Feed was supplied
in a daily amount of 3 times the maintenance energy
requirement [i.e., 106 kcal of ME/kg of metabolic
weight (BW0.75); NRC, 1998] of the smallest pig in each
replicate and divided into 2 equal meals that were fed
at 0800 and 1700 h. Water was available at all times.
Pigs were fed experimental diets for 12 d. The initial
5 d were considered an adaptation period to the diet.
Fecal markers were fed on d 6 (chromic oxide) and
11 (ferric oxide), and fecal collections were initiated
when chromic oxide appeared in the feces and ceased
when ferric oxide appeared (Adeola, 2001). Feces were
collected twice daily and stored at –20°C immediately
after collection. Urine was also collected and urine
collections started on d 6 at 1700 h and ceased on d 11 at
1700 h. Urine buckets were placed under the metabolism
cages to permit total collection. They were emptied in
the morning and afternoon and a preservative of 50 mL
of 6 N HCL was added to each bucket when they were
emptied. The collected urine was weighed and a 10%
subsample was stored at –20°C.