Y. Ramonet et al., The effect of dietary fibre on energy utilisation and partitioning of heatproduction over pregnancy in sows, BR J NUTR, 84(1), 2000, pp. 85-94
A low (L) and high-fibre (H) diet were fed to six multiparous sows during g
estation in a 2 x 2 repeated Latin square design. A single meal per day was
given that provided 37.2 MJ digestible energy/d. The kinetics of heat prod
uction (HP) and its partitioning (fasting HP, activity HP, and thermic effe
ct of feeding (TEF)) were determined. The TEF was partitioned between a dyn
amic component (TEFst) and a constant component (TEFlt). Digestibility of e
nergy and nutrients was lower for the diet H. In spite of the lower metabol
isable energy (ME) intake (33.9 v. 35.4 MJ/d for diets H and L respectively
), HP was higher for diet H (30.5 v. 28.9 MJ/d) resulting in a lower energy
retention. The estimated fasting HP was 270 kJ/kg body weight(0.75) per d
at day 0 of gestation and increased with advancement of pregnancy. The TEFl
t was not significantly different from zero for diet L, but represented 4.1
% of ME intake for diet H. The TEFst was not affected by the diet but diet
H delayed the postprandial peak of HP. Total TEF was higher for diet H tha
n for diet L (11.7 v. 8.2 % of ME intake). The longer duration of eating wi
th diet H was compensated for by less physical activity between meals, so t
hat activity HP was equivalent for both diets. The activity HP represented
20 % of ME intake but was variable between sows. The ME requirements for ma
intenance averaged 440 kJ/kg body weight(0.75)per d. Feeding high-fibre die
ts increases HP, delays the postprandial peak of HP and maintains the basal
HP at a higher level.