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Efeitos da aplicação de óleos essenciais à dieta de tilápia-do-nilo (Oreochromis niloticus)

Thu, 01 Jan 2026 00:00:00 GMT

Título: Efeitos da aplicação de óleos essenciais à dieta de tilápia-do-nilo (Oreochromis niloticus) Autor(es): Cunha, Angélica de Oliveira Portela Abstract: Global population growth poses challenges to sustainable food production, highlighting aquaculture as a strategic alternative for supplying animal protein. In this context, Nile tilapia (Oreochromis niloticus) stands out due to its high adaptability to intensive farming systems, rapid growth, and wide commercial acceptance. However, the intensification of production favors the emergence of diseases and the excessive use of antibiotics, driving the search for natural additives capable of improving fish performance and health. Thus, essential oils emerge as promising additives due to their antimicrobial, antioxidant, and immunomodulatory properties. The present study evaluated the palatability and the zootechnical and histological effects of dietary supplementation with different essential oils for juvenile Nile tilapia under controlled laboratory conditions. The essential oils of Cassia Cinnamon (Cinnamomum cassia), Lemongrass (Cymbopogon flexuosus), Eucalyptus (Eucalyptus staigeriana), and Oregano (Origanum vulgare) were individually supplemented at concentrations of 0.1, 1, and 10 mL/kg of commercial feed. Zootechnical performance was evaluated through Mean Weight, Total Weight Gain (TWG), Apparent Feed Conversion Ratio (FCR), and Survival, while palatability was assessed through feed intake tests and latency to the first feeding attack. The results demonstrated a positive effect of supplementation at intermediate concentrations (1 mL/kg), reinforcing the existence of an optimal inclusion range. Cassia Cinnamon and Lemongrass showed the greatest growth increments, with estimated additional gains of approximately 1.3 g and 1.2 g compared to the control group, respectively. Cassia Cinnamon presented the best overall productive performance, with greater zootechnical stability and absence of relevant histological alterations, whereas Lemongrass promoted growth enhancement associated with mild gastric alterations compatible with adaptation to dietary stimulus. Oregano stood out for its functional effects on palatability and feeding behavior, while Eucalyptus showed more discrete effects, mainly related to the initial acceptance of the diets. Overall, the essential oils proved to be biologically safe, maintaining high survival rates (92.5–100%) with no adverse effects on water quality or tissue integrity. It is concluded that the evaluated essential oils present potential as functional and attractant-palatability additives in Nile tilapia farming, especially at intermediate concentrations, highlighting Cassia Cinnamon as a promoter of productive performance, Lemongrass for its growth-stimulating potential associated with adaptive responses of the digestive tract, and Oregano as a modulator of feeding behavior and physiological responses in fish. Tipo: Dissertação

Substituição total e parcial da ração comercial por farelo de soja fermentado durante a fase de berçário intensivo do camarão Litopenaeus vannamei

Wed, 01 Jan 2025 00:00:00 GMT

Título: Substituição total e parcial da ração comercial por farelo de soja fermentado durante a fase de berçário intensivo do camarão Litopenaeus vannamei Autor(es): Gomes, Igor Gabriel Rodrigues Ferreira Abstract: The shrimp farming industry has been experiencing a movement towards intensification, which allows an increase in productivity with a better use and of natural resources. The growth of this sector is associated with the availability of quality post-larvae and juveniles. The use of intensive nursery is an important strategy for biphasic systems, providing better results during the grow-out phase, increasing survival and growth of farmed animals. Despite this, its use requires qualified labor and feeds with high levels of crude protein, which represent greater cost and a potential risk to the water quality, thus, to the health of the animals. Thus, it is necessary to develop strategies that allow the improvement of this culture system. This study aimed to evaluate the effect of replacing commercial feed with fermented soybean meal, using a commercial probiotic, composed of a mix of organisms, during the intensive nursery phase of L. vannamei carried out under commercial conditions. Thus, five replacement percentages were evaluated, as 0%, 25%, 50%, 75% and 100%. Zootechnical parameters, water quality, zooplankton density and standard plate count for bacteria of the genus Vibrio spp. in the nursery water were evaluated. It was possible to replace the commercial diet with 100% fermented soybean meal without affecting the final survival, specific growth rate (%) and feed conversion. It was possible to replace the feed up to 50%, without negative effect on average final weight (g) and daily weight gain (g/day). The final average productivity (kg/m³) and yeld (kg/m³) were affected only when the replacement level exceeded 75%. It was possible to replace up to 100% without prejudice to water quality parameters such as pH, dissolved oxygen (mg/L), total ammonia (mg/L), nitrite (mg/L) and alkalinity (mg/L of CaCO3). The total zooplankton density was higher in the SJ25% treatment, when compared to the others, which did not differ (p>0.05). The standard plate count of Vibrio spp. was not influenced by the different replacement levels, the exception being the SJ50% treatment, which reached the highest value (p<0,05). The results indicate that the use of fermented soybean meal can be used as food for L. Vannamei‘s post-larvae in intensive nursery. A maximum replacement rate of 50% is suggested, in order to maintain the pattern of development observed with the use of a protocol with commercial rations. Tipo: Tese

Criopreservação de espermatóforos do camarão marinho Penaeus vannamei em diferentes meios diluidores, adicionado de polissacarídeos sulfatados extraídos de Kelps ascophyllum nodosum, para uso em inseminação assistida

Thu, 01 Jan 2026 00:00:00 GMT

Título: Criopreservação de espermatóforos do camarão marinho Penaeus vannamei em diferentes meios diluidores, adicionado de polissacarídeos sulfatados extraídos de Kelps ascophyllum nodosum, para uso em inseminação assistida Autor(es): Moreira, Francisco Hiago Gadelha Abstract: Sperm cryopreservation constitutes a strategic biotechnology for genetic improvement programs and the conservation of aquatic resources, including shrimp farming. This thesis aimed to evaluate the effect of adding sulfated polysaccharides (SP) extracted from the brown alga Ascophyllum nodosum, as well as the use of powdered coconut water (ACP®) as a diluent, in cryopreservation protocols for spermatophores of the marine shrimp Penaeus vannamei. Two experiments were conducted: in the first, spermatophores were subjected to different freezing media (ACP®, seawater, or 0.2 M sucrose); in the second, the addition or absence of SP to the 0.2 M sucrose solution was evaluated. Spermatophores were frozen using a dry shipper or a freezing ramp, stored in liquid nitrogen for up to 12 months, and subsequently thawed for evaluation of sperm quality. Plasma membrane integrity, sperm morphology, and DNA fragmentation were analyzed, as well as the structural characterization of SP by Fourier-transform infrared spectroscopy. The results demonstrated that the tested protocols were effective in maintaining cellular integrity after thawing, even after long periods of cryogenic storage. The freezing solution and method significantly influenced sperm quality, with emphasis on the dry shipper, which showed better preservation of plasma membrane integrity, including when associated with the use of ACP®. Supplementation of freezing media with SP from A. nodosum positively contributed to the maintenance of post-thaw sperm quality. Assisted insemination using cryopreserved spermatophores resulted in fertilization. It is concluded that the use of algal-derived sulfated polysaccharides and diluents based on powdered coconut water and seawater represents a promising approach for improving cryopreservation protocols for P. vannamei spermatophores, with potential application in assisted reproduction programs and genetic conservation in shrimp farming. Tipo: Tese

Filmes à base de polissacarídeos sulfatados da alga marinha vermelha (hypnea pseudomusciformis) incorporados com óleo de babaçu: elaboração e caracterização

Thu, 01 Jan 2026 00:00:00 GMT

Título: Filmes à base de polissacarídeos sulfatados da alga marinha vermelha (hypnea pseudomusciformis) incorporados com óleo de babaçu: elaboração e caracterização Autor(es): Lima, Erivan Santos Abstract: The production of biodegradable packaging has increased, along with the interest of researchers and industries, aiming to reduce the impact caused by the use and disposal of packaging made from synthetic materials derived from fossil hydrocarbons. This study aimed to develop and characterize biodegradable films based on sulfated polysaccharide (SP) extracted from the red alga Hypnea pseudomusciformis, incorporated with babassu oil at different concentrations. Polysaccharide extraction was carried out using two methods (aqueous extraction - AE and refined aqueous extraction - RAE), with yields of 31.50% and 10.35%, respectively. Six treatments were prepared, varying the concentration of carrageenan (5%, 10%, 15%) and babassu oil (1%, 3%, 6%), using glycerol as a plasticizer. The films were evaluated for physical (thickness, moisture), optical (color, transparency), barrier (water solubility), thermal (DSC, TGA), chemical (FTIR) properties, and soil biodegradability. Statistical analysis included descriptive statistics, multivariate analysis, and the use of R software. The results showed that oil incorporation improved handling and visual homogeneity, especially in treatments with 5% polysaccharide + 1% oil (T4) and 15% polysaccharide + 6% oil (T6). FTIR analysis confirmed the carrageenan structure in the films and the presence of babassu oil through the band at ~1740 cm⁻¹. Biodegradability was high (>70% after 10 days), and the addition of oil increased the thermal stability of the films, with T6 showing the highest resistance (lowest mass loss). It is concluded that the combination of SP and babassu oil is viable for the production of biodegradable films, allowing their properties (such as transparency, moisture resistance, and degradation rate) to be adjusted through formulation, demonstrating their potential for specific applications in sustainable packaging. Tipo: Dissertação