Apparent and standardized total tract digestibility by growing pigs of phosphorus in canola meal from North America and 00-rapeseed meal and 00-rapeseed expellers from Europe without and with microbial phytase1

An experiment was conducted to deter­ mine apparent total tract digestibility (ATTD) and standardized total tract digestibility (STTD) by grow­ ing pigs of P in canola meal, 00­rapeseed meal, and 00­rapeseed expellers. Canola meal and 00­rapeseed meal are the coproducts produced after the residual oil has been solvent extracted from the prepressed canola seeds and 00­rapeseeds, respectively, whereas 00­rape­ seeed expellers is the coproduct from 00­rapeseeds that have been only expeller pressed. Two hundred sixteen barrows (18.0 ± 1.5 kg initial BW) were allotted to 36 diets and 6 replicate pigs per diet. Five samples of canola meal from solvent­extraction crushing plants in North America, 8 samples of 00-rapeseed meal from solvent­extraction crushing plants in Europe, and 5 samples of 00­rapeseed expellers from mechanical­ press crushing plants in Europe were used in the experiment. Eighteen diets were prepared by including 40% of each source of canola meal, 00-rapeseed meal, or 00­rapeseed expellers in 1 diet. Eighteen additional diets were formulated by adding 1,500 units of micro­ bial phytase to the diets. The only source of P in the diets was canola meal, 00­rapeseed meal, or 00­rape­ seed expellers. Pigs were placed in metabolism crates that allowed for total fecal collection. Pigs were fed at 2.5 times their estimated energy requirement for main­ tenance. Ingredients, diets, and feces were analyzed for P, and the ATTD and STTD of each source of canola meal, 00­rapeseed meal, and 00­rapeseed expellers were calculated. A value for endogenous P loss of 190 mg/kg DMI was used to calculate the STTD of P. Results indicated that the ATTD and STTD of P for canola meal were not different from values obtained in 00­rapeseed meal, and the ATTD and STTD of P in 00­rapeseed meal were not different from values for 00­rapeseed expellers. The ATTD and STTD of P increased (P < 0.001) from 44.99 and 48.82% to 64.08 and 67.97% for canola meal, from 46.77 and 50.36% to 63.53 and 67.29% for 00-rapeseed meal, and from 44.83 and 48.60% to 69.18 and 72.99%, respectively, for 00­rapeseed expellers by adding microbial phytase to the diets. In conclusion, although the concentration of ether extract is much greater in 00­rapeseed expel­ lers than in 00­rapeseed meal and canola meal, the ATTD and STTD of P for these ingredients are not different, and addition of microbial phytase results in improved digestibility of P in canola meal, 00­rapeseed meal, and 00­rapeseed expellers.