Ammonia and urea utilisation in lambs infected with
Trichostrongylus colubriformis and fed fresh lucerne (Medicago
sativa)
E.N. BERMINGHAM, N.C. ROY, G.W. REYNOLDS, B.R. SINCLAIR, J.S.
PETERS, I.A. SUTHERLAND, E.N. BERMINGHAM, N.C. ROY, G.W. REYNOLDS, B.R.
SINCLAIR, J.S. PETERS, I.A. SUTHERLAND, G.C. WAGHORN, D.K. REVELL AND
W.C. McNABB
Nutrition and Behaviour Group, AgResearch Limited, Grasslands,
Palmerston North, New Zealand
NZSAP 2002 Abstract No. 21
Proceedings of the New Zealand Society of Animal Production 62:
77-80
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 p-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.
Keywords: NZSAPAB;
ammonia; urea; Trichostrongylus colubriformis; sheep.
Last Updated 30/07/2002
