ABSTRACT: The objective of this experiment was to
determine the net energy requirements for maintenance
of growing and finishing pigs using regression models.
Thirty-six growing (27.38 ± 2.24 kg) and 36 finishing
(70.25 ± 2.61 kg) barrows were used and within each
phase. Pigs received a corn–soybean meal diet fed at 6
levels of feed intake, which were calculated as 0, 20, 40,
60, 80, or 100% of the estimated ad libitum ME intake
(2,400 kJ ME/kg BW0.6·d–1) of the pigs. Measurements
were conducted on 6 pigs per feeding level and per stage
of growth. After a 5-d adjustment period, barrows in the
fasted treatment were kept in respiration chambers for
2 d to measure the fasting heat production. Barrows in
the other treatments were kept individually in respiration
chambers for a 5-d balance trial followed by a 2-d
fasting period. Heat production (HP) in the fed state