Dietary energy levels for growing-finishing pigs fed ad libitum. 1. Growth performance

The NRC (1988) recommendations on nutrient standards for growing-finishing pigs assume a corn-based feeding regimen. However, the diets used in Western Canada are generally barley-based and consequently are usually lower in digestible energy (DE) and result in lower performance. Two experiments were therefore conducted, to evaluate the effect of DE level in relation to growth and feed conversion of pigs, by inclusion of corn and wheat in pelleted diets offered ad libitum. A total of 432 pigs was used, over the 20-98 kg live weight range. The inclusion of wheat or corn to barley-based diets during the grower period to raise the DE level resulted in more rapid and efficient growth. The faster growth obtained with the high-energy grains occurred during the grower period only, and was not observed in the finisher period. Results of including 5% of acidulated fatty acids (AFA) to raise the DE level were unfavourable.