Agriculture Reference
In-Depth Information
Paboeuf
et al.
, 2000). It should be noted, however, that in several studies comparing
isocaloric (based on estimated digestible energy (DE), metabolizable energy (ME) or
NE) fibrous diets with standard diets, either higher or lower body weight or backfat
gains are reported in the sows fed the high-fibre diets, which is partly due to over- or
underestimation of the energy content of the diet and its NE supply (Guillemet
et al.
, 2006,
2007b; Matte
et al.
, 1994; Mroz
et al.
, 1986; Noblet
et al.
, 2003, Van der Peet-Schwering
et al.
, 2003b). These variable effects on sow condition could, in turn, affect subsequent
performance during lactation. In addition, variation in weight gain in gestating sows fed
a fibrous diet can partly be explained by the greater weight of the gastrointestinal tract
or by intestinal repletion related to the digestive effect of dietary fibres (Danielsen and
Vestergaard, 2001). This hypothesis is reinforced by the fast digestive adaptation to a
concentrate diet after farrowing, with live weight decreasing by approximately 5-6 kg due
to a smaller size and repletion of digestive organs (Van der Peet-Schwering
et al.
, 2003b;
Vestergaard and Danielsen, 1998).
Numerous studies reported a beneficial effect of providing a fibrous diet during pregnancy
on the feed intake level (generally of a concentrate diet) during lactation (Courboulay
and Gaudré, 2002; Farmer
et al.
, 1996; Matte
et al.
, 1994; Quesnel
et al.
, 2009; Van
der Peet-Schwering
et al.
, 2003b; Table 5.3) and this, especially in the first week(s) of
lactation (Farmer
et al.
, 1996; Guillemet
et al.
, 2006). Such an effect can be explained by
an increased size and capacity of the digestive tract induced by the fibrous diets supplied
during pregnancy, thereby promoting feed intake especially at the start of lactation. This
effect, however, tends to trail away as lactation advances due to adaptive processes of the
digestive tract (Farmer
et al.
, 1996). Some authors suggested an alternative explanation,
and attributed the beneficial effect of high-fibre gestation diets on feed intake during
lactation to a lower backfat and leaner body condition of sows at parturition following a
pregnancy on fibrous diets (Matte
et al.
, 1994; Danielsen and Vestergaard, 2001). There
does not seem to be a relation, however, between the effects of fibrous gestation diets on
sow backfat measurements and on feed intake during lactation.
The increased intake during lactation appears to be greater with more bulky pregnancy
diets. Such an effect was seen with diets based on sugar beet pulp but not with diets based
on mixed fibre sources (wheat bran, oat and dried grass meal; Danielsen and Vestergaard,
2001). A greater increase in feed intake was reported with a diet based on oat compared
with a diet based on wheat bran, but the crude fibre of the oat-based diet was also much
higher (20.41 vs. 10.07 mg/kg of dry matter for oat and wheat bran diets, respectively) so
that this effect could be linked to fibre level (Matte
et al.
, 1994).
Few investigations were carried out on the effect of a fibrous gestation diet on the farrowing
process. These studies differ in the nature and incorporation rate of dietary fibre, and in
genetic breed which may explain discrepancy in the results. Some studies described a
decrease in parturition length ranging between 9 and 29% in sows fed a fibrous diet
during late pregnancy (Bilkei, 1990; Kurcman-Przedpelska, 1989; Morgenthum and
Bolduan, 1988), whereas others (Guillemet
et al.
, 2007b; Loisel
et al.
, 2013) reported
no significant impact on the duration of gestation or parturition. One study reported a
shorter interval between birth of the first and third piglet in sows fed a high-fibre diet
