Live Weight and Milk-Energy Yield in Holstein Cows

Abstract

Sixty-six records of 22 grade Holstein cows in a feeding experiment at Cornell for 3 successive seasons, show that milk-energy yield per unit initial live weight decreased with live weight during the first season, and increased with live weight during the second and third seasons. It is concluded that milk-energy yield tends to be a multiple of initial live weight (3 days after calving) under continued favorable, practical conditions.Sixty-one records of 32 daughters of the same Holstein bull in a breeding experiment at Beltsville show that milk-energy yield per unit average live weight decreased with live weight; 27 of the 61 records above average live weight show a similar tendency; 34 of the 61 records below average live weight show an opposite tendency. The 61 records show milk-energy yield per unit live weight is independent of age (r = −.01 ± .09); age-corrected milk is independent of age (r = −.07 ± .09). It is concluded that age-correction is an indirect way of allowing for live weight.