Cobalt deficiency and Ostertagia circumcincta infection in lambs
Ferguson, E.G.; Mitchell, G.B.; MacPherson, A.
Veterinary Record 124(1): 20
1989
ISSN/ISBN: 0042-4900 PMID: 2916300 Document Number: 346618
Cobalt-deficient lambs (from cobalt deficient ewes) fed a cobalt deficient diet, cobalt-depleted lambs (from sufficient ewes) but fed a cobalt deficient diet, and cobalt sufficient lambs (from sufficient ewes) fed a colbalt adequate diet were divided into infected (fed 2000 L3 O. circumcincta orally 3 times per week during the 16-week experiment) and non-infected subgroups. The mortality rate, in both infected and non-infected subgroups, was 87.5% (14/16) in deficient lambs compared with 18.2% (4/22) in depleted lambs. No losses were seen in the 22 sufficient animals. Liveweight gain was significantly reduced in deficient lambs compared with other groups, but no growth impairment was attributable to O. circumcinta infection in any group. Plasma pepsinogen levels and worm egg counts were significantly higher in deficient lambs than in the other groups. Infected lambs being depleted of cobalt reserves showed similar trends to the deficient lambs after 70 days, and by the end of the experiment the plasma pepsinogen levels and worm egg counts were significantly higher than in the sufficient lambs.