RESUMEN
BACKGROUND: Betaine and conjugated linoleic acid (CLA) may alter growth and body composition in pigs, although their mode of action is not well understood. Portal-drained viscera (PDV) have a disproportionate influence with respect to their masses, and this may affect the productivity of more profitable tissues. The objective of this study was to determine if the use of betaine and/or CLA in the diet affects PDV heat production. RESULTS: Postprandial portal blood flow (PBF) was greater (19.0%, P = 0.004) for control compared with the other three diets. The lowest (P < 0.001) value for postprandial PDV O2 consumption corresponded to betaine + CLA followed by betaine and CLA diets (32.7, 25.4 and 17.7% respectively with respect to control diet). Postprandial PDV heat production was greater (26.4%, P < 0.001) for control with respect to the other three diets, with the minimum value corresponding to betaine + CLA (34.1% lower than control). CONCLUSION: Supplementation with betaine and/or CLA reduced the PBF, O2 consumption and therefore PDV heat production with respect to control diet. This effect was more pronounced when betaine and CLA were supplemented together, potentially increasing the energy availability for other body tissues. © 2016 Society of Chemical Industry.