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[A1CR]

Pigs are a reasonable animal model for human CR, since they are
omnivors as are humans and not rodents or even non-human
primates. It appeared the CR, as distinct fron physical exercise,
decreased body heat production. "ADG = "average daily weight gain", it seems.

Lovatto PA, Sauvant D, Noblet J, Dubois S, van Milgen J.
Effects of feed restriction and subsequent refeeding on
energy utilization
in growing pigs.
J Anim Sci. 2006 Dec;84(12):3329-3336.
PMID: 17093225

An experiment was carried out to evaluate the metabolic
utilization of
energy in crossbred barrows during feed restriction and
subsequent
refeeding. Ten pigs, initially weighing 52 kg, were used in
5 blocks of 2
littermates each. A 7-d adaptation period (P1) was used in
which pigs were
offered feed at 2.60 MJ of ME.kg of BW(-0.60).d(-1). This
adaptation period
was followed by a 7-d period (P2), in which 1 pig of each
block continued to
receive feed at the same level of feeding, whereas for its
littermate a 40%
reduction in feed intake was imposed (i.e., 1.55 MJ of ME.kg of
BW(-0.60).d(-1)). During the subsequent 7-d period (P3),
both pigs were
offered feed at 2.60 MJ of ME.kg of BW(-0.60).d(-1). After
P3, pigs were
fasted for 1 d. Heat production (HP) was measured for all
pigs during the
last 3 d of P1 and on all days for P2 and P3. Heat
production was measured
using an open-circuit respiration chamber. Energy and N
balances were
determined for P1, P2, and P3. The HP was partitioned into
HP due to
physical activity, the short-term thermic effect of feeding,
and resting HP.
Feed restriction during P2 decreased (P < 0.01) total HP,
resting HP,
short-term thermic effect of feeding, and retained energy,
whereas HP due to
physical activity was not affected by feed restriction (P =
0.50). Likewise,
fecal and urinary N loss, protein gain, lipid gain, and ADG
were reduced
during feed restriction (P < 0.01). There were no
differences in components
of HP and metabolic utilization of energy between the 2
groups during P1 and
P3. Nevertheless, urinary N loss was decreased (P < 0.05)
and ADG increased
(P < 0.01) during P3 for pigs that were restricted in P2.
Compensatory
growth after a period of feed restriction does not seem to
be related to a
change in the metabolic utilization of energy for gain but
more likely is
due to gain in water and gut contents.