Differential Digestibility of Innate Versus Added Fat in the Diets of Growing Pigs

The objective of this experiment was to compare the apparent total tract digestibility (ATTD) of innate fat (ether extract innate in ingredients; ENEE) versus fat added to the diet (EX) in formulations that contain increasing quantities of co-product ingredients. Results of this experiment show that diets with EX were more digestible than diets only containing ENEE. Digestion of EX (calculated by difference) showed a surprisingly large difference with ENEE much more digestible. In conclusion, fat added to the diet is much more highly digestible than innate fat which exists in the tested ingredients; therefore, energy values from fat should be estimated according to each fat source