Presence of the calf affects secretion of prolactin in cows.
D000818:Animals; D000833:Animals, Suckling; D002417:Cattle; D005260:Female; D007774:Lactation; D010812:Physical Stimulation; D011247:Pregnancy; D011388:Prolactin / Q000378:metabolism*; D013037:Spatial Behavior; D013997:Time Factors
D011388:Prolactin