Incorporation of whole lupin, Lupinus albus, seed meal in commercial extruded diets for Rainbow Trout, Oncorhynchus mykiss: Effect on growth performance, nutrient digestibility, and muscle fatty acid composition

Whole lupin seed meal was evaluated as partial replacement for fishmeal in extruded diets for rainbow trout, with particular emphasis on the effect on growth performance and apparent digestibility coefficient (ADC) of protein, lipids, carbohydrates, and energy. Effect on muscle fatty acid composition was also evaluated. All diets were formulated to be isonitrogenous and isoenergetic and to contain approximately 45% crude protein and 5.5 kcal energy g/diet. Diets were formulated to include whole lupin seed meal at 0, 10, 15, and 20%. Triplicate groups of fish weighing 65.9 ± 15.1 g on average were fed twice a day until apparent satiation during 12 wk. Growth, feed intake, hepatosomatic index, hepatic histology, proximate composition of whole body, and muscular fatty acid profile were determined. Growth and feed utilization were similar in all treatments and whole-body composition did not vary among treatments. Polyunsaturated fatty acids of the n-6 and n-3 series remained constant in muscle as the amount of lupin in diets increased. Furthermore, the ADCs were similar among all diets. These results suggest that inclusion of whole lupin seed meal up to 20% in extruded diets for rainbow trout do not have any negative effect on growth, feed performance, or flesh quality. © Copyright by the World Aquaculture Society 201

Efectos del autoclave sobre el coeficiente de digestibilidad aparente de la harina descascarada de arveja (Pisum sativum) en trucha arco iris (Oncorhynchus mykiss)

The effect of autoclaving on the nutrients’ apparent digestibility coefficient (ADC), digestible protein and energy of pea seed meal (P. sativum) fed to Rainbow trout (O. mykiss) was examined. Two samples of the pea meal were autoclaved at 121ºC and 1.1 atm for 5 min (5’APM) or 15 min (15’APM), respectively. A third sample, used as control, was not treated (RPM). One reference diet (Basal diet) and 3 experimental diets were elaborated and labelled based on autoclaving time applied to the ingredient (RPM, 5’APM and 15’APM). The four diets were assigned using a completely randomised design, with each treatment having three replicates. 12 tanks were stocked each with 15 trouts with an average weight of 235 ± 10.4 g. Faeces were collected over a 7-day period using a settlement column and pooled within the tank. ADCs were determined using chromium oxide (Cr2O3) as an inert digestibility indicator. No significant differences (P>0.05) regarding protein ADC were found among all treatments. On the other hand, dry matter, energy and nitrogen free extract (NFE) ADC showed significant differences (p0,05) con respecto a los CDAs de proteína entre los tratamientos. Por otra parte, los CDAs de materia seca, energía y extracto no nitrogenado (ENN) fueron estadísticamente diferentes (P<0,05). Los resultados demostraron que el tratamiento 5’APM incrementó el CDA de materia seca, además de energía y proteína digestible de la harina descascarada de arveja