Methods
Experiments were conducted in accordance with the South Dakota State University Institutional Animal Care and Use Committee (Protocol #10-080F)
Exp. 1: determination of digestible and metabolizable energy of a corn-soybeans extruded product
A total of 12 crossbred barrows (Yorkshire Landrace ) with an initial body weight of 59.9 +1.4 kg were used in a two period crossover design.
Animals
Barrows were randomly blocked as pairs by crate assignments and randomly assigned to one of the two experimental diets as treatments within blocks.
Period one of the experiment was a nine-day diet acclimation period followed by a four-day total collection of urine and feces
There was a two day rest between periods, with a dietary treatment switchback occurring at the start of period two, which also was comprised of a nine-day diet acclimation followed by a four-day total collection of urine and feces
At the start of cach period, barrows were weighed and placed in individual, raised metabolism crates
Crate assignments and placement within the room were identical for period one and two
Crates allowed for separate but complete fecal and urine collection