Evaluation of correlation between crude protein levels and different space allowances under sawdust bed feeding system on growth performance, nutrient digestibility, blood profiles, and odour emission in growing-finishing pigs

A total of 96 growing pigs (25.11 +/- 0.69 kg) were used in this 14 wk feeding trial to evaluate the correlation between crude protein (CP) levels and different space allowances under sawdust bed feeding system on performance in growing-finishing pigs. Pigs were blocked with the following factors: (i) standard space (SS) allowance or wide space (WS) allowance and (ii) basal diet [control (CON)] or 10% reduction in CP of basal diet. The average daily feed intake was significantly increased (P < 0.05) in pigs fed with the CON in the SS. Pigs fed the 10% reduced CP diet in SS significantly increased (P < 0.05) the apparent total tract digestibility of nitrogen and dry matter. The blood urea nitrogen and cortisol concentrations of blood were significantly decreased (P < 0.05) in pigs fed with the 10% reduced CP diet in the SS. The ammonia emissions were significantly decreased (P < 0.05) in the pigs fed the 10% reduced CP diets. The fecal Lactobacillus concentration increased in pigs fed the 10% reduced CP diets in WS. In conclusion, the pigs fed with the 10% reduced CP diet in the SS reduced production cost and odour emissions, improved nutrient digestibility, fecal microbiota, and blood profile in growing-finishing pigs.