Good performance starts in the calf-rearing pen

The future performance and profitability of a dairy herd is often determined in the calf pen and yet eight out of 10 producers never review calf-rearing practices, delegates were told.

As a group, dairy farmers focus so much on the dairy cow and not the dairy calf, commented Maggie Gould, Volac’s technical manager, that priorities were often skewed. “Too often, on-farm, a new tractor occupied a clean shed while calves were tucked away in dingy buildings,” she added.

“We need to achieve good rearing performance,” she said. That meant a focus on survival, looking at early delivery of clean colostrum, a structured approach to tackling disease from day one, understanding nutrition and managing the calf’s environment.

All too often producers’ ability to rear replacements was poorer than they believed, warned Alistair Carson, project leader in sustainable livestock systems at the Agri-Food and Biosciences Institute, Hillsborough, Northern Ireland.

“A sample of 300 farms believed they calved heifers at 28 months old, but records showed it was actually 32 months – a huge difference between what they were doing and what they thought they were doing.”

The financial consequences were also stark, added Dr Carson. “Despite producers’ belief that average cost for rearing a heifer replacement was typically £700-800 apiece, actual farm costings showed it topped £1309,” he added.

Colostrum

From the start of a calf’s life, management was critical, starting with adequate colostrum in the first few hours of life, said Dr Carson. “Of calves bought in for post-mortem, 60% had insufficient colostrum antibodies in the body and that’s a major concern,” he said.

Inadequate colostrum meant insufficient protection from disease. An 2008 AFBI survey of dairy farms rearing calves highlighted that 32% suffered with pneumonia and 38% with scours. This highlighted a need to improve calf care, in particular, nutrition and management of the calf environment, he warned.

And that message was reinforced by vet Keith Cutler, who said that after creating a good, dry, airy environment colostrum was the key, as it provided fluid, nutrition, immunity to disease and was often available free from the dam. Although debate continued as to how much and when it was needed, a general rule of thumb was a lot as early as possible, he said.

The principal benefit of adequate colostrum and the antibodies it provided was a reduced risk of scouring – a serious issue on farms countrywide – from infectious agents such as E coli, Rotavirus, Coronavirus, Cryptosporidia, Salmonella and Coccidia. These infectious agents also emphasised the need for adequate hygiene in the calf rearing area, delegates learnt.

Vaccination was an option to the aforementioned infections, but had to be considered carefully, said Mr Cutler. “No single or combination of vaccines could protect calves fully,” he warned.

He also suggested in addition to good colostrum management, the aim for a modern, progressive calf-rearing unit should be all-in all-out, disinfected penning between batches of calves, a clean and dry environment, good ventilation, plenty of bedding and the availability of fresh food and water.

In a league table of calf-rearers Wheelton Farms, Cheshire, was at one time by its own admission bottom, but changes in calf management had made significant gains, delegates heard.

Martin Wheelton’s 500-cow spring-calving herd suffered calf deaths to typical causes, including scour, BVD and pneumonia.

The change came with a fresh calf management plan. Newborn heifers are taken off dams immediately (bull calves are usually dispatched as Holstein Jersey crosses and, therefore, of low value).

Use of bottle drenchers to get colostrum into calves quickly is used widely despite awareness of the impact on calves, however, results can be tremendous, he said.

The calf environment must be dry by choice and well ventilated. Milk replacer is offered once daily and thereafter clean water and hay, with calf pellets offered later.

Calves are weaned abruptly by weight not age. These go out onto clean pasture, such as silage aftermaths, and have 0.5kg concentrate fed daily.

Removing calves from dams at birth, using “clean” non-pooled colostrum to reduce risks of disease and monitoring herd health status could significantly reduce the impact of Johne’s disease, warned vets.

Johne’s was the hidden disease within UK herds, said Peter Orpin of the Park Vet Group, Leicester. “It can be picked up at birth and has a long incubation period often not seen until the animal is fully mature. Surveys suggest the disease can typically cost 1.5p/litre year-on-year.”

Johne’s can be transmitted in a number of ways. Bacteria can survive in slurry for up to a year so ensuring calving areas are clean is imperative. Risks are similar in housed and grazing areas as both harbour bacteria shed by older animals with a latent infection – ones not showing clinical signs of weight loss, dirty tails and hocks and condition loss in the rear quarter.

“It is worthwhile testing a portion of the herd for Johne’s,” said Mr Orpin. Blood samples were more effective than bulk milk samples.

“When you simply cull infected animals it will amount to a lot of cattle over a short period,” he said. Instead it would be better to take a structured approach starting by removing calves from their dams at birth as calves are susceptible to the disease bacteria from day one.

“Try not to pool colostrum unless you know it’s from cows with low levels of Johne’s as this can spread infection. The same goes for waste milk. In The Netherlands calves are grouped according to risk of having Johne’s and managed in groups accordingly.”

Vaccination was available but had its problems. The only long-term way to tackle Johne’s was through an ongoing structured approach, he warned.

“We don’t know the full extent of Johne’s. Often infected animals see milk yield fall by up to 24% along with fertility and many farms cull these animals simply as barren cows.”

Sometimes the only way to tackle Johne’s is to sell the herd, he remarked. Although unethical in practice it was a real threat faced by many flying herds looking to buy in replacements nationwide. Statistics suggest Johne’s is widespread, but figures are masked with only 5-10% of infected animals showing signs of the disease.

Conference chairman Tim Brigstocke told delegates use of herd health declarations, as used in Scotland, should be encouraged to make buying-in stock safer south of the border.

“Doing nothing is not an option,” concluded Mr Orpin.