ABSTRACT. With the rise of world fish farming, the national scenario is favorable for using native fish for intensive farming. Among the catfish, the Amazonian Jundiá (Leiarius marmoratus) is a robust candidate, easy to grow and with good organoleptic characteristics in its flesh. For productive success in captivity, it is necessary to consider some questions about the species, such as genetic variability, which must have an acceptable level in a breeding stock, in order to maintain a good diversity; this reduces losses due to inbreeding and low diversity. Therefore, the objective of this study was to characterize the genetic variability of commercial stocks of L. marmoratus from the State of Mato Grosso through microsatellite molecular markers. We analyzed 143 individuals from three stocks. The mean heterozygosity and the inbreeding coefficients observed were 0.060; 0.084; 0.141; and 0.539; 0.562; 0.514, respectively, for the stocks of Campo Verde, Juína, and Nova Mutum. The Deviation in the Hardy-Weinberg equilibrium was observed in most of the loci in the three populations. Considering the genetic differentiation, it is concluded that the three populations are very close genetically, which requires introduction of new genetic material in the stocks to enrich them genetically for a later reproductive program.

Abstract This study evaluated the effect of including clove essential oil (EOcl) in Nile tilapia diets on animal performance and antioxidant power, lipid oxidation, gene expression, texture, pH, color and sensory analysis in fillets. Three levels of EOcl in the diets were evaluated (0.70, 1.05 and 1.40 g/kg), provided over three periods before slaughtering the animals (15, 45 and 60 days). The antioxidant power in the diets increased after including EOcl. There was an interaction effect between the level and period of inclusion of EOcl on the antioxidant power and lipid oxidation of fillets stored up to 14 days after slaughter. Lipid oxidation was reduced by 43.3% compared with the control group. EOcl inclusion in the diet, regardless of level and period, improved texture and promote less gene expression of catalase and glutathione synthetase. This demonstrates that the antioxidant in the tilapia diet acts against the oxidative stress process. Considering the results for the interactions and parameters evaluated, including 1.05 g/kg of clove essential oil in the rations for 15 days before slaughter is indicated because it contributes to a higher fillet quality.

Resumo O objetivo deste trabalho foi avaliar a digestibilidade da proteína, dos aminoácidos e da energia bruta de hidrolisado de fígado e carne suínos pela tilápia-do-nilo (Oreochromis niloticus). Os peixes foram distribuídos em 12 tanques com fundo cônico, em delineamento inteiramente causalizado, tendo sido alimentados com as seguintes três dietas, com quatro repetições cada uma: dieta referência com farinha de soja e de peixe; e duas dietas teste, uma com hidrolisado de fígado suíno e outra com hidrolisado de carne suína. Os coeficientes de digestibilidade aparente foram elevados para ambos os hidrolisados, tendo sido acima de 83% para matéria seca, 95% para proteína bruta e 92% para energia. Em relação aos aminoácidos, os coeficientes permaneceram entre 98–100% para os dois hidrolisados. Os percentuais de digestibilidade dos hidrolisados foram maiores do que os dos ingredientes proteicos, tanto de origem vegetal como animal, comumente utilizados na fabricação de dietas para esta espécie de peixe. Os hidrolisados testados têm potencial para serem usados na formulação de dietas para tilápia-do-nilo.

Abstract The objective of this work was to evaluate the digestibility of the protein, amino acids, and gross energy of swine liver and meat hydrolysates by Nile tilapia (Oreochromis niloticus). The fish were distributed into 12 tanks with conical bottoms, in a completely randomized design, and fed with the three following diets, with four replicates each: a reference diet with soybean and fish meal; and two test diets, one with swine liver hydrolysate and the other with swine meat hydrolysate. The coefficients of apparent digestibility were high for both hydrolysates, being above 83% for dry matter, 95% for crude protein, and 92% for gross energy. Regarding amino acids, the coefficients remained at 98–100% for the two hydrolysates. The digestibility percentages of the hydrolysates were higher than those of the protein ingredients, both of plant and animal origin, commonly used in the formulation of diets for this fish species. The tested hydrolysates have potential to be used in the formulation of diets for Nile tilapia.

ABSTRACT The homeopathy has been practiced for many years, mainly using rodent as a research model. Zebrafish have been used as an animal model in different scientific areas and may represent an important model in studies with this therapy. This paper aimed to evaluate the action of Homeopatila 100® on the growth, the action on the liver and reproduction of zebrafish. The study was carried out with 192 six months old animals. The experimental period was three months, being evaluated the growth, the hepatosomatic and viscerosomatic indexes, the number of hepatocytes per area and the percentage of glycogen in these cells, performing the hepatic histology of males and females. It was evaluated the reproduction of the animals, checking the production and probability of hatching of the eggs. It was found that homeopathy increases the number of hepatocytes and glycogen in females, as well as improved the reproductive indices evaluated.

The cafeteria diet is widely used as a model for inducing obesity in animals, and the zebrafish (Danio rerio) has emerged as a promising model for this purpose. In this context, this study evaluated the effect of a cafeteria diet on the composition of fatty acids in zebrafish fillets. Zebrafish grown in tanks for a period of 60 days were treated with standard (ST) and cafeteria (CAF) diets. The CAF diet presented higher total lipid and energy values than ST diet, due to the addition of peanut, chocolate and biscuit in its preparation. Moreover, CAF diet showed the highest concentrations of palmitic (19.44 ± 0.55 mg g-1), oleic (102.58 ± 2.85 mg g-1) and linoleic (44.47 ± 1.32 mg g-1) acids. A significant increase in oleic and linoleic acid concentrations (39.77 ± 2.69 and 14.31 ± 0.86 mg g-1, respectively) and in the omega-6/omega-3 ratio (11.52 ± 0.81) was observed in the zebrafish fillets between 0 and 60 days for CAF diet, indicating incorporation of these fatty acids.

RESUMO. Objetivou-se avaliar a digestibilidade do hidrolisado proteico seco do resíduo da filetagem de tilápias (HPST) e sua inclusão em dietas para larvas de tilápia do Nilo. Para determinar os coeficientes de digestibilidade aparente, duas dietas foram elaboradas, referência e teste (com 20% do HPST) e para avaliação da inclusão, seis dietas foram formuladas com 0,0, 2,0; 4,0; 6,0, e 8,0% de HPST. Os coeficientes de digestibilidade aparente da proteína e energia bruta foram de 89,5 e 98,3%, respectivamente. Nos níveis acima de 4,0% de inclusão de HPST o peso e comprimento final e ganho em peso foram prejudicados, no entanto a sobrevivência foi maior (p < 0,05). O HPST pode ser utilizado em dietas para tilápias em função dos elevados coeficientes de digestibilidade para proteína bruta e energia bruta. A inclusão de até 4,0% de HPST não afeta o desempenho produtivo e a sobrevivência de larvas de tilápias do Nilo.

ABSTRACT. This study aimed to evaluate the digestibility of tilapia by-product protein hydrolysate powder (TBHP) from tilapia filleting by-product, and its inclusion in diets for Nile tilapia larvae. In order to determine the apparent digestibility coefficients, two diets were formulated, the reference diet and the test diet (20% of TBHP) and, to evaluate the inclusion, six diets were formulated, which were with 0.0, 2.0; 4.0; 6.0, and 8.0% of TBHP. The apparent digestibility coefficients of crude protein and gross energy were 89.5 and 98.3%, respectively. At levels above 4.0% of inclusion of TBHP, the weight, final length and weight gain were impaired, however, survival rate was higher (p < 0.05). The TBHP can be used in diets for tilapia due to the high digestibility coefficients for crude protein and gross energy. The inclusion of up to 4.0% of TBHP does not affect the reproductive performance and survival rate of Nile tilapia larvae.

Abstract The study was carried out with the objective of evaluating the influence of pre-slaughter stress on meat quality of Nile tilapia (O. niloticus) for 10 days of storage in ice. 75 whole fish were used eviscerated, with average weight and length of 825.75 ± 101.59 g and 28.25 ± 0.81 cm, respectively. The treatments consisted of time in which the animals underwent pre-slaughter hypoxia, being 0, 3 and 6 minutes. Rigor mortis and muscle pH were assessed besides the application of the Quality Index Method and analysis of total protein and blood glucose. Rigor mortis did not differ among treatments during the storage period, and after three hours all animals were in rigor stage. The muscle pH values varied widely during the study period, observing higher values on the third day of storage. Sensory analysis showed that after 10 days the tilapia from the different treatments did not differ in the evaluated quality parameters similarly, there was no difference regarding the evaluated blood biochemical parameters Thus, hypoxia of 6 minutes pre-slaughter does not influence the rigor mortis, muscle pH, qualitative perception of the meat quality, total protein and blood glucose of Nile tilapia.

RESUMO. O objetivo do presente estudo foi avaliar a digestibilidade dos ingredientes energéticos vegetais, milho, sorgo e farelo de trigo, com e sem suplementação de fitase pelo jundiá (Rhamdia voulezi). O delineamento experimental foi inteiramente casualizado, representado por oito tratamentos, os quais consistiram na elaboração de uma dieta-referência e uma dieta- teste para cada ingrediente avaliado (milho, sorgo e farelo de trigo), com e sem a suplementação de fitase. As dietas foram fabricadas de modo que continham 70% da ração referência e 30% do ingrediente teste. Os coeficientes de digestibilidade da matéria seca e proteína bruta foram influenciados significativamente somente em relação aos ingredientes avaliados. A fitase influenciou nos coeficientes de digestibilidade da energia e do fósforo, onde também foi observada a interação entre os alimentos e a inclusão da enzima. A interação entre esses dois fatores demonstra que a eficiência da fitase é dependente do tipo de ingrediente vegetal utilizado na dieta. Pelos resultados obtidos sugere-se a suplementação de fitase visando maior digestibilidade dos nutrientes, do milho, sorgo e farelo de trigo pelo jundiá (R. voulezi).

ABSTRACT. This study aimed to evaluate the digestibility of plant energetic ingredients, corn, sorghum and wheat bran, with and without phytase supplementation, in silver catfish (Rhamdia voulezi). The experimental design was completely randomized, represented by eight treatments, which consisted of the development of a reference diet and a test diet for each ingredient evaluated (corn, sorghum and wheat bran), with and without supplemental phytase. Diets were formulated so as to contain 70% reference feed and 30% test ingredient. The digestibility coefficients of dry matter and crude protein were significantly influenced only in relation to the evaluated ingredients. Phytase influenced the digestibility coefficients of energy and phosphorus, with interaction between food and the enzyme addition. The interaction between these two factors shows that the phytase efficiency is dependent on the type of vegetable ingredient used in the diet. The results suggest the supplementation of phytase for a higher nutrient digestibility of corn, sorghum and wheat bran by silver catifish (R. voulezi).