The precise nutritional roles of calcium and phosphorus and the synergistic effects and mechanisms in chicken

As essential mineral elements for poultry nutrition, calcium and phosphorus are not only the main components of bones and eggshells, but also participate in physiological processes such as energy metabolism and cell signal transduction. Calcium and phosphorus are also important factors affecting feed cost, in addition to energy and crude protein. As the poultry industry continues to develop towards intensification and large-scale operation, the dietary levels of calcium and phosphorus have been continuously increasing, leading to problems such as raising feed costs and environmental risks. This article aims to review the precise nutritional roles of calcium and phosphorus and the synergistic effects and mechanisms in chicken. A comprehensive literature search was conducted in PubMed, Web of Science (WOS), Scopus, and China National Knowledge Infrastructure (CNKI) for peer-reviewed articles published in English and Chinese between January 2000 and June 2026. The initial search returned 41506 records. After exclusion of 5714 duplicates, 35512 articles were screened by title, abstract and keywords, and 280 were assessed in full text. Ultimately, 97 studies were included for qualitative synthesis. These studies included dose-response experiments conducted on broilers and layers from different geographical regions, as well as studies related to the mechanisms and review articles. Based on this, this article reviews the precise nutritional roles of calcium and phosphorus, the nutritional sensitivity indicators, the effects of dietary calcium and phosphorus on eggshell quality and bone development, the calcium and phosphorus requirements of different chicken breeds, the calcium-phosphorus synergistic effect and the related mechanisms, and proposes some nutritional regulation measures for dietary calcium and phosphorus. It also looks forward to future research directions, providing important references for the research and application of precise nutrition of calcium and phosphorus in the chicken industry.