Archives

Latest indicator of feed efficiency could spur new generation of efficient cattle

A revolutionary, new way to measure feed efficiency in cattle could save Alberta beef producers millions in feed costs annually and keep the Canadian cattle industry at the forefront of beef genetics.

Net feed intake, the difference between an animal's actual feed intake and its expected feed requirements for maintenance and growth, is the next big thing in the endless drive to select the best genetics for beef production, says Dr. John Basarab, a research scientist and beef management specialist with Alberta Agriculture, Food and Rural Development. The concept of net feed intake was expanded in the 1990s by Australian beef researchers, and now a research project led by Basarab and funded by the Canada Alberta Beef Industry Development Fund (CABIDF) backs the Australian findings.

"We now feel that we have an excellent method to measure the feed efficiency of cattle, and that feed costs can be significantly reduced by selecting low net feed intake cattle over high net feed intake cattle," says Basarab. "Low net feed intake cattle also produce less manure and methane than high net feed intake cattle, producing a positive environmental spin-off."

Here's an example of how net feed intake works: A British-cross steer with a 453.6 kg bodyweight gaining 1.76 kg per day on a finishing diet has an expected feed intake of 14.5 kg per day, according to the National Research Council's Nutrient Requirements for Beef Cattle. However, if the actual feed intake for the steer were 10.2 kg per day, 4.3 kg less than expected, the net feed intake would be - 4.3 kg per day.

"Like a golf score, a negative value is better and indicates an efficient animal," he says. "In the past, it was thought if cattle were selected for improved average daily gain, feed efficiency would follow. But what seems to have happened is that we selected for a faster-growing, larger animal with increased appetite, but no better in terms of feed efficiency."

In a two-year serial slaughter study conducted by Basarab's team, 148 steers from five genetic strains were monitored for individual animal feed intake over a finishing period ranging from 71 to 183 days.

The variation in feed intake among different animals can be large and costly. Steers grew at 1.52 kg/day and had an actual feed intake of 12.3 kg/day while consuming a finishing diet. Even in a small pen of 75 head, individuals varied in net feed intake from efficient (-1.95 kg/day) to inefficient (+1.82 kg/day). This means that the efficient animal consumed 3.77 kg per day less than the inefficient animal for the same level of weight gain.

The study found that this variation in net feed intake represented a difference of more than $45 in feed costs (with feed costs pegged at $0.101/kg. as fed) during a 120-day test period, which represents about $109 million a year in feed savings for feedlot operators alone. "The benefit to cow-calf producers and seedstock operators is estimated to be at least as high," says Basarab.

The Alberta study revealed for the first time that animals with different net feed intakes were similar in carcass characteristics, empty body weight, relative proportions of most organs and tissues in empty body weight, he says. "This is important because people were worried low net feed intake cattle might have less fat and marbling, reducing meat quality," he says. "But that is not the case."

The major difference Basarab found among net feed intake groups was in heat production, with low net feed intake steers having an 11.2 percent lower heat production value than medium net feed intake steers and 17 percent lower than high net feed intake steers. "This confirms previous studies indicating that high net feed intake cattle have higher maintenance energy costs than low net feed intake cattle," he says.

Currently, Basarab is working with private and public partners to hone a testing system that singles out feed-efficient breeding bulls, in order to begin passing the valuable trait to Alberta's future cattle herd. "The Australians are ahead on getting low net feed intake genetics into their herd, so this also a matter of staying competitive," he says.

CABIDF is a joint $16.4 million fund of Alberta Agriculture, Food and Rural Development and Agriculture and Agri-Food Canada and has supported more than 50 projects in five categories. The fund is administered by the Alberta Beef Producers.

© 2003 Meristem Information Resources Ltd.
Meristem® is a registered trademark of Meristem Information Resources Ltd. All rights reserved.
Legal Disclaimer