@conference {41884,
	title = {Environmental and physiological mechanisms underlying wool growth rhythms in New Zealand coarse wool sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {66},
	year = {2006},
	month = {Jan},
	pages = {144-148},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Napier},
	abstract = {Coarse-woolled sheep breeds such as the Romney exhibit a pronounced annual cycle of wool growth with concomitant changes in fibre length growth rate and mean fibre diameter with maxima in summer and minima in winter. This cycle, which is entrained by seasonal changes in daylength via changes in circulating prolactin, parallels wool growth rate in Romney sheep. The cycle is also influenced by complex interactions between nutrient supply and hormones associated with reproductive status. A marked depression in wool production occurs during early pregnancy, which cannot be completely ameliorated by supplementary feeding, and does not directly involve prolactin. Additionally, in ewes, experimental and pharmacological increases and decreases in the prolactin concentration at parturition and during lactation are associated with increases and decreases, respectively, in spring and summer wool growth rate. A greater appreciation of the different mechanisms that temporally influence the wool growth cycle represents a potential means to change fleece characteristics. The development of sheep genotypes with a reduced amplitude of their wool growth cycle would significantly contribute to a reduction in fibre variability that can affect processing performance. },
	issn = {1176-5283},
	author = {Kendall PE and Sumner RMW and Pearson AJ}
}
@conference {41065,
	title = {Fleece production patterns in Romney ewes: Effects of photoperiod, pregnancy and lactation},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {59},
	year = {1999},
	month = {Jan},
	pages = {30-33},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Twenty one Romney ewes were housed indoors for 12 months from February to determine the effect of season, pregnancy and lactation on wool growth. Ten ewes were naturally mated in April to lamb in September. The ewes were fed to maintain constant maternal body weight and a midside patch harvested monthly to determine clean fleece growth rates. An effect of pregnancy on individual fibre length growth rate, determined by autoradiography, occurred as early as 21-35 days after joining. During the second month of gestation, fleece production and mean fibre diameter fell below that of non-pregnant ewes and continued to diverge until parturition. Wool production rose in the non-pregnant group from August, but did not increase in lambing ewes until after parturition. These data suggest that pregnancy is associated with an early hormonally-mediated depression in follicle output superimposed on the decline associated with winter photoperiod. },
	issn = {1176-5283},
	author = {Pearson AJ and Kendall PE and Ashby MG and Wildermoth JE}
}
