Canadian researchers took a look at just how variable heifer growth rates are between farms. To do this, they measured the heart girth circumference of 12- to 17-monthold heifers from 33 different farms in British Columbia. They converted the values to estimate bodyweight.
They also analyzed the effect of several factors, such as weaning method, time between weaning and moving to a new pen, size of the heifer group, frequency of regrouping heifers and times per day heifers were given fresh feed, on bodyweight. Only one variable was able to account for among-farm variation in heifer bodyweight, and that was average weight gain during the preweaning phase (i.e., 0 to 2 months of age).
"These results show considerable among farm variation in heifer weight gains, indicating that some farms are doing well, while others could improve performance," say the researchers. "Farms able to rear faster-growing heifers were also rearing faster-growing calves, suggesting that management of milk-fed calves is especially important."
The results were reported in July at the American Dairy Science Association's annual meeting in Phoenix.