MetaPrev: suivi longitudinal des teneurs en calcium du sang et du lait chez la vache laitière autour du vêlage : étude expérimentale sur 50 individus.

This file corresponds to the data set used in the analysis of the third work package of the research project MetaPrev. The main goal of the project was to refine strategies to prevent postpartum hypocalcemia in dairy cows in a European context of small farms (<200). The project was composed of 3 work packages: 1/ Assess french farmers practices related to the implementation and monitoring of prevention strategies, 2/ Assess the effect of prevention strategies on postpartum hypocalcemia incidence in commercial farms, 3/ Assess diagnostic tools to detect hypocalcemic dairy cows. The experimental study associated with this dataset was conducted in the Méjusseaume farm (INRAE, Saint-Gilles, France), belongs to the third package and aimed to assess the ability of milk calcium content to detect cows in hypocalcemia in the postpartum period in dairy cows. Thus, we performed a longitudinal analysis of 32 multiparous and 18 primiparous cows starting two weeks before the expected date of calving. Blood samples were collected on day -15 relative to expected calving; following this, blood and milk samples were collected simultaneously on a daily basis from day 1 (day of calving) to day 7, and again on day 15. Dynamics of plasma Ca and milk Ca were described separately for multiparous and primiparous cows using generalized linear mixed models with repeated values. We identified the sampling days that demonstrated the strongest correlations between plasma Ca and milk Ca and used this information to assess the ability of milk Ca to distinguish between different patterns of hypocalcemia via receiver-operating characteristic analysis.