Efficiency of Animal Production—Molding the Biological Components

Abstract

Major biological objectives in reducing production costs per unit of animal product value seem to be (1) greater total product value per female (e.g., milk, wool, eggs) relative to metabolic body size, (2) higher rate of reproduction, especially in cattle and sheep, to reduce breeding herd costs per meat animal marketed, (3) more efficient lean growth to market live weight and earlier sexual maturity, with minimum increase in mature size of females, especially in cattle, and (4) combining female (milk or wool) production and progeny lean meat production under intensive management. Changes in management systems and in product values will modify specific biological objectives and hence need to be anticipated as well as possible. Breeding programs need balanced emphasis on (1) evaluation and utilization of existing breed differences in commercial livestock production, and (2) continuing genetic improvement within the pure breeds or strains.