Effect of different technical treatments of rapeseed on the feed value for broilers and laying hens

The effect of different technical treatments of rapeseed on its feed value for broilers and laying hens was the object of the study. The technical treatments comprised different grinding procedures (whole seed, roller mill--coarse and fine adjustment, flake mill) resulting in different average particle sizes of the ground seed and thermal treatments of flaked seed (hydrothermal treatment, micronizer, jet sploder). Each thermal treatment was carried out at two temperatures. A marked increase in the digestibility of organic matter and of the AMEN content was observed as the average particle size of the seed was decreased to < or = 0.56 mm and was much more pronounced for the broilers. AMEN contents of 21.1 to 22 and 22.6 to 23 MJ/kg DM were observed at this particle sizes for broilers and hens, respectively. Thermal treatment of rapeseed improved the apparent crude fat digestibility slightly whereas the apparent crude protein digestibility tended to decrease especially at the higher temperatures. This resulted in inconsistent changes in the apparent digestibility of the organic matter and the AMEN content. Only the treatment with hot air (jet sploder) seemed to have preferential effects on the feed value for both broilers and hens. For the thermal treatments AMEN contents ranged from 18.8 to 21.9 and 19.0 to 24.3 MJ/Kg DM for broilers and hens, respectively.