1s. Loose-farrowing systems Improve the welfare of the sow whilst protecting the welfare of the piglet and have superseded the farrowing crate, now banned in three countries
Submitting InstitutionsUniversity of Edinburgh,
Unit of AssessmentAgriculture, Veterinary and Food Science
Summary Impact TypeTechnological
Research Subject Area(s)
Biological Sciences: Genetics
Medical and Health Sciences: Clinical Sciences
Summary of the impact
Impact: Policy, Animal Health and Welfare: Improved sow and piglet
welfare and recommendations and codes of practice for farrowing and
lactation systems that better meet sow and piglet needs.
Significance: Farrowing crates restrict sow movements interfering
with natural sow behaviour and increasing psychological distress. Used
predominantly to protect piglets, SRUC research demonstrated that piglet
survival improved in loose-housed environments, undermining crate use.
Beneficiaries: Farmers, sows and piglets, the general public
Attribution: Drs Baxter and Jarvis, Professors Lawrence and Roehe
(SRUC). Research collaboration was with Prof Sandra Edwards, University of
Reach: International legislative bans on farrowing crates;
voluntary industry uptake of non-crate systems; EU
recommendations/legislation on housing at farrowing, guidelines for
keeping pigs (e.g. RSPCA Freedom Food).
The use of the farrowing crate, designed to minimise space requirements,
protect piglets and make handling of sows easier produces a welfare
dilemma. The sow, during the pre-farrowing period, is highly motivated to
build a nest in preparation for birth. The restrictive nature of the
farrowing crate and its fully slatted flooring constrains this behaviour
by preventing provision of space and substrate. It persists as the
predominant housing type because it provides protection for the piglets
from crushing, which was the main reason it was introduced in the 1960s.
However, SRUC research (Drs Baxter (Researcher, employed 2002-onwards),
Jarvis (Behavioural Scientist, employed 1997-onwards), Profs. Lawrence
(Group manager, employed 1984-onwards), and Roehe (Senior Animal
Geneticist, employed 2004-onwards)) provided scientific evidence of
welfare issues that exist for the farrowing sow in a restrictive system
and related specific behaviours to physiological indicators of stress
[3.1, 3.2, 3.3].
Our programme of research (1993-onwards) took a systematic approach to
tackling the dilemma: observing and documenting the domestic sow's
species-specific behaviours in a natural environment and determining
whether these behaviours continue to be displayed in farrowing crates.
Then validating the behavioural evidence that farrowing crates thwart the
physiologically triggered need to perform nest-building behaviours
therefore causing psychological distress [3.1].
This validation work represents the main inception point of the impact.
To perform this validation we hypothesised that crating negatively
affected various stress and parturition-related hormones (e.g. prolactin,
oxytocin, vasopressin and plasma cortisol [3.1, 3.2]). By comparing
animals housed in traditional farrowing crates with those housed loose in
pens we confirmed our hypothesis showing that although parturition in
itself triggered an increase in cortisol, the plasma levels were
considerably higher in crated sows compared to loose sows, demonstrating a
physiological stress effect of crating supporting the behavioural evidence
Our research also questioned the piglet protective nature of the crate by
demonstrating that thwarting nest-building behaviour and disrupting
hormonal patterns that should prepare the sow for farrowing results in
increased negative maternal behaviours such as piglet-directed attacks by
the sow (savaging; [3.4]).
The next stage was to demonstrate that piglet survival could actually be
improved in loose-farrowing systems [3.5, 3.6]. Importantly, we conducted
detailed investigations to identify the key behavioural and physiological
attributes that underpin piglet viability and survival in a range of
farrowing systems, including outdoor loose-housed [3.5]. This work
gathered phenotypic evidence that supported a large genetic selection
experiment (involving collecting data on more than 20,000 piglets) that
successfully demonstrated that it is possible to breed for improved piglet
survival in loose farrowing systems [3.6]; within just one generation
perinatal mortality was reduced by three percentage points.
This body of research has provided a fundamental platform of robust
scientific evidence about the welfare detriments of crated sows whilst
also working on solutions to improve piglet survival that are translated
directly to the industry, thus advancing the welfare of both the sow and
References to the research
3.1) Lawrence, A. B., Petherick, J. C., McLean, K., Deans, L., Chirnside,
J., Vaughan, A., Clutton, E. and Terlouw, E. M. C. 1994. The effect of
environment on behaviour, plasma cortisol and prolactin in parturient
sows. Applied Animal Behavioural Science. 39: 313-33.
3.2) Lawrence, A. B., Petherick, J. C., Mclean, K. A., Deans, L.,
Chirnside, J., Vaughan, A., Gilbert, C. L., Forsling, M. L. and Russell,
J. A. 1995. The effects of chronic environmental stress on parturition and
on oxytocin and vasopressin secretion in the pig. Animal Reproduction
Science. 38: 251-264. http://dx.doi.org/10.1016/0378-4320(94)01361-O
3.3) Jarvis, S., Lawrence, A. B., McLean, K. A., Deans, L. A., Chirnside,
J., and Calvert, S. K. 1997. The effect of environment on behavioural
activity, ACTH, b -endorphin and cortisol in pre-farrowing gilts. Animal
Science. 65: 465-472.
3.4) Jarvis, S., Reed, B. T., Lawrence, A. B., Calvert, S. K. and
Stevenson, J., 2004. Peri-natal environmental effects on maternal
behaviour, pituitary and adrenal activation, and the progress of
parturition in the primiparous sow. Animal Welfare. 13: 171-181.
3.5) Baxter, E. M., Jarvis, S., Sherwood, L., Robson, S. K., Ormandy, E.,
Farish, M., Smurthwaite, K. M., Roehe, R., Lawrence, A. B. and Edwards, S.
A. 2009. Indicators of piglet survival in an outdoor farrowing system.
Livestock Science. 124: 266-276.
3.6) Roehe, R., Shrestha, N. P., Mekkawy, W., Baxter, E. M., Knap, P. W.,
Smurthwaite, K. M., Jarvis, S., Lawrence, A. B. and Edwards, S. A. 2009.
Genetic analyses of piglet survival and individual birth weight on first
generation data of a selection experiment for piglet survival under
outdoor conditions. Livestock Science. 121: 173-181.
Details of the impact
Impact on Policy
To date, three countries (Sweden, Switzerland and Norway) have banned
farrowing crate use completely and at least one other (Austria) has
initiated a phasing out of crates. In addition, there is voluntary
industry uptake of loose-farrowing alternatives (e.g. UK, Denmark, and
SRUC research on stress physiology of the farrowing sow has been used by
European veterinary committees and working groups as a basis for
recommendations for legislation which affects how all farmers in the EU
raise, house, and manage their livestock/pigs as well as in developing
guidelines for the keeping of pigs (e.g. Defra Welfare Codes, RSPCA
welfare standards for pigs). Although there is no full EU ban on crates,
the EU council directive 2008/120/EC says "...sows and gilts must be given
suitable nesting material in sufficient quantity unless it is not
technically feasible for the slurry system used in the establishment..."
This recognition that nest-building is an intrinsic need stems from the
scientific evidence reported and cited (SVC, 1997). Higher welfare
standards such as those laid down by the RSPCA for their Freedom Food
ensures substrate provision and has placed an imminent ban on crates (by
2014). Recently, the British Pig Executive (BPEX), in a document outlining
their vision for 2020, stated that they would "...continue to focus on
finding solutions that allow sow freedom around farrowing..." (http://www.bpex.org.uk/articles/301937/2020_Pig_Health_and_Welfare_Strategy.aspx).
This acknowledgement of the welfare issues has also been voiced by the
Danish Pig Industry who committed to ensuring 10% of their breeding herd
(equivalent to ~120,000 sows) would be loose-farrowing by 2020. Our
scientific evidence showing the unequivocal welfare detriments to sows
housed in farrowing crates and not permitted substrate for nest-building
is used repeatedly to support such decisions.
Impact on Piglet Mortality
The issue of piglet mortality continues to be a major welfare and
economic concern in all farrowing systems. Total pre-weaning mortality in
commercial piggeries ranges from 16-20% (cf. BPEX Pig Yearbook 2012),
equating to approximately 2 million piglet deaths per annum in the UK
alone. With every 0.5% increase in pre-weaning mortality, output is
reduced by 10kg/sow/year, a significant loss of income to producers and a
significant inefficiency within the supply chain. In order to reduce
piglet mortality and ensure no rise in piglet mortality in loose farrowing
systems, it was vital to identify the causes of death in different
farrowing systems and thus identify what contributes to piglet survival
[see reference 3.5 above]. A concern that piglet mortality is increased in
loose farrowing systems slows progress in abolishing the farrowing crate.
However, SRUC investigations into causes of piglet mortality and the
genetics of piglet survival, within loose farrowing systems have led to a
readily available breeding strategy to actually improve piglet survival.
When applied nationally, this approach reduces piglet mortality rates by
3% equating to 60,000 fewer piglet deaths, saving the industry £2.7
million annually. This work was conducted with breeding companies
and farmers and therefore translated directly to industry by incorporating
into breeding programmes.
This work has been distributed via the EU Welfare Quality programme
factsheets (available in 5 different languages), as well as disseminated
at invited presentations on improving piglet survival which include: 25
pig discussion groups, 2 industry workshops, 3 international conferences
and many on-farm consultations.
Sources to corroborate the impact
Sources 5.1, 5.2 and 5.3 all repeatedly cite our scientific research
(see section 3 references 3.1-3.4) as evidence of the welfare detriments
of the farrowing crates to both the sow (3.1, 3.2, 3.3) and the piglets
(3.4). Source 5.4 cites our research on piglet survival (3.5, 3.6) as
valuable evidence of the potential to breed for improved survival in
loose systems. Sources 5.5, 5.6 and 5.7 are examples of the translation
of our research into industry.
5.1) Evidence Deputy Director, Defra http://tinyurl.com/nv35p67
5.2) SVC, 1997. The welfare of intensively kept pigs. Report of the
Scientific Veterinary Committee. Directorate General XXIV of the European
Commission. Adopted 30th September 1997. Doc XXIV/ScVc/0005/97.
Scientific Veterinary Committee, Animal Welfare Section, Brussels,
5.3) Informs the EU Council Directive 2008/120/EC lays down the minimum
standards for the protection of pigs: http://tinyurl.com/pfdv88w
5.4) European Food Safety Authority 2007. Animal health and welfare
aspects of different housing and husbandry systems for adult breeding
boars, pregnant, farrowing sows and unweaned piglets  — Scientific
Opinion of the Panel on Animal Health and Welfare, EFSA. pp.1-13
5.5) European Food Safety Authority 2011. Scientific report updating the
welfare of pigs. Report 1. Update of animal health and welfare aspects in
relation to housing and husbandry of adult pigs and unweaned piglets,
including castration. http://tinyurl.com/qafmqan
5.6) Improving piglet survival. Welfare Quality. http://tinyurl.com/p6xjngb
5.7) RSPCA welfare standards for PIGS. 2012. http://tinyurl.com/pvw526v
5.8) BPEX — 20:20 Pig Health and Welfare Strategy http://tinyurl.com/ntg5lmg