RAPESEED MEAL-GLUCOSINOLATES AND THEIR ANTINUTRITIONAL EFFECTS .2. FLAVOR AND PALATABILITY

This paper has reviewed the current literature relating to the effects of glucosinolates on the palatability of rapeseed meal. The available evidence indicates that diet palatability can be adversely affected b y rapeseed meal inclusion and that this response is related to glucosi nolate level. However the response is variable and depends also on the species of animal, age and growth state. Younger animals, particularl y chicks, piglets and calves appear to be more severely affected and e xhibit reduced intake and hence depressed performance with diets conta ining high levels of glucosinolates from high glucosinolate rapeseed m eal. Palatability is substantially improved by the use of low glucosin olate rapeseed meal (LG-RSM) containing 10 - 30 mug/g and very low glu cosinolate rapeseed meal (VLG-RSM) containing 1-5 mug/g glucosinolates . From the findings of this review, it can be concluded that LG-RSM an d VLG-RSM can be included at levels up to 20% and 30% for calves and d airy cows respectively. Since piglets are particularly sensitive it is suggested that rapeseed is excluded from early starter diets but that low glucosinolate meals can be included at levels of 10% and 15% for grower and finisher pigs respectively. Growing poultry may be less sen sitive to palatability problems associated with rapeseed meal but the use of high levels is constrained due to the lower energy and higher f ibre contents of RSM compared with soybean meal.