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This study aimed to evaluate the in vivo effect of the macroalgae Ulva ohnoi, alone and combined with the probiotic Lactobacillus plantarum, on zootechnical, immunological, and microbiological performance, thermal resistance and survival of Litopenaeus vannamei challenged with Vibrio parahaemolyticus. The shrimp were fed four diets: control, seaweed, probiotic, and a combination of seaweed + probiotic. After six weeks, a significant difference between the control and probiotic, and the control and seaweed treatments was demonstrated in shrimp challenged with Vibrio, with the highest percentage of mortality being observed in the group fed only with seaweed, followed by probiotic, seaweed + probiotic, and control. The control and seaweed treatment groups also showed a significant difference in resistance to thermal shock. The animals treated with the control diet had the highest mortality rate, followed by seaweed + probiotic, probiotic, and seaweed. The zootechnical, immunological, and microbiological parameters did not differ significantly among treatments. In conclusion, the use of U. ohnoi alone demonstrated a positive effect on thermal shock resistance but did not demonstrate protection against infection caused by V. parahaemolyticus. On the other hand, its combined use with L. plantarum in the diets did not have a positive effect on the parameters evaluated. [ABSTRACT FROM AUTHOR]

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The present study aimed to evaluate the influence of different salinities on water quality, growth performance, and hematology of the Nile tilapia Oreochromis niloticus cultured in a biofloc system. Four different salinities with four replicates were evaluated: 2, 8, 15, and 22 PSU. The fish (200 ± 10 g) were stocked at a density of 15 fish m-3 in tanks with 800 L of useful volume for 56 days. Fish were fed with a 32 % crude protein commercial feed. Water quality remained stable throughout the study. The growth parameters differed, with the salinities of 2 and 8 PSU presenting higher growth and survival. The treatment of 15 PSU showed high survival, however, with reduced growth. The salinity of 22 PSU had lower results than the others for all parameters analyzed. The hematological evaluation showed differences in RBC, hematocrit, and glucose counts, indicating that salinity may have caused stress to animals cultured at higher salinities, thus, causing low growth and survival. These results indicate that Nile tilapia can tolerate high salinities when cultured in a biofloc system. However, salinities above 15 PSU may compromise its growth and weight gain. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the production of phenolic compounds, antioxidant activity and growth performance of Sarcocornia ambigua exposed to different periods of continuous irrigation in an aquaponics system with Litopenaeus vannamei reared in a biofloc technology (BFT) system, in addition to possible effects on shrimp growth performance, nitrogen recovery and water quality. Four treatments were evaluated as follows: 6, 12, 18 and 24 h of continuous irrigation per day, all set up in triplicate. Plants from the 12 and 24 h of irrigation treatments exhibited significantly higher values of phenolic compounds, 48.4 ± 1.8 and 47.7 ± 1.6 mg Gallic acid equivalent (GAE) 100 g−1 FW (fresh weight), respectively, when compared with the 6 and 18 h treatments, 42.6 ± 1.1 and 42.6 ± 1.3 mg GAE 100 g−1 FW, respectively (p < 0.05). Antioxidant activity also differed significantly between treatments (p < 0.05). The highest concentrations were found in treatments of 12 and 24 h of irrigation, which presented 41.3 ± 0.6 and 42.7 ± 0.8 μmol Trolox Equivalent Antioxidant Capacity (TEAC) 100 g−1 FW, respectively. For treatments of 6 and 18 h of irrigation, the concentrations were 29.9 ± 0.8 and 31.1 ± 1.5 μmol TEAC 100 g−1 FW. No significant differences between treatments were observed for plant and shrimp growth performance (p ≥ 0.05). There was also no significant effect of the different irrigation periods on water quality (p ≥ 0.05). The overall mean nitrogen recovery was 29.3% for all treatments. In conclusion, S. ambigua cultivated under 12 and 24 h of continuous irrigation exhibited higher production of bioactive compounds and antioxidant activity. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Ciencias Agroveterinarias is the property of Revista de Ciencias Agroveterinarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study evaluated the use of microalgae (Aurantiochytrium sp.) meal as a substitute for fish oil in the diet of juvenile Pacific white shrimp (Litopenaeus vannamei) reared in a clear-water system. Dietary treatments at five replacement levels (0%, 25%, 50%, 75%, 100%) were performed in triplicate. After 46 days, only a slight difference in shrimp final weight was observed among treatments (0.61 g). An increase in final weight was observed with replacement of up to 50% fish oil for microalgae meal, while the optimal percentage of replacement estimated was 44.7%. Feed conversion rate (FCR) of animals fed a diet of Aurantiochytrium sp.meal to replace up to 50% fish oil decreased, and the optimal percentage of replacement estimated was 49.3%. The fatty acids profile in shrimp muscle tissue demonstrated an increase in docosahexaenoic acid (DHA) from 10.03% to 14.28% with increased replacement of fish oil by microalgae meal in the diet. Therefore, the partial replacement of fish oil by microalgae meal resulted in improved shrimp growth and FCR, and total replacement of dietary fish oil had no negative effects on these parameters. In addition, inclusion of microalgae meal raises the level of DHA in shrimp muscle. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the use of microalgae meal (Aurantiochytrium sp. and Nannochloropsis spp.) as a substitute for fish oil in the diet of shrimp Penaeus vannamei reared in a clear water system. In the diet of these animals, the concentration of fish oil decreased as microalgae meal was inserted, and these were used in five different substitutions: 0, 25, 50, 75, and 100%. The treatments were carried out in triplicate, and after 49 days of cultivation, the zootechnical parameters and the composition of fatty acids in the animals' muscles were analyzed. In zootechnical performance, the shrimp obtained an average final weight of 16.59 ± 0.3 g, and the growth was approximately 1.89 ± 0.30 g week-1. In addition, feed conversion was, on average, 1.47 ± 0.28, and survival was greater than 97%. However, no significant difference was observed in these parameters. Regardless of the levels of fish oil replacement by microalgae meal, the composition of fatty acids in the shrimp muscle was ensured, as well as their quantity within groups, such as n-3 and n-6 polyunsaturated fatty acids. Thus, with the results obtained in the present study, it is suggested that it is possible to formulate a high-performance diet without any ingredients of marine origin (fish oil or fish meal), contributing to aquaculture's sustainability. [ABSTRACT FROM AUTHOR]

A supplementary diet with the probiotic bacteria Weissella cibaria on the efficacy of surubim hybrid immunization against a specific hemorrhagic septicemia caused by Aeromonas hydrophila was evaluated on the following treatments: fish fed a supplemented probiotic diet, vaccinated fish and vaccinated fish fed a supplemented probiotic diet, and untreated fish (control). Fish from the probiotic treatments were fed a diet containing W. cibaria for 41 days. On the 15th day of the experiment, fish from vaccine treatments were intraperitoneally vaccinated, with posterior oral booster for four days. One week after the oral booster, three fish from each experimental unit were sampled. The probiotic supplementation increased the number of thrombocytes and lysozyme concentration compared with surubim that did not receive W. cibaria in the diet. On the other hand, the vaccination increased agglutination titer, lysozyme concentration, and antimicrobial activity compared with surubim that were not vaccinated. However, there was no interaction between diet with probiotics and vaccination in the surubim hybrid in the analysed parameters. [ABSTRACT FROM AUTHOR]