Feeding Pigs Without Inorganic Phosphate Supplementation from Weaning to Slaughter: Contribution to More Sustainable Swine Production

The viability of raising pigs from weaning to slaughter with inorganic phosphorus (iP)-free diets using a hybrid 6-phytase was tested in two trials. Three experimental diets were formulated: T1, a control diet with monocalcium phosphate (MCP); T2, a diet without MCP + phytase (P and Ca phytase matrix formulation); and T3, a diet without MCP + phytase (P, Ca + extra nutrients in a phytase matrix formulation). Rapeseed and sunflower meal were used in addition to soybean meal as protein sources, in order to increase the phytate-P content. Performance was monitored from weaning to slaughter, and bones were sampled at the slaughterhouse to test for bone mineralization. In the second trial, gait scores were also assessed at 75, 110, and 134 days. Weight gain was not significantly affected by treatment in either trial. However, in Trial 1, males receiving T2 had a reduced overall feed efficiency than males receiving T1, whereas in Trial 2, a reduced overall feed efficiency was observed for T3 relative to T2 (p < 0.05), probably due to the extra nutrient reduction. No differences in bone mineralization or gait score were observed. In conclusion, it is possible to raise pigs without iP by using phytase in feeds containing phytate-P. This may contribute to more sustainable pig production with reduced P excretion and lower usage of rock phosphate, a limited resource.