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Abstract Sugarcane is a central crop for sugar and ethanol production. Investing in sustainable practices can enhance productivity, technological quality, mitigate impacts, and contribute to a cleaner energy future. Among the factors that help increase the productivity of sugarcane, the physical, chemical and biological parameters of the soil are amongst the most important. The use of poultry litter has been an important alternative for soil improvement, as it acts as a soil conditioner. Therefore, this work aimed to verify the best doses of poultry litter for the vegetative, reproductive and technological components of sugarcane. The experiment was carried out at Usina Denusa Destilaria Nova União S/A in the municipality of Jandaia, GO. The experimental design used was a complete randomized block design with four replications: 5 × 4, totaling 20 experimental units. The evaluated factor consisted of four doses of poultry litter plus the control (0 (control), 2, 4, 6 and 8 t ha−1). In this study, were evaluated the number of tillers, lower stem diameter, average stem diameter, upper stem diameter, plant height, stem weight and productivity. The technological variables of total recoverable sugar, recoverable sugar, Brix, fiber, purity and percentage of oligosaccharides were also evaluated. It was observed, within the conditions of this experiment, that the insertion of poultry litter did not interfere significantly in most biometric, productive and technological variables of the sugarcane. But it can also be inferred that there was a statistical trend toward better results when the sugarcane was cultivated with 4 t ha-1 of poultry litter.

Integrated systems are efficient technologies used for diversifying production and promoting agricultural sustainability. The benefits of double intercropping are well-established in research. With advancements in sustainable food production technology, some studies have explored triple intercropping by adding legumes. However, triple intercropping methods must be comprehensively understood. This study aimed to evaluate the production of dry mass, fermentation profile, and nutritive values of silage from maize based intercropping. The experiment was conducted in the field, in Instituto Federal Goiano, Campus Rio Verde, State of Goiás, Brazil, where we assessed silage production and quality in monoculture and intercropping systems, in a randomized block complete design with three replications. We evaluated 8 treatments, consisting of silage from: maize monoculture; Tamani guinea grass monoculture; Quênia guinea grass monoculture; Zuri guinea grass monoculture; Pigeon pea monoculture; maize + Tamani guinea grass + Pigeon pea; maize + Quênia guinea grass + Pigeon pea and maize + Zuri guinea grass + Pigeon pea. The results showed that maize silage intercropped with cultivars of Panicum maximum (Tamani, Quênia and Zuri guinea grasses) and Pigeon pea increased silage mass production by 37.8% and the crude protein content at 25.1% compared with that of the monoculture maize silage. It also improved the fermentation characteristics of silage, reducing 5.1% of pH, 32.5% of buffering capacity, 28.9% of ammoniacal nitrogen in total nitrogen, 15.7% of effluent production, and 20.0% of dry matter losses, compared with those of grass and legume silage in monoculture. Thus, the silage produced by the triple intercropping proved to be an efficient technique for sustainable forage production.

The preservation of fish and seafood represents a significant challenge for the food industry due to these products’ high susceptibility to microbial spoilage. Essential oils (EOs), classified as Generally Recognized as Safe (GRAS), have become a natural alternative to synthetic preservatives due to their antimicrobial and antioxidant properties. This review aims to analyze the specific potential of EOs in extending the shelf life of fish and seafood products, offering a natural and effective preservation solution. It provides a detailed overview of EOs applications and mechanisms, highlighting their role in controlling spoilage microorganisms while maintaining product quality. The main methods of EOs application include immersion, spraying, and pipetting, with antimicrobial effectiveness influenced by factors such as concentration, exposure time, and food characteristics like chemical composition and biofilms. Direct EOs application shows challenges that can be countered by exploring nanoemulsion technology as an effective strategy to enhance EOs stability and controlled release, maximizing their preservation impact. Additionally, coatings made from chitosan, gelatin, Farsi gum, and carrageenan, combined with EOs such as oregano, clove, and thyme have shown efficacy in preserving species like rainbow trout, mackerel, and shrimp. However, the commercial feasibility of using EOs in fish preservation depends on consumer acceptance and regulatory compliance. This review offers valuable insights for the industry and researchers by highlighting the practical applications and commercial challenges of EOs in seafood products, underscoring the importance of consumer acceptance and regulatory adherence for market viability.

Modern agriculture faces the challenge of increasing production without expanding cultivated areas, promoting sustainable practices that ensure food security and environmental preservation. Integrated crop–livestock systems (ICLSs) stand out as an effective strategy, diversifying and intensifying agricultural production in a sustainable manner, ensuring adequate soil cover, and improving nutrient cycling efficiency. Thus, this study aimed to explore and compare integrated crop–livestock systems with Zuri guinea grass (Panicum maximum cv. BRS Zuri) and Quênia guinea grass (Panicum maximum cv. BRS Quênia) against the conventional soybean/maize succession method in a tropical region, and how these systems affect biomass decomposition, C:N ratio, nutrient cycling, and fertilizer equivalents. A field experiment was conducted in two phases: the first in the second-crop season and the second in the main season, using a randomized block design with four replicates. The treatments consisted of two ICLS systems, one with Zuri and Quênia guinea grasses established after soybean, and a succession system with maize established after soybean. The results indicated that Quênia guinea grass showed greater desiccation efficiency, with an injury rate of 86.5% at 21 days, 8.5% higher compared to Zuri guinea grass. In terms of biomass, Zuri and Quênia guinea grasses had average productions of 7021.1 kg ha−1, which was 43.25% higher compared to maize biomass. The biomass decomposition of the grasses was faster due to their lower C:N ratio, resulting in greater nutrient release into the soil. Both forage grasses (Zuri and Quênia guinea grasses) are suitable for integrated crop–livestock systems, as they showed similar biomass production and nutrient accumulation. Soybean yield was not influenced by the different cropping systems, showing similar results between the biomass of Zuri and Quênia guinea grasses and maize. However, grass biomass enriches the soil more through the return of fertilizer equivalents, which in future studies could be considered for the reduction of mineral fertilizers, ensuring greater sustainability of agricultural systems.

Identifying and counting fish are crucial for managing stocking, harvesting, and marketing of farmed fish. Researchers have used convolutional networks for these tasks and explored various approaches to enhance network learning. Batch normalization is one technique that improves network stability and accuracy. This study aimed to evaluate machine learning for identifying and counting pirapitinga Piaractus brachypomus fry with different batch sizes. The researchers used one thousand photographic images of Pirapitinga fingerlings, labeled with bounding boxes. They trained the adapted convolutional network model with batch normalization layers added at the end of each convolution block. They set the training to one hundred and fifty epochs and tested batch sizes of 5, 10, and 20. Furthermore, they measured network performance using precision, recall, and mAP@0.5. Models with smaller batch sizes performed less effectively. The training with a batch size of 20 achieved the best performance, with a precision of 96.74%, recall of 95.48%, mAP@0.5 of 97.08%, and accuracy of 98%. This indicates that larger batch sizes improve accuracy in detecting and counting pirapitinga fry across different fish densities.

This study investigated the antimicrobial effects of lactic acid (LA) (3%) and peracetic acid (PA) (300 ppm) on tilapia fillets (Oreochromis niloticus) by fogging (15 min) or by immersion (2 s) in a pool of Escherichia coli (NEWP 0022, ATCC 25922, and a field-isolated strain), Staphylococcus aureus (ATCC 25923 and a field-isolated strain), and Salmonella Typhimurium (ATCC 13311 and ATCC 14028), as well as the effects on the physicochemical characteristics of the fillets. Fogging was effective and the best application method to control S. Typhimurium regardless of the acid used, promoting reductions of 1.66 and 1.23 log CFU/g with PA and LA, respectively. Regarding E. coli, there were significant reductions higher than 1 log CFU/g, regardless of the treatment or acid used. For S. aureus, only immersion in PA showed no significant difference (p < 0.05). For other treatments, significant reductions of 0.98, 1.51, and 1.17 log CFU/g were observed for nebulized PA, immersion, and LA fogging, respectively. Concerning the pH of the samples, neither of the acids used differed from the control. However, treatments with LA, and fogging with PA, reduced the pH compared to immersion in PA. As for color parameters, L* and a* values showed changes regardless of the acid or method used, resulting in an improved perception of fillet quality. These results indicate that fogging and immersion are alternatives for reducing S. Typhimurium, E. coli, and S. aureus in tilapia fillets.

The partial substitution of maize by tropical legumes for the production of silage has aroused interest, for bringing benefits of increasing the crude protein content of corn-only silage, constituting an important alternative for the production of food in a more sustainable way. In this context, the objective of this study was to evaluate the effect of addition 30% tropical legumes on the fermentative characteristics and nutritive value of maize silage. The experimental design was entirely randomized with three replications. The treatments consisted of the following silages: Maize; Stylosanthes cv. Campo Grande, Stylosanthes cv. Bela: Pigeon pea (Cajanus cajan cv. BRS Mandarim), maize + 30% Campo Grande; maize + 30% Bela and maize + 30% Pigeon pea, totaling 21 experimental silos. The results show that exclusive legume silage without preservatives present fermentative losses that compromise the silage quality. Addition of 30% legumes to maize silage improves the nutritional quality of the silage without compromising its fermentation profile. Stylosanthes cv. Campo Grande and Bela are the most recommended locations for maize silage. Thus, a mixed silage of maize and legumes is an alternative to improve the crude protein content of exclusive maize exclusive silage, greater sustainability, and reduced fermentative losses of legume silages.

Inter-cropping between annual crops with tropical forages through integration crop-livestock systems (ICL) is considered a sustainable option to increase crop diversity and soybean productivity. In this study, we evaluated (1) the biomass production, desiccation efficiency, nutrient accumulation, and biomass decomposition of soil crop residues produced by Panicum maximum plants intercropped with maize in two different sowing methods during the second harvest and (2) investigated how soil crop residues impact the productivity of soybean. The experiment was conducted in a complete block design with three replicates. We compared conventional soybean cultivation with soybean cultivated over soil crop residues produced by a previous integration between maize and two Panicum maximum cultivars: Tamani and Zuri guinea grass, within and between rows of maize plants. Our results showed that Tamani guinea grass showed the highest desiccation efficiency. Zuri and Tamani guinea grass cultivated within and between maize plants resulted in higher biomass production and nutrient cycling potential, resulting in an increase of 28.4% in soybean productivity, compared to soybean grown without soil crop residues. We concluded that ICL system is an efficient method to increase the sustainability of soybean cultivation.

Aquaculture produces more than 122 million tons of fish globally. Among the several economically important species are the Serrasalmidae, which are valued for their nutritional and sensory characteristics. To meet the growing demand, there is a need for automation and accuracy of processes, at a lower cost. Convolutional neural networks (CNNs) are a viable alternative for automation, reducing human intervention, work time, errors, and production costs. Therefore, the objective of this work is to evaluate the efficacy of convolutional neural networks (CNNs) in counting round fish fingerlings (Serrasalmidae) at different densities using 390 color photographs in an illuminated environment. The photographs were submitted to two convolutional neural networks for object detection: one model was adapted from a pre-trained CNN and the other was an online platform based on AutoML. The metrics used for performance evaluation were precision (P), recall (R), accuracy (A), and F1-Score. In conclusion, convolutional neural networks (CNNs) are effective tools for detecting and counting fish. The pre-trained CNN demonstrated outstanding performance in identifying fish fingerlings, achieving accuracy, precision, and recall rates of 99% or higher, regardless of fish density. On the other hand, the AutoML exhibited reduced accuracy and recall rates as the number of fish increased.

Crop–livestock integration systems are efficient technologies for diversifying production and promoting agricultural sustainability. However, less is known about the triple intercropping of crops for silage production. The objective of this study was to evaluate the dry mass production, fermentation profile, and nutritive value of sorghum silage intercropped with Tamani guinea grass and Stylosanthes cv. Bela in integrated systems. We used an experimental design with randomized blocks with four replicates. The treatments consisted of silage of (1) sorghum in monocropped; (2) Tamani guinea grass in monocropped (Panicum maximum cv. BRS Tamani); (3) Stylosanthes cv. Bela in monocropped (Stylosanthes guianensis cv. BRS Bela); (4) sorghum intercropped with Tamani guinea grass; (5) sorghum intercropped with Stylosanthes cv. Bela; (6) Stylosanthes cv. Bela intercropped with Tamani guinea grass; and (7) sorghum intercropped with Tamani guinea grass and Stylosanthes cv. Bela, totaling 28 experimental silos. Our results demonstrated that intercropping sorghum with tropical forages can be utilized in integrated silage production systems. This practice led to an increase in silage mass production per unit area while also providing pasture forage after the crop harvest for silage production, ultimately enhancing land-use efficiency in a sustainable manner. Silage produced from sorghum intercropped with Tamani guinea grass and Stylosanthes cv. Bela exhibited improved fermentative characteristics, as well as higher ether extract and total digestible nutrient contents compared with silage from monocropped forages. Tropical forages contributed to an increase in the crude protein content of monocropped sorghum silage, which could potentially reduce costs associated with acquiring protein salts for ruminant feed supplementation. Consequently, we recommend the triple intercropping of sorghum, Tamani guinea grass, and Bela for silage production, as it offers advantages for the cultivation of annual and tropical forage crops.

Tropical legumes are used to prepare mixed silages to enrich the crude protein (CP) content. In This context, objective of this study was to evaluate the dynamics of fermentation and quality of maize silage with different levels of Pigeon pea. The experimental design was entirely randomized, with four repetitions. The treatments comprised maize silages with six levels of added Pigeon pea (0, 20, 40, 60, 80, and 100%), calculated based on natural matter. The maize hybrid and Pigeon pea varieties used were B 2800 PWU and Cajanus cajan cv. BRS Mandarin, respectively. For the silage, the maize and Pigeon pea were harvested when they reached 335.7 g kg-1 dry matter (DM) and 281.3 g kg-1 DM, respectively. The results revealed that the added of up to 40% Pigeon pea in maize silages promote nutritive increment without compromising their fermentative profile of the silage. Exclusive Pigeon pea silage (100%) undergoes fermentative losses that compromise the silage quality. Therefore, mixed silages of maize with Pigeon pea, with appropriate levels of addition, are a viable alternative to increase the nutritive value of silages, mainly the CP content, contributing to reducing the cost of acquisition of protein salts.

Na alimentação animal as dietas são formuladas visando proporcionar totais condições para os expressarem todo seu potencial produtivo contudo maior parte dos ingredientes utilizados para compor as dietas balanceadas consequentemente aumentam o custo do produto final. O objetivo desta revisão é evidenciar quais os alimentos alternativos são disponíveis em território brasileiro com potencial uso para a serem utilizados na nutrição de coelhos. Percebeu-se que os principais alimentos alternativos utilizados são glicerina bruta, casca de soja, pólen apícola, polpa cítrica desidratada, farelo de algodão e coprodutos da cana-de-açúcar. Neste sentido, a utilização destes produtos secundários proporcionam maior sustentabilidade na produção cunícula sem proporcionar influências negativas sobre o desempenho ou sobre o metabolismo destes animais, auxiliando na redução os custos de produção com alimentação.

Abstract: The objective of this work was to evaluate how the parameterization and the application of different allometric values affect the obtention of the most adequate fit of von Bertalanffy’s model, in the description of the growth curve of meat-producing mammals (bovine, pigs, rabbits, and sheep). Among the nonlinear models, von Bertalanffy’s has been very often applied in several areas, with different parameterizations. This model has been commonly used with an allometric value of m = 2/3; however, for mammals, it is believed that this value can be m = 3/4. The analyzed data referring to the mass of meat-producing mammals according to their age were obtained from research institutions and from the literature. The results showed that von Bertalanffy’s model, with the allometric value of m = 3/4 and the used parameterization, provided better adjustments to quality evaluators. Besides, the model softened the overestimation of parameter a, giving a direct interpretation of parameter b, with the lowest values for curvature measurements, mainly for the parametric ones, and provided more reliable adjustments. Von Bertalanffy’s model can be used in the description of the growth curves of meat-producing mammals.

The objective of this study was to evaluate and characterize the fish consumption profile in the town of Lavras, Minas Gerais. A descriptive-quantitative study was conducted. A structured questionnaire elaborated using previously formulated questions and answers was used for data collection. The questionnaire was applied between March and May 2014 to the household reference person. A total of 402 households were sampled. The data were analyzed by analysis of the distribution of frequencies using the SPSS program. The results showed that fish meat occupied fourth place in the preference of household consumption in the town of Lavras, after beef, poultry and pork meat. It was also observed that fish is usually purchased as fillet and is consumed occasionally in the households. The price is an important factor for the choice of meat. Most respondents prefer to consume fried fish. The species most appreciated by consumers in the town of Lavras is Dourado. Most respondents usually buy less than 2.0 kg/household/year.

The knowledge of how animals deposited chemical components as water, protein, fat and ash in the carcass is importance for the formulation of a balanced diet, allowing maximum performance with a low environmental impact. So, the study was carried out to evaluate the influence of different tilapia strains (Chitralada, Commercial, Red and Universidade Federal de Lavras [UFLA]) on the deposition of bodily chemical components in the carcass. The bodily components analyzed were water, protein, fat and ash. For the determination of the bodily chemical deposition curves by age, the exponential, Brody, logistic, Gompertz and von Bertalanffy models were adjusted. The Commercial and UFLA strains deposited water at a faster speed (P0.05) for the logistic model parameter between Red, UFLA and Commercial strains for fat, which presented a maximum fat deposition (0.23 g) at 310 days of age. Regarding ash deposition, the Commercial strain presented a higher maximum deposition (0.10 g) at 337 days, occurring later than the other strains that presented maximum deposition (0.033g) at 254 days of age. Thus, it was concluded that the genetic strains evaluated differ in chemical deposition curves of water, protein, fat and ash.

Developing a rearing technology requires the determination of the optimum stocking density. This study aimed to determine the best stocking density for Brycon orthotaenia juveniles grown in net cages, during the rearing phase. The research was conducted at the Experimental Farm of EPAMIG, in Felixlândia, Minas Gerais State, in the Três Marias Reservoir. 9,000 fingerlings were distributed into 12 net cages, 2 m3each, according to a completely randomized design with three replications and four different stocking densities (150, 300, 450, 600 fish m-3). Random samples were taken from each net cage, at the onset of the experiment and at 60 rearing days, to assess production parameters, specific growth rate and uniformity. We verified a positive linear relationship (p < 0.05) for final biomass (r2 = 0.88), weight gain (r2 = 0.87), productivity (r2 = 0.86), apparent feed conversion (r2 = 0.96) and economic viability (r2 = 0.96). For survival (r2 = 0.98), the relationship was negative (p < 0.05). There were no significant differences between treatments (p > 0.05) for growth parameters, uniformity and final weight. It can be concluded that the density of 300 fish m-3 is the most suitable, because it provides higher net revenue, survival, and a good feed conversion.

O objetivo deste estudo foi verificar o efeito de doses específicas do composto 1-metilciclopropeno (1-MCP), após a colheita, nos aspectos fisiológicos e na qualidade físico-química de maçãs Eva durante o armazenamento refrigerado. Após a aplicação dos tratamentos com diferentes doses de 1-MCP (0, 10, 50, 100 e 500mg L-1), os frutos foram armazenados em câmara fria 0,5°C (±0,5) por até 135 dias. O armazenamento refrigerado juntamente com a aplicação de 1-MCP resultou em uma menor produção de etileno, principalmente nos frutos tratados com as doses de 10, 50 e 100mg L-1. O grupo controle perdeu 45% de sua firmeza, enquanto os grupos tratados perderam, em média, 27% de sua firmeza. O parâmetro C de cor identificou frutos com cor mais intensa aos 135 dias de armazenamento e o ângulo Hue mostrou que, quando tratados com as doses de 10 e 50mg L-1, os frutos apresentaram-se mais amarelados, evidenciando melhor ação do 1-MCP em baixas concentrações. Frutos que não foram submetidos aos tratamentos apresentaram maior relação sólidos solúveis e acidez, demonstrando assim maior atividade metabólica.

O objetivo deste trabalho foi determinar a densidade de estocagem de matrinxã (Brycon orthotaenia) em tanques-rede, considerando o desempenho produtivo. Foram utilizados 5.280 juvenis de Brycon orthotaenia com peso inicial de 115,2g±5,7, os quais foram distribuídos em 16 tanques-rede de 4³m nas densidades de 45, 70, 95 e 120 peixes m-3 em quatro repetições. Os peixes foram alimentados com ração comercial de 40% de proteína bruta durante o período experimental. Os dados foram submetidos à análise de variância e à regressão linear para estimativa do melhor ajuste a 5% de probabilidade. Os parâmetros produtivos como sobrevivência, peso inicial, peso final, conversão alimentar e taxa de crescimento específico não foram influenciados pela densidade de estocagem, assim como os parâmetros de qualidade da água. Entretanto, para a variável biomassa final, ganho de biomassa e consumo de ração total, o efeito foi significativo e estas apresentaram relação linear positiva com a densidade de estocagem. Avaliando os resultados, pode-se concluir que a densidade de estocagem de matrinxã (Brycon orthotaenia) até 120 peixes m-3 é a que proporciona maior produtividade e não representa efeitos negativos sobre o desempenho dos peixes.The objective of this study was to determine the stocking density of matrinxã (Brycon orthotaenia) in cages, considering the productive performance. Juvenile Brycon orthotaenia (n = 5280) were distributed in 16 cages of 4m³ at densities of 45, 70, 95 and 120 fish m-3. The fish were fed with commercial feed with 40% crude protein during all experimental period. Data were subjected to analysis of variance and linear regression to estimate the best fit using 5% probability. The production parameters such as survival, initial weight, final weight, feed conversion and specific growth rate were not influenced by stocking density, as well as the parameters of water quality. However, final biomass, biomass gain and feed intake showed a positive linear relationship with stocking density. Evaluating these results, it was concluded that the stocking density of matrinxã (Brycon orthotaenia) up to 120 fish m-3 represent the best productive performance.

The objective of this study was to evaluate the morphometric growth and weight gain of strains of tilapia (Thai, Red, UFLA and Commercial) by nonlinear models. Initially, 500 male fingerlings of each strain, at 85 (Red and UFLA) and 86 (Thai and Commercial) days of age, were stocked separately in raceways with 56 m³. Twenty fish of each strain were randomly sampled, weighed and measured monthly. Five nonlinear models (Brody, von Bertalanffy, Gompertz, logistic and exponential) were tested, choosing one that best fit to the data. The variables studied were: weight, standard length (SL), head length (HL), height 1 (H1), height 2 (H2), height 3 (H3), first distance (D1), second distance (D2), first width (W1), second width (W2) and third width (W3). The exponential model had the best fit to weight and morphometric data, with the exception of W2, in which the best fitted model was von Bertalanffy. The convergence of the exponential model to data indicates that the cultivation period studied was not enough for the strains to reach maturity weight. The UFLA strain presented the lowest value for parameter "a" (initial weight estimate), 8.71 g, and the highest for parameter k (specific growth rate), 0.0127, when compared with other evaluated strains. However, the highest k of UFLA was not enough to overcome the final weight observed for the Commercial strain (603.1 g), which was higher than all other strains. Regarding the morphometric measurements, the UFLA strain also had the highest k for the variables SL, HL, HH, H1, H2, H3 and D2, and similar k to Commercial and Thai strains for the variables D1 and W3 respectively. The strains differ as to weight gain and morphometric growth.

The objective of this study was to verify which morphometric measures and ratios are more directly associated with the weight and body yields of rounded fish. A total of 225 specimens of rounded fish (59 pacus, 61 tambaquis, 52 tambacus and 53 paquis) with average weight of 972.43 g (±115.52 g) were sampled, stunned, slaughtered, weighed, measured, and processed for morphometric and processing yield analysis. The morphometric measures taken were: standard length (CP); head length (CC); head height (AC); body height (A1); and body width (L1). For completeness, the following morphometric ratios were calculated: CC/CP, AC/CP, A1/CP, L1/CP, CC/A1, AC/A1, L1/A1, CC/AC and L1/CC. The yields of carcass, filet, rib and filet with rib were estimated after processing. Initially, a "stepwise" procedure was performed in order to eliminate multicollinearity problems among the morphometric variables, and the phenotypic correlations were then calculated for the dependent variables (weight and body yields) and independent variables (morphometric measurements and ratios). These correlations were later deployed in direct and indirect effects through path analysis, and the direct and indirect contributions of each variable were measured in percentage terms. The CC and A1 measures were important for determining the weight of rounded fish. The CC/A1 ratio was the variable most directly associated with carcass yield. For filet, filet with rib and rib yields, the L1/CC ratio was found to be more appropriate and can be used directly.

A identificação precoce do sexo em peixes é um procedimento importante para o desenvolvimento de estratégias que facilitem o manejo no plantel de reprodutores. A endoscopia pode ser utilizada para essa identificação, embora em peixes seu uso ainda seja restrito. Diante disso, o objetivo deste trabalho foi validar o uso do endoscópio rígido via poro urogenital para determinação do sexo do catfish de canal (Ictalurus punctatus). O equipamento utilizado foi um endoscópio Multipurpose Rigid™ 30º com 2,7 mm de diâmetro e 18 cm de comprimento. Foram examinados 60 peixes com peso variando entre 86 e 1.032 gramas nos quais foi introduzido o endoscópio via poro genital e, logo em seguida, eutanaziados para confirmação do sexo. Amostras de tecido gonadal foram coletadas para avaliação histológica do estádio de maturação e confirmação do sexo. Os resultados mostraram que dos 60 peixes examinados, 57 tiveram confirmação positiva do sexo via endoscopia, o que corresponde a 95% da amostra. A utilização da endoscopia para determinação do sexo em I. punctatus via poro genital é viável.

Trinta e cinco machos de tilápia com peso médio de 205 g foram mantidos em caixas de 250 litros para avaliar o metabolismo lipídico de tilápias-do-nilo (Oreochromis niloticus). O experimento foi conduzido durante 30 dias, entre os meses de outubro e novembro de 2006. Foram avaliadas cinco dietas, cada uma contendo óleo de oliva, óleo de milho, óleo de soja, óleo de linhaça ou óleo de peixe. Utilizou-se delineamento inteiramente casualizado, com cinco tratamentos e sete repetições. Avaliaram-se a composição química, o perfil lipídico muscular e a atividade hepática de glicose-6-P desidrogenase (G6PD) e enzima málica. Os dados foram submetidos à análise de variância com médias comparadas pelo teste de Scott-Knott (5%). Não houve diferenças significativas para os teores de umidade e cinzas, porém, foram observadas alterações nos teores de lipídios e proteína nos peixes alimentados com as rações contendo óleo de oliva, milho ou soja. O fornecimento de dietas ricas em ácidos graxos poliinsaturados aumentou a composição desses ácidos graxos nos peixes. A atividade da G6PD foi superior à da enzima málica e foi mais alta nos animais alimentados com rações contendo óleos de oliva, milho ou soja, o que evidencia maior deposição lipídica muscular nesses peixes.A total of 35 males of Nile tilapia, averaging initial weight of 205 g, were maintained in five 250 L metabolism boxes to evaluate the lipid metabolism of Nile tilapias (Oreochromis niloticus). The experiment lasted 30 days, from October to November 2006. The treatments were: control diet plus olive oil; control diet plus corn oil; control diet plus soybean oil; control diet plus linseed oil; control diet plus fish oil. The experiment was in a completely randomized design with five treatments and seven replicates. The evaluated parameters were: fatty acid profile of the muscle tissue and hepatic activity of glucose-6-phosphate dehydrogenase (G6PD) and malic enzyme (ME). The data were submitted to variance analysis and the means of the treatments were compared by Scott-Knott's test (5% of significance). The fish fed on a diet rich in polyunsaturated fatty acids presented increased contents of such fat acids in their lipid muscle composition. The hepatic activity of G6PD was superior to that of ME, being higher in the specimen fed rations containing olive, corn and soybean oil, thus, evidencing the highest lipid muscle deposition of these fish.

The study was carried out with the objective of verifying which measures and morphometric ratios are more directly related to the body yield of Nile tilapia, Oreochromis niloticus, in two weight classes. Data were analyzed from 257 specimens of tilapia divided into two weight classes: p1 = 400 to 599 g and p2 = 600 to 900 g. The morphometric measurements standard length (SL), head length (HL), body height (BH) and body width (BW), and the ratios of these measures (HL / SL, BH / SL, BW / SL, HL / BH, BW / BH, BW / HL) were evaluated. The following body yields were calculated: carcass (RCAR), fillet (RFILE) and head (RCAB). The data were initially submitted to the "stepwise" procedure to eliminate problems of multicollinearity among the morphometric variables, then the correlations between the dependent variables (body yield) and the independent variables (measured and morphometric relationships) were calculated. Later, these correlations were divided into direct and indirect effects through path analysis, and the direct and indirect contributions of each variable measured in percentage terms. The morphometric ratio BW/HL, for both weight classes, was the variable most highly correlated and with the highest direct effect on RFILE and RCAB, showing to be the most important morphometric variable studied for tilapia carcass trait determination.

ABSTRACT This study aimed to evaluate the reproductive performance of female Nile tilapia (Oreochromis niloticus) fed diets containing different levels of digestible energy (DE). The fish were housed in 15 fiberglass tanks (500 L) in a recirculating system at an average temperature of 27.5 °C. The treatments consisted of five diets with increasing levels of DE (3,200; 3,400; 3,600; 3,800; and 4,000 kcal/kg). The levels of DE did not significantly influence the final weight or the hepatosomatic, gonadosomatic, and visceral fat indices. The absolute fecundity was influenced by the treatments, for which the highest values were observed from the 3,600 kcal/kg DE level and upward. The proximate composition of the fish also had a significant effect on the variables crude protein, ether extract, and ash; the fish fed diets with higher levels of DE exhibited the lowest body protein content, while the accumulation of ether extract exhibited the opposite response. A level of 3,600 kcal/kg of digestible energy should be used in diets with 380 g/kg crude protein and a starch/lipid ratio of 1.33 for female Nile tilapia.

ABSTRACT This study aimed to impute the genetic makeup of individual fishes of Serrasalmidae family on the basis of body weight and morphometric measurements. Eighty-three juveniles, belonging to the genetic groups Pacu, Pirapitinga, Tambaqui, Tambacu, Tambatinga, Patinga, Paqui and Piraqui, were separated into 16 water tanks in a recirculation system, with two tanks per genetic group, where they remained until they reached 495 days of age. They were then weighed and analyzed according to the following morphometric parameters: Standard Length (SL), Head Length (HL), Body Height (BH), and Body Width (BW). The identity of each fish was confirmed with two SNPs and two mitochondrial markers. Two analyses were performed: one for the validating the imputation and another for imputing a genetic composition of animals considered to be advanced hybrids (post F1). In both analyses, we used linear mixed models with a mixture of normal distributions to impute the genetic makeup of the fish based on phenotype. We applied the mixed models method, whereby the environmental effects were estimated by the Empirical Best Linear Unbiased Estimator (EBLUE) and genetic effects are considered random, obtaining the Empirical Best Linear Unbiased Predictor (EBLUP) from the general (GCA) and the specific (SCA) combining ability effects. The results showed that validation of the genetic makeup imputation based on body weight can be used because of the strong correlation between the observed and imputed genotype. The fish classified as advanced hybrids had a genetic composition with a high probability of belonging to known genotypes and there was consistency in genotype imputation according to the different characteristics used.