Interpretive Summary: The effect of cow udder score on subsequent calf performance in the Nebraska Sandhills
By: Lindsay Tretter
Overall milk yield and weaning weight have been shown to be highly correlated, where an ideal conformational udder may result in a greater weaning weight. Early postpartum conformational issues, such as enlarged nipple size, may impact milk yield negatively, due to a lack of stimulation by the calf. Low milk yield can ultimately lead to an overall lower weaning weight of the calf, which will impact the producers profit margin for time and money.
In a 1982 study, data showed that a cow with a reduced number of bottle teats could eject more pounds of milk to the calf. The study included 5 years worth of data from 812 cows in the Gudmundsen Sandhills Laboratory. On the ranch there are 2 calving herds with a greater incidence of bad udders in the may calving females. Visual teat scores at the time of calving were completed on a scale of 1 to 2 being bad, and 3 to 4 being good; the scale goes up to 5 however none of the cows in the study scored a 5.
It was observed that there was no interaction between calving season and calf performance, so the study only discusses the effect of udder score. There was no difference in calf weaning weight based on sex or good vs. bad uddered females. Feedlot performance data of steers showed no difference in body weight at entry or exit from the feedlot. There was also no difference in dry matter intake, or average daily gain of female offspring having a good or bad udder in the feedlot.
The carcass characteristics of the steers showed those from dams with a good udder, had higher hot carcass weight (HCW), back fat (BF), and yield grade. There was no difference in loin or marbling between dam udder type.
The presenter explained that the differences in HCW and BF between dams with a good udder vs. bad, where due to fat being more efficiently deposited. However, specifically how the udder impacts the carcass characteristics was not presented. It was noted that older cow could potentially skew the results due to an increased milk yield leading to a heaver low conformationally ideal udder.