By Boelling, D. and Pollott, G. E., Animal Breeding Abstracts, 1997
Description
A review. Feet and leg traits have always been an important issue in cattle breeding and husbandry as they are associated with lameness, and thus exert a major influence on the welfare and profitability of dairy cattle. Firstly, studies on measurements of foot angle and rear leg side view, which are included among the linear type traits and are assessed visually, are reviewed. Their h2 is generally low, but the genetic correlation between the 2 traits is negative and of medium magnitude. Research has concentrated on the genetics of additional feet and leg traits, such as traits of the pasterns, front legs and other foot traits. Some of these traits have been recorded on a binary as well as a continuous scale, and exhibit considerable genetic variation. Investigations on the interactions between locomotor traits and herd life reveal that foot angle has the greatest influence, cows with a steep foot angle surviving to a greater age than cows with a shallow foot angle. As lameness is mainly caused by hoof disorders, studies have concentrated on the genetics of hoof measurements and disorders. The most important hoof measurements are foot angle, claw length, heel depth and diagonal, of which foot angle and diagonal have the highest h2. The relationships between claw disorders and hoof traits measured on different feet and by different research groups are inconsistent and hence do not encourage their direct use in breeding programmes. Therefore, lameness and locomotion have been investigated directly in some studies. Generally, these 2 traits have low to very low h2. Finally, the relationships between locomotor traits and milk yield are reviewed. High milk yield is correlated with unfavourable conformation, which might indicate that breeding only for production traits increases the risk of feet and leg problems
A review. Feet and leg traits have always been an important issue in cattle breeding and husbandry as they are associated with lameness, and thus exert a major influence on the welfare and profitability of dairy cattle. Firstly, studies on measurements of foot angle and rear leg side view, which are included among the linear type traits and are assessed visually, are reviewed. Their h2 is generally low, but the genetic correlation between the 2 traits is negative and of medium magnitude. Research has concentrated on the genetics of additional feet and leg traits, such as traits of the pasterns, front legs and other foot traits. Some of these traits have been recorded on a binary as well as a continuous scale, and exhibit considerable genetic variation. Investigations on the interactions between locomotor traits and herd life reveal that foot angle has the greatest influence, cows with a steep foot angle surviving to a greater age than cows with a shallow foot angle. As lameness is mainly caused by hoof disorders, studies have concentrated on the genetics of hoof measurements and disorders. The most important hoof measurements are foot angle, claw length, heel depth and diagonal, of which foot angle and diagonal have the highest h2. The relationships between claw disorders and hoof traits measured on different feet and by different research groups are inconsistent and hence do not encourage their direct use in breeding programmes. Therefore, lameness and locomotion have been investigated directly in some studies. Generally, these 2 traits have low to very low h2. Finally, the relationships between locomotor traits and milk yield are reviewed. High milk yield is correlated with unfavourable conformation, which might indicate that breeding only for production traits increases the risk of feet and leg problems
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