@conference {40200,
	title = {Growth responses of fat and muscle in the lamb to intra-arterial infusions of bovine insulin - Brief Communication},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {50},
	year = {1990},
	month = {Jan},
	pages = {91-92},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The purpose of this paper is to summarise recent findings on the   reproductive physiology of the Booroola ewe, with specific attention to   factors influencing ovulation-rate (OR). The ovarian antral follicle   populations, incidence of atresia, steroid secretion-rate and maximum OR   potential in the different Booroola genotypes (FF, homozygotes; F+,   heterozygotes; ++, non-carriers) are the same notwithstanding the fact   that FF, F+ and ++ animals normal ovulate >=5, 3-4 and 1-2 follicles   respectively during each oestrous cycle. Moreover, the Booroola F gene   does not appear to modify the characteristics of the follicle-   stimulating hormone (FSH) or luteinizing hormone (LH) receptors, or the   gonadotrophin-sensitive components of the cyclic AMP generating system   or the steroid or inhibin biosynthetic functions in follicular cells.   It seems that the F gene influences follicular growth before antrum   formation resulting in fewer granulosa cells at all phases of antral   growth and smaller sized follicles at ovulation. In essence, the >=5,   3-4 or 1-2 presumptive preovulatory follicles in FF, F+ or ++ ewes are   respectively 2.5-4.5 mm, 4-5mm and >5 mm in diameter just before   ovulation but the total populations of oestrogen-secreting follicular or   progesterone-secreting luteal cells in the different genotypes are the   same. These genotypic differences in ovarian characteristics have not   bee replicated by any of the known superovulation regimes.     At the level of the hypothalamus and pituitary no gene-associated   differences have been noted in the concentrations of gonadotrophin-   releasing hormone (GnRH) in the tissues or hypophyseal portal blood nor   in the binding characteristics of GnRH to the pituitary gland. However   F gene-specific differences have been noted in the plasma concentrations   of FSH and LH in ovary-intact and ovariectomized (OVX) Booroola ewes   (FF>++; P,0.05). The F gene-specific differences in FSH but not LH in   OVX ewes can be replicated by exogenous GnRH treatment of OVX ewes   deficient in endogenous GnRH following surgical disconnection of the   hypothalamus from the pituitary gland but with the superior hypophyseal   arteries being left intact. The greater frequency of high FSH values in   ewes is also observed in both intact and castrate Booroola FF rams   relative to ++ rams at P<=0.07. When considered altogether the evidence   suggests that Booroola sheep with the F gene have higher mean FSH   concentrations in plasma relative to ++ sheep. However the differences   are small with considerable overlap between animals of the different   genotypes. It therefore remains to be established whether modest   increases in plasma FSH concentrations in ++ Booroola ewes are   sufficient to modify follicular morphology and OR without altering   steroid secretion.    },
	issn = {1176-5283},
	author = {Wolff JE and Petrie DR}
}
