Comparisons of methods for in vitro dry matter digestibility of ruminant feeds

Apparent in vitro dry matter digestibilities of selected ruminant feeds were determined with the DAISY(II) incubator (ADD, ANKOM Technology Corp., Macedon, NY) and the Tilley and Terry technique (ADTT). True in vitro dry matter digestibility was also determined with the DAISY(II) incubator (TDD). The ADD and ADTT did not differ for grain crop silages and total mixed rations. The ADD was 9.0 percentage points higher than ADTT for grains and 3.4 percentage points lower than ADTT for grass and legume forages. The TDD was between 5.7 and 11.2 percentage points higher than ADD depending on the feed.