Research published in the March Journal of Dairy Science indicates that using genetic selection tools for body weight can make a difference in cow health.
Researchers from the University of Milan, Penn State University and Virginia Tech University tracked the body weight and body weight changes of 513 Holstein cows in the research herds at Penn State and Virginia Tech.
They conclude that body weight is a moderately heritable trait, and significant genetic relationships of body weight and body weight change with ketosis, metabolic diseases and infectious diseases suggest that selection for body weight traits could limit unfavorable changes in cow health when selecting for higher milk yields.
They suggest that installing automated cows weighting systems in progeny test herds could facilitate genetic evaluations of daily body weight and body weight change across lactations. “High heritability estimates suggest that daily measurements from a subset of progeny test daughters of a bull would help identify sires whose daughters lose less body weight during early lactation during early lactation,” the researchers note.
Furthermore, they add, associations of body weight and body weight change PTA (predicted transmitting ability) with genomic PTA also indicate that selection for less dairy form will help limit early-lactation body weight loss.