Song Xuerong, Cheng Veronica, Xu Li, Gituanjah Faith, Kibathi Chelsea, Garcia Bianca, Njeri Felix, Bakhshalinejad Reza, Wu Xiuyi, Kiarie Elijah G
Wuhan Sunhy Biology Co. Ltd., Wuhan, China.
Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada.
Poult Sci. 2025 Aug 6;104(11):105644. doi: 10.1016/j.psj.2025.105644.
A total of 2,060 d old male Ross x Ross 708 chicks were placed (22 birds/pen; Exp. 1) and (5 birds/cage, Exp. 2) to determine non-phytate phosphorous equivalence (NPPE) for a novel E. coli phytase in corn and soybean meal-based diets. Broiler chickens were fed common starter and transitioned to experimental diets for grower (d 8-21) and finisher (d 22-35) phases. Diets were formulated to meet specifications except for available P (AvP) that was reduced by 0.05 percent unit by adjusting monocalcium phosphorous (MCP) to create five titration diets. Phytase was supplemented in the diet with the lowest AvP at 250, 500, 1,000, 1,500 and 2,000 FTU/kg to create 10 test diets per phase. Diets were allocated to 8 (Exp. 1) and 6 (Exp. 2) replicates. Feed intake (FI), body weight (BW), BW gain (BWG), FCR, and bone attributes (breaking strength, BS, and ash content) were evaluated in Exp. 1, and apparent retention (AR) of Ca and P in Exp. 2. The BWG, FCR, and bone trait data were fitted in regression functions to estimate NPPE. Overall, increasing AvP linearly improved (P < 0.01) d 35 BW, BWG, FI, FCR, and BS. Overall (d 8-35) BWG, tibia and femur ash content increased linearly and FCR linearly and cubically in response to phytase (P < 0.05). The average NPPE values for the BWG and FCR during the grower phase were 0.060, 0.139, 0.175, 0.193, and 0.232 % at 250, 500, 1000, 1500, and 2000 FTU/kg, respectively. The corresponding values for the finisher phase were 0.122, 0.220, 0.316, 0.364, and 0.470 %, respectively. The average NPPE values for tibia and femur attributes were 0.075, 0.128, 0.180, 0.193 and 0.206 %, respectively for 250, 500, 1000, and 2000 FTU/kg. In conclusion, the study demonstrated the efficacy of the phytase in releasing phytate-bound P in corn and soybean meal diets, resulting in commensurate or superior growth and bone traits to diets enriched with inorganic P. The NPPE values will be valuable in formulating broiler chicken feeds.
总共2060只1日龄的罗斯×罗斯708雄性雏鸡被分组饲养（试验1每组22只；试验2每组5只），以确定一种新型大肠杆菌植酸酶在以玉米和豆粕为基础的日粮中的非植酸磷当量（NPPE）。肉鸡先饲喂普通的开食料，然后过渡到用于生长阶段（8至21日龄）和育肥阶段（22至35日龄）的试验日粮。日粮的配制符合规格要求，但可利用磷（AvP）除外，通过调整磷酸二氢钙（MCP）将其降低0.05个百分点，以配制五种滴定日粮。在最低AvP的日粮中分别添加250、500、1000、1500和2000 FTU/kg的植酸酶，每个阶段配制10种试验日粮。日粮被分配到8个重复组（试验1）和六个重复组（试验2）。在试验1中评估了采食量（FI）、体重（BW）、体重增加（BWG）、饲料转化率（FCR）和骨骼特性（断裂强度，BS，和灰分含量），在试验2中评估了钙和磷的表观存留率（AR）。将BWG、FCR和骨骼特性数据拟合到回归函数中以估计NPPE。总体而言，增加AvP可使35日龄的BW、BWG、FI、FCR和BS呈线性改善（P < 0.01）。总体而言（8至35日龄），BWG、胫骨和股骨灰分含量随植酸酶呈线性增加，FCR呈线性和三次方增加（P < 0.05）。生长阶段BWG和FCR的平均NPPE值在250、500、1000、1500和2000 FTU/kg时分别为0.060%、0.139%、0.175%、0.193%和0.232%。育肥阶段的相应值分别为0.122%、0.220%、0.316%、0.364%和0.470%。250、500、1000和2000 FTU/kg时，胫骨和股骨特性的平均NPPE值分别为0.075%、0.128%、0.180%、0.193%和0.206%。总之，该研究证明了植酸酶在释放玉米和豆粕日粮中植酸结合磷方面的功效，从而使生长和骨骼特性与添加无机磷日粮相当或更优。NPPE值将有助于肉鸡饲料的配方设计。
