@conference {40941,
	title = {Non-invasive pregnancy determination in mares by enzymeimmunoassay of estrone sulphate concentrations in faeces.},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {57},
	year = {1997},
	month = {Jan},
	pages = {234-236},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Measurement of faecal estrone sulphate by enzymeimmunoassay was evaluated as a non-invasive means of monitoring pregnancy status in mares. Faecal samples from non-pregnant mares had a mean {\textpm} s.e.m. estrone sulphate concentration of 23 {\textpm} 0.9 ng/g (N=242). In pregnant mares, mean faecal estrone sulphate concentrations increased progressively during the first half of gestation. The values rose from a mean {\textpm} s.e.m. of 49 {\textpm} 4 ng/g (N=121) for samples collected <80 days post-mating, to 122 {\textpm} 9 ng/g (N=30) for samples collected 161 to 180 days post-mating. Thereafter, faecal estrone sulphate concentrations remained relatively constant for the remainder of pregnancy. From 150 days post-mating onwards, <2\% of faecal samples from pregnant mares had an estrone sulphate concentration below 66 ng/g which was the value 3 standard deviations above the mean value found for non-pregnant mares. Following foaling or foetal death, faecal estrone sulphate concentrations returned quickly to non-pregnant levels. Using this estrone sulphate enzymeimmunoassay, mares may be confirmed pregnant once faecal estrone sulphate concentrations rise above the 66 ng/g cut-off value. Those mares in which faecal estrone sulphate concentrations have not risen above 66 ng/g by 150 days post-mating may be considered to be non-pregnant. Measurement of faecal estrone sulphate thus offers a convenient, non-invasive means of monitoring pregnancy status. },
	issn = {1176-5283},
	author = {Henderson KM and Perkins NR and Wards RL and Stewart JI}
}
