Agriculture Reference
In-Depth Information
11. Piglet mortality: causes and prevention
S.A. Edwards
1*
and E.M. Baxter
2
1
Newcastle University, School of Agriculture, Food and Rural Development, Agriculture
Building, Newcastle upon Tyne, NE1 7RU, United Kingdom;
sandra.edwards@ncl.ac.uk
2
Animal Behaviour and Welfare, Animal and Veterinary Sciences Group, Scotland's Rural
College (SRUC), West Mains Road, Edinburgh, EH9 3JG, United Kingdom
Abstract
The evolutionary biology of the pig means that it is predisposed to produce more offspring
than it is likely to rear, and this tendency has been exacerbated under farm conditions
by genetic selection pressure for increased prolificacy. Piglet mortality from birth to
weaning typically amounts to 16-20%, with the major causes attributed to stillbirth,
crushing and starvation. However, these ultimate causes mask the true predisposing
factors, with interactive risk factors arising from the biology of the sow and piglets and
the challenges of the neonatal environment. Intra-uterine competition for nutrients can
result in a stillborn piglet or a live-born piglet with reduced viability, low birth weight and
compromised chances for postnatal survival. Prenatal insults can impact on vigour and
thermoregulatory abilities, resulting in a piglet unable to survive the challenges of asphyxia
during birth, hypothermia following delivery and intense competition for colostrum.
Reduction in piglet mortality requires co-ordinated genetic, nutritional, management and
stockperson interventions. The incorporation of survival traits in genetic selection goals,
the optimisation of maternal nutrition during breeding and gestation, and the avoidance
of prenatal maternal stress through appropriate environmental conditions will promote
delivery of more vital piglets and stimulate good maternal behaviour. Supervision and
assistance during farrowing, with stockperson intervention to facilitate early and adequate
ingestion of colostrum by all piglets, provision of appropriate thermal microclimates to
reduce hypothermia, and skilful cross-fostering to ensure early establishment of litters of
appropriate size and uniformity, are all key components of success. With an increasing
societal focus on the ethical and welfare issues in pig production, but no alleviation of
the financial pressures on pig farmers to remain competitive, the requirement to achieve
a high number of piglets weaned per sow per year in an environment allowing adequate
expression of sow behavioural needs will continue to pose challenges.
Keywords:
neonate, survival, farrowing, behaviour, management
11.1
Introduction
The pig is a polytocous species and its natural biology is such that it over-produces
offspring. This evolutionary strategy is thought to be a form of parental optimism; the
production of numerous neonates allows replacement offspring in the event of one or
more members of the litter dying (Forbes and Mock, 1998; Mock and Forbes, 1995).
