Effect of different technical treatments of rapeseed on the feed value forbroilers 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 tre atments comprised different grinding procedures (whole seed, roller mill -c oarse and fine adjustment, flake mill) resulting in different average parti cle sizes of the ground seed and thermal treatments of flaked seed (hydroth ermal treatment, micronizer, jet sploder). Each thermal treatment was carri ed out at two temperatures. A marked increase in the digestibility of organ ic matter and of the AME(N) content was observed as the average particle si ze of the seed was decreased to less than or equal to 0.56 mm and was much more pronounced for the broilers. AME(N) contents of 21.1 to 22 and 22.6 to 23 MJ/kg DM were observed at this particle sizes for broilers and hens, re spectively. Thermal treatment of rapeseed improved the apparent crude fat d igestibility slightly whereas the apparent crude protein digestibility tend ed to decrease especially at the higher temperatures. This resulted in inco nsistent changes in the apparent digestibility of the organic matter and th e AME(N) content. Only the treatment with hot air (jet sploder) seemed to h ave preferential effects on the feed value for both broilers and hens. For the thermal treatments AME(N) contents ranged from 18.8 to 21.9 and 19.0 to 24.3 MJ/Kg DM for broilers and hens, respectively.