Abstract
The digestibility (apparent) of P and other nutrients from the RSM, SBM and 2 batches of maize, wheat and barley was investigated in two experiments with 24 castrated male growing pigs. The effect of supplemental microbial phytase (1,000 U/kg) was also evaluated. The diets contained 25% RSM (Exp. 1) or 40% SBM (Exp. 2) and had no inorganic P. In each period of digestive trial, after 9 days of adaptation, faeces were collected for 5 days. The digestibility of P contained in the RSM and SBM was calculated by difference method. The P digestibility in maize, wheat, barley was on average 20, 34 and 36%, respectively. The digestibility of P in the RSM and SBM estimated from maize-based diets were 19 and 24 %, respectively. Kind of cereal grain had significant (p < 0.05) influence on the digestibility of P which was lower in the diets based on maize than wheat or barley. The digestibility of P significantly increased with the supplemental microbial phytase (on an average of 17%). Moreover, inclusion of enzyme into the diets positively affected digestibility of other nutrients, namely the protein and organic matter.