Agriculture Reference
In-Depth Information
On the other hand, feed intake and intestinal function decrease such that the use of
external sources of energy is replaced by a catabolic state where there is mobilization of
internal reserves of energy such as muscle proteins and NEFA from fat deposits (Oliviero
et al.,
2009). In this catabolic phase, the energy content of the feed seems less important
than the quality of the feed itself. On the other hand, a prolonged feed restriction, albeit
mild in terms of quantities, during pregnancy appears to have a negative effect on udder
development and mammary gene expression at the end of gestation (Farmer
et al.,
2014).
As sows approach farrowing, a mild state of constipation is common because the intestine
is less active (Kamphues
et al.,
2000). The sow's body seems to have an inner ability to
reduce its intestinal activity in favour of other physiological needs, such as parturition.
Studies have also shown that increasing the energy of feeding in late pregnancy can
negatively affect the sow's feed intake during early lactation. This reduction in feed intake
is thought to be due to reduced glucose tolerance and to insulin resistance caused by
excess energy intake during late pregnancy (Fangman and Carlson, 2007).
10.8.2
Intestinal activity and constipation
As mentioned before, a mild state of constipation is common for sows in the very last
part of pregnancy and sows often experience a state of constipation just around farrowing
(Oliviero
et al.,
2009). In addition, water absorption in the intestine increases during this
phase due to the fluid request resulting from the onset of milk production (Mroz
et al.,
1995). Offering feed low in volume and fibre can worsen constipation, thus increasing
the risk for absorbing bacterial toxins targeting the udder (Smith, 1985). In other
studies, constipated sows showed higher rates of mastitis (PDS) than unconstipated sows
demonstrating evidence of a direct effect of constipation on udder health (Hermansson
et al.
, 1978; Persson, 1996). During late pregnancy, one common practice in sow feeding
aims at reducing the amount of feed offered and increasing the dietary energy. Such
concentrated diets usually contain limited amounts of fibre compared with standard
pregnancy diets. This practice is done to ensure that sows receive enough energy
during late pregnancy to satisfy the needs for upcoming milk production (Einarsson
and Rojkittikhun, 1993). This combination of a concentrated and low-fibre diet during
a period of physiologically low intestinal activity can lead to severe constipation. Such
a mass of solid faeces may create a physical obstacle during birth by pressing on the
birth canal, thus resulting in greater difficulty during the expulsive stage (Cowart, 2007).
There is a current lack of knowledge as to how much such a state of severe constipation
may be a source of intestinal pain for the sows contributing to their declining welfare.
Starting five days before expected farrowing, a faecal score can be used to monitor the
intestinal activity of sows for 7-10 days, with a daily qualitative evaluation of the faeces.
Every morning before the daily cleaning, faeces of the sow should be checked by visual
qualitative evaluation. A score value is assigned, ranging from 0 to 5 (Figure 10.4). When
the average score is between 1.9 and 3.5 the intestinal activity should be normal, values
from 0 to 1.8 indicate different grades of constipation, with a severe condition when the
score is under 0.9.
