Feed efficiency is one of the most economically important traits in beef cattle production. However, genetic improvements in feed efficiency have been limited and slow, primarily because measuring the actual feed intake of individual animals is extremely labor intensive, time consuming and expensive. A better understanding of how various physiological and metabolic processes influence feed efficiency is important to developing inexpensive, rapid methods of reliably predicting feed intake. Genetic relationships between efficiency and other economically important traits such as health and reproductive performance are also relatively unknown.
Funded by the National Check-off and Canada’s Beef Science Cluster, researchers are currently working to develop needed tools and information to allow the beef industry to effectively improve feed efficiency of beef cows.
To learn more, see the fact sheet: http://www.beefresearch.ca/factsheet.cfm/understanding-and-improving-feed-efficiency-of-beef-cows-141.
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In a time of consumers wanting to know more about their food and in particular sustainability, this research will provide a way of getting ahead of messaging to consumers. Being proud and talking about our continuous improvement in the field of efficiency in agriculture is imperative. Efficiency and sustainability go hand in hand.
What is your best method of currently evaluating Feed Efficiency? Regards, Sharon.
Hi Sharon
It depends. Feed efficiency is intended to measure animal productivity vs. feed inputs. Cost of gain is the make-or-break economic factor for commercial feedlot producers, so feed:gain or gain:feed ratio is the most intuitive measure for cattle feedlers. But feed:gain or gain:feed ratio isn’t ideal for seedstock selection. The problem is that an animal can have a really low (efficient) feed:gain ratio either by not eating much but growing normally, or by eating normally but growing really fast. So two animals could have the same feed:gain ratio, but for completely different genetic reasons. The “gain” part of the equation often drives the feed:gain ratio, so a low feed:gain may identify cattle that grow fast, rather than cattle that eat less. This means that selecting for low feed:gain could lead to larger mature cows that could actually have higher maintenance requirements.
The preferred way around that problem in seedstock selection is to use Residual Feed Intake (RFI), which is feed intake adjusted for maintenance requirements and growth (and often backfat depth). Some breeds are developing EPD’s (an EPD is the EBV x ½) for RFI, though none of the six most common Canadian breeds are reporting an RFI EPD yet. Fortunately, there is a positive genetic correlation between RFI and F:G, so if you use bulls with a low RFI, they should sire calves with a low F:G.
The relationship between RFI in yearling bulls with feed efficiency in cows isn’t as clear. For one thing, there is an obvious environmental difference. Young bulls are often developed in pens on a moderate energy diet containing some grain, whereas cows are maintained on predominantly forage diets, usually on pasture. There is also no widely accepted definition for “efficiency” in cows. It’s not feed:gain, because mature cows aren’t growing. The measure of efficiency on the cow side probably needs to be incorporate lifetime reproductive and calf performance. There are some indications that fertility may be later or lower in efficient (low RFI) bulls and heifers. It is not known whether these differences are large enough to have real or noticeable impacts in overall reproductive performance. But since reproductive performance is the make-or-break economic factor for cow-calf operations, it will be important to ensure that these things are monitored closely and appropriately accounted for in economic selection indices.