@conference {3678,
	title = {Ramguard {\textendash} Increasing the Tolerance to Facial Eczema in New Zealand Sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {74},
	year = {2014},
	month = {06/2014},
	pages = {154-157},
	address = {Napier},
	abstract = {Facial eczema (FE) is a metabolic disease resulting primarily from damage to the liver and bile ducts. It is caused in ruminants by the effects of a mycotoxin, sporidesmin, produced by the fungus Pithomyces chartarum. The disease causes significant loss in agricultural production mainly in northern New Zealand. Sporidesmin toxin is produced in a laboratory and made available to those sheep breeders who wish to increase the level of FE tolerance in their flocks. The sheep industry in NZ has made steady progress towards increasing genetic tolerance to FE by testing potential future sires in ram-breeding flocks with an artificial challenge of sporidesmin. Ramguard provides the sporidesmin to breeders to dose their sheep at a specified dose-rate which is dependent on the level of tolerance already obtained. The Ramguard service has operated from August 1988 and has 60 clients dosing a total of 800 to 1100 rams each year. Most of the long-term-testing flocks are now using a dose rate six times higher than at the outset, which indicates animals in these flocks are tolerant to all but the severest outbreaks of FE. The heritability estimate for resistance to facial eczema is high at 0.45 {\textpm} 0.03.},
	issn = {1176-5283},
	author = {Amyes NC and Hawkes AD}
}
@conference {41841,
	title = {Zearalenone challenge in sheep : urine sampling to measure response},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {65},
	year = {2005},
	month = {Jan},
	pages = {316-319},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {Zearalenone is a fungal toxin produced by Fusarium species commonly found on autumn pastures in New Zealand. It may interfere with reproductive functions in sheep. In a search for a genetic measure of susceptibility, ewe and ram lambs were dosed orally with a suspension of zearalenone at a series of rates, at 8 and 11 months of age. Urine samples were taken at intervals from 2 to 50 hours later. The concentration of urinary zearalenone and its metabolites (Zen) was assayed using an ELISA. Adjustment for urinary volume was made by measuring the urinary concentration of creatinine (Cr), and results were expressed as Zen/Cr ratio (loge-transformed). In a separate experiment, breeding ewes were dosed with zearalenone at a single rate, and Zen/Cr response was measured. The following effects were evaluated in lambs: a) sex difference (ewe versus ram lambs), b) responses to three dose rates, c) time-series response data. The heritability of Zen/Cr was determined in lambs and breeding ewes; results were analysed after standardising for each treatment and sampling group. Urinary Zen/Cr, 6 h after dosing, differed between ewe and ram lambs by a factor of 1.75 (ewe lambs higher; P < 0.01). Zen/Cr values for three dose rates (3, 6 and 9 mg zearalenone per lamb), averaged over three sampling time points after dosing, were 23.5, 43.2 and 59.3, respectively (P < 0.0001). Zen/Cr values for three sampling time points (2, 4 and 6 h after dosing), averaged over three dose rates, were 58.0, 35.8 and 29.0, respectively (P < 0.0001). By 50 h after dosing, the Zen/Cr average had fallen to 4\% of its 2-h value. The interaction between dose rate and time of urinary sampling was not significant for log Zen/Cr. A preliminary estimate of the heritability for standardised Zen/Cr was 0.32 {\textpm} 0.10 (P < 0.01). The dosing regime reported here could be used for a test of animal response to zearalenone in ram breeders{\textquoteright} flocks.
KEYWORDS: sheep; zearalenone; dose response; urine; heritability. },
	issn = {1176-5283},
	author = {Morris CA and Amyes NC and Sprosen JM and Hawkes AD and Finch SC and Miles CO}
}
