Do RFI ratings predict cattle performance on pasture?

Canadian Cattlemen, May 28, 2018 by Debbie Furber.

Producers often wonder if genetic markers for feed efficiency based on drylot tests reflect feed efficiency on pasture where terrain, water sources and plant diversity are very different from a pen setting.

Genetic markers for residual feed intake (RFI) have been identified that correlate well with actual RFI determined during the standard trials in pens with GrowSafe bunks to measure individual animal feed intake on silage-grain rations. Animals that eat less than expected for their weight, production and maintenance needs will have RFI scores below zero, indicating that they are more feed efficient than animals that eat more than expected and have RFI scores above zero.

The problem is that there isn’t a practical way to test for feed efficiency in a pasture setting where each animal picks and chooses what it eats and amounts can’t be precisely measured. To further complicate matters, energy expended while grazing can be quite variable among animals.

University of Alberta masters candidates with doctors Edward Bork and Graham Plastow took on the challenge of trying to determine whether and how genetic markers for RFI predict cattle performance on pasture. Read more about the Residual Feed Intake on pasture project.