By Kim Egan, DVM, Dairy Consultant Manager, Genex
"Income over feed cost is one of the efficiency benchmarks routinely analyzed by lenders," reports Kurt Petik of Rabo AgriFinance. Obviously, our cows need a good quality, readily-available ration to maintain health and productivity. So, in addition to analyzing ration components, what other tools can help improve income over feed cost long-term?
Let's consider feed costs. A readily-available, good quality ration is essential. Many producers have looked at the benefits of small-breed cows for feed efficiency, especially with limits on land availability. The Genex Ideal Commercial Cow index (ICC$) also selects for more moderate body size with weightings for marginal feed costs and body condition score.
The Nutrient Requirements of Dairy Cattle 2001 formula for estimating dry matter intakes considers body weight as larger cows require more and increased production raises dry matter intakes. Jim Linn from the Department of Animal Science at the University of Minnesota simplified these effects in his article "Energy in the 2001 Dairy NRC: Understanding the System." He states that a difference of 100 kg of body weight changes dry matter intake by 1.5 kg per day. This equates to 220 lbs of body weight changing dry matter intake by 3.3 lbs given the same production, or 110 lbs of body weight changing dry matter intake by 1.65 lbs per day.
In terms of feed cost, how much difference can 110 lbs of body weight make? Let's use $0.07 as the cost per pound of dry matter. A 1,000-cow herd of 1,500 lb Holsteins consumes an average of 52 lbs/head/day on a dry matter basis. This would cost $3,640 per day. If the same herd had an average body weight of 1,390 lbs, the requirement for intake would decrease to 50.35 lbs dry matter/head/day, costing $3,524 per day. That small difference in body weight would save $42,340 per year on this 1,000-cow example herd. Another benefit is the ability to feed more cows with the same land base.
Can cows with lower genetic stature produce as well? Simply, yes. The graph below depicts average energy-corrected milk production from 629 second lactation and greater cows from a single herd (same housing, same milking routine, same ration). All cows had estimated sire genetic milk between 0-200 and were between 40-305 days in milk.
These medium-sized cows get a blue-ribbon for efficiency. Talk to your Genex representative if you'd like to discuss the ICC$ index or look at the effects of stature in your herd.