Abstract

ABSTRACT Experiments were conducted to evaluate the nutritional value of meal derived from low glucosinolate cultivars of mustard (Brassica juncea) in comparison to samples of canola meal (Brassica napus, Brassica rapa). Samples of Brassica seed (four B. juncea, one B. napus, and one B. rapa) were processed using laboratory procedures to produce oil-extracted meals, which were examined for composition (DM basis), and nutritional value for broiler chickens as judged by nutrient retention (AMEn, ileal protein digestibility) and performance. Meals derived from B. juncea contained more CP and less total dietary fiber (TDF) on a dry basis than either B. napus or B. rapa, 45.9 vs 44.6 and 43.1 % CP and 27.22 vs 29.47 and 29.67 % TDF, respectively. Acid detergent fiber (ADF) and neutral detergent fiber (NDF) levels for B. juncea and B. rapa meals were similar to each other, but lower than those of B. napus, 12.79 and 13.20 vs 20.6 % ADF, and 21.15 and 19.58 vs 29.47 % NDF, respectively. Brassica juncea meals contained more glucosinolates than B. napus and B. rapa, 34.3 vs 21.8 and 25.5 mmol/g total glucosinolates, respectively. Brassica juncea meals were equal or superior to B. napus and B. rapa meals for AMEn and apparent ileal protein digestibility. Similarly, broilers fed B. juncea meals grew as quickly and converted feed to BW gain as efficiently to 21 d of age as those birds fed B. napus and B. rapa meals. Feeding meal from B. rapa reduced growth rate and gain to feed ratio. In conclusion, the nutritional value of meal from low glucosinolate mustard was equal or superior to that of canola meal samples derived from B. napus and B. rapa cultivars. (Key words: canola meal, mustard meal, low glucosinolate, nitrogen-corrected apparent metabolizable energy, broiler chick)