PERFORMANCE AND CARCASS EVALUATION OF SWINE FED FINISHING RATION WITH PHYTASE ASSOCIATED WITH THE WITHDRAWAL OF MICROMINERAL-VITAMIN SUPPLEMENT AND THE REDUCTION OF INORGANIC PHOSPHORUS

Abstract

The experiment aimed to evaluate the effect of phytase enzyme in rations for swine at the finishing phase without the use of mineral-vitamin supplement and with reduced levels of inorganic phosphorus on performance and carcass characteristics, ashes and mineral percentage in the bones and economic viability. Twenty-four hybrid females with starter weight of 66 ± 1.4 kg and final weight of 106 ± 1.8 kg were housed for 38 days in 24 stalls and allotted in a completely randomized experimental design with six treatments and four replications of two animals each. The following treatments were used: T1 –­­ basal feed; T2 – basal feed without micromineral-vitamin supplement; T3 – basal feed with phytase and without micromineral-vitamin supplement; T4 – basal feed with phytase, without micromineral-vitamin supplement and without 1/3 of inorganic phosphorus; T5 – basal feed with phytase, without micromineral-vitamin supplement ans without 2/3 of inorganic phosphorus; and T6 – basal feed with phytase, without micromineral vitamin supplement and without inorganic phosphorus supplementation. The withdrawal of the micromineral-vitamin supplemet, the reduction of inorganic phosphorus level and the addition of phytase enzyme did not affect (P>0.05) the carcass characteristics, but they reduced (P<0.05) feed intake and weight gain, and showed worse feed conversion. Likewise, reduction of inorganic phosphorus levels and  phytase addition did not improve economic efficiency when compared to basal feed.
KEYWORDS: Enzyme, finishing phase, pig, ration, weight gain.