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Feed Efficiency Should Be Monitored
Dairy Pipeline: May 2008
Charlie Stallings,
Extension Dairy Scientist,
Nutrition & Forage Quality
(540) 231-3066; cstallin@vt.edu
One way to define feed efficiency is to express milk produced per unit of dry matter consumed. This requires that dry matter intake be determined by knowing what was offered and how much was refused. On-farm dry matter determination is helpful when doing this, however, estimates can be made from lab TMR dry matter results. For those on our “P Project” we report an estimated dry matter intake for your herd based on body weight and milk produced. You can compare this to your estimates. Also, milk should be expressed on a 3.5% fat basis. The formula for 3.5% fat milk is (.432 times milk lbs.) plus (16.23 times milk fat lbs.). A herd producing 70 lbs. of 3.8% fat milk (70 X .038 = 2.66 lbs. fat) would be producing 73.4 lbs. of 3.5% fat corrected milk (FCM = (.432 * 70) + (16.23 * 2.66)). If this herd consumes 50 lbs. of dry matter per day the feed efficiency is 1.47 lbs. milk per lb. dry matter (73.4/50). Most Virginia herds average 150—200 days in milk and should expect efficiencies of 1.5 to 1.6. A large number of late lactation cows with average days in milk of the herd at greater than 250 might drop efficiency to 1.4. Early lactation cows or groups might have a feed efficiency of 1.8 or greater due to use of body stores to produce milk in early lactation. With feed costs now greater than $5 per cow per day, it is an excellent time to determine your feed efficiency. Make changes as needed to produce more milk per unit of feed consumed. This makes sense both economically and environmentally.