Feed efficiency has been a frustrating topic for dairy producers and their nutritionists ever since the concept of getting more production from the same amount of feed was devised. The “getting more milk” part is easy to measure. It’s the “from the same amount of feed” that’s tough.
How much does she eat?
With the evolution of more advanced feeding software, producers know with a relatively high degree of accuracy how much feed is being delivered to a pen of cows at any feeding. If they divide that amount by the number of cows in the pen, they get a per-cow average of how much feed is available to each cow.
But the problem lies in knowing how much a cow actually eats. A logical way to determine that figure is to measure how much the cows don’t eat then subtract it from what was delivered. But that requires a fairly labor-intensive process of collecting and weighing feed refusals, and most producers don’t find the resulting data valuable enough to bother with the extra effort.
Activity monitoring systems bring us closer to being able to monitor an animal’s feeding behavior, but there are still some holes to fill. We know how many times a day a cow eats, her rumination, etc. and algorithms associate those values with feed intake. But the technology isn’t quite perfect yet, since just because a cow visits the feed bunk more often, it doesn’t mean she eats more than a cow who goes less but eats more at each visit. We’re farther ahead than we were 15 years ago, but there’s still work to do.
Since the process of measuring actual feed intake is arduous, the industry has worked to eliminate the need to measure intakes while identifying those cows that may be more efficient than others.
Residual feed intake
Today a vast majority of dairy rations are put together using advanced nutrition software that formulates rations down to the most minute micronutrient. The software calculates how much your cows should be producing given age, lactation stage and so forth. For a given level of production, an animal that eats more than what the model says is less efficient than a cow that eats the same or less than the model’s prediction. If several cows are underperforming based on what the nutrition model predicts, then something is probably wrong that needs to be evaluated.
Residual feed intake plays a role in another factor impacting feed efficiency: genetic selection. It’s been assumed for some time that some cows are more efficient than others. Those cows that produce more than the nutrition model predicts are more efficient and therefore should be a part of your herd’s genetic future, while the one’s below the threshold can be bred to beef bulls.
Several organizations are working on identifying genetic markers around feed efficiency in order to make predictions in younger animals. These organizations include the Center for Dairy Cattle Breeding (CDCB) and the Foundation for Food and Agricultural Research (FFAR).
The CDCB developed a predicted transmitting ability (PTA) for Feed Saved which represents the expected pounds of dry matter saved per lactation above or below the breed average based on body weight composite and residual feed intake. Producers who breed animals with higher Feed Saved values should have a more feed-efficient herd over time.
Managing carbon
The FFAR is also interested in the genetics of feed efficiency, but more from a sustainability viewpoint. If we take the make-more-from-less approach a little further, we can see that what we are really talking about in terms of feed efficiency is carbon utilization. In its basic form, feed is made up of various elements such as hydrogen, nitrogen, oxygen, carbon and so forth. Any carbon that is fed to the animal has to go somewhere. It’s either turned into milk, meat or some bodily function (hair, hooves, a growing calf, etc.) or it leaves the body in undigested feed (manure) or as a gas, including methane. As we know, methane is one of the most important greenhouse gases and anything that can be done to reduce methane emissions is beneficial from a sustainability standpoint. So, it makes sense that if we can convert more of the feed a cow eats into products, i.e. milk and meat, then less carbon would leave the cow as methane resulting in a positive sustainability impact.
Feed efficiency used to be just a way to measure the productive efficiency of your herd. As the industry has pushed to better understand feed efficiency and how to achieve and measure it, we’re discovering more components that lead to creating and identifying more efficient animals. This has created opportunities not only for animals to be more productive but to help advance the industry’s sustainability platforms as well.
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