Using feed efficiency as the silver-bullet answer for questions of on-farm sustainability can be tempting. After all, feed costs represent 50 to 60 percent of the operating expenses of the average dairy farm. Feed production and its consumption are a considerable portion of the environmental footprint as well.
However, while measuring and understanding feed efficiency holds great value for individual farms, it is important to know these measures will not provide a valid “apples to apples” comparison of sustainability across farms. That’s because there are many ways in which feed efficiency can be calculated, and each method has different strengths and weaknesses.
Selecting the most useful method or combination of methods is extremely context-specific; what works best for one farm might not be as valuable for the farm next door.
Calculating feed efficiency for your farm
Even if calculating feed efficiency is not useful as a benchmarking measure of sustainability, it can be very useful to further sustainability goals for individual farms.
The most useful measures of feed efficiency, or most useful combinations of measures, vary by farm. Selecting which feed efficiency metrics to use requires beginning with clarity about an individual farm’s needs and goals and understanding that using several together might provide the best management insights.
Various on-farm measures of efficiency are described below. While the descriptions provide some indication as to what they measure and how, it is important to be aware of the advantages and limitations for each measurement to decide when and how to use them. And remember, none of these five feed efficiency measures by themselves equal sustainability.
- Physical feed efficiency is simply the amount of milk produced per unit of dry matter intake. This measure is easy to calculate but doesn’t account for nutrient density, feed cost or cow growth.
For example, increasing dietary fat can increase physical feed efficiency, but supplemental fat can be more costly than other energy sources, and feed cost is an important part of dairy sustainability. Physical feed efficiency as a benchmark for sustainable milk production has numerous limitations, making it necessary to evaluate other economic and efficiency measures concurrently.
- Efficiency of nutrient usage is typically used more by geneticists than nutritionists or environmentalists because it can be used to compare how efficiently specific nutrients are used by individual cows or breeds.
One measure in this category, gross energy conversion efficiency, is calculated as milk energy output divided by energy intake. This measure ignores the mobilization of body reserves, which will be higher in early lactation.
- Economic feed efficiency measures incorporate feed costs and help to bring economic profitability of a farm into the sustainability equation.
There are several calculations that fall into the economic feed efficiency category, the most common being milk income over feed cost, which is helpful for short-term feeding and management decisions but not recommended for the long term because it is dependent on fluctuating milk and feed prices.
Another is ration cost efficiency, which is the value of the milk produced divided by the dry matter consumed. This measure is limited by not accounting for bodyweight changes, heifer growth, forage losses and other variables.
Another measure is feed cost per hundredweight, or the accumulated feed cost for lactating and dry cows divided by the amount of milk shipped. This incorporates many variables, such as feed price and dry period length, but does not consider heifer enterprise and milk composition.
- Lifetime efficiency is the percentage of lifetime feed energy intake that is converted into milk or used for reproduction and growth. This metric does take into account the benefits of earlier calf and heifer growth and cow longevity but may be difficult for farmers to calculate given the availability of the data needed.
- Total dairy enterprise efficiency is a way of accounting for all nutrient gains and losses in the dairy enterprise, including losses associated with crops, manure, feeding management, the feed used for dry cows and other activities.
This measure requires integrating accurate farm data, including actual dry matter and nutrient intakes, with advanced nutrition models and whole-farm dairy models. This may be challenging but could also be the most effective way of maximizing dairy feed efficiency.
Feed efficiency has major effects on overall efficiency and dairy enterprise sustainability. Each of the on-farm feed efficiency measures described above has both advantages and limitations, and all can be informative but provide more appropriate guidance when examined simultaneously rather than in isolation.
In addition, feed efficiency goals should not be viewed as fixed but as moving targets specific to the current conditions of each dairy enterprise. For these reasons, dairy managers and nutritionists need to carefully consider the following to define reasonable dairy efficiency targets:
- Diet digestibility
- Rumen function
- Feed analysis results and associated variability
- Nutrient requirement estimates for the various animal groups
- Feed preparation, delivery and intake
- Production goals
All of these are factors to more sustainable dairy operations. Considerations and Resources on Feed and Animal Management from the Innovation Center for U.S. Dairy is a good resource on this topic (see Section 1.5: Dry Matter Intake and Feed Efficiency). PD
References omitted but are available upon request. Click here to email an editor.
- Vice President of Sustainability Research
- Innovation Center for U.S. Dairy
- Email Juan Tricarico
Why is measuring and communicating the sustainability of dairy so important today?
Measuring sustainability efforts can provide real business benefits. Additionally, in today’s marketplace, sustainability is a new indicator of quality. Consumer brands, retailers, financial institutions and customers are increasingly evaluating environmental, social and economic indicators as benchmarks of performance.
The Stewardship and Sustainability Guide for U.S. Dairy – a tool created through the farmer-founded Innovation Center for U.S. Dairy – provides cooperatives, dairy marketers and other businesses a standardized way to assess, communicate and celebrate dairy’s long-standing sustainability story to buyers and stakeholders.
Unlike individual measures of feed efficiency, topics included in the guide are useful for measuring and benchmarking sustainability on individual dairy farms as well as across farms. The online Farm Smart tool (farmsmart.usdairy.com) can be used to measure and track some of the indicators in the guide.