Caracterización y mejoramiento de la harina de Cannavalia ensiformis como alimento balanceado para Oreochromis niloticus

Background. The legume Cannavalia ensiformis is an excellent source of energy, protein, vitamins and minerals to be used in animal production; however, it contains antinutritional factors (ANF), which limit its use for fishes. Goals. In this study 7 flours obtained from the processes of hydration, acid extraction, decorticating, cooking, germination, autoclaving and degreasing of the seeds of C. ensiformis were evaluated as means of elimination of ANF. Methods. The nutritional values of the meals were corroborated with proximal chemical analysis and in vitro digestibility, determining the degree of hydrolysis (GH%) of the flours of C. ensiformis obtained by pH STAT, the release of total amino acids (TAAL, μg mL-1) was calculated, using multienzymatic extracts of stomach and intestine of O.niloticus juveniles. Results. The acidic/alkaline GH values for cooked C. ensiformis flour were 0.76 ± 0.01% / 6.04 ± 0.37%, being significantly higher with respect to the other flours. The values of acidic/alkaline TAAL (mg mL-1) of this cooked flour (0.02 ± 0.006 / 0.40 ± 0.02) were significantly higher in the alkaline phase in relation to the other treatments. Conclusion. We detected that cooked meal of C. ensiformis, allow to be used as a source of protein in diets for Oreochromis niloticus.Antecedentes. La leguminosa Cannavalia ensiformis es una excelente fuente de energía, proteína, vitaminas y minerales para ser utilizada en la alimentación animal; sin embargo, contiene factores antinutricionales (FAN), que limitan su utilización en la alimentación de peces. Objetivo. En este estudio se evaluaron 7 harinas obtenidas de los procesos de hidratación, extracción acida, decorticado, cocción, germinado, autoclave y desgrasado de las semillas de C. ensiformis como medios de eliminación de FAN. Métodos. La calidad nutricional de las harinas fueron corroborados con análisis químicos proximales y digestibilidad in vitro, determinando el grado de hidrolisis (GH, %) de las harinas de C. ensiformis obtenidas mediante pH STAT, se calculó la liberación de aminoacidos totales (AALT, μg mL-1), utilizando extractos multienzimaticos de estómago e intestino de juveniles de O. niloticus. Resultados. Los valores de GH acido/alcalino para la harina de C. ensiformis cocida fue de 0.76 ± 0.01%/ 6.04 ± 0.37%, siendo significativamente mayor con respecto a las otras harinas. Los valores de AALT acido/alcalino (mg mL-1) de esta harina cocida (0.02 ± 0.006/ 0.40 ± 0.02) fueron significativamente mayores en la fase alcalina en relación a los otros tratamientos. Conclusión. Se detecto que la harina cocida de C. ensiformis, permite ser utilizada como fuente de proteína en dietas para Oreochromis niloticus

Sustitución de pasta de soya por Cannavalia ensiformis en el crecimiento, sobrevivencia y actividad enzimática de tilapia (Oreochromis niloticus) (Perciforme: Cichlidae)

Cannavalia ensiformis has nutritional characteristics as feed supplement in fish. Is a good source of energy, protein, vitamins and minerals, but it has antinutritional factors which limit its utilization. The effect of Cannavalia inclusion in the growth, survival and enzymatic activity in tilapia were determined. Soy paste was substituted (PS) for boiled C. ensiformis meal (HCe): T1 (0% HCe-100% PS), T2 (25% HCe-75% PS), T3 (50% HCe-50% PS), T4 (75% HCe-25% PS), and T5 (100% HCe-0% PS). Results indicated better growth of O. niloticus with T1. Survival was affected on T2 (91.1%) and 100% (94.4%). The greatest enzymatic activity was on T5 followed by T2 on acid proteases and alkaline; thetrypsine activity was not significant; the chymotrypsinactivity showed greater enzymatic activity on T5, being significant in all treatments. Results indicated that better inclusion level of C. ensiformis was on 25%, growth was inversely proportional to inclusion percentage.Cannavalia ensiformis posee características nutricionales como suplemento alimenticio en peces, es fuente de energía, proteína, vitaminas y minerales, pero posee factores antinutricionales, limitando su utilización. Se determinó el efecto de inclusión de Cannavalia cocida en crecimiento, supervivencia y actividad enzimática digestiva de Tilapia. Se sustituyó pasta de soya (PS) por harina de C. ensiformis cocida (HCe): T1 (0% HCe-100% PS), T2 (25% HCe-75% PS), T3 (50% HCe-50% PS), T4 (75% HCe-25% PS) y T5 (100% HCe-0% PS). Resultados indican el mejor crecimiento O. niloticus fue con T1. La supervivencia se vio afectada con T2 (91.1%) y 100% (94.4%) de HCe. La mayor actividad enzimática fue en T5 seguida de T2 en proteasas ácidas y alcalinas, la actividad de tripsina no fue significante, la actividad de quimotripsina mostró mayor actividad enzimática en T5, siendo significante en todos los tratamientos. Los resultados indican que el mejor nivel de inclusión de C. ensiformis es al 25%, crecimiento fue inversamente proporcional al porcentaje de inclusión.

Dietary protein requirement in common snook (Centropomus undecimalis ) juveniles reared in marine and brackish water/ Requerimiento de proteína dietaría para juveniles de robalo blanco (Centropomus undecimalis) cultivados en agua marina y salobre

A total of 300 Centropomus undecimalis juveniles, with an average initial weight of 3.16 ± 0.28 g and average total length of 7.17 ± 0.22 cm, were reared for eight weeks using a recirculating system to determine the dietary protein requirement for their growth and survival. The e ect of ve experimental diets containing 40, 45, 50, 55 and 60% total protein content and two salinities (brackish water, BW at 5 UPS and marine water, MW at 36 UPS) were assessed. Fish were fed ve times per day at 2.5% of total biomass. All treatments were performed in triplicate, recording the individual weight and total length every 15 d, while weight gain and daily growth rate were recorded at the end of the experiment. Mean weight increased proportionally as protein content increased, with the greatest growth occurring with a 60% protein diet for sh reared in brackish water, and 55% for sh in marine water. We consider that the protein requirement in C. undecimalis juveniles is high; in addition, it differs depending on the salinity, which may be due to the higher energy expenditure derived from the processes of osmoregulation in fish reared in marine water

Intestinal Lipase Characterization in Common Snook (<em>Centropomus undecimalis</em>) Juveniles

The common snook (Centropomus undecimalis) is a euryhaline fish with high commercial demand in the Mexican southeast, Caribbean, and South America. However, some aspects of its digestive physiology are still unknown, particularly in relation to lipid hydrolysis. Therefore, the characterization of the digestive lipase of this species was carried out. Our results show that the digestive lipase’s optimal temperature is 35 °C, being stable between 25 and 35 °C, and shows maximum activity at pH 9, with stability between pH 5 and 8. Different degrees of inhibition were presented by Orlistat (61.4%), Ebelactone A (90.36%), Ebelactone B (75.9%), SDS 1% (80.7%), SDS 0.1% (73.5%), and SDS at 0.01% (34.9%). Orlistat and Ebelactone A and B completely inhibited the lipase band in the zymogram, but not SDS addition. Lipase showed a molecular weight of 43.8 kDa. The high lipase activities in the digestive tract indicate the importance of lipids in the diet of C. undecimalis

Expression of long-chain polyunsaturated fatty acids biosynthesis genes during the early life-cycle stages of the tropical gar Atractosteus tropicus

Long-chain (≥C20) polyunsaturated fatty acids (LC-PUFA), including eicosapentaenoic acid (EPA, 20:5n-3), arachidonic acid (ARA, 20:4n-6) and docosahexaenoic acid (DHA, 22:6n-3), are essential in multiple physiological processes, especially during early development of vertebrates. LC-PUFA biosynthesis is achieved by two key families of enzymes, fatty acyl desaturases (Fads) and elongation of very long-chain fatty acid (Elovl). The present study determined the expression patterns of genes encoding desaturases (fads1 and fads2) and elongases (elovl2 and elovl5) involved in the LC-PUFA biosynthesis during early life-stages of the tropical gar Atractosteus tropicus. We further analyzed the fatty acid profiles during early development of A. tropicus to evaluate the impact of Fads and Elovl enzymatic activities. Specific oligonucleotides were designed from A. tropicus transcriptome to perform qPCR (quantitative polymerase chain reaction) on embryonic and larval stages, along with several organs (intestine, white muscle, brain, liver, heart, mesenteric adipose, kidney, gill, swim bladder, stomach, and spleen) collected from juvenile specimens. Fatty acid content of feeds and embryonic and larval stages were analyzed. Results show that fads1, fads2, elovl2 and elovl5 expression was detected from embryonic stages with expression peaks from day 15 post hatching, which could be related to transcriptional and dietary factors. Moreover, fads1, fads2 and elovl2 showed a higher expression in intestine, while elovl5 showed a higher expression in liver, suggesting that the tropical gar activates its LC-PUFA biosynthetic machinery to produce ARA, EPA and DHA to satisfy physiological demands at crucial developmental milestones during early development.The study was financially supported by Consejo Nacional de Ciencia y Tecnología (CONACyT) by project CB-2016-01-282765. Authors thank CONACyT for the fellowship grants

Dietary protein requirement in common snook (Centropomus undecimalis) juveniles reared in marine and brackish water

ABSTRACT. A total of 300 Centropomus undecimalis juveniles, with an average initial weight of 3.16 ± 0.28 g and average total length of 7.17 ± 0.22 cm, were reared for eight weeks using a recirculating system to determine the dietary protein requirement for their growth and survival. The effect of five experimental diets containing 40, 45, 50, 55 and 60% total protein content and two salinities (brackish water, BW at 5 UPS and marine water, MW at 36 UPS) were assessed. Fish were fed five times per day at 2.5% of total biomass. All treatments were performed in triplicate, recording the individual weight and total length every 15 d, while weight gain and daily growth rate were recorded at the end of the experiment. Mean weight increased proportionally as protein content increased, with the greatest growth occurring with a 60% protein diet for fish reared in brackish water, and 55% for fish in marine water. We consider that the protein requirement in C. undecimalis juveniles is high; in addition, it differs depending on the salinity, which may be due to the higher energy expenditure derived from the processes of osmoregulation in fish reared in marine water.RESUMEN. Un total de 300 juveniles de Centropomus undecimalis con peso inicial promedio de 3.16 ± 0.28 g y longitud de 7.17 ± 0.22 cm se cultivaron por ocho semanas en un sistema de recirculación, con el objetivo de determinar el requerimiento de proteína dietaría en el crecimiento y supervivencia de los juveniles de C. undecimalis. El experimento consideró los niveles de proteína de 40, 45, 50, 55 y 60% en agua salobre, AS a 5 UPS y agua marina, AM a 36 UPS. Los peces se alimentaron cinco veces al día con una ración del 2.5% de biomasa. Los tratamientos se realizaron por triplicado, registrándose el peso individual y la longitud total cada 15 d, mientras que la ganancia en peso y la tasa de crecimiento diario se registró al final del experimento. El peso promedio incrementó con relación al aumento de la proteína, siendo mayor el crecimiento en los peces alimentados con 60% de proteína en agua salobre y con 55% de proteína para los peces cultivados en agua marina. El requerimiento de proteína en el cultivo de juveniles de C. undecimalis es alto, además de diferir en función a la salinidad, lo que puede deberse al mayor gasto energético derivado de los procesos de osmorregulación, de los peces cultivados con agua marina