Pig production systems

Summary
The project comprehended a survey on four private organic pig-producing farms and a series of experiments with slaughter pigs on the ecological research station, Rugballegård. In the private organic herds grass con-trol concerning the sow herd and health aspects of the entire pig herd were in focus. At the research station, experiments were carried out with roughage, size and arrangement of the outdoor area and the importance to weaned piglets of shift of environment.

No general, serious health or welfare problems caused by the organic production form were found. Appar-ently, there are no serious nor welfare threatening loss of weight or udder damage to the sows caused by the seven weeks of weaning. The most important risk factors for the sows are the burrowed in areas, which may cause lameness, and sun scorching if there are no shade/wallow possibilities.

Among the slaughter pigs several health risks were found in connection with the arrangement of the slaugh-ter pig paddocks, i.a. due to lack of experience and inappropriate slaughter pig housing. An excellent lung health of the slaughter pig was found. Diarrhoea in weaners was pronounced at times.

The experiments with slaughter pigs were carried out in three different housing systems with outdoor areas and indoors arranged as deep litter, straw flow or partial deep litter pens. All housing systems functioned well. The major part of the manure was dropped on the outdoor areas, which gave a good indoor environ-ment and concentrations of NH3, CO2, total dust and respirable dust considerably lower than in traditional slatted floor pig units. Moreover, the use of straw was considerably smaller than in traditional deep litter pens. None of the housing systems had a mass rearing of endoparasites. When the outdoor area was in-creased to 1 m2 per pig, more pigs stayed outdoors, but no differences in the aggression between pigs were seen.

The allocation of roughage and/or possibility of finding shelter in the outdoor areas influenced the behaviour of the animals significantly. The two things combined resulted in a better welfare of the pigs, although they had access to straw and relatively roomy conditions already. E.g. fewer scratches and wounds on tail, ears and body were found when allocating roughage. Furthermore, the manure behaviour was affected. The results may serve to arrange the pens so that the manure is dropped in the most appropriate places in relation to indoor environment and collecting possibilities.

Reducing the concentrate allocation while giving fresh grass or grass silage ad libitum resulted in a higher roughage intake, lower daily growth rate, better feed conversion, increased lean percentage and less ten-derness in the pork, whereas no difference in flavour attributes, taste or juiciness were seen. Comprehensively seen, roughage has a feeding value for the pigs, but only limited energy intake can be obtained hereof. The roughage, however, may permit a control of the growth rate of the pigs and the lean percentage.

Frequently, the ecological pigs are born outdoors, whereas the fattening takes place in pens with an outdoor area. Thereby the pigs are exposed to a drastic change of environment. An initial visual assessment, based on a comparison between pigs born indoors in their future pen with pigs born outdoor and moved, is that pigs born outdoors manage the environmental change well.