Effects of nutrition on digestion efficiency and gaseous emissions from slurry in growing pigs: III. Influence of varying the dietary level of calcium soap of palm fatty acids distillate with or without orange pulp supplementation

Abstract The aim of this study was to establish the relationships between faecal fat concentration and gaseous emissions from pig slurry. Five diets were designed to meet essential nutrient requirements: a control and four experimental feeds including two levels (35 or 70 g/kg) of calcium soap fatty acids distillate (CSP) and 0 or 200 g/kg of orange pulp (OP) combined in a 2 × 2 factorial structure. Thirty growing pigs (six per treatment) were used to measure dry matter (DM) and N balance, coefficients of total tract apparent digestibility (CTTAD) of nutrients, faecal and urine composition and potential emissions of ammonia (NH 3 ) and methane (CH 4 ). Increasing dietary CSP level decreased DM, ether extract (EE) and crude protein (CP) CTTAD (by 4.0, 11.1 and 3.5%, respectively, P P P 4 emissions, both per gram of organic matter ( P  = 0.021) or on a daily basis ( P P P  = 0.031) faecal excretion with no effect on urine N excretion. This resulted in lesser ( P  = 0.036) NH 3 potential emission per kg of slurry. Addition of OP decreased CTTAD of EE (by 7.9%, P  = 0.044), but increased ( P P  = 0.012), and aNDFom decreased greatly (from 483 to 404 g/kg DM, P 4 potential emission. Inclusion of OP in the diet also led to a significant decrease of CP CTTAD (by 6.85%, P P 3 emission. No significant interactions between CSP and OP supplementation were observed for the gaseous emissions measured.