Mineral Nutrition Research Division, State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; Hebei Key Laboratory of Specialty Animal Germplasm Resources Exploration and Innovation, College of Animal Science and Technology, Hebei Normal University of Science and Technology, Qinhuangdao 066004, China.
Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China.
Poult Sci. 2023 Aug;102(8):102851. doi: 10.1016/j.psj.2023.102851. Epub 2023 Jun 10.
The dietary needs of calcium (Ca) and phosphorus (P) are interdependent, thus accurate evaluation of Ca and P requirements of broilers to support skeleton health and optimal growth is critical. The present study was carried out to investigate the effects of dietary Ca and nonphytate P (NPP) levels and their interactions on growth performance, tibiotarsus characteristics, tibiotarsus metabolism-related enzyme and proteins, and their gene expression of broilers, so as to provide a rational recommendation for Ca and NPP levels in diet. A total of 540 one-day-old Arbor Acres male broilers were randomly allotted to 1 of 15 treatments with 6 replicate cages of 6 birds per cage for each treatment in a completely randomized design involving a 5 × 3 factorial arrangement of treatments (5 levels of Ca × 3 levels of NPP). The birds were fed the corn-soybean meal diet containing 0.60%, 0.70%, 0.80%, 0.90%, or 1.00% Ca and 0.35%, 0.40%, or 0.45% NPP for 21 d. Dietary Ca level affected (P < 0.03) the bone mineral density, bone mineral content (BMC), breaking strength, ash percentage and ash Ca contents in tibia, which showed linear (P < 0.006) responses to dietary Ca levels. Dietary NPP level affected (P < 0.05) tibia BMC, ash percentage, and FGF23 mRNA level. Broilers that received 0.40% and 0.45% NPP had higher (P < 0.04) tibia BMC and ash percentage than those that received 0.35% NPP, but no differences (P > 0.05) were found between 0.40% and 0.45% NPP. Broilers that received 0.40% NPP had higher (P = 0.02) tibia FGF23 mRNA level than those that received 0.35% NPP, but no differences (P > 0.05) were detected between 0.40% and 0.45% NPP or 0.45% and 0.35% NPP. The interactions between dietary Ca and NPP affected (P < 0.05) ADG, ALP activity, bone gal protein, FGF23 contents, and the mRNA expression levels ALP and bone gal protein in tibia of broilers. Results from the present study indicate that dietary Ca and NPP interaction influences growth, tibiotarsus development, and related gene expression of broiler chickens. Considering all the criteria, the dietary levels of 0.90% Ca and 0.45% NPP would be optimal for both growth and tibiotarsus development of broilers fed a conventional corn-soybean meal diet from 1 to 21 d of age.
钙（Ca）和磷（P）的膳食需求是相互依存的，因此准确评估肉鸡的 Ca 和 P 需求以支持骨骼健康和最佳生长至关重要。本研究旨在探讨饲粮 Ca 和非植酸磷（NPP）水平及其互作对肉鸡生长性能、胫骨特性、胫骨代谢相关酶和蛋白及其基因表达的影响，为饲粮中 Ca 和 NPP 水平提供合理建议。选用 540 只 1 日龄爱拔益加雄性肉鸡，采用完全随机设计，设 15 个处理，每个处理 6 个重复，每个重复 6 只鸡。试验设 5 个 Ca 水平[0.60%、0.70%、0.80%、0.90%和 1.00%]和 3 个 NPP 水平[0.35%、0.40%和 0.45%]，配制玉米-豆粕型饲粮，试验期 21 d。饲粮 Ca 水平显著（P < 0.03）影响胫骨的骨密度、骨矿物质含量（BMC）、断裂强度、灰分百分比和灰分 Ca 含量，呈线性（P < 0.006）反应。NPP 水平显著（P < 0.05）影响胫骨 BMC、灰分百分比和 FGF23 mRNA 水平。饲粮 NPP 水平为 0.40%和 0.45%时，胫骨 BMC 和灰分百分比显著（P < 0.04）高于 NPP 水平为 0.35%时，但 0.40%和 0.45% NPP 间无显著差异（P > 0.05）。饲粮 NPP 水平为 0.40%时，胫骨 FGF23 mRNA 水平显著（P = 0.02）高于 NPP 水平为 0.35%时，但 0.40%和 0.45% NPP 间及 0.45%和 0.35% NPP 间无显著差异（P > 0.05）。Ca 和 NPP 的互作显著（P < 0.05）影响肉鸡的 ADG、碱性磷酸酶（ALP）活性、骨钙素、FGF23 含量及胫骨中 ALP 和骨钙素的 mRNA 表达水平。本研究结果表明，饲粮 Ca 和 NPP 的互作影响肉鸡的生长、胫骨发育和相关基因表达。综合所有指标，1~21 日龄肉鸡饲粮中 Ca 水平为 0.90%、NPP 水平为 0.45%时，肉鸡的生长和胫骨发育最佳。
