Profit rate for a meat production enterprise can be decomposed into the unit price for meat and herd efficiency.

Optimal slaughter mass maximizes herd efficiency which, at its maximum, can be expressed in terms of a product of powers of growth and reproduction efficiencies. Likely regions of optimality for slaughter mass are indicated for cattle, sheep, pigs and chickens. Herd efficiency is tabled in terms of percentages of reproduction efficiency and the allometric slope between body mass and cumulate feed intake. Optimal replacement involves either the minimum or maximum rate that can be achieved, and depends on the relative costs and output involved in the keeping of different age classes of reproduction animals. Finally, the relationship between replacement rate and herd age structure is explained.

Keywords:   Breeding objectives, herd efficiency, meat production, replacement rate, slaughter mass