A variety of environmental and genetic factors affect udder quality in cows under six years of age. We assume these cows were spring calving based on when they were culled. Although no breeds were mentioned, there are substantial differences between breeds for udder conformation. Likewise, there is as much variation within breeds. The quality of udders in beef cows is under a moderate amount of genetic control. Estimates indicate that 20 to 30% of the variation in udder quality is due to genetics, while the balance is environmental.
Some producers have experienced more udder problems in cows that calve in summer (May-June-July) versus winter or spring calving. The increased incidence of teat and udder problems in summer calving cows is likely due to a high plane of nutrition after calving. This higher level of nutrition enables the cows to divert more energy to lactation, which increases milk volume and places additional stress on udder conformation. The high plane of nutrition can be compounded by having cows in high body condition scores at calving. This effect has been noted in summer calving season but could also be associated with supplementation strategies that dramatically increase energy intake in cattle after calving or with cows that are in high body condition at calving.
We often refer to “bad bags” or “udder score,” but actually the most important component is 1) teat size and shape, followed by 2) udder suspension. A 1 to 5 udder score (5 = best, 3 =average, 1= cull) is simple and can be quickly taught. Several breeds have different systems for reporting seedstock data.
Again, the major emphasis should be on teat size and shape. Not nearly enough seedstock breeders score their cows at calving for “udder score” and castrate bulls from bad udder cows. Commercial producers should at least note cows with bad udders and avoid saving a replacement heifer from such a cow. If replacement heifers are raised, a “bad mark” system of identification (flag on paper record or notch on tag/ear) should allow you to avoid daughters of cows with bad udders. If replacements are purchased, investing some time in locating supplier herds that have a program to enhance udder function might pay dividends over the long haul.