Outdoor pig breeding systems for growing and fattening phases

The experimental outdoor pig farm is situated in the South of Italy (Crotone). The enclosures for the pig breeding were dimensioned to keep 12-14 pigs/each (100 m2/head) and were arranged with a hopper trough, a drinker, a water nozzle, a hut with insulated roof (covered surface of 10 m2) and a shading net. The huts were located on the ground with different expositions of the open side (West and East), in two close fences. During the trials pigs of Large White breed in growing phase were reared. Microclimatic and behavioural parameters were collected both in winter and in summer. The values of air temperature and contact temperature inside the two huts were very close to the outside temperature. In winter the average air temperature was higher in the hut with West open side (13.4°C vs. 11.0°C), with relative humidity lower on average. In summer the average air temperature was higher in the hut with East open side (1.4°C; 27.1°C vs. 25.7°C) and relative humidity levels almost equivalent. Concerning the behavioural data, during the winter season the pigs devote the 83% of the time to resting, especially inside the huts (80%). Only the 3% of the resting time is registered outside. The 17% of the time is spent for outside activities. During the summer the animals spend the same time (83%) for resting, but they use less the hut (only 62% of resting time inside the hut). The 83% of the time destined to resting both in winter and in summer season can be considered as indicative of good welfare conditions, taking into account that in outdoor enclosures the pigs can satisfy instinctive behaviours such as rooting and exploring. In conclusion: a) the huts used during the trials enable to mitigate the outside temperatures in a rather limited way; b) in winter season it is advisable to arrange a partial closing of the open side and to use great amounts of straw; c) the open side exposed to West gives a better thermal comfort to the pigs, related to East exposition, both in winter conditions and in summer conditions.