Agriculture Reference
In-Depth Information
(most important) and improved energy balance of the sow. However, benefits of such
strategies seem rather marginal with our modern sows that have been selected for short
weaning-to-oestrus intervals and not all sows respond to the treatment. After weaning,
follicle development should be further stimulated by appropriate nutrition, boar contact
and by avoiding stressful conditions. This should lead to a group of sows with short
and synchronous weaning-to-ovulation intervals. However, since the post-weaning
follicular period is normally very short, even optimal post-weaning conditions may not
be sufficient to optimize post-lactational fertility. Another possibility would be to allow
primiparous sows to recover from lactation by postponing the post-weaning oestrus and
insemination (e.g. by short term use of a progesterone analogue). Subsequently, optimal
fertilisation rates of the good quality follicles can be achieved by appropriate timing of
good quality inseminations. The scheme in Figure 17.4 summarizes the aspects dealt
with in this chapter. It is important to note that a crucial aspect of reproductive success
relies on the presence of skilled staff who realises the importance of their actions for the
reproductive physiology of sows.
Regular management
Additional options
Lactation
'Optimize follicle development'
- gilt development
- pregnancy feed intake
- feed intake pattern
- feed composition
- room temperature
- water intake
Avoid lactational weight loss
- split weaning
- intermittent suckling
Reduce suckling stimuli
Weaning-to-oestrus interval
'Optimize follicle development'
- feed intake
- feed composition
- boar contact
- stress
- skip-a-heat
- altrenogest treatment
Regular interval
Extended interval
Oestrus and insemination
'Maximise fertilisation'
Timing of insemination
- oestrus detection
- boar contact
- stress
- ovulation induction
- boar contact
- stress
- AI technique/dosage
Around insemination
Figure 17.4. Summary of major management aspects affecting reproductive performance of the weaned sow.
