Quinlan, J.; Steyn, H.P.; Van Rensburg, S.W.J.; Alexander, R.A.; Clark, R.; Sterne, M.; Louw, J.G.; Van der Reyden, D.; De Kock, V.E.
(Published by The Government Printer, Pretoria, South Africa., 1951)
(1) Observations were carried out on the oestrous cycle of 30 mares from
January, 1944, to June, 1946.
(2) The mares were stabled at night and ran out in a small paddock during
the day. They were never let out to grazing ...