LAUSR

Abstract Sixty-four cross bred 6 week-old intact male pigs (initial BW = 13.8 ± 2.3 kg) were randomly distributed to 4 separated modules using a three-phase feeding program in which two dietary crude protein (CP) and total dietary fiber (TDF) levels were tested in a 2 × 2 factorial arrangement under a commercial-like production system. The room air was sampled and analyzed for NH3 and CH4 while the slurry pit air was sampled and analyzed for CH4 content during the early growing (phase I, 13.8–38.6 kg of body-weight), growing (phase II, 38.6–72.8 kg of body-weight) and finishing periods (phase III, 72.8–108.7 kg of body-weight); at the end of the finishing phase, 16 random pigs were sacrificed and cecum and colon contents were sampled to determine fermentation and microbial parameters. The pH and ammonium content increased with digesta transit being lower in cecum (6.0 and 69.7 mg/L) than in colon (6.3 and 156.3 mg/L) whereas the opposite trend was seen for total VFA and acetate (175.2 mM and 62.6 mol/100 mol vs. 141.1 mM and 57.2 mol/100 mol, respectively; P