Foot and Leg Scores

Quality foot and hoof structure in beef cattle favorably contribute to the longevity of beef cows and bulls by reducing voluntary culling due to poor or malformed feet or involuntary culling due to injury or lameness. Seedstock and commercial beef producers have long recognized the importance of foot/hoof soundness. However, unlike type-trait evaluation in the dairy industry, recommendations for the appraisal and genetic evaluation of feet and leg structure in beef cattle have only recently been explored.

Phenotype

A number of hoof, foot and limb attributes may be suitable for genetic evaluation. Several studies include the use of conformation data scored separately for front and rear leg phenotypes . Scores taken for hoof, foot, and limb attributes are typically taken at yearling age, but can also be evaluated annually on mature cows.

Hoof, foot and leg scores should be gathered using a subjective measurement on a 1-9 scale, with the optimum falling in the middle of the scale. A visual rubric is helpful in scoring phenotypes.

Animals should be evaluated on dry, hard, level ground under good lighting. Observers should have a clear and unobstructed view of the animal’s feet and should observe the animal while standing still. Animals should not be evaluated in a chute or other restraint.

BIF recommends that organizations establish a minimal set of phenotypes that can be routinely scored and meet the improvement objectives of the breeders. BIF recommends, at a minimum, organizations collect claw set/shape and foot/hoof angle using a 1-9 rubric.

Hoof Claw Shape:

Hoof claw shape is described as the relative size and curvature of the lateral and medial claw on an individual hoof where the distance between claws serves to indicate the level of divergence. A score on the low end of the scale represents an extremely weak, open and divergent claw set, where a score on the high end represents an extreme scissor or corkscrew claw with noticeable curling of one or both claws. BIF recommends to score the worst hoof.

Hoof Angle:

Hoof angle is measured as the degree of angularity from the toe and the base of the hoof to the base of the coronary band. Heel depth plays a significant role in hoof angle. A score on the low end of the scale represents an extremely straight and rigid pastern and hoof, where a score on the high end represents an extremely shallow heel and long claw, which is commonly associated with weak pasterns. BIF recommends to score the worst hoof.

Animals to evaluate

Phenotypes should be collected on yearling bulls and heifers, evaluating all animals in the contemporary group. Cows and bulls may also be evaluated annually. It is suggested to collect these records while collecting other mature animal phenotypes such as mature weights or heights. Breeds may adopt reporting strategies to gather this information coincidental to other phenotypes (yearling weights or mature weights) or breeders may submit this data independently. Animals should be evaluated prior to any foot or hoof trimming.

Scorer/technician training or certification

Some breeders may feel unequipped or undertrained to provide a reliable and consistent evaluation of these phenotypes. BIF recommends that organizations develop a standardized rubric or scoring criteria based on the information provided in these Guidelines. Images illustrating each category of the phenotype are useful in both training and routine observation to provide a consistent application of the scoring system. It may be useful to provide hands-on training events at expositions or field days to assist breeders in skill set development. Further, online training modules may prove useful.

Adjusted Value

No adjustments factors have been developed for foot and leg scores.

Contempory Group

Foot and leg contemporary group is a group of yearling animals of the same sex, of similar age and have been raised in the same management group. It is best to score whole contemporary groups for all hoof, foot and leg traits on the same day.

Because foot and leg traits may change over time, mature cows may be scored once annually until removed from the herd. Mature cow foot and leg contemporary grouping is defined as the herd and year born. It is suggested to collect these records while collecting other mature animal phenotypes such as mature weights or heights.

Organizations may adopt reporting strategies to gather this information coincidental to other phenotypes (yearling weights or mature weights) or breeders may submit these data independently. Mature bulls should not be scored for feet and leg traits for use in a genetic evaluation. Rarely will whole contemporaries of mature bulls be available for an accurate comparison.

Genetic Evaluation

American Angus

The American Angus Association began gathering hoof and foot phenotypes in 2015 and in 2018, began genetic evaluation of two research foot score EPDs (claw set and foot angle). Although repeated observations may be available on individuals, the current processes use only the most recent observation in the genetic evaluation. Thus, scores from mature cows are included in the evaluation and may replace an animal's score from a yearling observation. The evaluation uses only scores 5-9 in the evaluation; censoring out scores 1-4. A low (closer to zero) EPD produces animals closer to a score of five within each trait. The EPDs of sires with some accuracy range to ~0.80 units of score. The genetic evaluation is conducted using two univariate models including age at measure as a covariate. Scores 1-4 may be evaluated as a separate trait if needed but are currently not considered. Contemporary groups are included as a fixed effect and consists of Yearling Group (previously divided by gender) and a separate management code for further division. At present no genetic correlation between traits is fit. Heritability of both traits is ~25%.

Future

Currently, no other U.S. beef organizations produce foot and leg genetic predictions. However, several organizations are interested in collecting data and producing EPDs to improve structural soundness. The guidelines presented here provide for a framework on which to build an improved genetic prediction. Identifying correlated traits and utilizing all scores may substantially enhance the value of future EPDs.

Usage

Hoof, foot and limb traits are useful for defining soundness in beef cattle. Foot and leg scores serve as indicator traits for longevity (Boldman et al. 1990; Foster et al. 1989; and Rogers et al. 1989). Foot and leg scores are indicator traits and should not be considered as ERT.

Foot and leg scoring of mature cows and bulls can be a useful herd management tool. Also, evaluating candidate replacement heifers and yearling bulls prior to sale is important to avoid problems.

Attribution

This article is derivative of work performed by the BIF DRAFT Foot and Leg Guidelines sub-committee and Lane Giess.

Chairman: Bob Weaber, K-State

Members: Mark Enns, Colorado State; Dan Moser, Angus Genetics Inc.; Kajal Devani, Canadian Angus Association; Lane Giess, American Simmental Association; Joe Mushrush, Mushrush Red Angus; Matt Perrier, Dalebanks Angus; Megan Rolf, K-State; Lauren Hyde, American Simmental Association