Robie Allan Bombardelli

The objective of the work was to evaluate the effects of adding lemongrass essential oil on growth and oxidative stress in the rearing phase of Oreochromis niloticus. Two hundred Nile tilapia fingerlings (0.974±0.007g) were used, at a density of 10 fish per aquarium (70 L). The treatments consisted of five levels of lemongrass essential oil (EO) (0.00; 0.89; 1.78; 2.67; and 3.56mg kg-1) added to the feed, with four replicates. The animals were fed ad libitum, four times a day, for 37 days, at low temperatures. At the end of the experiment, the fish were anesthetized, weighed, euthanized, and dissected to obtain vicerosomatic and hepatosomatic index parameters. Liver samples from five animals from each experimental unit were collected for biochemical analysis of lipoperoxidation, catalase, glutathione S-transferase, superoxide dismutase, and protein carbonylation. The feeding with lemongrass essential oil influenced fish survival, and the other productive performance parameters did not show significant differences. At redox equilibrium, a decrease in glutathione S-transferase and increased superoxide dismutase activity were observed. It is concluded that the addition of up to 3.56mg kg-1 of lemongrass EO does not interfere with the productive performance improves survival and influences the redox balance of the animals.

The increasing concern about Cd contamination, a toxic metal that accumulates in the environment and enters the food chain, poses risks to human health and the environment. This research focuses on remediation methods such as phytoremediation using Crambe abyssinica and bioremediation with plant growth-promoting bacteria (PGPB), highlighting their potential to reduce Cd bioavailability. The experiments were carried out in a protected cultivation system in Paraná, Brazil, using a randomized block design. Seeds were inoculated with A. brasilense and P. fluorescens under varying Cd doses. Evaluated variables included plant growth, anatomical characteristics, and concentrations of macronutrients and Cd in plant tissue and soil. Results showed that bacterial inoculation significantly increased plant growth even under Cd contamination. Inoculated plants exhibited greater root and shoot length, as well as improved vascular structure in xylem and phloem. Nutrient analysis revealed better macronutrient uptake and greater Cd accumulation, especially in aerial plant parts. The results confirm that phytoremediation and bioremediation are effective strategies for mitigating Cd contamination in agricultural soils. Inoculation with PGPB not only improved plant health and growth but also enhanced Cd accumulation capacity, supporting their use in sustainable remediation strategies. The techniques presented offer sustainable approaches for managing environmental risks associated with toxic metals.

This study evaluated the impact of transporting Nile tilapia at stocking densities of 250 kg/m³ and 500 kg/m³ for 1 h, with post-transport resting periods of 0, 2, 4, and 6 h, on biochemical parameters and fillet quality. A 2 × 4 factorial design was employed for the experiment, with 15 repetitions per treatment. The density of 500 kg/m³ resulted in a longer time to rigor mortis after 4 h of rest, while shorter rigor times were observed at 0 and 2 h. Fillets taken from fish transported at 250 kg/m³ for 4 h exhibited greater intensities of red and yellow color. The highest weight loss during cooking occurred in fish transported at 500 kg/m³ without rest. High-density stocking increased the pH of the fillets, reduced color intensity, and increased weight loss and drip loss. Resting periods of 4 and 6 h resulted in firmer fillets with improved water retention. Fish rested for 6 h at 250 kg/m³ recovered glycogen and glucose levels, indicating restored homeostasis. In contrast, fish subjected to high-density transport showed impaired metabolic recovery and compromised fillet quality. These results support the use of resting periods to improve fish welfare and product quality in aquaculture systems.

1. This study evaluated the inclusion of golden mussel meal (GMM) of varying particle sizes in broiler chicken diets on performance, bone variables, serum biochemistry and gene expression.2. Male Cobb 500 broiler chicks (n = 900) were distributed in a completely randomised design, comprising five treatments, 10 replicate pens and 18 birds per pen, aged from 1 to 42 d.3. The treatments consisted of a control diet (calcite limestone 376 μm) and treatments GMM 299, 375, 436 and 551 μm.4. From 1 to 21 d of age, GMM 375 μm improved body weight gain (p = 0.041), while GMM 551 μm increased feed conversion ratio (p = 0.009). At 40 d of age, GMM 436 μm increased the serum aspartate aminotransferase level (p = 0.046).5. At 21 d of age, the tibial Seedor index was increased in the broilers fed GMM 375 μm (p = 0.044). The femoral mineral matter (MM) content was increased in the broilers fed GMM 375 (p = 0.047). Tibial MM content was increased in the broilers fed GMM 551 μm (p = 0.047). At 40 d of age, MM content was increased in the broilers fed GMM 375 μm (p = 0.027). Femoral calcium content was reduced in the broilers fed GMM 299, 436 and 551 μm (p = 0.004) and the tibial phosphorus content was increased in the broilers fed GMM 375 μm (p = 0.003).6. In conclusion, limestone can be replaced with GMM of different particle sizes to feed broilers from 1 to 42 d of age.

Corn and soybeans are commodities and ingredients of global interest, whose prices fluctuate based on global demands. In this sense, this study aimed to assess ora-pro-nóbis (Pereskia aculeata) leaf meal (OLM) as an alternative to be included in the diets of Nile tilapia (Oreochromis niloticus). The optimal inclusion level of OLM in tilapia diets is investigated herein, aiming to improve their growth performance and health. Five diet variations containing OLM (0%, 5%, 10%, 15%, and 20%) were tested. Feed conversion and protein efficiency rates in the 5% and 10% OLM groups were statistically similar to the control group (p ≤ 0.05) and lower in the 15% and 20% OLM groups. Fish fed 5% and 10% OLM diets showed better feed efficiency, while higher OLM levels (15% and 20%) led to reduced carcass protein and ether extract levels. Increasing OLM levels enhanced intestinal villi height and area, associated with improved nutrient absorption and decreased liver fat degeneration, suggesting dietary adaptation and healthier liver conditions. Thus, OLM can be included up to 10% in tilapia diets, improving their growth performance, feed efficiency, and intestinal absorptive capacity without adversely affecting other parameters.

This study aimed to determine the protein requirements of the fattening phase for Nile tilapia (Oreochromis niloticus) fed fish meal-free diets. A total of 75 Nile tilapia were maintained in a water recirculation system, and five isoenergetic diets were formulated with increasing protein levels encompassing three repetitions each. The findings revealed that protein levels significantly affected (p < 0.05) certain Nile tilapia performance, yield, and composition parameters. The determined parameter values clearly indicated that Nile tilapia can be fed fish meal-free soybean meal and corn-based diets. Furthermore, the metabolic plasticity of this species concerning dietary protein concentrations was also demonstrated, with adequate performance results achieved in treatments containing from 267 to 294 g/kg digestible protein (DP), or 298 to 327 g/kg crude protein (CP), where the balance between essential and non-essential amino acids and energy resulted in adequate performance correlated to satisfactory feed conversion values and filet yields and composition. A DP concentration of 267 g/kg (298 g/kg CP) is recommended when offering corn and soybean meal-based diets during the Nile tilapia fattening phase to fish weighing between 400 and 700 g.

Incorporating essential oils as dietary supplements in aquaculture is increasing in popularity. In prawn farming, their use is associated with reduced disease outbreaks, enhanced immunity, and improved animal growth and welfare. Herein, we explored the use of lemon beebrush essential oil (Aloysia triphylla; EOAT) in the diet of juvenile giant freshwater prawns (Macrobrachium rosenbergii) and its potential impact on growth performance and oxidative status of the hepatopancreas. Four hundred juvenile M. rosenbergii (0.40 ± 0.19 g, similar weights between sexes) were fed diets containing concentrations of EOAT at 0.0% (control), 0.1%, 0.2%, or 0.3% for 50 days. Each experimental group had five replicates, with 20 prawns per experimental unit. Prawn survival remained above 84% for all experimental groups. Prawn weight gain, specific growth rate, feed conversion ratio, and body condition were similar among all experimental groups. Dietary EOAT increased activities of the enzymatic antioxidants, catalase and superoxide dismutase, and varied glutathione S transferase activity in the hepatopancreas of prawns when compared to those fed the control diet. Dietary EOAT did not affect malondialdehyde (lipid peroxidation) levels. While EOAT had no impact on survival and growth of M. rosenbergii, it may modulate the detoxification capacity of the hepatopancreas (i.e., metabolic resistance). Future work should prospect EOAT as part of a nutraceutical blend, especially when combined with known growth enhancers and immune stimulants. Based on our results, dietary inclusion of 0.2% EOAT is the most suitable for juvenile M. rosenbergii farming.

O aumento da produtividade na aquicultura pode ter várias implicações para a saúde dos peixes. Sabe-se que dietas contendo vitaminas, aminoácidos, minerais e ácidos graxos, são essenciais para os peixes, evitando sinais de deficiência e uma boa saúde. Os minerais são de fundamental importância para inúmeros processos metabólicos e, a inclusão de minerais na ração de peixes é fator determinante, não só como elemento nutricional, mas também como imunomodulador, promotor de saúde e de crescimento. Visando a importância que os minerais têm na alimentação animal o objetivo desse trabalho é fazer um levantamento bibliográfico sobre os minerais na alimentação de peixes. Na reprodução de peixes, o selênio é um antioxidante que ajuda a proteger os ovos e embriões contra danos oxidativos, contribuindo para a viabilidade embrionária e a qualidade da prole, já o cobre é essencial para a formação de enzimas envolvidas na reprodução, incluindo aquelas que participam da síntese de hormônios sexuais. Na larvicultura de peixes, o ferro é essencial para a formação da hemoglobina, a proteína responsável pelo transporte de oxigênio no sangue e o manganês está associado à formação de ossos e ao sistema nervoso e aumento da imunidade de peixes. No crescimento de peixes, o selênio é conhecido por suas propriedades antioxidantes e por sua capacidade de prevenir o estresse oxidativo nas células dos peixes. Além disso, o selênio pode influenciar a textura e a cor da carne, contribuindo para uma carne mais firme e saudável. O ferro no crescimento de peixes, é necessário para a formação da hemoglobina, que é essencial para o transporte de oxigênio. Em suma, é unanimidade que inclusão de microminerais na alimentação de peixes melhoram os índices produtivos. Um melhor entendimento das exigências de microminerais dos peixes pode ajudar a formular dietas mais precisas, minimizando o desperdício de nutrientes e maximizando a produtividade da cadeia produtiva no setor da piscicultura.

In this study, the effects of adding nucleotides to diets for broodstock and offspring of Nile tilapia (Oreochromis niloticus) were evaluated. Nile tilapia broodstock were fed diets containing 0.0, 2.5, and 5.0 g of Ascogen®/kg for five months. After this period, the eggs were collected and incubated. The offspring, at five days of age, were fed diets containing 0.0, 2.5, 5.0, and 7.5 g of Ascogen®/kg for 100 days. Analyses of digestive enzyme activity and the morphology of hepatic and intestinal tissues of juveniles were conducted. An interactive effect (p<0.05) between the diets of broodstock and offspring on trypsin activity was observed. The highest activity of this enzyme was recorded when diets containing 2.5 g/kg were used for broodstock and 7.5 g/kg for offspring. Juveniles from broodstock fed with 0.0 g/kg and offspring fed with 7.5 g/kg showed a significantly greater (p<0.05) height of enterocytes. Hepatic tissue was not influenced by the diets regarding its morphology. It is concluded that 7.5 g/kg of Ascogen® in offspring's diet promotes alterations in intestinal morphology in terms of enterocyte height. Under this condition, when associated with 2.5 g/kg of Ascogen® for broodstock, it enhances trypsin activity in the offspring.