The effects of Ile and Val supplementation
of a low-CP, corn-wheat-soybean meal-based piglet
diet on growth performance, incidence of diarrhea,
and N balance were studied using 60 Landrace × Duroc
male piglets in a 4-wk experiment. The 60 individually
caged piglets were divided into 5 dietary treatments,
each consisting of 12 piglets. Diet 1 was a positive control
diet (20% CP); diet 2 was a low-CP negative control
diet (17% CP); diets 3, 4, and 5 were low-CP diets to
which Ile, Val, or the combination of Ile and Val were
added, respectively. All diets were supplemented with
Lys, Met, Thr, and Trp to provide the required concentrations
of these AA according to the 1998 NRC. Average
daily gain and ADFI were similar among pigs fed
the positive control, Val-added, and the Val plus Ileadded
diets. On wk-2 and wk-4, fecal score was greater
(softer feces) in piglets fed the 20% CP level compared
with the remaining treatments (P < 0.01). Nitrogen intake
was decreased (P < 0.0001) in pigs fed diets containing
low levels of CP compared with pigs fed the
20% CP diet. Fecal N excretion (g/d) was decreased (P
< 0.05) in piglets fed low-CP diets at wk 1 and wk 4
of feeding, and in urine at wk 4 of feeding. Crude protein
levels or AA supplementation had no effect on N
retention efficiencies. These results indicate that the
supplementation of Val alone, or in combination with
Ile, to a low-CP piglet diet with adequate levels of Lys,
Met, Thr, and Trp is necessary to achieve maximum
performance in pigs consuming corn-wheat-soybean
meal-based diets
