Eduardo da Silva

O trabalho avaliou a suplementação na dieta de óleo essencial de C. longa sobre os parâmetros zootécnicos e hematológicos de tilápia-do-nilo (Oreochromis niloticus) em sistema de bioflocos e sua sobrevivência após infecção por Streptococcus agalactiae. Um total de 240 peixes foram divididos em 2 tratamentos: TR1 = 0% e TR2 = 0,1% (óleo essencial de C. longa) divididos em 8 caixas, 30 peixes em cada e alimentados durante 60 dias. Após o período de alimentação foram avaliados os parâmetros hematológicas e de desempenho zootécnico. Ao final foi realizado desafio experimental com a bactéria S. agalactiae. As tilápias foram infectadas com a bactéria através de injeção intraperitoneal, e a mortalidade monitorada durante 10 dias. Os parâmetros hematológicos da tilápia-do-nilo não apresentaram diferenças estatisticas significativas entre os tratamentos, com exceção da hemoglobina que foi significativamente superior nos peixes alimentados com ração suplementada com óleo essencial. Os resultados de peso final, ganho de peso semanal, taxa de crescimento específico e produtividade foram significativamente maiores nos peixes do grupo controle. No teste de desafio, as tilápias alimentados com óleo essencial apresentaram sobrevivência de 96 % em relação as não alimentadas com óleo, com uma sobrevivência de 79 %, o que representa uma diminuição de quase 17 % na sobrevivência. O estudo mostrou que o óleo essencial de Curcuma longa aumenta a resistência à estreptococose em tilápia, demonstrando o papel antibacteriano dessa espécie vegetal.

This study evaluated the effects of Lippia sidoides essential oil (LSEO) as a growth and health promoter for juvenile tilapia subjected to stress induced by air exposure and experimental infection with Aeromonas hydrophila. Juvenile were allocated to 15 tanks (in triplicate) and fed diets containing 0.0% (Control), 0.05%, 0.1%, 0.2%, or 0.4% LSEO for 33 days. For the air exposure challenge, five fish from each tank were exposed to air for five minutes after the feeding period. Blood samples were collected for hematological analysis. For the infection challenge, six fish from each tank were intraperitoneally inoculated with 100 µL of A. hydrophila and monitored for ten days. Hematological and histomorphometric parameters were assessed. The results indicated that the 0.4% LSEO supplementation reduced feed conversion ratios (P < 0.05). Before the challenges, LSEO concentrations influenced total counts of neutrophils, basophils, and monocytes (P < 0.05). After the air exposure and infection challenges, no significant differences were observed among treatments for these parameters (P > 0.05). Regarding hematimetric indices, all parameters were affected by LSEO concentrations prior to the challenges (P < 0.05). Although LSEO supplementation improved feed conversion, it did not mitigate the hematological alterations caused by the stress challenges.

Traditional shrimp maturation uses high water exchange, conflicting with sustainable farming and biosecurity, although broodstock production systems have been updated by the adoption of closed-cycle production. So, this study evaluated BFT for Penaeus vannamei broodstock maturation, comparing it against a conventional system. The research compared two treatments, BFT and CW, in three replicated tank systems. Each experimental unit was a circular fiberglass tank with 5.63 m³ working volume. BFT tanks involved a 3.12 m² mobile triangular cage for viewing and capturing mated females. Parameters monitored included water quality, reproductive performance and hemato-immunological responses. The BFT system resulted in greater water quality stability, significantly lower water consumption, and lower Total Ammonia Nitrogen (TAN) concentrations, indicating efficient ammonia recycling. Also, reproductive performance and most hemato-immunological parameters did not differ significantly between treatments. Although CW showed slightly higher broodstock survival and sperm viability, BFT males exhibited a significantly higher Total Hemocyte Count (THC). Overall, BFT is suitable for sustainable P. vannamei broodstock maturation, as it promotes stable environmental conditions without compromising reproductive or immunological performance. Further research is recommended, particularly regarding effects of zero-water-exchange on male shrimp and improvements on capture structures.

Aims: This study investigated a sustainable and innovative alternative to improve animal welfare in swine production through the topical application of Cymbopogon citratus essential oil (CCEO) in newly weaned piglets. Study design: Completely randomized design. Place and Duration of Study: The experiment was conducted at the Swine Teaching and Learning Unit of the Federal Institute of Education, Science and Technology of Santa Catarina (IFC), Araquari Campus, Brazil, between February 2019 and April 2020. Methodology: A total of 124 newly weaned piglets were randomly assigned to four groups: a control group and three treatments with CCEO applied at concentrations of 1.25%, 2.50%, and 5.00%. At each weaning, piglets received 1 mL of the solution on the dorsal region and were observed for 3 hours for behavioral recording through photos and videos, without observer interaction. Skin lesions were mapped 24 h after weaning and classified by anatomical region. The study was structured in three stages: (I) an initial observational survey of the behavioral repertoire, (II) development of an ethogram with zootechnical parameters, and (III) validation of the ethogram with detailed behavioral analysis. Zootechnical performance (body weight, average daily gain, and mortality rate) was assessed in stages II and III. Results: Chemical analysis confirmed citral (87.53%) as the predominant component of the oil. CCEO significantly influenced several non-agonistic behaviors (P < 0.05), increasing calm and exploratory activities—particularly at 2.50% and 5.00%. While aggression frequencies did not differ among treatments, CCEO-treated piglets showed a consistent numerical reduction in skin lesions 24 h after weaning. Zootechnical performance was not negatively affected, with higher concentrations showing a tendency toward improved growth. Conclusion: Overall, topical CCEO promoted more positive social interactions and reduced the severity of agonistic outcomes without compromising productivity. These findings indicate that CCEO is a simple, low-cost, and practical strategy that can be readily implemented to enhance welfare during the critical post-weaning period.

This study evaluated the technical and economic feasibility of the biofloc technology (BFT) system during the fry rearing phase of Nile tilapia (Oreochromis niloticus), focusing on suspended solids management, stocking density, and economic performance at a pilot scale. Three trials were conducted. The first assessed the effects of four total suspended solids (TSS) ranges (0–200, 200–400, 400–600, and 600–800 mg·L⁻¹) on larval performance and water quality. TSS levels between 200 and 600 mg·L⁻¹ promoted improved water quality and zootechnical performance. The second trial tested five stocking densities (2, 4, 6, 8, and 10 larvae·L⁻¹), evaluating their impact on water quality, survival, and size uniformity. Higher densities negatively affected survival (R² = 0.84) and final weight (R² = 0.92), while also increasing solids and nitrogenous compounds, thus impairing performance (p < 0.05). The third trial monitored six production cycles at pilot scale, evaluating zootechnical parameters, sex reversal efficiency, and economic indicators. All cycles showed survival rates above 85%, sex reversal close to 100%, and positive net margins (18.5 to 41.9%), demonstrating the viability of BFT for commercial fry operations. The results emphasize the importance of controlling suspended solids and stocking density to maintain water quality and optimize larval performance. Furthermore, the system proved economically viable, with good feed conversion rates and profitability, even without water exchange. These findings support BFT as a sustainable and efficient alternative for tilapia fry production, offering significant water savings and promising economic returns when properly managed.

This study evaluated the efficacy of dietary supplementation with Biotronic® Top 3—a blend of selected organic acids, their salts, and a phytochemical—on the zootechnical performance and immune response of fish during a natural outbreak of francisellosis caused by Francisella spp., an intracellular bacterium that leads to high mortality in aquaculture systems. The trial was conducted in a commercial fish farm using 24 net cages (20,000 fish each) divided into two treatments: one group received feed supplemented with Biotronic (without antibiotics), while the control group was fed a standard diet and treated with Florfenicol (40 mg kg−1) after clinical diagnosis of the disease. The results showed that fish in the Biotronic group achieved significantly higher final body weight and daily weight gain (p < 0.05) compared to the control. However, no significant differences were observed in feed conversion ratio or survival rates. Histopathological analyses of the spleen indicated the presence of retroactive granulomas exclusively in the Biotronic group, suggesting an enhanced immune response and possible recovery stage of the infection. These findings indicate that Biotronic® Top 3 supplementation improves growth performance and stimulates the immune system during bacterial challenge, supporting its use as a prophylactic strategy in aquaculture. This approach may contribute to reducing antibiotic use and promoting more sustainable and health-conscious fish production systems.

Animal welfare is something that has become very important for understanding animals in general nowadays, and is an accurate way of determining whether an animal has a good or bad quality of life. This article was created with the aim of understanding whether a specimen of domestic cat, when exposed to visual stimuli from television, can improve its quality of life and whether it may have capabilities to have favorites programs and characters. The way to analyze the animal was by reading its body language, since cats have one of the most expressive body languages it was the perfect option to know about what it’s feeling and trying to communicate with the others who are near it. Four factors were selected as the most conclusive for the collection of data, being the time of: Watching, Sleeping, Distracted and Cleanliness. For the collection of data this article was divided in two experiments, one with a wider variety of types of program and one with only one to comprehend the animal more specifically. The feline does not see the act of watching a television as a necessity, it’s more a choice of the animal who desires do go and watch something on the screen. The most important factors that were noticed happen in behavior that could be considerate both negative and positive, and an improvement between the relationship of the tutor with the cat.

The objective of this study was to determine the optimal concentration of Cinnamomum zeylanicum essential oil (CZEO) as an anesthetic for Rhamdia quelen and to evaluate the effects of exposure on stress responses. A total of 60 animals (245.75 ± 17.61 g) were used, divided into five treatment groups (140, 160, 180, 200, and 220 μL L-1 of CZEO) and a control group (without CZEO). Additionally, to assess the effects of CZEO exposure on stress responses, 30 animals (200.71 ± 30.18 g) were divided into two treatment groups: Basal (control levels) and CZEO (exposure to 200 μL L-1 of CZEO). Blood samples were collected to measure plasma levels of cortisol, lactate, and glucose. The induction time was significantly shorter (P < 0.05) than three minutes at CZEO concentrations of 180, 200, and 220 μL L-1. The concentration of 200 μL L-1 was considered optimal, as it was the lowest concentration that anesthetized the fish in less than three minutes. No statistically significant differences (P > 0.05) in plasma cortisol and glucose levels were observed between the CZEO and Basal treatments. However, plasma lactate levels were significantly higher (P < 0.05) in the CZEO group compared to the Basal group. No mortality was observed throughout the experiment. In conclusion, 200 μL L-1 of CZEO is safe and effective for use as an anesthetic in R. quelen.

Este estudo avaliou o desempenho da tilápia-do-nilo alimentada com dieta sem farinha de peixe, suplementada com taurina. Juvenis de tilápias-do-nilo (n = 150) foram divididas em dois grupos: peixes alimentados com ração suplementada com taurina e sem suplementação (controle). Os peixes foram alimentados três vezes ao dia, e os parâmetros de qualidade de água (temperatura, oxigênio dissolvido, pH e compostos nitrogenados) foram monitorados semanalmente, juntamente com a biometria para ajuste alimentar. Após 24 dias, cinco peixes por grupo foram anestesiados para coleta de sangue e sacrificados para coleta de órgãos para análise hematológica e índices corporais. Observou-se que o grupo suplementado apresentou peso final e ganho médio diário menores que o grupo controle (p < 0,05), porém, os demais parâmetros zootécnicos não diferiram entre os tratamentos (p > 0,05). O índice hepatossomático aumentou (p < 0,05) no tratamento com taurina. Os peixes do grupo controle apresentaram um aumento no número de monócitos (p < 0,05). Os parâmetros de qualidade da água permaneceram estáveis entre os tratamentos (p > 0,05). Conclui-se que a suplementação com taurina comprometeu o desempenho de crescimento e alterou índice hepatossomático, sem afetar a saúde dos peixes ou a qualidade da água.