Genetics for Feed Conversion Efficiency

Dairy women and men have been increasing the output of their animals while reducing their carbon footprint for decades. They are resilient, hardworking and devoted to the land and animals under their care. In recent years, more than ever, management of land, water and feed resources needs to be handled with a precise and strategic approach. That is why STgenetics® is dedicated to our continued research on EcoFeed® and identifying and breeding cattle for Feed Conversion Efficiency. By increasing Feed Conversion Efficiency through selecting high EcoFeed® animals, you will be able to continue to feed the world with reduced feed costs, more profitability and less environmental impact.

 EcoFeed® is a Feed Conversion index to identify animals with superior Feed Conversion Efficiencies. This index is necessary because identifying individuals with superior Feed Conversion Efficiency requires measuring individual feed intake records and performance for a large group of animals from current genetic populations which is costly and labor intensive. STgenetics® began our EcoFeed® research in 2014 at the Ohio Heifer Center with the goal of establishing a pipeline for testing for Feed Conversion Efficiency in growing dairy heifers. By combining the individual feed intake records for heifers with their genomic data, we have been able to isolate the genetic components that affect Feed Conversion Efficiency; therefore, we can make genomic predictions of other females without feed intake records with high accuracy. Our first genomic evaluations for EcoFeed®heifer were released in 2017 and since then, over 750,000 females have received EcoFeed® evaluations at Genetic Visions-ST™.

Since the EcoFeed® program’s inception, our goals have expanded to include EcoFeed® research on lactating cows and Beef on Dairy calves, making it the largest Feed Conversion Efficiency database in the world.

STgenetics®’ Holstein bulls now include an evaluation for EcoFeed®heifer and EcoFeed®cow, so our customers can identify bulls that meet their goals for production, health, reproductive and type traits along with Feed Conversion Efficiency during the growing period as well as in lactation. Customers who select high EcoFeed® bulls can expect the progeny of these bulls to consume less feed than their inefficient counterparts while maintaining productivity.


EcoFeed®heifer predicts the Feed Conversion Efficiency of heifers in the growing or rearing phase of life while EcoFeed®cow predicts the Feed Conversion Efficiency of a cow during her lactations. When considering females for selection to make replacements, it is important to identify females with ideal production, reproductive and health traits while also identifying females with superior EcoFeed®heifer and EcoFeed®cow scores.

The EcoFeed®heifer and EcoFeed®cow indexes are positively correlated which means that if you select for either index, you will not be negatively impacting the other index. The EcoFeed®heifer index can range from 77 to 123 while the EcoFeed®cow index can range from 46 to 157. The reason for the difference in range between these two indexes is simply that cows consume about twice as much feed per day as heifers, so there is more variation in their feed intake. All females that are genomic tested at Genetic Visions-STTM will receive an EcoFeed®heifer and EcoFeed®cow evaluation. Every 10 points of EcoFeed® represents 1 pound of dry matter (DM) saved per day. This means that a female with a score of 120 is expected to consume 3 pounds (DM) less per day than a female with an EcoFeed® score of 90.


In addition to the new EcoFeed®heifer and EcoFeed®cow traits individually allowing dairy farmers to aim for increased Feed Conversion Efficiency in their growing heifers and milking cows, the EcoFeed®plus designation for bulls will allow you to identify bulls that are superior for both EcoFeed®heifer and EcoFeed®cow. Higher Feed Conversion Efficiency over the lifetime of your females will translate to more feed cost savings and higher farm profitability.

As feed expenses continue to rise and stewarding land resources continues to be paramount, selecting animals with higher EcoFeed® scores is the solution for cost savings and environmental stewardship. EcoFeed®heifer alone has already shown 15% savings in feed consumption, 21% savings in water ingestion and 15% savings in methane emissions*1. Now, the new EcoFeed®cow and EcoFeed®heifer indexes are amplifying those results of reduced feed costs, more profitability and less environmental impact*2, with further accuracy, precision and reliability.

*1 Source: Wilkerson V.A., Casper D.P., Mertens D.R. 1995. The prediction of methane production of Holstein cows by several equations. J. Dairy Sci.78:2402- 2414; US EPA
*2 Source: Kebreab, E., J. R. Johnson, C. Heuer, and J. Deeb. 2021. Genetic Selection Through EcoFeed Index Reduces Carbon Footprint in Heifers. J. Anim. Sci. 99: Supplement 3: 145-145. DOI:10.1093/jas/skab235.266