@conference {40010,
	title = {Preliminary investigation into factors affecting lamb growth from birth to weaning on Taranaki hill country},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {46},
	year = {1986},
	month = {Jan},
	pages = {139-144},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The aim of the present study was to examine the influence of the ram on plasma FSH concentrations in progesterone-primed Romney ewes which were: (1) anoestrous; (2) devoid of ovaries; (3) or anoestrous but induced to ovulate by a pulsatile injection regimen of luteinising hormone (LH). The results showed that there was an abrupt fall in the mean FSH levels in anoestrous or LH-pulsed ewes at 1 hour after ram introduction and that this level of suppression (~40\%) was maintained for ~22 hours in anoestrous ewes and for 12 hours in LH-pulsed ewes. Also, an FSH reduction (~20\%) was observed in the ovariectomised ewes. In the anoestrous ewes, the FSH changes were observed without any associated oestrous or ovulatory behaviour. In the LH-pulsed group, all ewes showed oestrus and 75\% produced normal corpora lutea. Collectively, the evidence suggests that when attempts are made to achieve fertile matings in hormone-treated anoestrous ewes, there may be advantages in delaying ram introduction until ~24 hours after progesterone withdrawal.},
	issn = {1176-5283},
	author = {Thomson NA and Mace MJ and Wright LA and Bishell SM}
}
