Canadian dairy farmers will soon see a new, first in the world, change to the way cow feet and legs are classified.
The feet and legs category, which has been in used since 1927, will become foot and mobility.
Stakeholders in the dairy breeding sector were advised of the pending change in April and the implementation has been targeted for fall, 2021. The original decision stemmed from two days of discussions in December, 2019 by Holstein Canada’s Classification Advisory Committee – made up of producers, a veterinarian, and a dairy genetics company representative, along with Holstein Canada directors.
Why it matters: Feet and legs has been the single most difficult conformation trait to improve in the Holstein breed, despite rapid improvement in other areas.
Cows being classified will continue to be given a rating between one and nine for the two foot and mobility areas. The foot rating will be based on two minor traits, heel depth and foot angle and there are six minor traits for mobility, including locomotion, front leg view, bone quality, rear leg side view, rear leg rear view and thurl placement.
Locomotion and front leg view are new minor traits to be added to the classification regime. According to Holstein Canada’s Manager of Classification and Field Services, Brad Eggink, “The only (other) direct change to the classifiers is the output, as there will be five major scorecard sections as opposed to four.”
An article in the July/August edition of the organization’s Info Holstein magazine explained the reasoning for the change: “Though we have seen drastic gains in genetic merit and improved management systems, the breed is seeing an increase in cows that are straight legged, and when combined with front legs that knock inward or bow out, this causes major mobility issues.”
“Although connected, the foot has different functions for the cow than the leg,” said Eggink, when contacted by Farmtario.
He cited a bull that may score a plus 5 for feet and legs on its proof sheet, but repeatedly sires daughters with straight legs.
“Similar can be said for sires that may show a proof for a great leg, but sire daughters with low heel depth, a trait strongly correlated to digital dermatitis.
“Separating feet and legs allows for more benefits from a producer section model when they are looking for traits to improve,” Eggink noted.
According to the Info Holstein article, all Canadian dairy breed organizations have agreed to the switch.