Department of Animal Science, Federal University of Paraná, Curitiba, Brazil, 80035-050.
Department of Animal Science, Federal University of Paraná, Curitiba, Brazil, 80035-050.
Poult Sci. 2021 Mar;100(3):100917. doi: 10.1016/j.psj.2020.12.015. Epub 2020 Dec 11.
This study evaluated the effects of high phytase doses and soybean meal (SBM) with different CP content on growth performance, ileal nutrient digestibility, digestible energy, plasmatic myo-inositol, phosphate release in vitro, and bone composition of broiler chickens. One thousand two hundred 1-day-old broilers were distributed in a 2 × 2 completely randomized factorial arrangement, with 2 phytase doses (1,000 and 2,500 phytase units [FYT]/kg of feed) and 2 SBM with different CP concentrations (45 and 47%), totaling 4 treatments with 12 replicates of 25 birds each. The chickens received feed and water ad libitum. Diets were based on corn and SBM, with different inclusions of soybean hull used to dilute the CP content of SBM according to each treatment. The inclusion of 2,500 FYT increased weight gain from 0 to 21 d (P < 0.05), whereas growth performance from 22 to 42 d was not affected, and SBM had no effect on growth performance. At day 21, ileal digestibility of dry matter, ash, and P, and digestible energy were greater in diets with 2,500 FYT/kg (P < 0.05), as well as phosphate in vitro release (P < 0.01) compared to the lower dose. At day 42, diets with SBM 47% CP and 2,500 FYT/kg promoted greater digestibility of dry matter, ash, CP, Ca, P, and digestible energy (P < 0.001), and greater phosphate release (P < 0.05) in comparison to other treatments. myo-inositol level in the plasma at 21 and 42 d was higher with the use of 2,500 FYT compared to 1,000 FYT (P < 0.05). The higher phytase dose increased tibia ash, toe ash, and Seedor Index (P < 0.05) at day 21, and the Ca content in tibia was higher with 2,500 FYT and SBM 47% CP at day 42. In conclusion, higher phytase doses for broilers improve weight gain, myo-inositol provision, and bone mineral composition. Nutrient ileal digestibility can be enhanced by higher phytase doses when in combination with SBM of greater nutritional quality.
本研究评估了高植酸酶剂量和不同 CP 含量的大豆粕（SBM）对肉鸡生长性能、回肠养分消化率、可消化能、血浆肌醇、体外磷酸盐释放和骨骼组成的影响。1200 只 1 日龄肉鸡采用 2×2 完全随机因子设计进行分配，设 2 个植酸酶剂量（1000 和 2500 植酸酶单位[FYT]/kg 饲料）和 2 个 SBM 具有不同的 CP 浓度（45 和 47%），共计 4 种处理，每个处理有 12 个重复，每个重复 25 只鸡。鸡自由采食饲料和水。日粮以玉米和 SBM 为基础，根据每个处理，用不同比例的大豆皮来稀释 SBM 的 CP 含量。添加 2500 FYT 增加了 0 至 21 日龄的体重增加（P<0.05），而 22 至 42 日龄的生长性能不受影响，SBM 对生长性能没有影响。在 21 日龄时，高剂量植酸酶组的干物质、灰分和 P 的回肠消化率以及可消化能（P<0.05）高于低剂量组，体外磷酸盐释放（P<0.01）也更高。在 42 日龄时，SBM 47%CP 和 2500 FYT/kg 组的干物质、灰分、CP、Ca、P 和可消化能的消化率更高（P<0.001），磷酸盐释放更高（P<0.05）。与使用 1000 FYT 相比，使用 2500 FYT 使血浆中肌醇水平在 21 和 42 日龄时更高（P<0.05）。较高的植酸酶剂量在 21 日龄时增加了胫骨灰分、脚趾灰分和 Seedor 指数（P<0.05），而在 42 日龄时，胫骨中钙的含量随着 2500 FYT 和 SBM 47%CP 的增加而增加。综上所述，高剂量的植酸酶可以提高肉鸡的体重增加、肌醇供应和骨骼矿物质组成。当与营养价值更高的 SBM 结合使用时，较高的植酸酶剂量可以提高养分的回肠消化率。
