@conference {40357,
	title = {Screening herds for cows with a history of twin calving},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {51},
	year = {1991},
	month = {Jan},
	pages = {447-452},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {A monoclonal antibody to oestron sulphate (ES) was generated,  and used in the development of a radioimmunoassay to measure ES  concentrations in whole milk of cows. The mean },
	issn = {1176-5283},
	author = {Morris CA}
}
