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Feed Efficiency: Improve Your Profit Margin by Increasing the Milk Made by Every Pound of Dry Matter Fed

Posted: August 25, 2011

Feed efficiency is increasingly important during times of high input and low output costs.

Feed efficiency (FE), or dairy efficiency as it is sometimes called, is a simple measure to determine the relative ability of cows to turn feed nutrients into milk. In the simplest terms it is the pounds of milk produced per pound of dry matter consumed. This measure should always be a consideration of dairy diets and becomes increasingly important during times of high input and low output costs. A way to combat decreased profit margins is to increase the milk made from every pound of dry matter fed. An added benefit to increasing cows’ feed efficiency is that fewer nutrients will be excreted in manure, so feed efficiency affects both economic and environmental efficiency. This is of considerable importance to dairies struggling with manure application management.

There are two ways to improve feed efficiency, one is to increase milk yield for the same dry matter intake and the other is to decrease dry matter intake and maintain the same milk yield. Most things that increase milk yield will also increase feed efficiency. This is generally true because as the cow produces more milk, the proportion of energy used for maintenance becomes smaller. In other words, the “fixed costs” of the animal are spread out over more pounds of milk, making the animal more cost and energy efficient. Once the fixed costs are achieved, producing additional milk takes less energy and protein. However, a problem arises with these “fixed costs;” they are not exactly fixed. As dry matter intake increases there is a decrease in feed digestibility. So the cow becomes somewhat less efficient at extracting energy from the ration. This decrease in digestibility grows larger as intake increases and becomes a real issue in high producing dairy cows with high intakes. Therefore, it is important to optimize rather than maximize dry matter intake in the cow. However, in many situations, getting more dry matter intake in a producing dairy cow is a good thing to do.

There are several important factors to consider when measuring and calculating feed efficiency.

Use Actual Dry Matter Intake (DMI): Accurate DMI data is vital for accurate estimates of FE. This means weighing not only what was fed but also refusals. DMI can be measured for herds or groups, even for individual cows in tie-stall barns.

Measure DM of Ration Components: It is important to monitor the DM content of the TMR and the forages used in the ration to obtain accurate FE estimates. Fermented forages and TMR should be checked for DM content weekly.

Convert to Energy-Corrected Milk (ECM): It is very common to standardize FE by using ECM yield. This standardization allows for comparison across breeds or dairies that vary substantially in milk composition.

The following formula should be used to convert to ECM yield:
ECM = (12.82 × fat lbs) + (7.13 × protein lbs) + (0.323 × milk lbs)

Table: Recommended Feed Efficiency (FE; lb milk/lb DMI) for various lactation groups and stages of lactation

Group Days in Milk
FE
One group, All cows
150 to 225
1.4 to 1.6
1st lactation group
<90 1.5 to 1.7
1st lactation group
>200 1.2 to 1.4
2nd + lactation group
<90 1.6 to 1.8
2nd + lactation group
>200 1.3 to 1.5
Fresh Cow group
<21 1.3 to 1.6
Problem herds/groups
150 to 200
<1.3

Source: M Hutjens, University of Illinois
*These recommendations are based on DMI not ECM values

To further improve the accuracy of calculating FE, intake could be corrected for energy content much like milk production is. Corrected feed DM to a standard Mcal/lb would increase the accuracy of calculating FE and allow for comparisons between rations of different compositions. Or perhaps FE could be calculated as the Mcal of milk produced per Mcal of feed consumed. Determining FE this way would eliminate the variability associated with the energy density of the TMR and forage digestibility. This method would put a greater focus on the cows’ ability to produce milk efficiently, rather than FE being a product of the feed. This would be a more effective approach when comparing animals for genetic selection, which may become more common in the future.

 - By Daryl Mulfair, graduate assistant, and Dr. Jud Heinrichs, professor, Penn State Department of Dairy and Animal Science