Plasma prolactin variations and cyclic ovarian activity in ewes submitted to different light regimens J. THIMONIER, J. P. RAVAULT, R. ORTAVANT, N. POULAIN and A. BEGUÉY Ann. Biol. anim. Bioch. Biophys., 18 5 (1978) 1229-1235 DOI: 10.1051/rnd:19780612