Agriculture Reference
In-Depth Information
288
240
192
144
96
Sows sorted by weaning to oestrus interval and ovulation time
Figure 17.3. Example of evaluation of insemination timing in a group of weaned sows. Oestrus detection was
done twice daily to determine onset and end of oestrus (straight lines) and ovulation time was estimated
to occur at two-thirds of oestrus (dotted line). In this group of sows, oestrus duration clearly declined with
later onset of oestrus. First insemination (closed circle) for most sows was perfectly timed at 0-24 h before
insemination. Nevertheless, the majority of sows received a second insemination (open circles) after ovulation.
This second insemination is redundant and possibly harmful (data obtained from P. Langendijk).
17.5.5
Developments in artificial insemination techniques
Developments in artificial insemination techniques have largely aimed at using less
sperm cells for a fertile insemination and reducing labour input around oestrus and
insemination. A reduction in the number of sperm cells needed for a fertile insemination
allows a higher efficiency of valuable breeding boars which ultimately benefits genetic
progress and might eventually allow the efficient use of cryopreserved or sex-sorted
semen (reviewed by Roca
et al.
, 2011). On the other hand, low dose inseminations place
higher demands on timing and quality of inseminations.
Insemination technique and dosage
Up to approximately the year 2000, all artificial inseminations in sows were intra-cervical.
The pipette was fixated halfway into the cervix and a dosage of approximately 80-100
ml, containing up to 2-3×10
9
sperm cells, was used. Currently, most inseminations
worldwide still use cervical inseminations, but pipettes for intra-uterine or post-cervical
