Nutritional strategies can help fish manage stress, and functional feedstuffs are an interesting nutritional option. Therefore, this study evaluated the potential functional effect of spray-dried plasma (SDP) on Nile tilapia growth performance and the capacity of SDP to improve fish health under cold-induced stress (CIS). A total of 440 fish (12.64 ± 0.64 g) were randomly distributed into 40,250-L aquaria and fed five diets containing graded levels of SDP (0, 16.6, 33.2, 49.7 and 66.3 g kg − 1) for 60 days. The growth performance, villus height:crypt depth ratio, and hematological parameters were analyzed, and the same hematological parameters were then analyzed after 7 days of CIS. Based on the broken-line analysis of the FBW, SGR, RWG and FCR, the optimum dietary level supplementation of SDP was determined to be 49.70, 50.16, 51.83 and 41.83 g kg − 1 diet, respectively. The crypt depth and villus:crypt ratio were positively affected by SDP supplementation. After CIS, hematocrit of fish fed 16.6 g kg − 1 of dietary SDP was significantly lower than fish fed 66.3 g kg − 1 level (P < 0.05). The supplementation level of dietary SDP and the CIS affected the leukocyte, lymphocyte and neutrophil counts. The monocyte count was affected by the dietary SDP supplementation level both before and after CIS (P < 0.05). Total plasma protein concentration in the fish fed 49.7 and 66.3 g kg − 1 SDP were significantly higher than fed 16.6 g kg − 1 SDP after CIS (P < 0.05), and CIS led to a higher Albumin:Globulin ratio (P < 0.05). Dietary SDP supplementation improved the growth performance, intestinal health, hematological profile and CIS resistance of the studied fish. Based on our results, we recommend a dietary supplementation level of 51.83 g kg − 1 SDP for Nile tilapia.

Objetivou-se com este trabalho avaliar a influência de dois níveis de energia digestível (3.250 e 3.500 kcal kg-1) em combinação a três níveis de proteína bruta (25, 30 e 35%) sobre o desempenho produtivo de juvenis de jundiá (Rhamdia voulezi). Utilizaram-se 240 juvenis de jundiá com peso inicial de 95,55±6,70 g e 20,43±1,13 cm de comprimento total, distribuídos ao acaso em 24 tanques-rede (370 L cada) em delineamento fatorial com seis tratamentos e quatro repetições. O arraçoamento foi realizado quatro vezes ao dia, à vontade. Ao final do período experimental, a análise fatorial de variância evidenciou influência significativa nos parâmetros zootécnicos avaliados. Foram observados melhor ganho de peso e comprimento final médios e menor deposição de gordura visceral nos peixes alimentados com a dieta contendo 30% de proteína bruta e 3.250 kcal de energia digestível kg-1. Portanto, recomendam-se para juvenis de jundiá dietas que contenham no mínimo 30% de proteína bruta e 3.250 kcal de energia digestível kg-1 de ração.

RESUMO -Avaliou-se o efeito da inclusão de um complexo enzimático em dietas para tilápias-do-nilo (Oreochromis niloticus) sobre o desempenho, a composição química da carcaça e a qualidade da água. Foram utilizados 200 alevinos revertidos (4,57 ± 1,24 g), distribuídos em delineamento inteiramente casualizado em 20 tanques de 500 litros, com quatro tratamentos e cinco repetições, considerando a unidade experimental uma caixa com dez peixes. Os peixes foram alimentados com dietas contendo 0; 0,033; 0,066 ou 0,099% de complexo enzimático. As dietas foram processadas na forma peletizada e fornecidas quatro vezes ao dia, às 8, 11, 14 e 17 h. Os valores médios de pH, condutividade elétrica, oxigênio dissolvido, temperatura, fósforo total, amônia e nitrato da água de cultivo não foram influenciados pela dieta. A inclusão do complexo enzimático na dieta não afetou o ganho de peso, as taxas de sobrevivência e de crescimento específico, mas influenciou o consumo de ração e a conversão alimentar, cujos valores foram maiores nos peixes alimentados com a dieta com 0,066% de complexo enzimático. Não foram observadas diferenças nos teores de matéria seca, umidade, proteína bruta, matéria mineral, cálcio e fósforo na carcaça dos peixes, no entanto, o teor de extrato etéreo reduziu de forma linear com o aumento do nível de complexo enzimático. A utilização de complexo enzimático (amilase, protease, celulase, lipase, pectinase, xilanase, β-glucanase e fitase) no nível de 0,066% em dietas para juvenis de tilápia-do-nilo piora a conversão alimentar, mas não influencia o desempenho e a composição corporal dos peixes.Palavras-chave: enzimas, nutrição, peixes, qualidade de água Performance of juvenile Nile tilapia fed diets with enzymatic complexABSTRACT -The aim of this study was to evaluate the inclusion of an enzimatic complex in diets for Nile tilapia (Oreochromis niloticus) on performance, carcass chemical composition as well as water quality. The experiment was performed in 62 days. It was used two hundred reverted fingerlings (14.57 ± 1.24 g) distributed in a complete randomized design in 20 500 L-tanks with four treatments and five replicates, considering a box with 10 fish as a experimental unit.The fish were fed diets containing 0; 0.033; 0.066 and 0.099% of enzimatic complex. The diets were processed in peletized way and supplied four times a day (8:00 a.m., 11:00 a.m., 2:00 p.m. and 5:00 p.m.) The pH average values, electric conductivity, dissolved oxygen, temperature, total phosphorus, ammonia and water nitrate of the cultivation were not influenced by the inclusion of the enzimatic complexin the diet. The inclusion of enzymatic complex in the diet did not affect weight gain, survival, and specific growing rate; however, it affected diet consumption and food conversion, whose values were greater for fish fed 0.066% of enzimatic complex diet. No differences were observed on dry matter, humidity, crude protein, mineral matter, calcium and phosphorus in the fish carcass, nevertheless, the ether extract decreased linearly as t...

ResumoO objetivo do presente estudo foi avaliar o processo da salga seca e salga úmida em filés de pacu (P. mesopotamicus), provenientes do cultivo em tanques-rede. Os filés com pele foram salgados na proporção de 40% de sal em relação ao peso inicial, por um período de 10 dias. Após processamento, foram avaliados os parâmetros microbiológicos e de composição centesimal dos filés submetidos a salga, bem como a determinação da concentração de cloreto de sódio (NaCl) e cálculo de rendimento. Quanto à composição centesimal foram avaliados os teores de proteína, extrato etéreo, umidade e matéria mineral da matéria-prima in natura e nos produtos processados por salga. As análises microbiológicas compreenderam a determinação de coliformes a 45°C, Salmonella sp e Staphylococcus coagulase positiva. Os pacus submetidos a salga úmida e seca mantiveram-se dentro dos padrões microbiológicos estabelecidos pela legislação. AbstractThe goal of this study was to evaluate the process of salting and dry salting of fillets in pacu (P. mesopotamicus), from cultivation in cages. Fillet with skin were salted at a rate of 40% of salt in relation of the initial weight, for a period of 10 days. After processing, were evaluated for microbiological and centesimal composition of fillets subjected to salting and determining the concentration of sodium chloride (NaCl) and calculation of income. The centesimal composition were evaluated the protein, ether extract, moisture and ash of the raw material fresh and processed products by salting. The microbiological analysis included the determination of coliforms at 45 ° C, Salmonella and Staphylococcus coagulase positive. The pacus subjected to umided and dry salting were within quality control standards established by the legislation. The content of umided, protein, lipids and chlorides showed differences (p< 0.05)Recebido para publicação 08

The effect of the ethanolic extract of propolis (EEP) on Aeromonas hydrophila was analyzed by determination of minimum inhibitory concentration (MIC). Then, the effects of crude propolis powder (CPP) on growth, hemato-immune parameters of the Nile tilapia, as well as its effects on resistance to A. hydrophila challenge were investigated. The CPP (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0%) was added to the diet of 280 Nile tilapia (50.0 ± 5.7 g fish -1 ). Hemato-immune parameters were analyzed before and after the bacterial challenge. Red blood cell, hematocrit, hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and hydrogen peroxide (H 2 O 2 ) and nitric oxide (NO) were evaluated. The MIC of the EEP was 13% (v/v) with a bactericidal effect after 24 hours. Growth performance was significantly lower for those fish fed diets containing 2.5 and 3% of CPP compared to the control diet. Differences in CPP levels affected fish hemoglobin, neutrophils number and NO following the bacterial challenge. For others parameters no significant differences were observed. Our results show that although propolis has bactericidal properties in vitro, the addition of crude propolis powder to Nile tilapia extruded diets does not necessarily lead to an improvement of fish health.