The utilization of dehulled lupin as a partial replacement for ®sh meal was studied in diets of rainbow trout. Fish were fed diets with 0%, 10%, 20%, 30%, 40% and 50% of dehulled lupin, at a daily feeding rate of 2% body weight for 8 weeks at 15 T 0.5°C. Growth performance generally decreased with increasing dehulled lupin in the diet (R 2 = 0.81, P < 0.0001). However, there was no signi®cant difference between 0%, 10%, 20%, 30% and 40% dehulled lupin fed groups. Feed conversion ratio generally increased at higher inclusion levels of dehulled lupin (R 2 = 0.74, P < 0.002). The protein ef®ciency ratio, protein productive value, lipid ef®ciency ratio and lipid productive value were similar in all groups but the energy ef®ciency ratio was signi®cantly lower (P < 0.01) in the 50% dehulled lupin fed group. Different treatments showed similar digestive enzyme activity, villus height, pyloric caeca and hepato somatic indexes. None of the nonspeci®c immune responses, with the exception of total plasma protein and neutrophils, was affected by different inclusion level of lupin. Results show that dehulled lupin can be included at up to 40% of a rainbow trout diet without a signi®cant effect on growth performance or nutrient utilization. Rainbow trout utilize dehulled lupin protein as ef®ciently as ®sh meal protein but have a lower ability to utilize the energy content of dehulled lupin at higher inclusion levels.

Effect of enzyme supplementation to dehulled lupin-based diets on growth, feed efficiency, nutrient digestibility and carcass composition of rainbow trout, Abstract High inclusion levels of dehulled lupin (Lupinus angustifolius) in salmonid diets signi¢cantly decrease growth rates. This may be caused by the high concentrations of non-starch polysaccharides including oligosaccharide (OS) in lupin. The antinutritive e¡ects of OS have not yet been fully investigated in ¢sh. The objective of this study was to determine the e¡ect of enzyme supplementation of dehulled lupin-based diets on the ¢sh performance. There were two control diets: a ¢sh meal-based diet with no plant protein (FM) and a diet that contained 50% dehulled lupin (L). Four experimental diets based on diet L and containing four di¡erent exogenous enzyme supplements were used: diet L(E) (Energex TM ); diet L(B) (Bio-Feed TM Pro); diet L(a) (Alpha galactosidase TM ); and diet L(Mix), which contained all the enzymes. Fish were randomly stocked into tanks in duplicate groups of 38 ¢sh, 16.58 AE 0.169 (SE) g, and were fed twice a day for 6 weeks. The supplemented enzymes did not improve weight gain in ¢sh fed lupin-based diets. However, mixed enzyme signi¢cantly improved Protein E⁄ciency Ratio (PER). Apparent digestibility of DM, CP and GE signi¢cantly improved in ¢sh-fed L(E) diet. None of the supplemented enzymes a¡ected digestive tract indices or carcass composition. Surprisingly, weight gain was signi¢cantly higher in ¢sh-fed L(a), L(E) and L(Mix) diets as compared with FM diet. Feed intake was signi¢cantly higher in ¢shfed L, L(a) and L(E) diets compared with the FM diet. It is concluded that storing of lupin kernel under a suitable condition may have partially hidden the positive e¡ects of exogenous enzymes through activating the endogenous enzymes.

No abstract

This study aimed to compare the efficacy of dietary a-tocopherol with that of DL-a-tocopheryl acetate, both either alone or in combination with vitamin C (ascorbic acid), on the growth performance, survival, and stress resistance of angelfish, Pterophylum scalare, juveniles. Juveniles were fed ad libitum for four weeks with Artemia enriched with no vitamins (control), vitamin C (T c ), a-tocopherol (T a ), DL-a-tocopheryl acetate (T DL ), a-tocopherol and vitamin C (T a+C ), and DL-a-tocopheryl acetate and vitamin C (T DL+C ). After four weeks, an osmotic stress test was performed using seawater (25 g/L) to evaluate juvenile's resistance to stress. Whole-body glucose and cortisol were used as stress indicators. At the end of the feeding trial, growth performance and survival of the juveniles fed vitamin-enriched Artemia were significantly (P \ 0.05) higher than for the control fish. Best performance was recorded for the T a+C group. Survival, however, was not significantly (P [ 0.05) different between the vitamin-fed groups. Osmotic stress significantly elevated the stress indicators, whole-body cortisol and glucose levels (P \ 0.05), highest and lowest values being observed in control and T a+C groups, respectively. Survival after osmotic stress of juveniles fed the T a+c diet was significantly higher (by 46.2%, P \ 0.001) than for controls. Results suggested that a-tocopherol has greater efficacy than DL-a-tocopheryl acetate and enriching Artemia with a-tocopherol and vitamin C together improves growth performance, survival, and stress resistance of angelfish juveniles.