Every dairy herd manager is well-aware of the negative effects that lameness and impaired mobility have on the bottom line. These negatives occur in the growing pen, in the milk pail, in poorer conception, and in extended days in the dry pen. Genetic progress has been made in some feet and leg areas. However, to this day, there is not an easily applied genetic-based selection formula that helps achieve a long-lived animal with healthy feet and excellent locomotion for dairy animals.
What Causes Lameness and Mobility Problems?
There are many causes for why dairy cattle suffer from lameness and impaired mobility – due to sub-par farm facilities and practices, diseases, genetics, nutrition, …etc.
To date, the focus for avoiding lameness has been on management. Regular hoof care, foot baths, animal exercise, and environment adjustments are front of mind for herd managers to minimize lame and immobile animals. As well, most farms have adopted feeding programs so that diets are balanced and do not contribute to problems.
How Do Dairy Farmers See the Genetic Improvement of Their Animals for Feet and Locomotion?
Farmers recently surveyed in the Alberta Lameness Reduction Initiative study reported that they primarily rely on their hoof trimmers and veterinarians for the hoof care of their animals. It is as if improvement through genetic selection is not considered possible. Some dairy farmers have moved to crossbreeding to improve the feet and mobility of their animals.
Clearly, farmers, at least in confined housing environments, have accepted that they must incur the added costs associated with frequently trimming all animals’ feet and the premature culling of problem animals. Currently, many Holstein farmers are also expressing concern over a recent increasing prevalence of cows with straight rear legs (side view) often also involving the lack of flex in rear leg joints (spastic paresis).
The bottom line, from a genetic perspective, is that farmers do not know which sires or bloodlines to use to genetically improve their animals’ feet and locomotion.
Does the Cost of Lameness Justify More Attention?
Both North American and European dairy industry officials estimate that every case of lameness in milking cows costs between $300 and $500 in lost net lactation income. That figure does not include the lost income for the cows that do not exhibit lameness but are not performing 100% in milk production. Nor does it include the increased replacement costs due to premature culling. Managers also must add on the lost opportunities and costs associated with calves, heifers and dry cows that are lame.
The short answer is that, with half the cows having at least one lameness case of their lifetime, lameness and impaired locomotion cost the global dairy industry big time in performance and profits as well as a negative consumer image for the industry.
Common Terms Are Not Used
Universal terms are not used throughout the dairy cattle world when it comes to defining problems associated with feet and animal movement.
ICAR uses the terms lameness and locomotion with data definitions for each. ICAR recommends that they be evaluated independently. Yet in many countries, including USA, Oceana and Nordic Countries, mobility is the term used instead of locomotion. In some cases, mobility may also be considered to cover both feet and an animal’s ability to move properly.
For this article, we will not be concerned with which terms are used but rather the steps needed to genetically index and then breed animals that are superior for their feet and their locomotion.
Is it Possible to Genetically Improve Lowly Heritable Traits like Feet and Locomotion?
Where once it was considered impossible to improve traits for which the heritability is low or for which there was no data, now much has changed. It started many years ago with the capture of data for genetic defects followed by calving ease, conception rates, udder health, … plus many more. What it took to move to eliminating these negative attributes was to implement methods of data capture either by farmer observations or laboratory analysis. Once there was an adequate amount of data, genetic evaluations were conducted. Then genetic indexes were used in animal selection with positive outcomes.
Traditional Thinking for Genetically Improving Feet and Locomotion
Having breed ideals, evaluating animals compared to those ideals, and producing genetic indexes for the ideal form for feet and legs has not stopped the downward slide in the genetic merit of animals for feet and locomotion. In the USA, the genetic correlation between Feet & Leg Composite (FLC) and longevity (PL) is zero (+0.08). In Canada, only the feet and leg descriptive traits heel depth and rear legs rear view have even a low moderate positive genetic correlation (+0.30 & +0.21) with longevity (HL). Genetically evaluating feet and legs solely on body form (type classification) should not take the entire blame that genetic improvement for feet and locomotion has not occurred. Without accurate genetic information for feet and locomotion, sires with inferior parents have not been excluded from entry into A.I.
Breeding to Avoid Hoof Disease Has Started
Data for foot diseases has recently been captured and forwarded by hoof trimmers to genetic evaluation centers which have produced Holstein sire genetic indexes for Hoof Health in Canada and Nordic Countries. (Read Bullvine’s “Put Your Best Foot Forward.”) Therefore, the process for having more useful genetic indexes for breeding healthy feet is started.
Recently published Cornell research findings from New York dairy farms shows that cows that become thin after calving are more prone to feet problems due to the loss of fat cushioning in their feet. The condition is known as loss of digital cushion thickness. Could it be that bulls that sire cows that are able to retain body condition, while early in lactation and producing heavily, are genetically superior for avoiding hoof health problems?
How Feet and Legs Function Now Drawing Attention
Currently, studies are underway in numerous universities, companies, and countries to capture lameness and locomotion data using cameras/devices/owner reporting. There are two uses for the data – on-farm animal management and conducting genetic evaluations. Of course, as with any system where genetic indexes are produced, all animals in a herd must be monitored and reported to achieve high genetic prediction accuracy. The extent of the traits evaluated varies from study to study and includes a degree of lameness, distribution of weight to each limb, back carriage, length of stride, ease of movement, … etc. One study currently underway is a survey by Lactanet on crampiness (inherited periodic spasticity) in dairy animals.
Dairy farmers can expect to see reports from these studies for both feet and locomotion in the next couple of years. The challenge then for dairy farmers will be how to interpret and use the sire indexes for the many different traits.
A Total Approach Is Need to Genetically Address Lameness and Lack of Proper Locomotion
The time has come for the silos between organizations and disciplines to come down. Silos when it comes to analyzing and combining all the data for feet and locomotion to arrive at identifying both superior and inferior animals. The scope of that data must include body parts, health/disease and the functioning of body parts. This data could also be captured and reported to genetic evaluation centers for heifers and genomic sires.
One study currently underway that combines all data areas is being led by CDCB and includes farmers, hoof trimmers, an electronic animal monitoring company and geneticists. A full description of the study can be found at https://www.progressivedairy.com/topics/a-i-breeding/cdcb-leads-efforts-to-reduce-lameness-with-genetics. The study has put in place a total data framework for feet and locomotion covering data from the farm to the genomic profiles.
The Bullvine Bottom Line
With dairy cattle breeding expanding to include health, animal care and efficiencies, the opportunity exists for all stakeholders in the milk production industry to address and support research and development on genetically improving the feet and locomotion of today’s dairy cattle.
Ultimately dairy farmers and the entire dairy cattle industry can be the winners. Lame animals and animals with inferior locomotion are dysfunctional. The desirable genes exist in dairy cattle, it is a matter of identifying the superior animals for genetically avoiding lameness and locomotion problems.
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