Reproductive hormone concentrations in faeces during the oestrous cycle and pregnancy in cattle (Bos taurus) and muskoxen (Ovibos moschatus)

Difficulties associated with blood sampling of wild animals are a deterrent to reproductive research but might be circumvented by the development of noninvasive techniques. Samples of faeces were collected from 4 cyclic and 19 pregnant domestic cows and from 6 female muskoxen during anoestrus, the oestrous cycle, and pregnancy. In cows, the faecal progesterone profile corresponded well with plasma values in cyclic and pregnant animals. Increased concentrations of 15-keto-13,14-dihydroprostaglandin F 2α could be detected in bovine faeces during luteolysis using data from a group of animals. A large increase in total oestrogen occurred in both faeces and plasma after the 12th week of pregnancy, confirming that faecal oestrogen levels can be used for pregnancy diagnosis. In the muskox, faecal concentations of total oestrogen and progesterone were correlated with reproductive status, and animals that were anoestrous, oestrous, pregnant, or in the luteal phase of the cycle could be recognized.