<p>Sow litter sizes have been increasing over the years.
Increasing litter sizes typically result in an increased duration of farrowing
which can be detrimental to piglet survival due to the increased risk of <i>in-utero</i>
asphyxiation. The cumulative effect of repeated contractions over extended time
results in increased pressure on the umbilical cord. This causes an
interruption of blood and oxygen to the piglet brain, increasing the risk of
death. Although asphyxiation is the cause of the majority of stillbirths,
piglets who are born alive can also suffer from <i>in-utero</i> asphyxiation.
These piglets are considered to be of low vitality and are severely
disadvantaged in regard to survival and growth. Different methods have been
explored on ways to decrease farrowing duration, reduce stillbirths, and
improve piglet survival, but the neonatal mortality rate is still rather high
and is not decreasing. Therefore, new methods need to be investigated in the
hopes of successfully decreasing the farrowing duration of sows.</p>
<p>The first project aimed to shorten the farrowing duration
and improve piglet survival in farrowing crates via the provision of nesting
material and enriched piglet mats. There have been several studies on the
effects of nesting material in farrowing crates, but most of those studies use
materials that will fall through the slatted floors and block the liquid manure
systems. The current study implemented the use of jute as the nesting material
and proposed a novel way to present the material, by attaching it to the side
of the crate, to prevent it from falling through the slatted floors and
disrupting the manure systems. The enriched piglet mats were made from a
microfiber material to promote homeothermy and reduce heat loss, thus
potentially positively impacting piglet growth and survival. Twenty sows were
randomly assigned to 1 of 2 treatments: 1) farrowing crate with jute nesting
material (Nest; n = 10; 3 pieces of jute, each 40.6 cm x 21.6 cm) and two
enriched piglet mats made from an acrylic board (28.0 x 86.4 cm) covered with a
microfiber material, or 2) farrowing crate without nesting material (Control; n
= 10) and 1 standard rubber mat (28.0 x 86.4 cm) for piglets. Sows had access
to the jute material from approximately d 113 of gestation until they finished
farrowing, while piglets had access to the mats for the first 3 d of age. Sow
saliva was collected to measure Immunoglobulin A (IgA) and cortisol to assess
stress on d -1, 0, 1, and 2, relative to farrowing, and a final sample at
weaning (d 16.9 ± 0.18). Piglet plasma Immunoglobulin G (IgG) was collected
from 4 piglets/litter at 48 h, 7 d, and weaning. Piglet skin temperature was
measured from two piglets/litter using an infrared camera for 3 d after birth.
Video was continuously coded for observations of jute-directed and
crate-directed interactions. Nest sows performed less crate-directed behavior
than Control sows (<i>P</i> = 0.02), while both groups performed the same
amount of total nesting behavior (the sum of crate-directed plus jute-directed
behavior) (<i>P</i> > 0.05). Cortisol tended to be less in Nest sows (<i>P</i>
= 0.08), but there was no difference in IgA concentrations (<i>P</i> > 0.4).
Nest piglets tended to be heavier on d 7 (<i>P</i> = 0.095), had greater IgG
concentrations (<i>P</i> = 0.03), and greater skin temperatures (P = 0.02).
There were no differences in farrowing duration or number of stillbirths (<i>P</i>
> 0.7). </p>
<p>The second study investigated the effects of a dietary
supplement, 6.6% resistant starch (RS), on sow farrowing performance and piglet
survival and vitality. Since RS has been shown to help stabilize blood glucose
levels post-prandially, it was hypothesized that RS would decrease farrowing
duration by improving the energy status of sows during farrowing. Forty-two
sows were balanced for parity and randomly assigned to 1 of 2 treatments:
standard lactation diet (n = 21) or diet containing RS (n = 21). Sow blood was
analyzed for glucose concentrations at baseline, after 1 wk of being on their
respective diets, and during farrowing. Blood glucose for RS sows increased
between the beginning and end of farrowing while Control sow blood glucose
decreased (P = 0.04). However, there were no other effects on sow blood
glucose. Farrowing duration and number of stillbirths did not differ between
treatments (P > 0.05). Piglet blood glucose concentrations for RS piglets
tended to increase as the birth order increased, while blood glucose for the
Control piglets tended to decrease. The other piglet vitality measures, assessed
by blood lactate, pH, partial pressure of carbon dioxide (PCO<sub>2</sub>),
partial pressure of oxygen (PO<sub>2</sub>), total carbon dioxide (TCO<sub>2</sub>),
bicarbonate (HCO<sub>3</sub>), base excess (BE<sub>ecf</sub>), and oxygen
saturation (sO<sub>2</sub>) did not differ between treatments (<i>P</i> >
0.05).</p>
<p>In conclusion, farrowing duration was not successfully
decreased by the provision of jute nesting material attached to the side of the
farrowing crate or by supplementation of RS. However, the jute nesting material
and enriched piglet mats did positively impact sow welfare and piglet measures
to an extent, although this did not translate into improved piglet survival.
The resistant starch supplementation seemed to impact sow glucose during
farrowing, but not enough to impact farrowing performance or piglet survival or
vitality. These results could be because the nesting treatment was not robust
enough to allow sows to fully express their nesting behavior needs in order to
impact farrowing performance, while the RS supplementation may have been too
low of a dosage, not fed long enough, or a less effective type of RS. Novel
ways to optimize sow farrowing performance and piglet survival are still
needed.</p>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/17147786 |
| Date | 19 December 2021 |
| Creators | Mary L Markland (11811572) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/thesis/Investigating_Strategies_to_Optimize_Farrowing_Performance_and_Piglet_Survival/17147786 |
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