Growth Patterns in Swine

Postweaning rate of growth appears to be linear, or nearly so, for the ages and weights likely to be utilized in the near future. Furthermore, rate of growth is highly correlated with feed efficiency. Since maternal maintenance costs are restricted by limit feeding of the breeding herd, high mature weights are not realized and are of little concern to swine programs. Therefore, rate of growth is of major interest in swine breeding programs. Backfat, fat and protein depositions in the carcass are nearly linearly associated with increases in weight or age. Since fat increases more rapidly than protein, there is a gradual, constant change in their relative proportions. The decrease in feed efficiency with increasing weights is primarily due to increased maintenance costs and not to increased fat deposition.