For years, we have listened to breeders, show judges and trained experts talk about the way our cows move. Each authority focusses on a different outcome: winning in the show ring; producing in the milking line or remaining healthy in the barn or pasture. To name a few. We have many pieces from a lot of sources, but we still are unable to fit all the pieces of the puzzle together to improve bovine locomotion. Are we so focused on our own piece, or even lack an interest in locomotion, that we are failing to see the big picture?
If man had not domesticated bovines, they would still most likely have a mature size of 660-880 pounds (300 – 400 kgs) and would have been able to leap over rocks, and bushes like our deer in the wild can do. But I am thinking it is more than the larger size that has slowed down today’s bovines. Some breeds, especially, are less mobile that would be ideal.
Mankind – A Help or a Hindrances?
Perhaps there is not one answer that applies to all breeds of dairy cattle. Some have straighter and some more sickled legs. Foot structure, bone quality, and strength of pasterns vary from breed to breed.
Over a pan of more than three centuries breeders have changed the cow from only being able to feed her calf with perhaps a little extra milk for the owner’s household to being able to produce large volumes of nutritious milk that can feed many families. But at what price? Shorter lifespans? Perhaps! And now we have animals with much less ability to move, run and jump freely.
Many Experts have Opinions
Show judges a few times, at every show, will comment on how one cow moves compared to another. Their comments are usually about gait and strength of pasterns.
Classifiers have, for over ninety years, looked at feet and legs and evaluated them compared to the breed ideal. Most frequently, in the past, they would only see the cow standing in a stall. How can they know how a cow will move from only looking at form and not looking at and recording an evaluation on function? With so many parts to feet and legs evaluation and by not recording movement, it is little wonder that the heritability for feet and legs, using type classification data, is less that 10%. Knowledgeable breeders have told me that they feel the heritability of feet and legs is like udders at 30%.
Hoof trimmers mainly see only the bad feet of a herd, but they do not record that feet form information or do animal movement coding for genetic evaluation purposes. Of course, to get the full range of feet in a herd, they would also need to evaluate the good feet that they do not trim. For trimmers to go one step further and record data on locomotion may not be totally objective as the feet, just trimmed, are not likely to immediately function properly. One promising note is that Canadian hoof trimmers and CDN are currently working together on capturing data on cow’s feet as they are trimmed. By default, they will be able to identify sires and cow families that have feet problems.
Researchers, both veterinarians, and geneticists are interested in locomotion, and there have been studies, reports and videos to rate cows from excellent to poor for locomotion. But, beyond showing animal differences, little is known for breeders to use to improve the ability of their cattle, when it comes to locomotion.
It’s a Big Puzzle
Legs are large appendages that are attached mainly by muscles, ligaments, and cartilage. And while we know a considerable amount about the genetic improvement of skeletal structure, we know relatively little when it comes to the genetics of the function of feet and leg parts.
Type classification programs observe, capture and analyze large volumes of data on leg and foot form. But not on leg function. With more and more animals housed in a non-tied format, there must be a way to also capture data on leg and foot function.
Judges appear to be paying more attention, than in the past, to dairy animal leg movement in the show ring. Definitely, in the beef animal show rings animals are expected to be able to walk smoothly at a fast gait. However, for either dairy or beef, so few animals ever see the show ring, and those animals that make it there will have had their feet trimmed and be trained to walk unnaturally slow …. the result being that breeders cannot depend on the show ring for the evaluation of locomotion.
It is very costly to video a large number of animals moving in barns or on pastures and after that ’translate’ the results into actual sire rankings for locomotion. Perhaps someone will develop a means by which stationary or drone cameras can capture accurate mobility data. Now, that is a challenge for a scientist to develop an evaluation method. For another scientist, the challenge is to link the mobility index to the DNA and produce genomic mobility indexes.
Certainly, it is a big puzzle at this time. However, big challenges require big picture thinking.
Why Bother to Solve the Puzzle?
There are many things that “don’t” happen when locomotion is poor. In short cows that can’t or don’t walk properly don’t spend as much time foraging or at the feed bunk. They don’t come into heat or don’t mount to show heats. If they don’t move forward (i.e. have good locomotion), your dairy operation is probably slowing down or standing still too!
Recently Dr. Jeff Bewley and Associates at the University of Kentucky have documented that cows with poor mobility do not consume as much feed and lay for longer time periods. Less dry matter intake results in less production and long laying times, also exposing teat ends to more bacteria.
With over 10M dairy cows in the US and Canada and with an estimated 40% with minor to severe mobility problems even a $250 reduction in annual net income for those affected cows equates to annual losses of $1B. Additionally adding even half a lactation to every cow’s lifetime, that is going from 2.7 to 3.2 lactations, is worth billions.
Now, it is not possible to estimate what it would cost the dairy cattle industry if people outside of our industry were to stop buying our end products because the milk or milk products they consume could possibly come from lame cows.
The Bullvine Bottom Line
The challenge to improve the genetic merit of dairy animal mobility cannot be ignored. It is a necessity! Resources have been allocated to less important issues. The global dairy cattle improvement industry needs to stop saying that the challenge is too big, too costly, that there is no data or there are too many unknowns. Poor animal locomotion is a puzzle that must be solved!