Determination of apparent digestibility coefficients in 6-, 12- and 18-week-old ostriches

1. The apparent digestibility coefficients (ADC) of a diet consisting of a concentrate and of alfalfa grass in a 4:1 ratio were measured in 6. 12-and 18-week-old ostriches. 2. These coefficients were measured in 4 animals eating ad libitum using bo th a total collection method, and internal marker methods with acid deterge nt lignin (ADL) and with acid insoluble ash (AIA). 3. The ADC of dry matter, organic matter, crude protein, ether extract and energy were not influenced by the age of the ostriches. The ADC of structur al carbohydrates, however, were significantly higher (P<0.01) in the 12-and 18-week-old animals. 4. The results obtained by the total collection and ADL methods were simila r: The AIA method, however; overestimated the values due to the very high m arker recovery rate (128.0%).