[Toasted rapeseed meal in broiler fattening diet]

A fattening trial of six week duration using male broiler chicks of the TETRA 82 genotype has been performed to evaluate the feeding value of rapeseed meal derived from the following rapeseed origins of so-called double-zero quality: Canola (Cananda), Jantar (Poland) and the new-bred East German-genotype BNW 1.43, each at a diet level of 12%. Moreover, the indigenous origin has been investigated at levels of 6 and 18% in practical broiler rations as a protein source instead of soybean meal (partial replacement). The fattening results (live weight development, intake and conversion of feed, mortality) do not show disadvantageous effects by the different rapeseed meal origins, and the various levels too. The chemical whole-body composition gives reduced fat and more protein in broiler's carcass at a diet level of 12 and 18% of BNW 1.43-rapeseed meal. Blood plasma levels of T3 and T4 have refered to beginning status of hypothyreodism, higher percentages of rapeseed mean had been fed. Weight of broiler's thyroid varied independtly of treatment. Also by the means of histometrical investigation of these glands the effects known for conventional rapeseed meals could be demonstrated, however in an important weakly extent. In comparison to discrepancies in the literature results regarding the possible inclusion of double-zero rapeseed meal in broiler diets, it seems a maximum diet level of 12% of toasted rapeseed meal of used qualities could be recommended for practical diet formulation (without of performance depressions). However, further investigations are be essential in these questions.