The use of synthetic prostaglandin analogue to induce oestrus in mares.
A clinical trial involving 359 mares was conducted to ascertain the clinical value of a synthetic prostaglandin analogue (fluprostenol, ICI-81,008) structurally related to PGF2oc for treating mares in prolonged dioestrus. Some 263 mares (73.3%) displayed oestrus within 5 days of a first intramuscular injection of 250 mug fluprostenol and, of those mares later examined for pregnancy, 108 (40%) were found to have conceived during the first induced oestrus. A further 21 mares (8%) cycled normally and conceived to services during the second oestrus. Most (80.3%) of the plasma samples obtained from 242 mares prior to treatment showed a progesterone concentration greater than 1 ng/ml, thereby indicating the presence of functional luteal tissue in the ovaries. The results support earlier observations that most non-pregnant mares which fail to cycle during the breeding season are in a state of prolonged dioestrus rather than anoesturs.
D000818:Animals; D004971:Estrus / Q000187:drug effects*; D005260:Female; D006736:Horses / Q000097:blood / Q000502:physiology*; D007774:Lactation; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D011460:Prostaglandins F / Q000494:pharmacology; D011465:Prostaglandins, Synthetic / Q000494:pharmacology*
D011460:Prostaglandins F; D011465:Prostaglandins, Synthetic; D011374:Progesterone