Thursday, October 14, 2021

Calf immunity studies resume

 A University of Alberta dairy researcher is picking up where scientists left off 40 years ago, trying to solve an ongoing problem with calf health.

Up to 30 per cent of dairy calves worldwide don’t get enough vital antibodies before birth to ward off the risk of diarrhea caused by E. coli and other bacteria. The condition can be deadly to the young animals, said Becs Hiltz, a PhD candidate in animal science in the Faculty of Agricultural, Life & Environmental Sciences.

Though calves do get antibodies through colostrum — their mother’s milk — they don’t develop immunity right away.

“Calves are born with a functional immune system, but it is slow and can take two to three weeks to respond to any sort of disease they may encounter.”

In addition, they can only absorb the antibodies within the first 12 to 24 hours of life — something Hiltz wants to change through a better understanding of how the antibodies are absorbed.

The last research exploring that specific function was done in the 1980s.

“I want to start up where those studies left off”

She is tagging antibodies in colostrum to track when it’s picked up by the calves, concentrating on the middle intestine area. Biotin is one of the trackers and gold is the other.

Through a 2019 study she did as a master’s student, Hiltz was able to determine that butyrate, a fatty acid that increased antibody uptake in piglets, had the opposite effect in calves by actually decreasing their already brief window of absorption.

She aims to find out how to improve antibody absorption and maybe widen the window of time calves have to absorb antibodies.

“That gives the farmer more time to get colostrum into their calves, especially those born overnight or between work shift changes. If we could get the absorption window to two days instead of 12 to 24 hours, that would be incredible,” she said.

“How a calf is fed in its first hours of life will affect its milk production two years down the road; if calves get enough antibodies, they’ll produce more milk in their first two lactations,” she said.

“So the first four hours of life is essential to get colostrum into calves, and any extra time we can give farmers is going to be huge.”

Hiltz’s work is supported by the Natural Sciences and Engineering Research Council of Canada, Zinpro and the Alberta Milk Endowment Fund.