Effets d'une restriction alimentaire et d'une réalimentation sur les performances et le métabolisme de porcs européens (Large White) et caribéens (Créole) en croissance en climat tropical

Reduction of feed intake is a common physiological response of growing pigs facing stressful environmental conditions. The aim of the present experiment was 1) to study the effects of a short-term drastic feed restriction and subsequent refeeding on pig metabolism, and 2) to study the differential response between 2 breeds, the Large White (LW) breed that has been selected for high growth performance and the Creole (CR) breed, which is characterized by its good adaptation to harsh tropical environmental conditions. An assay with a total of 36 castrated male pigs (18 LW and 18 CR) was carried out. For each breed, half of the animals were restrictively-fed at 50% of the standard allowance for 7 days and were then fed normally for the next 15 days. Growth performance, thermoregulatory responses and plasma metabolites were measured before, during and after feed restriction in the 2 groups. Results show that for all the measured traits, the difference in the response between the 2 breeds is small and rarely significant. Irrespective of breed, during feed restriction, ADG and feed efficiency were reduced (-75%, P< 0.001; -58%, P< 0.05, respectively), but that was counterbalanced by an increase in those same parameters during refeeding (+25%, P< 0.001 ; +49%, P< 0.001, respectively). Feed restriction also reduces skin temperature (-0.6°C, P< 0.01), rectal temperature (-0.4°C, P< 0.01) and respiratory rate (-12 breaths per minute, P< 0.01). Moreover, the results suggest that certain metabolites, such as alkaline phosphatase and blood urea, could be potential biomarker candidates for feed restriction