meta Feed Efficiency Indexes – Which One Will You Use? :: The Bullvine - The Dairy Information You Want To Know When You Need It

Feed Efficiency Indexes – Which One Will You Use?

Today farmers are focusing on maximizing net returns, productivity, efficient use of inputs and resources, and keeping costs under control. Environmental responsibility and producing what buyers need and will pay for also affect outcomes. With all these pressures farmers are aware that feed costs are seventy percent of the variable on-farm costs. As a result, income over feed costs (IOFC) is being more closely monitored and used by dairy farmers and their advisors.

Dairy Farmers Know that Feed Costs are Important

Dairy farmers easily report the production of each of their cows but not individual cow feed intakes. To do that takes constant monitoring and manually it would be a costly and time-consuming process. It would be too costly to justify the savings in the cost of production. It is not that dairy farmers are not interested in knowing the differences between their cows in feed conversion efficiencies. As with other important traits, if sires could be ranked by their daughter’s ability at converting feed to milk, then genetic improvement should be possible. Remember that 90% of the possible genetic improvement in dairy cattle can be achieved by using the highest-ranked sires.

Where Feed Efficiency Genetic Indexing Got Started

In 2015 Australian researchers and genetic evaluators commenced publishing sire rankings for their daughters’ feed efficiency and they called the trait Feed Saved. This has been followed by many other countries and some breeding companies conducting research and developing systems to rank sires for feed conversion efficiency. The initial investigations utilized feed intake, milk production, and body weight changes from research study cows. Since then, data from commercial herd cows has been captured and used to add to the analysis to identify sire daughter differences in their ability to convert feed into milk, all the time accounting for levels of milk production (Energy Corrected Milk) and body weight and changes in body weight.

Feed Efficiency Genetic Indexes are Coming into Vogue

Today, in 2021, dairy farmers in seven countries have access to sire indexes for feed efficiency. Indexes for females are also being published by some countries. However, a major challenge is that with many different indexes being published, farmers have questions including – what are the indexes based on and which one to use when selecting sires for their herd and when mating females?

There are essentially two methods of expressing animal feed efficiency indexes. These will be explained in the following two sections.

Base Indexing for Feed Efficiency

The basis for determining differences between milking cows in metabolic feed conversion efficiency compares differences between cows in feed consumed (Dry Matter Intake) and milk produced (ECM), while factoring in a cow’s requirements for body maintenance and level of production. The term used to describe the number arrived at is Residual Feed Intake (RFI). It is measured in mid-lactation and is the residual between what a cow is expected to consume to produce and maintain her body compared to what she actually consumes. Cows consuming less than expected are the ones given positive ratings for feed efficiency and conversely, cows consuming more than expected receive negative ratings. In heifers, the comparisons between animals are based on feed consumption and growth.

Expanded Indexing for Feed Efficiency

Farmers know that feeding animals on dairy farms goes beyond what happens within any given cow’s body. On herd and animal population bases many other things are affected when there is – less land used to grow feeds – less feed harvested – less greenhouse gas emission – less manure produced – as well as other factors impacting the environment. Both farmers and society gain by having more feed efficient animals.

Australian researchers coined the term Feed Saved for the combination of RFI plus the less feed required for body maintenance by smaller cows. Some other countries and some breeding companies are following the Australian lead and are producing sire indexes based on Feed Saved

Feed Efficiency Indexes Dairy Cattle Breeders Will See

Currently, many feed efficiency indexes are published and promoted for use by dairy cattle breeders.  A partial list follows:

National Feed Efficiency Indexes

  • United States – CDCB calculates and commenced (Dec 2020) publishing RFI indexes for sires. Effective in August 2021, animal Feed Saved indexes will be included in the NM$, CM$, FM$ and GM$. For many years body weight has already been included in some USA total merit indexes. The data set used to establish Feed Saved base numbers includes past and present national and international Holstein research study cows. An average animal will receive a rating slightly above zero in lifetime dollar savings based on the Feed Saved formula.
  • Canada – Lactanet calculates and publishes feed efficiency indexes based on RFI animal indexes. Lactanet describes their feed efficiency indexes as – “The overall aim for Lactanet’s ‘Feed Efficiency’ rating is selection for cows that use less feed at the same level of production and body size after the peak of lactation and is not aimed at reducing maintenance requirements by lowering body weight”. The data set used to calculate the Lactanet RFI indexes are the same international data set used by CDCB. An average animal will receive a rating of 100 for ‘Feed Efficiency’.
  • The Netherlands – CRV calculates and in 2020 started publishing animal feed efficiency indexes based on the Feed Saved formula. CRV bases the calculations on a data set of over 7,000 cows including over 2,500 cows on twenty commercial farms.
  • Nordic Countries – Nordic Cattle Genetic Evaluation (NCGE) calculates and publishes animal feed efficiency indexes using its own program called Saved Feed. Saved Feed is different than Feed Saved and its formula is based on combining NCGE breeding values for body maintenance and metabolic efficiency.
  • Australia – DataGene calculates and publishes animal feed efficiency indexes based on the Feed Saved formula.

Other countries, primarily from Western Europe, are studying and developing national feed efficiency indexes which will soon be available for dairy farmers to see and use.

Company Feed Efficiency Indexes

  • Sexing Technologies– STgen has allocated considerable resources to monitoring thousands of animals in its herds for feed conversion efficiency. It started by monitoring heifers for consumption and performance, followed by monitoring those heifers as milking cows. Its calculations are based on RFI independent of body size and performance. The program is called EcoFeed and an average sire for feed efficiency is rated 100.
  • Select Sires Inc – SSI rates sires according to FeedPRO which “optimizes selection for increased production and moderate body size while maintaining body condition score and daughter fertility. This rating designates sires with the genetics to improve income over feed costs and maintain health and reproductive traits”.
  • Viking Genetics – Viking Genetics works closely with NCGE including providing cameras that daily capture individual heifer and cow feed consumptions and other animal events for Holsteins, Jersey and Red Dairy Cattle.
  • Holstein Association USA – US Holstein calculates and publishes its FE$ index for animals. FE$ has been based on the added cost of maintenance for larger animals and the value of an animal’s genetic merit for fat and protein over added feed costs for the extra production. Effective April 2021 an animal’s genetic merit for Feed Save was included in the FE$ formula. FE$ forms part of the TPI formula and top-ranking sires receive a FE$ value of 250 and above.

Heritability, Correlations, and Reliability for Residual Feed Indexes

  • Heritability – All sources calculate the heritability of RFI to be moderate (0.14 to 0.25), like the heritability for production traits. Using RFI indexes, animals can be improved for feed efficiency through selection.
  • Correlations to Other Traits – The correlation of RFI to other traits have been universally found to be very low (most ranging between -0.10 to 0.10). To improve RFI, it must be selected independent of other traits.
  • Reliability – Because of the current limited number of animals for which there is total basic RFI information, the reliability of animal genetic indexes for RFI and Feed Saved are low (below 50% REL). Until there is much more animal data for RFI calculations (genomic and daughter proven indexes), caution should be practiced when selecting animals based solely on RFI or Feed Saved.

Why Include Body Weight when Indexing for Feed Efficiency?

Dairy farmers are modifying the importance they place on stature. Currently, some farmers are yet to be convinced that the bodyweight of milking cows needs to be decreased. Recent research has found that the 2001 NRC published energy requirements for body maintenance underestimate the actual requirement by 50%. Thus, body weight is more important in the cost of feed to produce milk than previously considered to be the case. Approximately 70% of the emphasis on Feed Saved is for the feed required to maintain an animal’s body weight. Additionally, body size and weight affect areas beyond feed for milking cows including – stall sizes, need to revamp facilities for larger animals, extra feed to grow animals larger to first calving, higher feed costs during the dry period, … to name a few. Farmers can expect to see more studies conducted by researchers and organizations on determining optimum body size and weight.

What About Breed Differences in Feed Efficiency?

As yet, there is not adequate animal feed intake and performance data to accurately compare breeds for feed efficiency.  So far there are only feed efficiency indexes for Holsteins.

Which Feed Efficiency Index is the Best One?

It is too early in having feed efficiency indexes available to know if any one of the indexes is more accurate than the others. And if any indexes rank animals in a similar manner.

Feed Efficiency Indexes Will Be Included in Total Merit Indexes (TMI’s)

In August 2021 Feed Saved will be added to the NM$ total merit index. Adding Feed Saved to NM$ will cause re-visions to trait emphasis. The emphasis for traits in NM$ will be: Production (M/F/P) 48%; Productive Life 16%; Feed Saved 13%; Cow Health & Livability 8%; Reproduction & Calving 8%; Type 4%; and Heifer Traits (EFC & CLIV, both new to NM$) 2%. With the multiple enhancements to NM$, there will be a wider range in NM$ indexes. The very top Holstein sires will have values of $1,200 and higher.

Dairy farmers concerned about a possible reduction in cow body weight by adding Feed Saved to NM$ should be aware that leading USA geneticists estimate that the current trait weightings in NM$ will result in mature cows weighing 52 lbs. less a decade from now. The weighting for Feed Saved in TPI is predicted to hold or slightly lower cow weight.

Feed efficiency is included in Australian and Nordic TMI’s. Other countries will likely soon include feed efficiency indexes in their national TMI’s.

Include Feed Efficiency Indexes When Doing Your Sire Selection

Herds breeding to increase the IOFC for their milking cows should avoid using sires that are below average for feed efficiency. It is preferable to only use sires that are in the top 25-35% for feed efficiency.

The Bullvine recommends that dairy farmers first shortlist sires of interest to them based on a TMI index (NM$, CM$, TPI, LPI, Pro$, … etc.). Then eliminate the sires that are not above average for feed efficiency.

What will be the Benefits of having Feed Efficiency Indexes?

The potential benefits, as reported by various organizations, include:

  1. CDCB estimates that implementing Feed Saved will improve US dairy farm profitability by US$ 8M per year.
  2. CRV predicts that the top 25% of the cows for feed efficiency in a herd will produce 0.4-0.5 kgs more milk per day on the same feed as the 25% lowest cows for feed efficiency.
  3. Viking Genetics has calculated that the difference in feed consumption between the most and least feed efficient cows in a herd to be one ton of dry matter consumed per 305-day lactation for animals giving the same amount of milk.
  4. STgen research shows that high rated heifers for feed efficiency consume 24% less feed per day with equal performance (growth and health).
  5. By using top ranked sires for F+P, RFI/Feed Saved and PL, within two generations a farm will be able to produce 10-20% more milk for the same feed costs;  and
  6. Of course, beyond the efficiencies at the cow level there are the savings at the herd, industry, and society levels.

The Bullvine Bottom Line

With feed efficiency indexes breeders now have a new tool in their genetic toolbox that can be used to improve farm profit.

Dairy farmers should acquaint themselves with the details and benefits of breeding their herds for feed efficiency (Feed Saved) and their animals for feed conversion efficiency (RFI).

The breeding of dairy cattle is in ‘Change Mode’. Where once large higher producing cows was the goal, the concept of doing more with less and breeding for efficiency and maximizing net returns are now the goal of proactive progressive dairy farmers.




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