Free ranging of pigs within the crop rotation in organic agriculture.

Brandt, Michael; Farke, Antje; Sundrum, Albert and Weißmann, Friedrich (2004) Ganzjährige Freilandhaltung von Mastschweinen als ein Fruchtfolgeglied im Ökologischen Landbau. [Fattening pigs in an outdoor system as a part of the crop rotation within organic farming]. Department of Organic Agricultural Sciences, University of Kassel, Department of Animal Nutrition and Animal Health.

Aim of the project was to assess the effect of substitution of concentrates by home grown feedstuffs on pig performance, variation of carcass quality and nutrient losses in a free range organic system. In five treatments three different genotypes (Ha x Pi) x (Du x GL), Pi x (LW x GL) and Pi x (Du x GL) and 4 different crops as forage for the pigs were used: Turnip (T), Ryegrass (R), Jerusalem Artichoke (J) and barley stubble (S). The amount of supplemented concentrates differed in relation to the season and the crops available on the paddocks.
The results show that fattening pigs achieved an average daily live-weight gain (ADG) of 740 g. Differences in ADG between treatments were primarily due to the different genotypes.
When pigs were kept on the paddock with Jerusalem artichoke, they reached a similar and even higher ADG compared to other treatments although the amount of concentrate offered was clearly reduced. Lean meat content (LMC) of the carcasses was about 55 % on average. There were no significant differences in LMC between genotypes, however, clear differences between treatments.
Feed rations based purely on concentrates lead to high inputs of N and P in the soil, being higher than accepted under the organic framework conditions. Due to shifting the equipments (huts, feeding and watering troughs) partial nutrient accumulations in these areas decreased clearly. Portioning the paddock increased the activity of the pigs at this area. More faeces were placed at the paddock and nutrients were distributed more uniform.
It can be concluded that under free range conditions fattening pigs can achieve acceptable levels of ADG and carcass yield. Concentrates can be substituted to a certain degree by offering forage on the paddock. However, further studies are needed to evaluate the feed intake of crops by pigs under free range conditions.

Federal Agency for Agriculture and Food (BLE Project No. 03 OE 407)

• Department of Soil Biology at the University of Kassel
• University of Hohenheim, State Institute of Chemistry
• University of Wageningen, Institute of Animal Science

• Final report in Organic Eprints