Effects of milk yield and quality at post-calving period on Algerian cows’ reproductive performances

Résumé 0

This study was carried out to determine the association between milk production characteristics at the start of lactation (the first three month of lactation) and the performance of reproduction within dairy cows of Algeria. Data were collected from Holstein cows (n=920) that calved between October 2017 and October 2019. Reproductive parameters included in the study were: calving to first-service interval (CFSI, days), calving to conception interval (CCI, days), services per conception (SPC), and conception rate at first-service (CRFS %). Milk parameters such as peak milk yield, cumulative milk yield in the first 30 days (Milk30), 60 days (Milk60) and 100 days (Milk100) postpartum of the cows. The milk composition traits analyzed were milk fat concentration (MF %) and milk protein concentration (MP %). These variables were used to calculate fat to protein ratio (FPR) for each stage of lactation (stage 1: 15–30 days, stage 2: 45–60 days and stage 3: 75–90 days postpartum). Pearson’s correlation analysis was used to determine the correlation between reproductive parameters and milk production variables.The obtained results showed that peak milk yield, cumulative milk yield in the first 60 days (Milk60) and 100 days (Milk100) were significantly and positively (P