Rechnet sich der Einsatz von Kleegrassilage in der ökologischen Schweinemast?

The feeding of protein in line with animal needs from regional sources is a challenge in organic pig fattening. One way to achieve this is the use of clover-grass silage, which so far has received only limited attention. In this working paper an overview and economic analysis of trials of the Thünen Institute of organic farming of feeding clover-grass silage to fattening pigs are presented. On the experimental organic farm in Trenthorst, fattening pigs are housed on straw. They were split into two groups: one group was fed clover-grass silage and a concentrate mix with reduced protein content; the control group was fed a normal mixed ration with typical protein content. The biological performance, rations and feed quantities were evaluated, supplemented with standard data for organic production from the KTBL (Kuratorium für Technik und Bauwesen in der Landwirtschaft). Subsequently, cost calculation of the trial data was carried out and compared with organic standard data without the use of roughage from KTBL. As expected for trials, daily gains, feed conversion, finishing weight, dressing percentage and feed consumption are better for both groups of the Trenthorst fattening trials, compared to the KTBL data. The two trial variants differ only very slightly in performance and costs; both groups are clearly more cost-effective than the KTBL assumptions due to lower concentrate consumption. But the feeding clover-grass silage by hand causes higher labour costs, compared to the control group. Higher prices for the other protein feeds, especially grain legumes, improve the competitiveness of clover-grass feeding, as does lack of an alternative use, if clover-grass is grown on the farm's as part of crop rotation. In summary, feeding clover-grass silage is — also financially — an interesting alternative for fattening pigs organically. For wider use on farms further improvements of labour organisation are needed. In particular, cost-effective mechanisation of feeding silage still needs to be developed.