Agriculture Reference
In-Depth Information
and increases by 76% the consumption of colostrum by low birth weight piglets (<900 g).
Such effects could either be due to altered maternal behaviour during the periparturient
period (Farmer
et al.
, 1995), or be related to changes in piglet vitality. Che
et al.
(2011)
also reported that providing a high-fibre gestation diet resulted in relatively higher
weights of liver, heart and kidney in newborn piglets, and in a tendency for a reduced
intralitter variation in birth weight.
The effect of dietary fibre on the number and weight of piglets at weaning is variable
(Meunier-Salaün
et al.
, 2001; Philippe
et al.
, 2008). Loisel
et al.
(2013) found a reduced
preweaning mortality and Veum
et al.
(2009) reported a larger number of piglets
weaned over three production cycles. Positive effects on weaning weight were reported
by Guillemet
et al.
(2007b) and Quesnel
et al.
(2008), and some studies described litter
growth rate until weaning to be increased by 13 and 20% (Evert, 1991; Matte
et al.
, 1994).
In contrast, Che
et al.
(2011) found a negative effect on pig weight at day 22 for litters
from sows fed a high-fibre diet in first parity.
In summary, the effects of dietary fibres on sow reproductive performance are variable,
depending on the dietary fibres used and their inclusion rate, and also depending on the
reproductive cycle number of females. Positive effects are present on sow lactation feed
intake but the effects on piglet performance are still not clear.
5.6
Conclusions
This review highlighted the beneficial impact of dietary fibres on the behaviour and
welfare of gestating sows that are restricted-fed. Fibrous diets generally decrease the
occurrence of stereotypies, and reduce restlessness and aggression around feeding. This
is most likely due to the behavioural (prolonged duration of feeding) and physiological
effects of the dietary fibres which promote satiation and satiety. Moreover, in most
studies, dietary fibres provided during gestation increased the feed intake of sows during
lactation, probably due to their effects on the size and capacity of the gastrointestinal
tract. Studies on the effects of fibres on reproductive performance are rather scarce and
show variable results, with could partly be related with inaccuracy in the measurement
of the NE supply during pregnancy. Nevertheless, the amplitude of the effects of dietary
fibres depends on many factors related to the fibre per se (incorporation rate, fibre source,
physicochemical properties), to environmental conditions (feeding and housing systems)
and to individual factors (parity). In most studies looking at the impact of dietary fibre on
performances, sows were housed individually for one reproductive cycle only, suggesting
that further research on grouped-housed sows, implemented in the recent European
policy on the animal welfare regulation, and over multiple reproductive successive cycles,
is warranted. The variation of the effects according to the source of dietary fibre on the
behaviour, despite close physicochemical properties, remains to be explored. Recent
investigations shed light on the physiological mechanisms by which fermentation and
bulkiness promote satiety, and on the long term effects of fibre intake on voluntary intake
and reproductive performance. Yet, further research is still needed to fully acknowledge
the satiating effects of fibres with different physicochemical properties.
