@conference {40253,
	title = {Factors influencing the success of a large scale artificial insemination programme in sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {50},
	year = {1990},
	month = {Jan},
	pages = {427-430},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Two experiments were conducted to compare PMSG injection to GnRH   infusion for induction of breeding in anoestrous ewes. In Experiment   One, sixteen Suffolk ewes were pre-treated for 14 days with 30 mg   Cronolone sponges. At sponge removal half of the ewes received 0.125   ug/hr GnRH for 72 hours via subcutaneous osmotic pumps. The other half   received a single injection of 750 iu PMSG. Plasma LH levels gradually   increased and were sustained for 24 hours. Estrus, ovulation and   corpus luteum function were expressed in half of the ewes treated   with GnRH. All ewes treated with PMSG exhibited estrus, ovulated and   formed functional corpora lutea.     In Experiment Two, 24 ewes were divided into two groups and the same   treatments as in Experiment One were applied. Fertile rams were   introduced to all the ewes at the time of sponge removal. Estrus was   detected in 75\% of the GnRH treated ewes vs 100\% in PMSG treated ewes.   Lambing rates were 44\% and 56\% in GnRH and PMSG groups respectively.     These results suggest that the induction of fertility using continuous   infusion of GnRH is encouraging. However, other GnRH delivery systems   should be investigated.    },
	issn = {1176-5283},
	author = {Shackell GH and Kyle B and Littlejohn RP}
}
