The response of pigs weaned at 5 weeks of age to digestible energy and lysine concentrations in the diet

Abstract

AbstractEight-hundred-and-fifty-two pigs were weaned at 5 weeks of age, and at an average weight of 8·5 kg were allocated in pens of 14 or 15 to diets having 13·6 or 14·6 MJ digestible energy (DE)/kg combined with 11·0 or 11·8 g lysine per kg.Over a 5-week experimental period, pigs receiving the diet with the higher DE content had a lower daily feed intake, improved feed conversion efficiency (FCE) but a similar rate of gain to those getting less DE/kg. Efficiency of utilization of energy was poorer when DE content was higher.Increasing lysine level increased daily feed intake and rate of gain while improving FCE. There were significant energy x lysine interactions. At the lower energy density, increasing the lysine level resulted in increased daily feed intakes whereas the reverse was the case at the higher energy density. Daily gain increased when lysine level was increased at the lower energy density but was unaffected at the higher density. Efficiency of energy utilization was improved by increasing lysine at the higher but not at the lower energy level.