Agriculture Reference
In-Depth Information
influence the occurrence of stereotypic behaviors. Holt
et al.
(2006) reported increased
total time spent in stereotypic behaviors for sows fed twice daily compared with sows fed
one meal per day, but farrowing and lactation performance was unaffected. Twice daily
feeding simply encouraged sows to display feeding-induced stereotypies at two meals
daily instead of just one meal. Feeding sows 6 times per day compared with twice per day
decreased aggressive interactions among pen-housed sows but had no effect on farrowing
or lactation performance (Schneider
et al.,
2007). Behavior and farrowing performance
of gilts was unaffected by twice compared with 6 times daily feeding. So, it appears there
is little advantage in feeding sows multiple times daily compared with a single feeding.
One main solution to this problem is to feed high-fiber diets to gestating sows, and this
is covered in details in Chapter 5 (Meunier-Salaün and Bolhuis, 2015).
A critical aspect of any gestation feeding system is ensuring that every sow receives her
entire allotment of feed. This is particularly important because gestating sows are usually
fed relatively small quantities of a nutrient-dense diet. When sows do not receive their
complete allotment of feed (even for very short periods of time), performance can suffer
(Kongsted, 2006) which might lead to premature culling. This is especially important
in group-housing situations where aggression among sows might disadvantage the less
aggressive sows at the lower end of the social hierarchy. The pen design, feeding system
employed and stockmanship all play important roles in ensuring that sows receive their
proper allotment of feed during gestation. This is discussed at length in Chapter 3 on
gestation group-housing of sows (Spoolder and Vermeer, 2015).
The drive toward continual improvement in efficiency of pork production has prompted
interest in more targeted feeding approaches for gestating sows. Energy and nutrient
requirements during gestation are influenced heavily by body weight and condition of
sows. Traditionally, sows are fed a base level of diet which is increased or decreased based
on visual appraisal of sow body condition. However, feeding sows based on measured
body weight and backfat depth to achieve a target backfat depth at farrowing was
evaluated by Young
et al.
(2004). Their more targeted feeding approach was successful
in marginally reducing the incidence of fat sows at farrowing but did not significantly
decrease that of thin sows at farrowing. Farrowing and lactation performances were not
different between the traditional and the more targeted feeding approaches. Yet, more
targeted feeding led sows to consume less feed during pregnancy for the same lactation
performance, which would infer better utilization of feed resources. It is important to
note that sows fed according to targets for individual body weight and backfat depth
also gained less body fat and protein during pregnancy than traditionally-fed sows. The
long-term consequences of this observation warrant investigation since this study was
conducted for only one parity.
Energy and amino acid requirements of gilts and sows are not constant throughout
gestation (NRC, 2012). Requirements of young females (gilts and parity 1 sows) and
older sows also differ (NRC, 2012). Energy and nutrient requirements increase in late
gestation due to the rapid growth of the products of conception (Noblet
et al.
, 1985;
Ullrey
et al.
, 1965). This important change in requirements suggests that dietary supply
of energy and nutrients should change to match physiological needs based on age of the
