By McDaniel, B. T., Zuchtungskunde, 1995
Description
The goal of evaluating feet and legs is to identify bulls that transmit resistance to lameness. To be effective, this must be done accurately, cheaply, and in the initial progeny test based on first lactation progeny. Our experience indicates that we must use traits of feet and legs that are easily and accurately scored by eye to be efficient when evaluating progeny groups. Actual measurements are certainly more accurate than scores for most if not all traits, but not enough so to be justified for large progeny groups. The heritabilities of single eye scores or judgements of most traits of feet and legs are usually low. Thus, efforts must focus on sire progeny groups rather than on individual cows. Our criteria fbi determining the relative value of individual claw and leg traits is their ability to predict longevity, individually and collectively. Leg traits that appear to best fit these criteria are leg set viewed from the rear and leg set viewed from the side. Higher foot angles have proven to be associated with longer life and fewer claw problems. Research in the Netherlands, Germany and our preliminary findings in the USA indicate claw diagonal predicts longevity more accurately than other individual claw traits or combinations of them. Eye judgements of locomotion will require careful standardization and continuous training of evaluators. For highest efficiency, 40 or more progeny of bulls should be scored in commercial herds once for 1-2 claw traits, 1-2 leg traits, and locomotion. The goal of scoring or measuring claw and leg traits is to increase animal well-being, reduce lameness and the true costs of producing milk
The goal of evaluating feet and legs is to identify bulls that transmit resistance to lameness. To be effective, this must be done accurately, cheaply, and in the initial progeny test based on first lactation progeny. Our experience indicates that we must use traits of feet and legs that are easily and accurately scored by eye to be efficient when evaluating progeny groups. Actual measurements are certainly more accurate than scores for most if not all traits, but not enough so to be justified for large progeny groups. The heritabilities of single eye scores or judgements of most traits of feet and legs are usually low. Thus, efforts must focus on sire progeny groups rather than on individual cows. Our criteria fbi determining the relative value of individual claw and leg traits is their ability to predict longevity, individually and collectively. Leg traits that appear to best fit these criteria are leg set viewed from the rear and leg set viewed from the side. Higher foot angles have proven to be associated with longer life and fewer claw problems. Research in the Netherlands, Germany and our preliminary findings in the USA indicate claw diagonal predicts longevity more accurately than other individual claw traits or combinations of them. Eye judgements of locomotion will require careful standardization and continuous training of evaluators. For highest efficiency, 40 or more progeny of bulls should be scored in commercial herds once for 1-2 claw traits, 1-2 leg traits, and locomotion. The goal of scoring or measuring claw and leg traits is to increase animal well-being, reduce lameness and the true costs of producing milk
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