Adição de fitase concentrada na alimentação de suínos na fase de crescimento e terminação (25 a 135 kg)

Abstract

Concentrated doses of phytase are used to obtain better results in non-ruminant animals, with improvements in performance and digestibility. Therefore, this study was conducted to evaluate the effect of the inclusion levels of concentrated phytase in diets with reduced nutritional requirements of 22.73% calcium, 48.39% phosphorus, and 20% sodium, on zootechnical performance, nutrient digestibility, blood biochemical parameters of pigs in the growth and finishing phases, carcass characteristics, and meat quality. Forty-two entire male pigs (24.52 ± 0.84 kg BW) were used, assigned in a randomized block design with six treatments: (1) Positive control (PC) without phytase and without reduction of calcium, phosphorus, and sodium; (2) Negative control (NC) without phytase and with a reduction of 22.73% calcium, 48.39% phosphorus, and 20% sodium reduction; (3) Negative control with the addition of 500 FTU/kg phytase and mineral reduction (NC+500) (4) Negative control with the addition of 1000 FTU/kg phytase and mineral reduction (NC+1000) (5) Negative control with the addition of 1500 FTU/kg phytase and reduction of minerals (NC+1500); (6) Negative control with the addition of 2000 FTU/kg phytase and reduction of minerals (NC+2000). The experimental period was 93 days divided into four phases: growth I, growth II, finishing I, and finishing II (99.60 ± 5.13 kg to 128.61 kg ± 6.35 kg). The apparent digestibility coefficients of the nutrients were evaluated. Biochemical parameters and zootechnical performance of the animals were also evaluated. All statistical analyses were performed using the General Linear Models procedures of the SAS University Edition statistical software. For the performance variables in growth phases I and II, animals fed the NC diet had (P = 0.035) lower feed intake, with similar intake to the NC+500, NC+1500, and NC+2000 treatments. In the finishing phase II, the effect on feed intake was (P = 0.008) for animals fed the NC, NC+500, and NC+2000 diets, which showed lower intake. There was no effect on blood parameter variables. Regarding digestibility, in the growth phase, the treatments with phytase presented higher coefficients of digestibility of dry matter, organic matter, gross energy, crude protein, calcium, phosphorus, digestible dry matter, digestible energy, and digestible protein, compared to the positive treatment. In the finishing phase, the positive control treatment showed the highest values for most variables, followed by the treatments with phytase, with the NC+2000 treatment showing the lowest performance. Effects were obtained for carcass temperature 24 hours post mortem (P=0.005), liquid loss due to thawing (P=0.024), and shear force (P=0.041). It was concluded that the best concentration to be added to the feed of pigs in the growth phase is 1,100 FTU/kg of feed, and for the finishing phase, 1,500 FTU/kg of feed.