Published online by Cambridge University Press: 02 September 2010
1. Forty entire male pigs between 7 and 28 days of age and forty entire male pigs between 28 and 56 days of age were fed ad libitum basal diets of wheat and lupins containing 2·4 and 1·9 g of methionine per kg respectively. These were supplemented with 0, 0·3, 0·6, 0·9 and 1·2 g of synthetic methionine per kg of diet.
2. The methionine required for maximum performance and nitrogen retention was 3·0 g/kg of dry matter between 7 and 28 days of age and 2·5 g/kg between 28 and 56 days of age. These values were equivalent to 1·14 and 1·19g/100g of dietary crude protein at the two ages. The cystine contents of the diets were 3·7 and 3·1 g/kg respectively.
3. The concentration of methionine in the blood plasma did not give a clear indication of methionine requirement.