Milk genetic merit is known to impact commencement of luteal activity (CLA) in dairy cows. This effect is usually considered to be related to energy exported in milk. The present study aimed to identify and quantify the effects of genetic characteristics (breed and estimated breeding value (EBV) for milk yield and solids content) and feeding system on CLA of primiparous cows. From 2006 to 2013, an experiment was conducted on 194 primiparous dairy (Holstein) and dual purpose (Normande) cows at the INRA farm of Le Pin-au-Haras. Within breeds, 2 groups were created based on EBV: cows with relatively high milk yield EBV (M) and cows with relatively high fat and protein contents EBV (C). Within breeds, exported energy in milk and weight loss were similar for both genetic groups. Two grazing based strategies were used, a High (H) feeding system (maize silage in winter and grazing plus concentrate) and Low (L) feeding system one (grass silage in winter and grazing with no concentrate). CLA was studied performing survival analyses (Weibull regression). Milk yields and body condition were studied using logistic regression, Chi2- test and ANCOVA. H cows produced more milk (+1,690 kg, P<0.001) and lost less body weight (BW) from week 1 to 14 pp (+3.8 kg/wk, P<0.001) than the L ones. Holstein cows produced more milk (+1,450 kg, P<0.001) and lost more BW (-1.4 kg/wk, P<0.01) than Normande ones. As expected, Normande cows had a shorter median CLA than Holstein ones (30 and 33.5 days respectively). However, C cows had shorter CLA (associated RR=2.0, P=0.001) than M ones. No effect of milk yield or feeding system on CLA was found. In conclusion, CLA was only affected by genetic characteristics. Beyond breed, the genetic merit to export energy through milk solids had a beneficial effect on post-partum ovarian recovery.