The effect of dietary supplements of copper, zinc and iron sulphates alone or with a chelator on survival in experimental fowl typhoid in the chick.
Nutritionally adequate diet supplemented with an extra 200 mg/kg of copper (Cu), zinc (Zn) or iron (Fe), each as the sulphate, or with 1 g/kg of disodium dihydrogen ethylenediaminetetra-acetate (Na.edta), and all combinations of these substances, was given to groups of chicks (Gallus domesticus) from the 12-26th days of age. The birds were infected orally when they were 15 days old with 10(6A) living Salmonella gallinarum and those which gained at least 10 g in weight between the 8th and 11th days after infection were deemed to be survivors of the resulting acute disease. Compared with standard diet, that supplemented with Zn plus Na. edta significantly (P < 0.05) enhanced survival from the acute disease. Those supplemented with Cu or Fe were much less active in this respect and the Zn supplement significantly depressed any response to the Cu supplement. Further experiments confirmed that Zn, in even larger amounts, did not enhance survival in the absence of Na. edta and showed that Cu supplement at 400 mg/kg of diet produced significantly higher survival than at 200 mg/kg.
Hill
R
R
Royal Veterinary College, University of London, Potters Bar, Herts., England.
Smith
I M
IM
Leech
F B
FB