Bull buyers will pay for feed efficiency, according to John Paterson, Montana State University (MSU) Extension beef specialist. And, when packaged with other economically important traits, commercial cow-calf producers are willing to invest in bulls that will help them move their ranch forward.

Feed efficiency is important, Paterson says, because 70% of cash outlay goes for feed. He related a study that looked at several hundred calves from birth to slaughter. The calves that were the most efficient, expressed as a feed:gain ratio, made the most money. “The fastest-gaining ones were second, the leanest were third, the fattest cattle were fourth and the ones with the biggest appetite lost us the most money,” he says.

Given the reality of high feed prices, Paterson says the search is on for cattle that have low feed intake but good productivity. And, cowmen who buy bulls at the Midland Bull Test sale in Columbus, MT, have added feed efficiency into the factors they consider when buying bulls.

Paterson looked at sale data for the past several years and found the No. 1 trait that bull buyers honed in on in the 2008 and 2009 sales was birth to yearling gain EPD. Birthweight EPD was second, age of bull ranked third, residual feed intake (RFI) ranked fourth, and ribeye area was fifth. So, while RFI was important, there was a definite ranking of preference in the traits that bull buyers emphasized.

“Then we got the 2010 data and something different happened,” Paterson says. In 2010, all the traits ranked No. 1, meaning that instead of ranking bulls by trait, bull buyers began to look for balanced bulls with good birthweight and gain EPDs as well as negative RFI numbers.

But adding RFI to the mix is important, Paterson says. Using statistical models, MSU researchers determined that each unit change in RFI for bulls sold in 2008 was worth $80. In 2009, it moved to $140. By 2010, bull buyers had jumped to paying $400 for each unit change in RFI. That means, Paterson says, a bull progressing from 0 RFI to a -1 was worth an additional $400. Comparing a bull that was 0 for RFI with a bull that was a -4 netted an additional $1,600.

But how do progeny from low-RFI bulls perform? Using a GrowSafe™ system, MSU researchers looked at 120 Angus-Simmental crossbred heifer calves, which had an average intake of 26.5 lbs./day during the last trimester of pregnancy.

But it’s important to note that averages can be misleading. The low-RFI heifers ate 10 lbs. less/day than the highest-RFI heifers, but there was no effect on gain. Bodyweight at calving was statistically the same and there was no effect on calf birthweight or on weaning weight. During the next breeding season, there was no statistical difference between the low RFI heifers and the high RFI heifers in pregnancy rates. “The only difference we could see was a difference in intake,” Paterson says.

Which means that selecting for RFI has advantages. Paterson says if you can reduce forage intake in your cowherd by just 2 lbs./day, you can save 730 lbs. of feed/cow/year. “If we’ve got a 250-cow outfit, that’s 90 tons less forage a year,” he says.

Looking at another way, it means a rancher could run an additional 16 cows on the same forage base.