Nutrient Digestibility Determination Protocol

Dried digesta and feeds were used to measure the titanium dioxide, GE, EE, and CP. Gross energy was measured using a calorimeter bomb (Parr 6200–Parr instrument company, Moline, IL, USA). The ether extract was measured following AOAC [28 ] (Method 920.39). Nitrogen was measured using TruSpec N Nitrogen Determinator (LECO Corp., St. Joseph, MI, USA) to calculate CP (Method 992.15; AOAC [28 ]).
The AID of the nutrients was calculated using the following equation [29 (link)]:
where TiO_2feed and TiO_2digesta were the concentrations of titanium dioxide in the diet and the digesta; Nutrient_digesta and Nutrient_feed were the concentrations of nutrients in the digesta and the diet.