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Doctoral thesis, 2016

Welfare, performance and emissions in a stationary housing system for organic growing-finishing pigs

Olsson, Anne-Charlotte;

Abstract

High standards of animal welfare and health and providing animals with a natural environment and organic feed are primary objectives in organic pig farming. However, housing solutions in organic pig farming are not uniform. Stationary systems have permanent buildings with concrete areas outdoors and/or pasture, mobile systems have outdoor huts on pasture, and mixed systems have both stationary buildings and huts. This thesis examined the pros and cons of stationary housing systems for organic growing-finishing pigs in studies carried out at Odarslöv Research Farm, SLU, Alnarp. The uninsulated and naturally ventilated building was fitted with eight pens (8 x 16= 128 pigs), four with a deep straw system and four with a ‘straw-flow’ system. Each pen had access to an outdoor concrete area and, depending on the experimental set up, also to pasture. No difference in health, daytime pig activity, or pen hygiene was detected between the deep straw and straw-flow systems. Pigs with access to pasture were not more active during daytime behaviour studies than pigs without access to pasture. However, the pigs with access to pasture occupied themselves more on the pasture than on the concrete outdoor area. Pigs from straw-flow pens had higher carcass meat percentage at slaughter than pigs from deep straw pens, but there was no difference in performance between pigs with and pigs without access to pasture. Nitrogen losses from the organic pigs were estimated to be 26-27% of N excreted. This gives approximately three to four times higher ammonia emission than standard values from conventional pigs when assuming that all losses consist of ammonia. A larger fouled area, particularly outdoors, may partly explain this result. Measures to improve hygiene, reduce fouling and decrease nitrogen emissions from the outdoor concrete area were tested. The intention was to direct the excretory behaviour of the pigs by introducing rooting yards with attractive rooting material. Our investigations on rooting yard design revealed that a larger rooting yard (8.4 m2) with one high wall (LH) was a more optimal option than a smaller (5.3 m2) one. In the LH design it was revealed that any rooting material of wood shavings, peat, peat + feed pellets was more attractive than the control yard without rooting material. Visual hygiene evaluations showed improved hygiene for all rooting materials tested. However, to reduce ammonia emission, peat was clearly in favour compared to wood shavings.

Keywords

organic pigs; stationary housing; ammonia emission; mass balance

Published in

Acta Universitatis Agriculturae Sueciae

2016, number: 2016:76
ISBN: 978-91-576-8654-1, eISBN: 978-91-576-8655-8
Publisher: Department of Biosystems and Technology, Swedish University of Agricultural Sciences

Authors' information

Olsson, Anne-Charlotte
Swedish University of Agricultural Sciences, Department of Biosystems and Technology

UKÄ Subject classification

Agricultural Science

URI (permanent link to this page)

https://res.slu.se/id/publ/77212