Housing of pregnant sows in loose and confined systems--a field study 1. Vulva and body lesions, culling reasons and production results.

Norwegian Pig Health Service, Central Veterinary Laboratory, Oslo.
Acta veterinaria Scandinavica (Impact Factor: 1.38). 02/1995; 36(2):185-200.
Source: PubMed

ABSTRACT A field study was carried out in 18 herds with loose housing of pregnant sows (loose herds) and in 18 herds with tethered or stalled pregnant sows (confined herds). Three of the loose herds were excluded due to different kind of flooring from the rest of the herds. The remaining 15 herds had partly slatted concrete floors and electronic sow feeding. The frequencies of sows with vulva and body lesions, thin sows as well as the culling reasons and production results were used as animal welfare indicators for the herds. Vulva lesions were found only in the loose herds and the mean prevalence proportion of sows with lesions within these herds was 15.2%. All vulva lesions observed in this study seemed to be caused by biting. The relative risk of vulva lesions was 2.6 times higher in the loose herds with no roughage feeding as compared to loose herds with appetite feeding of roughage. The sows in the loose herds, that had a feeding station with a mechanical hind gate had 1.8 greater risk of vulva lesions than sows in the loose herds that used a feeding station with an electronic gate. The mean prevalence proportion of sows with body lesions was 13.1% in the loose herds and 4.0% in the confined herds. Aggression between sows seemed to be the main cause of body lesions in the loose herds, while decubitus ulcers on the shoulders were the main cause of body lesions in the confined herds. Sows in loose herds that were not fed additional roughage feeding had 1.7 times greater risk of body lesions than sows in herds that used additional roughage feeding. The main culling reasons and production results were similar in the loose and confined herds. This study showed that there were welfare problems both in confined and loose herds, however, with improved management, many of the welfare problems associated with loose housing can be reduced.

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    The Welfare of Pigs, 1st Edition edited by Jeremy N Marchant-Forde, 01/2009: chapter INTRODUCTION TO THE WELFARE OF PIGS: pages 1-12; Springer., ISBN: 978-1-4020-8908-4
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    ABSTRACT: At any one time, a female breeding herd comprises both dry sows and farrowing/ lactating sows. The term 'dry sow' encompasses all gestating sows, sows awaiting service and barren sows within the herd. There is a great diversity of dry sow housing systems currently in use. Over the last few decades, sow housing has generally seen a move from somewhat extensive systems towards intensive systems, although this trend is reversing within Western Europe and a reversal is also beginning to show emergence in the pig industries of other developed countries, such as the U.S.A., Canada and Australia. Until this recent reverse, the major factor behind sow housing design was that of economics of production. Since World War II, there have been steady reductions in the number of individual pig producers, but increases in the size of herds. The trend away form extensive systems with small herd numbers towards larger intensive units was initially fuelled by price incentives in the late 1940s, when the production of cheap, plentiful food to meet post-war demand was often supported by governments. The intensification accelerated in the 1950s as new system-based technology was applied. The cyclical, profit-loss nature of the pig industry also accelerated the decline of the small producer. It made eco-nomic sense to increase herd size, increase stocking densities and decrease labor costs by mechanising where possible. The ultimate developments, in terms of gestation housing, were those of stalls and tethers. Keeping the sows in permanent confinement gave the farmer a number of advantages over less intensive systems. For example: 1) Stocking density. A larger number of sows could be housed in a given area compared with loose housing systems 2) Cost effectiveness. Housing sows on concrete with incorporation of a mechanized slurry handling system reduced both straw and labor costs
    The Welfare of Pigs, Edited by Jeremy N Marchant-Forde, 01/2009: chapter Welfare of Dry Sows: pages 95-139; Springer., ISBN: 978-1-4020-8909-1