Group housing may be the most cost-effective option for tailoring calf nutrition to stage of growth.
Why it matters: The veal and dairy industries continue to weigh the pros and cons of individual versus group calf housing, and studies could tip the scales toward group housing.
Attendees at the virtual edition of the Healthy Calf Conference, held Nov. 24 by the Veal Farmers of Ontario, learned from three featured speakers about tailored calf feeding.
All of them highlighted that the predominant regime used on dairy and veal farms — frequent colostrum for the first day, followed by two times per day feeding of between three to five litres of milk or milk replacer, often by bucket, through to weaning — is not the natural way for bovine mammals to feed their young.
“Calves should not scour,” said Dr. Mike Nagorske, director of research at the Saskatoon Colostrum Company Limited (SCCL).
He suggested scours are rare on well-managed cow-calf beef operations, where calves suckle from their dam whenever she allows it. Yet, on many dairy or veal operations, scouring is perceived as commonplace and a part of doing business.
“There’s something very non-obvious when it comes to scours,” he said, arguing that blaming it on genetics is like saying a tree with termite-infested roots fell over from the wind. The non-obvious solution, he said, is transition milk.
“Colostrum management isn’t just about the first 24 hours; it’s the first two weeks.”
A role for colostrum replacer?
Nagorske’s presentation outlined recent studies into combining colostrum or colostrum replacer with the calf’s regular diet to “mimic” the milk a calf would naturally receive for several days after birth.
University of Kentucky-based Dr. Joao Costa, meanwhile, as part of a longer presentation about the benefits of group housing, tackled gradual weaning and the effects of restricting milk access.
Costa says typical studies of dairy calves nursed by their dams show them consuming 10 litres per day. One study in which he participated during his PhD studies at University of British Columbia had one calf consuming 16 litres when given unrestricted access to a milk feeder.
It is common practice to limit calves to six litres as a way to encourage dry matter intake before weaning.Although Costa is a proponent of gradual weaning of at least two weeks, he says limiting milk for longer periods has been shown to have no benefit.
Although the milk-limited calves may consume more dry matter during the early pre-weaned period than the other calves, by the time they’re fully weaned on a gradual regime, the non-limited calves in one study were eating the same amount.
Paired housing means more feed consumption
His recent research involves moving calves from individual housing immediately post-birth, to paired and eventually grouped housing.
In one study, dry matter intake was higher at six weeks of age for calves put into pairs at two weeks old versus those housed individually or paired at four weeks of age.
At 10 weeks of age, the early-paired calves again outpaced the rest, but the late-paired had also increased their DMI compared to the individuals.
The increase, he suggested, is due to the increased adaptability and readiness to compete among socially raised calves compared to those housed individually.
Cornell University’s Mike Van Amburgh outlined a gradual weaning protocol his researchers have been working on to maximize gut health at weaning.
“Creating an environment that allows calves to teach each other about starter grain is a good goal,” said Van Amburgh.
Nagorske, as part of his role with SCCL, watches for all new colostrum research. He says the benefits go “way, way beyond antibodies.”
The fat in colostrum has been shown to bind to some strains of coronavirus. The oligosaccharides are important for promoting strong gut microflora. There is 10 times the amount of vitamin A in colostrum compared with regular milk, and “it’s chock full of a lot of nutrients” and more than 100 different proteins — half of which are found exclusively in colostrum as opposed to regular milk.
Bovine colostrum seems particularly beneficial. There are studies showing benefits in mice with influenza, and in piglets with gut disfunction. And in humans, forms of bovine colostrum have been shown to mitigate diarrhea and respiratory infections.
Nutrient usage critical early in life
Van Amburgh’s work tracks the calves’ use of the nutrients they consume. In the first three weeks, much of that goes toward development of the rumen, which is high in protein but very low in fat. The animal’s need for fat only begins to outstrip the need for protein after several weeks of age.
“One of the things this tells us is that starter (feeds) might have to evolve a little bit if we’re going to achieve those nutritional goals” at different stages of development.
And, for Costa, this brings it all back to group housing. With increasing evidence that diets should be tailored for calves depending on age, or if they’re stressed by environment or disease, or even if they’ve started on their own to consume more calf starter in what he called a “self-weaning” model, the challenge becomes how to accomplish that.
“Group housing is giving us that possibility” due to the option of automated feeding. It may mean that “we’re managing data as opposed to managing animals,” but the long-term benefits may be worth it in the end.