Phosphorous transformation in pig slurry due to diet and intermittent aeration treatments

The experiment was conducted to study the transformation of phosphorus (P) in slurry from pigs fed two different diets, i.e. the regular maize-soya bean meal diet with or without a supplement of 9% sugar beet pulp (SBP). The slurry was collected and treated either without or with aeration and intermittent aeration (aeration on/off ratio = 10 h:14 h) at an airflow rate of 0.6 l m(-3) s(-1) for 15 days. Slurry sources and treatments were composed of a 2 by 2 factorial design. The results indicated that aeration increased (probability P < 0.01) the slurry pH by 0.5-0.8 within 24 h, from 6.5 to 7.0 for the SBP slurry, and from 6.9 to 7.7 for the control slurry, but the pH reached 7.6 and 8.0 for the SBP and control slurry in 3-4 days. The average pH of the SBP slurry was lower (P