Digestibility of wet cage layer excreta and an excreta-supplemented diet by cattle as determined by two methods

Digestibility studies were carried out with cattle to determine coefficients of digestibility for residual nutrients in wet cage layer excreta (CLE), and the effect of incorporating CLE in a maize silage-based diet, on nutrient digestibility. Two methods were used and compared — total collection, and the use of the recently identified internal marker, acid insoluble ash (AIASH).Digestibility coefficients for cage layer excreta were: dry matter, 74.0; organic matter, 73.1; crude protein, 76.8; energy 71.3; acid detergent fibre, 71.8%. Substituting CLE for soya bean meal or urea in the maize silage-based diet did not adversely affect nutrient digestibility. Comparable digestion coefficients were obtained with both the total collection method and the AIASH marker technique, confirming the results of others that the AIASH marker gives satisfactory estimates of nutrient digestibility.