Relationships Between Net Income, Days of Productive Life, Production, and Linear Type Traits in Grade and Registered Holsteins

¹ Department of Dairy Science, College of Agriculture and Life Sciences, Virginia Polytechnic and State University, Blacksburg 24061-0315

Relationships between production, linear type traits, relative net income (with opportunity for calving through 60 mo of age), relative net income adjusted for opportunity cost, and days of productive life were examined in Holsteins. Records were available for 7479 grade and 64,245 registered cows. Correlations between relative net income adjusted for opportunity cost and first lactation product value were .55 and .59 for grade or registered cows, .21 and .23 between relative net income adjusted for opportunity cost and dairy form, and .16 and .20 between relative net income adjusted for opportunity cost and final score. Partial correlations (adjusted for first lactation product value) were lower than simple correlations for dairy form and final score but were higher for fore udder attachment and udder depth in both grade and registered cows. Prediction of relative net income, relative net income adjusted for opportunity cost, and days of productive life with first lactation product value and an additional type trait showed very little increase in R² over use of first lactation product value alone. The increase in R² was greater for days of productive life than for the two net income functions. The most profitable cows were high producers. Physical characteristics of the cow did not enable prediction of lifetime profit with appreciably greater accuracy than production alone.

Key Words: type traits • production • longevity • income

Submitted on March 12, 1992
Accepted on July 31, 1992