Justin Sexten: Less Is More
With much of the country drier than ideal, optimizing feed resources are top of mind heading into winter. Even for those who enjoyed timely summer rains, the marginal economics of the cattle business and rising feed costs continue to cause nearly everyone to search for ways to do more with less.
A recent article from Emily Andreini in the Journal of Animal Science looked at a couple different approaches to efficiency. The primary research related to further understanding residual feed intake (RFI) with a secondary review of limit feeding.
For those less familiar with RFI it is a biological efficiency measure the beef industry continues to explore. In short, RFI is a comparison of what an animal actually consumes relative to predictions of feed intake. So smaller or negative numbers suggest a more biological efficient animal.
Initial RFI reports focused on simply sorting efficient and inefficient cattle. This approach focused on selecting low RFI heifers and sires to build efficiency into the herd. Building efficiency into a herd like most traits not a short term process.
Beyond simply selecting cattle that eat less, researchers continue looking at factors related to RFI using advances in behavior monitoring and individual feed intake. The same technology discussed for predicting calving, lameness or respiratory disease can be used to further understand the mechanism of efficiency.
Dr. Andreini and her University of California, Davis coworkers evaluated the effects of cattle movement and eating preferences on high and low RFI cattle. When comparing inefficient and efficient cattle on full feed the efficient group (Low RFI) consumed 12% less feed.
The theory behind behaviors contributing to a 12% feed intake difference is comparable to “efficient humans”. Cattle that selectively consume greater amounts of energy dense grains relative to roughage or “exercise” less should meet energy needs with less feed intake. While a logical model, in this report there were no differences between efficient and inefficient cattle for diet preference nor lying activity.
One notable idea for those looking to develop starter feeds this time of year. Both groups selected against the finest feed particles when on full feed. Diet ingredients less than 0.15 inches were least preferred compared to larger roughages and processed grains. Using this data consider starting low-intake or stressed cattle with a conditioned diet or pellet to ensure supplements are not sorted in the bunk.
When considering the role activity plays in efficiency it is important to remember Dr Andreini’s team monitored the number, frequency, and duration of lying events. With no differences reported one can conclude there is no efficiency difference due to inactivity or the activity when not resting is a more important factor.
The effect of feed restriction was the primary interest of the research. Whether limit-fed or program fed to a target ADG previous work supports improved efficiency due to restricting nutrients in growing cattle. A similar approach in feedyards seeks to optimize efficiency and performance offering cattle just enough feed to leave crumbs the next day.
If limit feeding improves efficiency in average cattle, the research team wanted to see how metabolic efficiencies change when applied to the RFI groups. When cattle were limited to 75% of full feed the differences in efficiency between groups expanded. When limit fed the maintenance requirements on inefficient cattle declined by 18% with a 32% decrease observed for efficient calves.
The enhanced efficiency observed in low RFI cattle suggests there is opportunity to stack mechanisms. The selection process for metabolically efficient cattle is a slow process and the mechanisms are still unclear. However the opportunity exists to begin building an efficient foundation into the genetics of the cow herd.
For the backgrounders, this research focused on traits outside your purchase order, yet it reinforces what market reports clearly signal. The next segment in the supply chain seeks efficiency as “fleshy” cattle sell at steep discounts. The opportunity to do more with less stacking feeding and management technologies exists regardless of the efficiency ranking when the cattle walk off the truck.
