Betaine supplementation affects energy partitioning in broilers

Abstract

The gastrointestinal tract consumes up to 25% of the total body oxygen consumption, thereby utilizing a large part of total ingested energy. Furthermore, around 35% of this energy is associated with the maintenance of ionic homeostasis (Jessop, 2000). Betaine is believed to reduce energy costs of the ion pump when acting as an organic osmolyte. However, the consequences of such an effect on energy utilization in broiler chickens are not well known. This study examined the effect of betaine supplementation on energy partitioning in broilers using indirect calorimetry. Male broilers (Ross 308 strain, N=36) were randomly assigned into three treatment groups in closed-circuit respiratory chambers (Swick et al., 2012). Each treatment consisted of six replicates of two birds per chamber. A basal diet based on wheat, soybean meal, meat bone meal and canola meal met the Ross 308 nutrient specifications. Betaine was added to the basal diet at 0, 0.75 and 1.50 g/kg of feed. The heat production (HP), apparent metabolisable energy (AME) and net energy (NE) of feed were estimated from 25 d to 27 d. The Brouwer equation was used to calculate the HP via the oxygen consumption and carbon dioxide production in the chambers and then estimate the NE (Noblet et al., 2010).