Economic values of traits for pig improvement. II. Estimates for New Zealand conditions

A computer model simulating life cycle production of a breeding sow and growth performance of her offspring was used to estimate economic values of reproduction and growth performance traits. The model simulated digestion and metabolism of dietary nitrogen in growing pigs (20 to 85 kg), based on the linear/plateau relationship between daily protein deposition and digestible energy intake. Economic values (EVs) of reproduction and growth performance traits were calculated by simulating effects of genetic changes in several biological components, in a farrow-to-finish production system, assuming ad libitum feeding. Results demonstrated that economic values of traits depended on the average genetic merit in the pig herd and its interaction with the management circumstances (level of feeding, nature of the diet, life cycle length) of the production system.