Cattle producers rate feed as their biggest expenditure. The simplest way to reduce this cost is to genetically select animals who consume less while maintaining growth, production, and body composition.
The significance of cow efficiency
Feed efficiency is a foundation component of profitable, sustainable livestock production. Prioritizing this trait in genetic selection and management of commercial beef herds is more important than ever.
“For sustainability, feed efficiency is number one in my book,” says Matt Brown, MJB Ranch owner.
Brown’s ranch, located in Lodge Grass, Montana, runs about 800 registered cows and 3,000 acres of cropland. “Our margins are becoming tighter, and we need to do more with less,” he says. “If we can lower our input costs, it’s the best way to impact the bottom line and protect sustainability.”
Residual feed intake (RFI) is the preferred method for measuring feed efficiency because it is independent of body weight and helps mitigate the risk of selecting for larger mature body weight, an important consideration in managing a cow herd. Calculation of RFI is typically performed in growing cattle in confinement with delivered feed. A key consideration for commercial ranchers is how well RFI measured in these conditions translates to efficiency on pasture and rangeland.
Research and trials
Measuring feed efficiency in extensively managed cows is certainly a challenge, and there is much less published research available where cow efficiency is directly measured. The difficulty is certainly due in part to the complexity of measuring how much forage is consumed. But one must also consider that the adult cow is quite dynamic – cycling through gestation, lactation, variation in body condition, and considerable variability in forage quality.
A number of published trials help provide strong evidence of the association between RFI and relevant outcomes under grazing conditions.
- Herd et al (Anim Prod in Australia, 1998) used controlled release inert markers to quantify feed intake in 44 three-year-old females grazing oat pasture during their second trimester or gestation. These cows had been previously tested for RFI as growing heifers. The study showed that while there were no observed differences in feed intake, the cows that had more favorable RFI as growing heifers maintained a higher body weight (P < 0.05) at the same degree of condition (as determined by rib and rump fat thickness) and tended to wean heavier calves (P = 0.07).
- Sprinkle et al (J Anim Sci, 2020) monitored 30 two-year-old females that were classified as low (i.e., favorable) RFI or high RFI through late-season grazing on low quality forage in Idaho. The heifers’ RFI values were based on a feed efficiency trial conducted when they were growing heifers. Over the course of a 78-day grazing season, all the heifers lost weight and decreased in body condition score (BCS), but the low RFI heifers lost less weight and had smaller declines in BCS than the high RFI heifers, indicative of greater feed efficiency in a challenging environment.
- A 2016 study published by scientists from the University of Illinois (Cassady et al, J Anim Sci) monitored over 600 crossbred steers and heifers through grain-based and forage-based feeding trials. This study demonstrated a strong correlation (r = 0.63) between RFI measured in growing and finishing phases of production.
Applying RFI in grazing environments
Despite the inherent differences in the biology of feed efficiency consuming grain vs. pasture or growing animals vs. mature cows, it is clear that RFI measured during growing phases is indicative of what would be observed in extensively managed cow herds. This should provide confidence in the ability to link feed efficient genetics to lifetime performance in cow-calf herds.
“The main reason to use negative RFI-tested bulls is the level of opportunity in the numbers,” Brown says. “There can be a +/- 20% difference in cattle efficiency. It’s a huge number. Feeding 500 cows for 5 months, the difference becomes up to $40,000 yearly.”
The fact we typically measure RFI in confined bulls shouldn’t discourage us from valuing their future female progeny as they will sire more feed-efficient males and females.
Spin-off benefits
“Over the years we can run more cows without giving up performance, plus we’ve probably increased our pregnancy rates because feed-efficient cattle maintain their body condition better,” Brown says. “They also tend to breed back quicker. We receive more rewards than we planned for.”
Additionally, this connection extends to greenhouse gas emissions. Whether consuming grass or grain, cattle consuming more feed will, on average, produce more methane. It follows that animals with superior RFI will produce the same while eating and emitting less.
Count on Vytelle SENSE to help
There is no shortcut to changing a herd’s profitability or environmental impact. Measuring and selecting for feed efficiency is a proven and scalable way to impact profit. Ensure bulls have completed feeding trials with Vytelle SENSE data and associated RFI calculations to inform more accurate buying decisions.
“Vytelle SENSE is the best tool to measure individual efficiency and compare animals to their contemporary group,” Brown says. “It’s accurate and reliable making it really hard to argue with the results.”
References
C. J. Cassady, T. L. Felix, J. E. Beever, D. W. Shike. 2016, Effects of timing and duration of test period and diet type on intake and feed efficiency of Charolais-sired cattle. J. Anim. Sci, 94.
R.M. Herd, E.C. Richardson, R.S. Hegarty, R. Woodgate, J.A. Archer, and P.F. Arthur. 1998, Pasture intake by high versus low net feed efficient Angus cows. Animal Production in Australia, Vol. 22.
J.E. Sprinkle, J.B. Taylor, P.E. Clark, J.B. Hall, N.K. Strong, and M.C. Roberts-Lew. 2020, Grazing behavior and production characteristics among cows differing in residual feed intake while grazing late season Idaho rangeland. J Anim Sci, 98(1).