In today’s cow-calf production environment with high replacement and development costs for females, the ability of a cow to produce a calf every year and remain in the herd for an extended time becomes increasingly valuable. Researchers in Brazil recently reported on an extended analysis of cow productivity, stayability and growth, based on 30 years of data from 70 locations. Cattle types in the analysis included Brazilian Nelore cattle and composite breeds including influence from Bos indicus and tropically adapted English and Continental Bos taurus breeds. The researchers analyzed relationships between traits including post-weaning gain, yearling weight, scrotal circumference, stayability and average annual cow production. They defined “stayability” as calving every year, if given the opportunity to breed, to six years of age. They calculated an index for cow production based on a combination of cow fertility and calf growth.
The researchers found that cow production and stayability were highly genetically correlated, while genetic correlations between post-weaning gain, yearling weight or scrotal circumference with cow production or stayability were all low. Estimates of annual genetic change were positive for all five traits. The authors concluded that simultaneous selection for growth, productivity and stayability is possible.