title: Reproductive efficiency of bulls in natural service: effects of male to female ratio and single- vs multiple-sire breeding groups.
mesh_terms: D000818:Animals; D001947:Breeding; D002417:Cattle / Q000502:physiology*; D004971:Estrus; D005260:Female; D005298:Fertility; D005306:Fertilization; D008297:Male; D011247:Pregnancy; D012098:Reproduction; D012726:Sexual Behavior, Animal; D012930:Social Dominance