| Popis: |
Rapeseed of winter type, 21.4 mmol glucosinolates kg−1 dry matter (DM), glucosinolate degradation products (aglucones) not detectable, was ground or ground, soaked (11 water kg−1 rapeseed) and dried at 60°C. Ground seed had 93% of the initial glucosinolate content. The combination of moisture and heat treatment caused a reduction to 2.1 mmol glucosinolates kg−1 DM. Aglucones were not detectable. The glucosinolate degradation is possibly due to the activation of endogenous myrosinase by moisture. During heating the resultant aglucones are volatile or may react with further dietary constituents to less harmful compounds. In a 5 day preference test 30 growing pigs were allowed to select between two diets with ground rapeseed either untreated or soaked and dried. The pigs were divided into five groups with increasing rapeseed content of the feed. Pigs consumed similar quantities of diets with untreated or treated rapeseed up to 40 g kg−1 dietary rapeseed level. There was a preference for diets with treated seed in the case of diets containing the higher levels of rapeseed. Pigs consumed two-thirds of total intake of diet with 160 g kg−1 soaked and dried rapeseed vs. one-third of this diet with untreated rapeseed. In an 8 week feeding experiment with two groups of eight growing pigs, diets with 150 g kg−1 ground rapeseed either untreated or soaked and dried were tested. Treatment of rapeseed improved the feed intake by 10% (P < 0.01), the live weight gain by 11% (P < 0.05). The feed/gain ratio was not affected. |
