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

摘要

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.