Feed costs account for nearly 55% of the daily cost for a milking cow. As well feed costs contribute to a significant portion of daily costs for calves, heifers, and dry cow. Daily margins are currently under severe pressure, and it is only a matter of time until breeders start asking their genetic suppliers for facts and figures on how to select for animals that are superior for converting feed into growth, milk and milk solids. Breeders are now hearing or reading claims by breeds, genetic suppliers, and even other breeders that their genetics are the best buy for feed efficiency. But is there evidence to support those claims?
The Bullvine feels it is time to collect and comment on some of the known facts and the areas where breeders can expect to see information on feed conversion efficiency.
What History Tells Us
Breeds of dairy cattle have been developed over centuries and are an adaption of bovines to the regions they originated from. Whether is was an island, country or continent, all breeds were developed mainly based on the climate, the crops available or the milk and/or meat products produced. Measurements such as feed intake were not collected on an animal by animal basis to determine which animals were the most efficient at converting what they ate into meat or milk.
So, in fact, history tells very little about any breed’s feed conversion abilities or any of their differences in ability to convert feedstuffs to meat and milk energies that humans can utilize. The data for analysis does not exist. Therefore, to date, breeding for feed conversion efficiency has been by impression or at best by indirect selection using other documented traits.
Feed Efficiency – What is It?
Michael VandeHaar from Michigan State and his five associates (from U of Wisconsin, Iowa State, MSU and Wageningen UR) have produced a very complete and forward-looking paper called ‘Harnessing the genetics of the modern dairy cow to continue improvements in feed efficiency.’ They published it in the Journal of Dairy Science in April 2016 (JDS 99:4941-4954). Some summary excerpts from that paper follow.
“Feed efficiency is a complex trait for which no single definition is adequate. Generally, feed efficiency describes units of product output per unit of feed input, with units being mass, energy, protein or economic value. For dairy cattle, the primary product is milk, but the energy or value of tissue captured cannot be neglected. Losses or gains of body tissue can result in misleading values of feed efficiency if the only product considered is milk. Feed efficiency should be considered over the lifetime of a cow and include all feed used as a calf, growing heifer and dry cow and all products including milk, meat, and calves.”
There is much to consider in the previous paragraph, but VandeHaar also adds “In addition, we should consider that feed efficiency is more complicated than just feed and product. At the farm level, economic efficiency is clearly a priority.”
More Facts about Feed Efficiency
VandeHaar and Associates also report.
- “Feed efficiency, as defined by the fraction of feed energy or dry matter captured in products, has more than doubled for the US dairy industry in the past 100 years.
- This increased feed efficiency was the result of increased milk production per cow achieved through genetic selection, nutrition, and management, with the desired goal being greater profitability.
- With increased milk production per cow, more feed is consumed per cow, but a greater portioned of the energy is used toward milk instead of maintenance or body growth.
- The dilution of maintenance has been the overwhelming driver of enhanced feed efficiency in the past, but its effect diminishes with each successive increment of production relative to body size and therefore will be less important in the future.
Predictions about the Future for Determining Feed Efficiency
VandeHaar and Associates make some interesting predictions about the future relative to feed efficiency.
- Research will be needed on new ways to enhance digestive and metabolic efficiency. One way to examine the variation in efficiency among animals is the measurement of residual feed intake (RFI) a measure of efficiency that is independent of the dilution of maintenance. Study on about 6000 cows by the VandeHaar team has identified that RFI is 17% heritable – so there is definitely the possibility to improve animals through genetic selection.
- Cows that convert more efficiently and, thereby, are potentially more profitable, will also need to be healthy, fertile and produce a product that generates high revenue.
- Genomic technology will help to identify the animals that have high genetic merit and therefore the animals to be used as parents in genetic improvement programs.
- At the farm level, nutrition and management will continue to play a major role in feed efficiency. Animal groupings and precise nutrient balancing in group TMR’s will play a role.
- New computer-driven technologies that consider genomics, nutrients, management, grouping and environment will be a reality.
All of these facts make us realize that much more work must be done on feed conversion efficiency before is can be applied at the farm level.
It Goes Beyond Feed
The Bullvine called on Jack Britt Ph.D. for input on the topic of feed efficiency. He is a very respected agricultural consultant and formerly a scientist, teacher, and leader at three universities.
Britt comments include:
- The use made of the milk produced is significant. Farm gate revenue can be maximized with high solids milk for cheese production, whereas lower solids milk is likely best when the use is liquid.
- Conversion feed efficiency must be considered along with a host of other factors, beyond genetic, nutrition and management, including methods of harvesting forages; climate and environment; animal housing; and economics
- As yet there is not enough data to know if feed efficiency for maintenance and growth is different than feed efficiency of milk production. Therefore, selecting for RFI based on milk production may or may not result in less feed for maintenance and growth in heifers and young cows.
- For the immediate future, producers need to focus their attention on factors they can control including profit per cow per day; feed quality; dry matter intake; cow comfort; enhanced management techniques; improved reproduction; animal health and increased production.
Some Salient Facts
In our study of this topic, The Bullvine has noted the following important facts:
- We can not expect to have feed conversion data for all cows. Measuring exact input and outputs for individual cows is costly. There may be hope regarding estimating feed intake. Dr. Jack Bewley (Kentucky) is currently researching using remote camera technology to capture changes in feed volume in front of cows.
- Both inputs and outputs are important. It is profit per cow, per group or per herd that drives viability and sustainability. In the immediate term, producers are advised to think and manage regarding income over feed costs (IOFC) or return over feed cost (ROF) on a per cow, per group or herd basis.
- Breeders can expect to see various terms used to rank sires and cows for their feed conversion efficiency. The formulae for these rankings, at this point, have only limited scientific backing.
- Large cows must produce more milk than smaller cows of the same breed to have equivalent feed efficiency.
- Changes in body condition scores must be accounted for in estimating feed efficiency because a cow losing condition will appear to be more efficient than one gaining condition if only feed intake is measured.
The Bullvine Bottom Line
Accurate genetic information on feed conversion efficiency of dairy cattle is in its early stages. Making decisions on selecting animals for this is not recommended at this time. Expect to see genomic animal ratings in the coming years but take care to consider the accuracy of those ratings. If and when there are reliable feed efficiency indexes, expect to see them included in total merit genetic indexes like NM$ and Pro$. The answer to the question is “NO”. Breeders should continue to focus on breeding, feeding and managing for profit using the tools currently available.
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