There were no treatment effects (P > 0.05) on pH of feces
and ileal digesta (Table 6) although pH of ileal digesta of
pigs on Acid 1 and 2 was numerically lower (P > 0.10) than
those of pigs on other treatments. Apparently the acidifying
effect of the dietary acids reduced acid secretions into the
stomach or was partially overcome by the buffering capaci-
ty of the secretions into the ileum. The pH of ileal digesta
was lowest, followed by colon digesta and feces. The pH of
colon digesta was lowest (P < 0.05) in pigs on Acid 1, while
it was lower in pigs on Acid 2 than in pigs on the herb
(Table 6). Risley et al. (1992) reported that Cl
– concentra-
tion steadily decreased from a high in the stomach and
jejunum to a low in the cecum and lower colon. Maribo
et al. (2000) observed that the pH in gastrointestinal tract
was reduced and lactobacilli density was lower in the small
intestine and higher in the cecum and colon of pigs fed diet
added lactic acid. Treatment effects on pH in colon are more
likely to reflect effects on microbial fermentation and pro-
duction of volatile fatty acids than direct effects of dietary
acids (Piva et al. 2002).