A 45-day feeding trial was carried out to evaluate the use of shrimp protein hydrolysate (SPH) in diets for Oreochromis niloticus, L. SPH was included in isonitrogenous diets replacing fish meal protein by 0, 5, 10, and 20% and offered to Nile tilapia juveniles (1.7 ± 0.4 g) stocked in 40-L glass aquaria. The inclusion of SPH produced no significant differences (P C 0.05) in final weight, survival, weight gain, average daily gain, specific growth rate, feed conversion ratio, protein efficiency ratio, or apparent net protein utilization. The inclusion of SPH Nile tilapia diets significantly affected (P \ 0.05) the final fish body composition. Protein and ash contents decreased and fat content increased slightly with the increase in SPH. This study has demonstrated that SPH is a promising protein feedstuff and could account for as much as 6% of Nile tilapia diets with no adverse effects on growth and nutrient utilization.
This study evaluated the toxicity of ammonia and nitrite to different larval stages of Macrobrachium carcinus. Three replicated groups of larvae in the zoea stages II, V, and VIII (hence named Z2, Z5, and Z8, respectively) were exposed separately to five ammonia (5, 10, 20, 40, and 80 mg total ammonia nitrogen [TAN]/L) and six nitrite concentrations (5, 10, 20, 40, 80, and 160 mg NO2‐N/L), plus a control treatment with no addition of ammonia and nitrite, at a salinity of 20 g/L. The ammonia LC50 values at 96 h for Z2, Z5, and Z8 were 8.34, 13.84, and 15.03 mg TAN/L (0.50, 0.71, and 0.92 mg NH3‐N/L), respectively, and the nitrite LC50 values at 96 h for Z2, Z5, and Z8 were 3.28, 9.73, and 34.00 mg NO2‐N/L, respectively. The estimated LC50 values for NO2‐N were lower than those for TAN in most of the stages evaluated. This observation suggests that M. carcinus larvae are more tolerant to ammonia, except at Z8, in which larvae had a higher tolerance to nitrite. Based on the lethal concentrations at 96 h, it may be concluded that the tolerance of M. carcinus to ammonia and nitrite increases with larval development. Safe levels were estimated to be 0.834 mg TAN/L (0.05 mg NH3‐N/L) and 0.328 mg NO2‐N/L; therefore, efforts should be made to maintain lower concentrations of these compounds throughout the larval rearing of M. carcinus.
RESUMO -O presente trabalho avaliou o desempenho do camarão marinho Litopenaeus vannamei alimentado com dietas de diferentes níveis protéicos em sistema de bioflocos com e sem a adição de probiótico. Foi adotado um delineamento experimental inteiramente casualizado com arranjo fatorial 4×2, com quatro níveis de proteína na dieta (20, 25, 30 e 35% PB), como primeiro fator (P20, P25, P30 e P35), e a adição de probiótico na água de cultivo, como segundo fator (P20 Pro , P25 Pro , P30 Pro e P35 Pro ). Foram utilizados 24 tanques em fibra de vidro (800 L volume útil) estocados com 300 camarões m -3 (peso inicial 1,55±0,01 g). As variáveis de qualidade da água foram mensuradas periodicamente e não apresentaram diferença estatística, exceto o teor de nitrito, influenciado significativamente (P<0,05) pelos níveis de proteína. Após 50 dias de cultivo o peso médio final dos camarões foi de 7,2±0,4 g (P≥0,05) entre os tratamentos. A interação entre os níveis protéicos e a adição de probiótico influenciaram significativamente (P<0,05) na sobrevivência (70,5-90,0%) e na biomassa final (1,3-2,0 Kg m -3 ). Dessa forma, em cultivo intensivo de L. vannamei, com utilização de bioflocos como fonte de alimento suplementar, é possível reduzir os níveis de proteína da ração de 35 para 25% sem comprometer o desempenho zootécnico dos camarões e a qualidade da água. Palavras-chave:Litopenaeus vannamei. Flocos microbianos. Melaço. Proteína. Sem renovação de água. MARINE SHRIMP CULTURE WITH BIOFLOCS UNDER DIFFERENT PROTEIN LEVELS WITH AND WITHOUT PROBIOTICABSTRACT -This study aimed to evaluate the culture of Litopenaeus vannamei marine shrimp fed with different protein levels diets in heterotrophic systems with and without probiotic addition. It was adopted a completely randomized design with 4x2 factorial arrangement, using four dietary protein levels (20, 25, 30 e 35% CP), as the first factor (P20, P25, P30, and P35), and probiotic addition in the water, as the second factor (P20 Pro , P25 Pro P30 Pro e P35 Pro ). For this were used 24 fiberglass tanks (800 L working volume) stocked with 300 shrimp m -3 (initial weight 1.55±0.01 g). Water quality parameters were analyzed periodically and showed no significant differences, except nitrite that was influenced by the protein levels (P<0.05). After 50 culture days, shrimp final weight averaged 7.2±0.4 g (P≥0.05). The interaction of protein levels vs. probiotic addition influenced significantly (P<0.05) the survival (70.6 to 90.0%) and final biomass (1.3-2.0 Kg m -3 ). In Litopenaeus vannamei intensive culture with the utilization of biofloc as the supplemental food, it is possible to reduce the protein levels of feed from 35 to 25%, without compromising the shrimp growth performance and water quality of the culture.
O Ecolume integra as práticas dos conceitos de geração de energia fotovoltaica com a captação de águas pluviais, a reutilização de águas residuais e a produção de alimentos orgânicos ao longo do ano. A combinação de água da chuva coletada nas superfícies dos painéis solares e a reutilização de água cinza e preta, para irrigação de pomares e viveiros de mudas nativas, orienta um novo paradigma de desenvolvimento socioeconômico no semiárido, tornando este projeto um processo de adaptação eficaz às mudanças climáticas. O semiárido do Nordeste brasileiro mostrou uma redução na precipitação total anual, na forma de secas severas recorrentes. A abundância de energia solar pode ser uma fonte de desenvolvimento socioeconômico na região, ferramenta poderosa para adaptar-se às mudanças climáticas. O tratamento e a reutilização de águas cinza e negra têm como objetivo produzir água de boa qualidade para irrigar mudas em viveiro (umbu - Spondias tuberosa) e garantir a redução da poluição. A produção de mudas nativas de umbu é para reflorestar a vegetação da Caatinga (bioma local). O projeto Ecolume qualificou mais de 700 pessoas em tecnologia de energia solar, reuso e tratamento de água cinza e preta, mudas e produção de alimentos usando o sistema aquapônico.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.