Effects of dietary cellulose levels on the estimation of endogenous amino acid losses and amino acid digestibility for growing pigs

Two experiments were conducted to investigate the effects of dietary cellulose levels on the determination of the ileal endogenous losses (IEL) of amino acids (AA), apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of AA in corn-soybean meal diets for growing pigs. In the first experiment, 28 pigs (BW, 45.1 ± 2.0 kg) that were fitted with simple T-cannulas at the distal ileum were fed 4 nitrogen-free diets consisting of 4 dietary cellulose levels (0, 3%, 6% and 9%) in a randomized complete block design. In the second experiment, 28 pigs (BW, 45.6 ± 2.0 kg) fitted with simple T-cannulas at the distal ileum were fed 4 corn-soybean meal diets consisting of 4 dietary cellulose levels (0, 3%, 6% and 9%) in a randomized complete block design. There were 7 replicates per diet with 1 pig as a replicate in each treatment. Both experiments consisted of a 7-d adjustment period and a 2-d ileal digesta collection period on d 8 and 9. Chromic oxide was used as an indigestible marker to calculate IEL and digestibility of AA. The results showed that the IEL of AA for growing pigs was not influenced by dietary cellulose supplementation (P > 0.05). The AID of Thr, Ser, Glu, Cys, Ile, Tyr, Phe, Lys and His decreased with increasing cellulose supplementation levels for pigs fed corn-soybean meal diets (P < 0.05). The SID of Thr, Ser, Cys, Val, Ile, Tyr, Phe, Lys and His decreased with increasing cellulose supplementation levels in corn-soybean meal diets (P < 0.05). In summary, dietary cellulose levels had no effect on the estimation of IEL of AA for growing pigs. The AID and SID of most AA in corn-soybean meal diets decreased with increasing levels of dietary cellulose supplementation.