response of growing pigs exposed to cold with varying amounts of straw bedding

Confinement housing of pigs allows optimal thermal conditions to be maintained thus reducing the thermal demand placed on the pig. Alternatives tend to cost less to construct, use less energy to operate and possibly have higher welfare standards than conventional housing; however, the thermal demand on the pig could be greater. An experiment consisting of two trials was conducted to examine the effect of varying amounts of straw bedding on the performance and behaviour of growing pigs while exposed to cold conditions. Four straw bedding treatments were studied and referred to as Least (20 kg), Medium-low (80 kg), Medium-high (137 kg) and Most (196 kg) straw usage. Results from the analysis of the two trials indicated that pigs with the three greatest amounts of straw gained more weight than pigs with the Least straw (P < 0.05). Pigs with the Least straw huddled with a sternal posture and piled more than pigs in the other three treatments (P < 0.05). Pigs with the two highest amounts of straw adopted a lateral posture while huddling more than pigs with the two lowest amounts of straw (P < 0.05). Pigs with the Most straw were also lying alone with a lateral posture more than pigs with the two lowest amounts of straw, and burrowed more than pigs in the other three treatments (P < 0.05). This study provides information on the adaptability of growing pigs exposed to different environmental conditions. Straw bedding was shown to be an important resource used by pigs to aid in thermoregulation in cold environments. Behavioural responses were also shown to be an effective means of adaptation.