PSIV-14 - Feeding Broiler Chicks with S. pombe-expressed Phytase-containing Diet Improves Growth Performance, Phosphorus Digestibility, Toe Ash, and Footpad Lesions

Abstract: A total of 390 one-day-old broiler chicks with an average initial body weight of 42.15 ± 0.17 g were used to evaluate the effects of dietary supplementation of S. pombe-expressed phytase on growth performance, apparent ileal digestibility, organ indexes, meat quality, toe ash, and footpad lesions score. All birds were randomly assigned to 5 groups based on the initial body weight (42.15 ± 0.17 g), there were 6 replicate cages per treatment and 13 birds (mixed sex) per cage. The experimental period was 45 days, including 4 periods (starter, days 1-10; grower, days 11-24; finisher 1, days 25-38; finisher 2, days 39-45). Dietary treatments were based on a corn-soybean meal-basal diet and supplemented with 500, 750, 1000, and 1500 FTU/kg S. pombe-expressed phytase. One phytase unit (FTU) was defined as the amount of enzyme that catalyzes the release of one micromole phosphate from phytate per minute at 37°C and pH 5.5. The inclusion of increasing levels of phytase in the diet linearly increased the body weight gain during days 1-10 (P = 0.001), 25-38 (P = 0.016), 39-45 (P = 0.018), and 1-45 (P = 0.004), feed intake during days 25-38 (P = 0.032), feed conversion ratio during days 1-10 (P = 0.001), 39-45 (P = 0.038), and 1-45 (P = 0.012), carcass weight (P = 0.035), toe ash (P < 0.001), and apparent ileal phosphorus digestibility (P = 0.049). However, the footpad lesions score (P = 0.040) decreased linearly with the increase in phytase levels in the diet. Therefore, dietary supplementation of S. pombe-expressed phytase was beneficial to the growth performance, toe ash, apparent ileal phosphorus digestibility, and footpad lesions of broiler chicks in a dose-dependent manner.