@conference {41911,
	title = {A simple HPLC method for measuring sulfate in ultra filtered sheep plasma},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {66},
	year = {2006},
	month = {Jan},
	pages = {284-289},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Napier},
	abstract = {Plasma sulfate concentration is a useful indicator of sulfur amino acid oxidation. Measurement of sulfate in water and other fluids has been made by turbidimetric, ultra-violet (UV) absorption or ion chromatography HPLC methods. The turbidimetric method is variable and suffers from interferences and both turbidimetric and UV methods are less sensitive than ion chromatography. We describe a quick and simple HPLC method, where sample preparation is a centrifugal filtration and the sulfate measurement is by single column HPLC using one buffer at a constant flow rate. Recoveries from spiked samples were 99.5 \% (RSD 1.8 \%) and the RSD of repeated standards over 6 weeks was 0.7 \%. Using this method, we measured plasma sulfate levels in both growing lambs with intestinal parasites and in sheep fed fresh Lotus corniculatus containing condensed tannins (CT) or other fresh forages. The CT in Lotus corniculatus decreased (P < 0.05) plasma sulfate concentration while parasite infection did not (P > 0.05). Our method provided quick and reliable data that could be transferable for measuring sulfate in blood, serum and other biological fluids and could be used as a biomarker of whole body sulfate status under various physiological conditions in farm animals. },
	issn = {1176-5283},
	author = {Sinclair BR and Tavendale MH and Bermingham EN and Burke JL and McNabb WC and Roy NC}
}
@conference {41319,
	title = {Ammonia and urea utilisation in lambs infected with Trichostrongylus colubriformis and fed fresh lucerne (Medicago sativa)},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {62},
	year = {2002},
	month = {Jan},
	pages = {77-80},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Palmerston North},
	abstract = {The effect of a Trichostrongylus colubriformis infections on ammonia and urea fluxes across the mesenteric-drained viscera (MDV), portal-drained viscera (PDV), and liver was investigated using an arterio-venous preparation in lambs fed fresh lucerne (Medicago sativa). The lambs were infected with 6000 T. colubriformis L3 larvae per day for 6 days (n=5) or kept as parasite free controls (n=5). On day 48 of the experiment, the lambs were infused continuously for 8 hours with r-aminohippuric acid (688 mg/h) into the mesenteric vein in order to measure plasma flow across the MDV, PDV and liver. Blood was continuously collected from the mesenteric artery and vena cava for consecutive two hour periods throughout the infusion period and plasma was harvested. Plasma concentrations of ammonia and urea were unaffected by the presence of intestinal parasites. Ammonia fluxes across the MDV, PDV, and liver were similar between treatment groups. Urea fluxes were also similar between treatment groups with the exception of the PDV, which showed a net release of urea in the parasite group and a net uptake by the control group (P=0.03). This suggests that the presence of a sub-clinical T. colubriformis infection does not increase the demand on the lamb for amino acids for ureagenesis. },
	issn = {1176-5283},
	author = {Bermingham EN and Roy NC and Reynolds GW and Sinclair BR and Peters JS and Sutherland IA and Waghorn GC and Revell DK and McNabb WC}
}
@conference {41266,
	title = {The effect of condensed tannins in sainfoin (Onobrychis viciifolia) and sulla (Hedysarum coronarium) on the digestion of amino},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {61},
	year = {2001},
	month = {Jan},
	pages = {116-119},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {Two experiments were conducted in order to compare the effect of condensed tannins (CT) in sainfoin (Onobrychis viciifolia) and sulla (Hedysarum coronarium) on the flux of amino acids (AA) through the gastrointestinal tract of sheep. In each experiment, one group of sheep (PEG group; CT inactive) received an intraruminal infusion of polyethylene glycol (PEG) to inactivate the CT present in the forages, while the other group received an intraruminal infusion of water (Tannin group; CT active). The CT in sainfoin (38.1 g/kg DM) had no significant effect on apparent AA absorption from the small intestine. However, in the sulla-fed sheep, AA absorption in the small intestine was significantly increased by CT (P<0.05; CT = 64.4 g/kg DM). In both forages a shift in AA digestion from the rumen to the small intestine was seen with increased abomasal fluxes of AA in the Tannin group of sainfoin- (92 versus 101 g/day in the PEG and Tannin group, respectively; P<0.05) and sulla-fed (65 versus 83 g/day; P<0.001) sheep. Differences in the digestion and absorption of AA in the two forages may be associated with differences in chemical structure of the CT. },
	issn = {1176-5283},
	author = {Bermingham EN and Hutchinson KJ and Revell DK and Brookes IM and McNabb WC}
}
