@conference {40287,
	title = {Sheep map: The New Zealand programme to map the sheep genome},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {51},
	year = {1991},
	month = {Jan},
	pages = {85-86},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {A series of four trials, each involving 1200 ewes have been  conducted over the period 1986 to 1990. Ewes have been treated with  various synchronisation treatments and the time to onset of oestrus  monitored each month of the year. Results indicate that while overall  mean values for each year don{\textquoteright}t differ, there were significant seasonal  effects within years with the interval to onset being shorter during the  breeding season. However, the maximum difference between monthly means  in any one year varied from 27 h to 17 h. Significant effects of  synchronisation device were seen with ewes treated with sponges having a  longer (+ 8 h) interval to onset than ewes treated with CIDR devices.  While effects of ewe age and ewe liveweight were seen in some trials no  consistent trend was identified. On most occasions significant  interactions with month of year indicated inconsistency of effect within  any one trial. The recorded variation in interval from device removal  to onset of oestrus is in agreement with that reported between flock in  the field. This variation is sufficient to effect conception rates to  artificial insemination performed on a time basis and evaluation of  contributing factors is required for the development of protocols for  this activity.  },
	issn = {1176-5283},
	author = {Hill DF and Broad TE}
}
