age. Although it is rarely fatal, it can cause extensive gut damage and ill-thrift and is commonly seen under intensive management conditions with high stocking rates.

Autumn-born calves are at greater risk, with Cocci requiring warmth and moisture. A wet September and October increases infection risk as the environment becomes more favourable for the occysts to spread from calf to calf.

Veterinary specialists Murray Direct said calves become infected by consuming coccidiosis eggs from pasture, feed, waste and bedding, or by licking contaminated calves. The parasite can exist for months in their surroundings and failure to control the disease can influence future productivity levels, including growth rates, as well as delaying the onset of puberty, leading to milk loss production in dairy calves.

Third-generation dairy farmer, Darren Coombes, who farms with his son Tim on 890 acres near Bridgwater, Somerset in the UK, believes feeding a coccidiostat to his dairy calves can help control the disease. He recently had an outbreak affecting a fifth of his calves. 

Coombes milks 425 cows – year-round calving Holsteins – supplying Muller and Sainsbury’s. Animals are milked twice daily, producing 10,500 litres at 4.3% fat and 3.25% protein.

“We didn’t lose any calves, but we lost a lot of growth and it took the calves a long time to recover,” he said.

His vet recommended the calves be fed the coccidiostat Deccox and, alongside improved cleanliness, it has helped get on top of the outbreaks.

Coombes said newborn calves receive colostrum for the first 3 days. Calves are kept in pens for the first week and at day 4 they transition onto a milk replacer with 3 litres fed in a bottle twice a day. From birth, calves are given clean water and free access to fresh straw and Mole Valley Farmers’ NSP NPP Calf Rearer 18+ Deccox, which is an 18% protein rearer nut with an added coccidiostat to help treat and manage coccidiosis.

“It is a very consistent, palatable product and calves love it. After 7 days, calves move onto one of the 2 Forster-Technik automatic milk feeders where they are kept in groups of 30. Calves get fed 4 feeds a day and can have a maximum of 8 litres in 24 hours. At day 49, the milk is gradually reduced and calves are weaned at day 56.”

Calves stay in the same group until they are 6 months old. After 5 months they are introduced to 1kg of homegrown rolled barley and ad-lib grass silage with the rearer nut cut back to 1kg. Deccox is removed at 9-10 months. Coombes notes: “It has completed kept coccidiosis at bay. We tried different things and we could never really get to the bottom of it until we introduced the Deccox.”

But hygiene is key, too. Calf sheds are disinfected and steam-cleaned between batches and straw bedding is also replenished liberally to keep calves dry.

Andy Adler of Molecare Farm Vets said preventing faecal contamination of water and feed troughs is crucial in controlling coccidiosis. “Raising feed and water troughs alongside regular cleaning is very important to prevent faecal-to-oral transmission. Straw bedding should be replenished often so calves are only eating fresh, clean straw.”

Scientists have collaborated to produce the first gene-edited calf with resistance to bovine viral diarrhoea virus (BVDV). The study, published recently in PNAS Nexus, is the result of a collaboration between several universities and industry players. BVDV is one of the most important viruses affecting the health and well-being of cattle worldwide and has been studied by researchers since the 1940s when it was first identified. The virus does not affect humans, but is highly contagious among cattle and can cause severe respiratory and intestinal disease. BVDV can be devastating to pregnant cows, as it can infect developing calves, causing spontaneous abortions and low birth rates. Some infected calves survive to birth and remain infected for life, shedding massive amounts of virus to other cattle. Over the past 20 years, the scientific community has discovered the key cellular receptor (CD46) and the site where the virus binds to this receptor and causes infection in cows. In this latest study, scientists have modified the virus binding site to block infection. Aspen Workman, lead author and researcher at ARS’ US Meat Animal Research Center (USMARC) in Clay Center, Nebraska, said, “Our goal was to use gene-editing technology to slightly modify CD46 so that it doesn’t bind the virus but still retains all its normal functions in cattle. The scientists first tested this idea in cell culture. After seeing promising results in the lab, Acceligen edited cattle skin cells to develop embryos carrying the modified gene. These embryos were transplanted into surrogate cows to test whether this approach could also reduce viral infection in live animals. It worked, and the first CD46 gene-edited calf, named Ginger, was born healthy on 19 July 2021. The calf was followed for several months and then challenged with the virus to see if it could become infected. She was housed for a week with a BVDV-infected dairy calf that was born shedding virus. Ginger’s cells showed significantly reduced susceptibility to BVDV, resulting in no observed adverse health effects. Scientists will continue to monitor Ginger’s health and ability to produce and rear her own calves. This promising trait is still in the research phase and no associated cattle are currently entering the US food supply.

A Holstein cow at the ripe old age of 14 has set a new lifetime production record in the USA. Owned and bred by the Dankert family at Nor-Bert Farm in Bremen, Indiana, the cow named Nor-Bert Colby Connie has pumped a record 486,300 pounds (over 22 tonnes) of milk. And she is still producing, as Connie has just calved again and is increasing her production every day. Connie has equally impressive results for her milk quality components with a lifetime record of 12,275kg of fat and 8,045kg of protein in her last completed lactation. These massive fat and protein totals are currently the highest lifetime fat and protein totals in the Holstein Association USA database. This new production record comes in quick succession to that set by another US cow, Chrome-View Charles 3044, who set the record earlier this year with a total of 217 tonnes of lifetime milk. These lifetime production records have highlighted the scope of what Holstein cows can achieve.