Published online by Cambridge University Press: 02 September 2010
Forty-eight Large White × Landrace weanling pigs weighing initially 9·69 (s.e. 013) kg were used to evaluate the dietary methionine requirements of weanling European pigs reared under a humid, lowland, tropical environment. Response criteria used were growth rate, efficiency of food conversion, carcass quality, and the weights of some organs and individual muscles. The pigs (three male castrates and three females per treatment) were given a cassava flour-soya bean meal diet containing 202 g crude protein per kg dry matter and supplemented with increments of multiples of 0·8 g DL-methionine per kg diet. Total dietary methionine levels ranged from 2·3 to 7·9 g per kg diet dry matter. All diets contained 14·75 MJ digestible energy per kg dry matter. The experiment lasted 42 days, at the end of which the pigs were slaughtered at an average live weight of 17 kg.
Growth rate and feed efficiency were significantly improved when the basal diet was supplemented with DL-methionine (P< 0·001). No significant treatment differences in organ weight were found. Methionine requirement was significantly influenced by sex and age of the pigs, with castrates having lower requirements than females. Pooled estimated methionine requirements for optimum growth rate and efficiency of food conversion were 4·0 and 4·3 g/kg diet dry matter respectively. Maximum proportion of lean was recorded on the diet containing 3·1 g total methionine per kg dry matter.