English to German Science Livestock / Animal Husbandry animal feed

From an abstract of a study, published for marketing purposes:

Objective [of the study]
To determine the apparent total tract digestibility (ATTD) of gross energy and the concentration of DE and ME in 4 differently processed soybean products and conventional soybean meal when fed to weanling pigs.


Ich hab vor allem mit dem total tract Teil Probleme, der Rest ist über AID = apparent ileal digestibility - scheinbare ileale Verdaulichkeit klar.
Scheinbare Gesamttrakt-Verdaulichkeit? Ein einsames Googleergebnis...