The effect of constant photoperiod on the expression of oestrus in the ewe.
D000818:Animals; D002940:Circadian Rhythm; D004971:Estrus; D005260:Female; D006801:Humans; D008027:Light; D010507:Periodicity; D011247:Pregnancy; D011627:Puberty; D012756:Sheep / Q000502:physiology*; D014626:Vaginal Smears