Effects of methionine, threonine and tryptophan supplementation on productive performance and carcass traits of growing-finishing pigs raised under commercial conditions

Abstract

The aim was to determine whether the supplementation of methionine, threonine and tryptophan in the diets of growing-finishing pigs raised under commercial conditions improved their productive performance (feed intake, weight gain, feed conversion rate, carcass quality) and whether this strategy was economically viable. The experiment was performed simultaneously in 2 commercial pig farms, with animals fed during their grower-finisher period (30 – 100 kg) with a diet that met their ideal protein requirement and a diet supplemented with an additional 20% methionine, threonine and tryptophan. There were no effects (P>0.05) of the diet on feed intake, average daily gain or feed conversion rate in any of the grower-finisher stages, or when the whole testing period was analyzed. Furthermore, there were no differences between diets for the lean meat percentage, the value for each kilogram of meat or the value of the whole carcass. The animals that consumed the supplemented diet showed a tendency (P=0.07) to have a higher back fat thickness (13.46 mm) compared to those that were fed the control diet (12.62 mm). Moreover, the animals fed with the supplemented diet also showed a tendency (P=0.08) to have a higher carcass yield (80.10%) compared to the animals that consumed the control diet (79.54%). It can be concluded that methionine, threonine and tryptophan supplementation did not improve the productive performance of pigs raised under commercial conditions and, under the current productive setup, is not economically viable.