2.3.2. Chemical analysis
D) was determined using the methods of The Association of Analytical Chemists (AOAC, 1990).
The feed and faeces samples for chemical analysis were oven-dried at 708C for 24 h. The feed samples were then ground to pass through a 1-mm Wiley mill screen. Kjeldahl nitrogen and ash were determined according to AOAC (1990) standard procedures. Neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL) were ob tained using the method of Van Soest and Robertson (1985). Calcium was determined by flame atomic absorption and phosphorus by spectrophotometry (AOAC, 1990). Silica was determined as the ash after the ADF ash was leached for one hour with 48% hydrobromic acid.