Effect of reduced dietary calcium on the performance of growing-finishing pigs

The effect of reduced dietary Ca on the performance of 160 growing-finishing pigs is assessed. The current recommendation of 9 g per kg diet is compared to a level calculated as 2.9 times the digestible P dietary content. Because microbial phytase may not only improve P, but also Ca digestibility, two additional feeding regimens are used to evaluate the equivalency of 0.5 g of Ca per 250 FTU from Natuphos®. Irrespective of the treatment, digestible P are 2.5 and 2.0 g per kg, in the growing and finishing diets, respectively.There is no significant diet effect on zootechnical performances and carcass characteristics. The average mineral content of external metacarpal exceeds 50 % of dry matter for all treatments. This experiment demonstrates that dietary Ca may be reduced by 15 and 30 %, in growing and finishing diets, respectively. In practice, it is relevant to retain a Ca to digestible P ratio of 2.9, and reduce the dietary Ca in diets supplemented with microbial phytase by 0.5 g for 250 FTU.