Every year at "preg" checking time, ranchers evaluate cows and make
decisions as which to remove from the herd. One criteria that should be
examined to cull cows is udder quality. Beef cattle producers are not as
likely to think about udder health and shape as are dairy producers,
but this attribute affects cow productivity and should be considered. It
may be easier to be accurate in your culling decisions, if you exam the
udder soundness of the cows shortly after calving when they are at the
peak of lactation and the udder is as large as at any time. Take time
now during the peak of lactation to write down which spring-calving cows
have unsound udders. Record the cow numbers of those to be culled next
fall due to unsound udders. Their heifer calves would be undesirable
prospects to become replacement heifers for your herd.
The heritability estimates of udder characteristics are variable. A
study done in Brahman cattle for the heritability of udder soundness
indicated that progress could be made by selecting for udder
soundness. They reported that 25% of the differences in udder soundness
was due to genetics. Beef Improvement Federation Guidelines have
suggested that the heritability of udder soundness in beef cattle is
estimated at .16 to .22 which means that some progress can be made by
selecting against unsound udders.
Recent research at Kansas State University (Bradford, 2014 KSU
Cattlemen’s Day) with large numbers of Hereford data has given even
greater hope that improvement in udder quality can be made. They found
heritabilities of .32 for overall udder score, .31 for suspension, and
.28 for teat size. Plus, genetic correlations between traits were strong
(.83). This means that selection for one trait (teat size or
suspension) will result in improvement in the other trait.
An experiment conducted at the OSU Range Cow Research Center near
Stillwater gives some indication as to the impact of mastitis on beef
cow performance. They found that cows with one or two dry quarters had
calves with severely reduced weaning weights (50 - 60 pounds) compared
to cows with no dry quarters. This represents a sizeable economic loss
at weaning time.
An evaluation system for udder soundness has been developed and used
by some breeds. Teat shape and udder suspension are the two primary
characteristics evaluated.
