The experiment (Table 1) comprised four trials with two experimental pen replicates of each of the four treatments: Treatment A (conventionally reared Danish pigs fed 100%concentrate according to Danish recommendations ) was compared with three different organic pig production systems with access to out-door area, where the pigs were fed either Treatment
B(100% organic concentrate according to Danish recommendations (without roughage)), C (70% organic concentrateac cording to Danish recommendations (restrictedly) plusad libitum organic barley/pea silage) or D (70% organ icon centrate according to Danish recommendations(restrictedly) plus organic ad libitum clover grass silage, where the relative levels of concentrate feeding refer to an age-related scale).