Effects of a novel 6-phytase (EC 3.1.3.26) on performance, phosphorus and calcium digestibility, and bone mineralization in weaned piglets

A trial was conducted with 144 weaned pigs (26 d of age) to evaluate a newly developed bacterial 6-phytase (Enzyme Commission number [EC] 3.1.3.26) at different dose levels. Pigs were kept in 48 pens and fed 6 diets consisting of a positive control (PC; adequate in Ca and P), a negative control (NC; limiting in Ca and P), and the same NC supplemented with 125, 250, 500, or 1,000 phytase units (FTU)/kg of the phytase under test. Piglets' performance (for 42 d) and Ca and P apparent total tract digestibilities (ATTD) were investigated using TiO2 as an indigestible marker. Mineralization of the left os metacarpale III from 8 piglets per treatment was also determined at d 48. Piglets on the PC and the phytase-supplemented diets had higher ADG and ADFI than those on the NC diet (P < 0.05). Phytase improved ATTD for P at all levels and for ash and Ca at levels above 250 FTU/kg compared with the NC (P < 0.05). The os metacarpale III of pigs fed the phytase diets had higher weight and ash content than those of pigs fed the NC (P < 0.05). Linear responses (P < 0.05) to phytase addition were observed for ADG, ADFI, and G:F; P, Ca and ash ATTD; and os metacarpale III weight and ash content. It is concluded that the novel 6-phytase strongly improves performance, Ca and P digestibility, and bone mineralization in piglets fed Ca- and P-limiting diets.