Agriculture Reference
In-Depth Information
the mother-litter conflict was gradually intensifying with the ongoing lactation. Hence,
the number of nutritive nursings, which is the behavioral measure most closely related
to milk output but which is infrequently recorded, may be almost stable across the first
4 weeks of lactation (Valros
et al.
, 2002). Importantly, daily milk yield of commercial
sow breeds increases until the mid-third week and then remains stable until day 30 of
lactation (Hansen
et al.
, 2012).
It has been proposed that in housing systems that allow greater freedom of movement
for the sow, the gradual weaning processes progress faster (Drake
et al.
, 2008). Indeed,
lactating sows housed in 'get-away' pens, where they can leave piglets and stay in a
piglet-free area, have approximately 10% lower nursing frequencies than sows housed
in regular pens (Drake
et al.
, 2008; Pajor
et al.
, 2002). However, preventing the piglets
from approaching their mothers is an unnatural restriction. Data from other types of
housing do not show a clear difference in nursing frequency at week 4-6 between sows
housed in individual pens, group pens and outdoor runs (Newberry and Wood-Gush,
1985; Šilerová
et al.
, 2006).
In conclusion, there are prominent changes in nursing initiation and termination taking
place over the first weeks of lactation. However, the nursing frequency and lactation
output indicate that milk transfer is not weakened by natural weaning processes before
the piglets are separated from the sow at 4-6 weeks and is not substantially different in
various housing systems.
13.5
Conclusions
Nursing in swine is complex because of specific features including brief milk ejection,
long udder massage by the piglets, nursing synchronization, non-nutritive nursings
and ontogenetic shifts in nursing initiation and termination. In order to understand
pig nursing fully, knowledge about the underlying physiology must be combined with a
thorough elucidation of the behavior of the sow and the piglets including the acoustic,
olfactory and tactile communication. The functional view on nursing behavior, based on
the evolutionary theory, is useful in highlighting the potential for both cooperation and
conflict between the sow and her progeny.
References
Algers, B. and Jensen, P., 1985. Communication during suckling in the domestic pig. Effects of
continuous noise. Applied Animal Behaviour Science 14: 49-61.
Algers, B., Madej, A., Rojanasthien, S. and Uvnäs-Moberg, K., 1991. Quantitative relationships
between suckling-induced teat stimulation and the release of prolactin, gastrin, somatostatin,
insulin, glucagon and vasoactive intestinal polypeptide in sows. Veterinary Research
Communications 15: 395-407.
