@conference {40858,
	title = {Partial failure of multiple ovulations - a question of uterine efficiency or embryo quality?},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {56},
	year = {1996},
	month = {Jan},
	pages = {362-364},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Amongst individuals that produce multiple ovulations, and conceive, a  variable proportion fail to deliver all potential offspring at term. This source  of reproductive inefficiency has been termed partial failure of multiple  ovulation (PFMO). In the case of twin ovulators, PFMO is manifest as  single births. Most reports in the literature have attributed PFMO to uterine  capacity or efficiency factors. An alternative model is proposed, in which it  is assumed that a given reproductive outcome is determined by independent  binomial effects of embryos and uterine/maternal factors. Using this model,  it can be demonstrated that PFMO in twin ovulators can only occur because  one of the two embryos is not competent to survive - that is, the  uterine/maternal component plays no role in determining variation in  PFMO. It follows that in pregnant farm animals with twin ovulations 100\%  twin births is possible, but is only constrained by low embryo quality. All  published data examined to date in sheep cattle and goats are consistent with  this alternative model.},
	issn = {1176-5283},
	author = {McMillan WH}
}
