Comparison of Culling Rates, Reasons for Disposal, and Yields for Registered and Grade Holstein Cattle

Abstract

Survival of cows was investigated using data from the USDA files for daughters of 199 Holstein sires with at least 500 progeny each. Records included cows that first calved from 1965 to 1980 (n = 1,145,616). A smaller subset of data (n = 199,982) was summarized for age at first and last record, termination codes, Modified contemporary deviations of milk yield, and calving intervals. Grade cows leaving the herd were more likely sold for low production and less likely sold for dairy. Modified contemporary deviations in first lactation averaged 339 kg for grade cows and 331 kg for registered cows. Cows with only one record had lower yields in first lactation by 589 kg (grade) and 506 kg (registered). Compared with cows with more than two lactations, cows with two records had lower yields in first lactation by 199 kg (grade) and 259 kg (registered) and longer first calving intervals by 3.5 d (grade) and 5.0 d (registered). Grade and registered daughters of these sires left herds at different rates and for different reasons.