Justifications for the greater dose of formic acid-ammonium
formate in the nursery phase included the possibility
of insufficient secretion of HCl within the stomach;
stress from weaning, changing diets, and regrouping;
use of feed ingredients (such as plant or animal
protein meals and minerals), which are high in acidbinding
capacity; and lower feed intake compared with
that of grower-finisher pigs. Despite the greater inclusion
rate in the nursery phase, there was no increase
in gain in response to formic acid-ammonium formate
in the current study. However, feed intake decreased
(P = 0.04) and G:F was improved (P = 0.04) in pigs fed
the formic acid-ammonium formate-treated feed in the
combined nursery periods compared with those fed the
control feed. Lack of a response on ADG was observed
also in a 4-wk nursery study in which K-diformate was
used (Canibe et al., 2001) and a 5-wk study with formic
acid (Baustad, 1993).