Animals were reared in an outdoor systemfromPorco Celta
(Galician Cooperative, located in Goo, O Incio, Lugo, Spain). Animals
were fed a commercial feed “ad libitum”with a composition of 17% protein,
2.4% fat and 3250 kcal/kg metabolic energy and access to water.
Table 1 shows the chemical composition of the commercial diet. As animals
were placed in a natural environment, part of the diet was
obtained from the natural vegetation. There were campsite style huts
and enough trees to provide shade. The animals were kept, maintained
and treated in adherence to accepted standards for the humane treatment
of animals. All animals were weighed every 15 days and
slaughtered at different ages at a liveweight of 165 kg. The standard deviations
of this target live weight were 11, 12 and 7.5 kg for pure C,
C × L and C × D, respectively.