Genomic analysis could allow B.C. dairies to predict which calves will become elite milkers, with the promise of huge savings for farmers who don’t have to raise inferior cows that will ultimately be made into hamburgers and bologna.
Using cells recovered from hair samples taken from young heifers, veterinarian Martin Darrow and University of B.C. animal reproduction biologist Ronaldo Cerri can examine 12,000 genetic markers in each animal’s DNA to determine which are most likely to be elite milk producers.
Dairy farmers have to raise young cows for a little over two years at a cost of about $2,500 each before they can determine which animals can produce milk with superior volume, fat content and protein. This test identifies promising animals at two months.
Poor milk producers are usually sold into the beef industry at a loss, because culled dairy cows fetch a much lower price than quality beef cattle, explained Darrow, director of embryo transfer services and genomic research for Greenbelt Veterinary Services in Chilliwack.
The results of a genomic test can identify poor producers as early as two months of age, so the animal can be removed from the herd or impregnated with an embryo from a cow with better genetic potential, said Darrow.
“In effect, the dairy removes the worst genetics from the heifer herd while promoting the most advanced genetics to produce the next generation,” he said.
Simple genomic tests cost as little as $45 and have been widely used for several years by farmers to identify genetically superior bulls for breeding.
Dairy farmers make educated guesses about which cows to raise based on the milk production of the calf’s mother and the pedigree of the sire, when that information is available. A genome-based test can be twice as reliable at predicting future production.
“Seven in ten times it will be right,” said Darrow.
This $70,000 project — funded by Genome B.C., Investment Agriculture Foundation of B.C., WestGen Endowment Fund, Zoetis, Greenbelt and participating farms — aims to create an affordable, commercially available genomic test for dairy farmers.
The researchers are collecting samples from about 2,000 animals on 14 farms in the Fraser Valley and nine in the Okanagan.
Dairy farmers are licensed to produce a certain volume of milk under a quota allotment system.
“My approach is, why milk 100 cows to fill that quota when you can milk 80, keep only the best cows and don’t raise the worst ones,” Darrow said. “What we are trying to do is take the science out of the laboratory and show the farmers how to apply it.”
Darrow is confident that farmers who are reticent to add another expense in the form of a genomic analysis on every calf born will quickly be won over by the savings that can be earned through earlier selection of more productive cows and the production of better milk with higher fat and protein content.
Source: The Vancouver Sun