Careful management of colostrum intakes is helping a Welsh dairy farm overcome health problems associated with young calves.
Newborn calves from the 420-cow high yielding Holstein herd at Marian Mawr, near Rhyl, are encouraged to suckle the first colostrum feed from their mother.
If that fails, the cow is milked at the next milking or on a mobile milker and the calf is given four litres of her colostrum.
Calves, which are reared initially in individual pens, continue to have their mothers’ milk for three days before milk replacer is introduced at a rate of two litres twice a day.
“Once we are happy that the calf is established on a teat we move in into a group pen with an automatic feeder, usually at five to seven days,’’ explains Aled Morris, who farms with his wife, Jo, and mother, Morfydd.
Calves are weaned at eight weeks and moved to an offlying farm where their diet consists of ad lib barley straw and 4-5kg of 21% protein rearing nuts.
More than 100 heifers are reared annually as replacements and to facilitate expansion – the aim is to have 500 cows in the herd by the spring of 2021.
Mr Morris regards heifer calves as the most valuable animals on the farm. “If a calf has had a good start then it has a better chance of achieving targeted growth which is important on our system for calving at 24 months. Spending a bit of time and money getting it right from birth really does pay off.’’
Calves that receive insufficient colostrum within the first few hours of birth risk infections and pneumonia, yet up to 50% of calves receive it too late or at inadequate levels, according to vet Gwyn Jones.
He says dairy farmers are risking the long-term health and productivity of their heifer replacements by incorrectly managing and feeding colostrum.
Scour, pneumonia, navel infections and meningitis are four of the biggest killers of calves under 12 weeks of age.
In Wales, one-in-eight calves dies between birth and 12 weeks of age, but the best performing dairy farmers lose just one in 25 calves.
Good quality colostrum is key to preventing deaths, says Mr Jones.
“Immunoglobulin in colostrum is the most important factor in determining the morbidity and mortality of young calves.’’
Mr Jones, of Wern Vets, Ruthin, says calves that do not take in sufficient quantities of the antibodies present in colostrum are four times more likely to die than those with an optimum antibody status.
Colostrum is at its prime when a cow is freshly calved.
“The level of antibodies in the first feed is 6% but that falls to 4.2% in the second and 2.4% in the third, so the first feed is far superior to anything else. Always feed the newborn calf colostrum collected at the first milking.
“Even if you don’t milk a cow her colostrum antibody levels drop if left in the udder because the cow needs those antibodies, her body is programmed to absorb them. Levels are halved within 12 hours if she isn’t milked or if her calf doesn’t suck.’’
The protective value of these antibodies is not just beneficial for the first few weeks of life but for at least eight weeks.
Mr Jones advises feeding three litres of colostrum within six hours of birth, or two litres followed by another two litres six hours later. After six hours, absorption efficiency is 30% lower than at birth so timing is critical.
Storing colostrum at too high a temperature will cause scours. If stored at room temperature, the number of bugs it contains will double within just 20 minutes, Mr Jones explains. He advises storing colostrum in the fridge if it is to be used within 24 hours.
If antibody levels are insufficient, calves can succumb to viruses and bacteria, notably E.coli, rotavirus, coronavirus and cryptosporidium.
“If scours occur within five days of birth it is likely to be E.coli, one to three weeks, rotavirus and three to five weeks, coronavirus,’’ Mr Jones says.
Salmonella is a less common but serious cause of scour – a tell-tale sign is the presence of blood in scour, mostly in older calves. Cryptosporidium is probably the most prevalent cause of calf scour and can occur at any time but particularly from 10 days onwards.
Good hygiene is key to prevention. Scouring calves should be separated from healthy animals, Mr Jones says.
“Once a calf is scouring it becomes a virus factory, shedding millions of germ cells.’’
“There is also a risk of humans spreading infection so good hygiene protocols between treating an infected calf and handling healthy animals are essential.’’
He recommends assigning a stomach tube specifically for feeding sick calves instead of using one tube for all animals.