Phytase in Pig Diets: Technical and Economic Evaluation

Despite the widespread use of phytase in swine diets, there is a need to update the current evidence on its effects on performance, carcass traits, and economic outcomes. This meta-analysis evaluated the impact of phytase supplementation on growth performance, carcass traits, and economic returns in growing–finishing pigs, combining meta-analysis with economic modeling. A systematic review (Web of Science, ScienceDirect, PubMed, and Scopus) revealed 1049 studies, 17 of which met the inclusion criteria (PRISMA). Three treatments were considered: a basal diet (BD), a reduced-P diet without phytase (DRP), and a reduced-P diet with phytase (DRP + P), with effect sizes expressed as weighted mean differences (WMDs). The meta-analysis included performance traits (daily feed intake, DFI; daily weight gain, DWG; feed conversion, FC; and final weight, FW) and carcass traits (carcass weight, CW; carcass yield, CY; backfat thickness, BT; loin eye area, LEA; lean meat percentage, LMP; and lean meat yield, LMY). With respect to BD vs. DRP, P reduction impaired performance and decreased ADG, DFI, and final weight (p < 0.001), especially at reductions ≥0.12%. In DRP + P vs. BD, phytase had no significant effects on performance (WMD = 0.008 kg/day) or carcass traits. In DRP + P vs. DRP, phytase improved performance (ADG: +0.068 kg/day; DFI: +0.106 kg/day; FW: +4.630 kg; FC: −0.115; p < 0.001), with stronger effects in males and at greater P reductions. In DRP + P vs. DB, carcass traits were not significantly affected, whereas DB vs. DRP reduced LEA (WMD = −1.820, p < 0.00), and DRP + P vs. DRP produced subgroup-dependent changes in CW, LEA, and LMY according to sex, phytase source, and diet composition. Economically, phytase increased profit by up to US$ 2.66 (vs. BD) and US$ 5.14 (vs. DRP), remaining advantageous even with enzyme price increases of up to 4×. Overall, phytase supplementation improved performance and economic returns, representing an effective strategy for the development of swine production systems.