Prediction of Lifetime Relative Net Income from First Lactation Production and Individual Type Traits in Holstein Cows ,

Abstract

Official type classification data and Dairy Herd Improvement Registry production records of Holstein cows calving between January 1, 1967, and June 1, 1976, were used to estimate contributions of individual descriptive type traits evaluated in first lactation to lifetime profitability as measured by a profit function, relative net income. Relative net income estimated total profit from variables available through Dairy Herd Improvement. Contributions of individual type components to profitability were estimated from least squares constants adjusted for all descriptive type traits and for linear and quadratic effects of final score, first lactation production, age at first calving, herdlife opportunity, stage of lactation, and age when classified.For the model to predict total profit, regressions were most significant for udder traits. Significant positive regressions were for plain or coarse head; firmly attached high and wide rear udder; and desirable teat size and placement. Significant negative regressions were for narrow and pinched, loose or broken rear udder; lack of defined udder support; and winged shoulders.Differences in total profit for body, feet, and hind legs were relatively unimportant as compared with alternative codes for udder traits. Codes considered conformationally most desirable for rear udder, udder support, and teats were also most desirable for total profit.