Efficiency of fat deposition from different energy sources in pigs using multivariate regression analysis

The aim was to estimate the energetic cost of fat deposition from fermentable non-starch polysaccharides (fNSP), starch, and unsaturated fatty acids. A slaughter trial was conducted with a total of 58 individually housed pigs (48-106 kg). The energetic efficiency was monitored at two energy levels; the lysine supply of the pigs was limiting for protein deposition. Control diets were fed either at two or three times of maintenance energy requirement, and the treatments were achieved by isoenergetic addition of the daily nutrient intake (0.2 MJ DE/kg(0.75)) derived either from fNSP, or digestible starch (dSt), or digestible fat (dFat) above the nutrients from the control diets. Chemical composition of the pigs was determined at 48+/-4 kg (10 pigs) or 106+/-3 kg body weight (BW) (48 pigs). In conclusion, under protein limiting conditions, the energetic transformation of fNSP, dSt, and dFat for fat retention (NEfat/DE) was 62%, 80%, and 57%, respectively. The efficiency of fat deposition from a specific energy source was constant, irrespective of the actual feeding level.