Resumo: O objetivo desde trabalho foi avaliar como a parametrização e a aplicação de diferentes valores alométricos afetam a obtenção do ajuste mais adequado do modelo de von Bertalanffy, na descrição da curva de crescimento de mamíferos produtores de carne (bovinos, porcos, coelhos e ovelhas). Entre os modelos não lineares, o de von Bertalanffy tem sido frequentemente aplicado em diversas áreas, com diferentes parametrizações. Em geral, esse modelo tem sido utilizado com um valor alométrico de m = 2/3; no entanto, para mamíferos, acredita-se que o valor possa ser m = 3/4. Os dados analisados quanto à massa dos mamíferos de corte de acordo com a sua idade foram obtidos de instituições de pesquisa e da literatura. Os resultados mostraram que o modelo de von Bertalanffy, com o valor alométrico de m = 3/4 e com a parametrização utilizada, forneceu melhores ajustes aos avaliadores de qualidade. Além disso, o modelo suavizou a superestimativa do parâmetro a, o que possibilitou interpretação direta ao parâmetro b, com menores valores das medidas de curvatura, principalmente as paramétricas, e forneceu ajustes mais confiáveis. O modelo de von Bertalanffy pode ser utilizado na descrição da curva de crescimento de mamíferos produtores de carne.

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.

Abstract The study aimed at investigating the anatomic and DNA content characteristics of 12 Anthurium genotypes. A large genomic amplitude was observed in the genotypes, ranging from 4.95 to 22.74 pg of DNA. Differences in DNA content, assessed by flow cytometry, allowed the differentiation between the genotypes A. andraeanum, A. affine, A. bomplandii, and A. gracile and the hybrid (A. lindmanianum × A. guianesis) and clustered the group A. raimundii, plowmanii and jemanii of IFT 258, in all analyses. Anatomical studies clustered the genotypes A. andraeanum (Astral and Rubi) and distinguished the hybrid and A. bomplandii from the other genotypes, with anatomical features specific to each genotypes. Cluster analysis allowed grouping of the genotypes A. raimundii and A. affine, bomplandii and gracile, A. jemanii and plowmanii, and the cultivars Astral and Rubi, and isolated the hybrid. Demonstrated the importance of grouping in the diagnosis of species belonging to the genus Anthurium.

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.

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.

O conhecimento de como os animais depositam componentes químicos como água, proteína, gordura e cinzas na carcaça é importante para a formulação de uma dieta equilibrada, permitindo o máximo desempenho com baixo impacto ambiental. Logo, o trabalho foi conduzido, com o objetivo de avaliar a influência de diferentes linhagens de tilápia sobre a deposição de componentes químicos na carcaça. Os componentes corporais analisados foram água, proteína, gordura e cinzas. Para a determinação das curvas de deposição química corporal em função da idade foram ajustados os modelos exponencial, Brody, logístico, Gompertz e vonBertalanffy. Houve ajuste apenas do modelo exponencial para a água, tendo as linhagens UFLA e Comerciais as que depositaram numa velocidade mais rápida (P<0,05) em relação às demais linhagens. Quanto à proteína, a linhagem Vermelha foi a que teve menor peso à maturidade, estimado (49,37g) e foi mais precoce quanto à deposição máxima em relação as outras linhagens (Chitralada, UFLA e Comercial), no qual obtiveram peso a maturidade estimada em 231,5g e deposição máxima aos 337 dias de idade. Não houve diferença (P>0,05) dos parâmetros do modelo logístico entre as linhagens Vermelha,UFLA e Comercial para extrato etéreo, sendo a deposição máxima (0,23 g) aos 310 dias de idade. Em relação à deposição de cinzas, a linhagem Comercial teve maior deposição máxima (0,10 g) e, aos 337 dias de idade, sendo mais tardia em relação as outras linhagens que obtiveram deposição máxima de 0,033 g, aos 254 dias de idade. Portanto, conclui-se que as linhagens genéticas avaliadas diferem quanto às curvas de deposição química de água, proteína, extrato etéreo e cinzas.

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 (P<0.05) compared with the remaining strains. As for protein, the Red strain had a lower estimated maturity weight (49.37 g), and was more precocious (202 days) with regard to maximum deposition in comparison to the other strains (Chitralada, UFLA and Commercial) in which there was an estimated maturity weight of 231.5 g and maximum depositionfor 337 days. There were no differences (P>0.05) 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.

Para o desenvolvimento de uma tecnologia de cultivo é necessária a determinação da densidade de estocagem ideal. Objetivou-se determinar a melhor densidade de estocagem para juvenis de Brycon orthotaenia, cultivados em tanques-rede, durante a fase de recria. A pesquisa foi conduzida na Fazenda Experimental da Epamig, em Felixlândia, Estado de Minas Gerais, na represa de Três Marias. Foram utilizados 9.000 alevinos, distribuídos em 12 berçários com 2 m³ em tanques-rede, seguindo o delineamento inteiramente casualizado, com três repetições e quatro diferentes densidades de estocagem (150, 300, 450, 600 peixes m-3). Amostras aleatórias de cada tanque-rede foram coletadas para as avaliações, no início do experimento e aos 60 dias de cultivo. Foram estimados os parâmetros produtivos, índice de crescimento específico e uniformidade. Obteve-se uma relação linear positiva (p < 0,05) para biomassa final (r² = 0,88), ganho de peso da biomassa (r² = 0,87), produtividade (r² = 0,86), conversão alimentar aparente (r² = 0,96) e para viabilidade econômica (r² = 0,96). Para sobrevivência (r² = 0,98), a relação linear foi negativa (p < 0,05). Não houve diferença significativa entre os tratamentos (p > 0,05) para os parâmetros de crescimento, uniformidade e peso final. Conclui-se que a densidade de 300 peixes m-3 é a mais indicada, pois, proporciona maior receita líquida, sobrevivência e boa conversão alimentar.

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 m³ each, 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.

The objective of this study was to investigate the effect of specific doses of the compound 1-methylcyclopropene (1-MCP), after harvest, on the physiological and physicochemical quality of apples Eva during refrigerated storage. After applying thetreatment with different doses of 1-MCP (0, 10, 50, 100 and 500mg L-1), fruit were stored in cold 0.5°C (±0.5) for up to 135 days. The cold storage with the application of 1-MCP resulted in a lower production of ethylene in fruits treated with doses of 10, 50 and 100mg L-1. The control group lost 45% of its firmness, while the treated groups lost on average 27% of their firmness the parameter C fruit color identified with a more intense color to the 135 days of storage and Hue angle showed that when treated with doses of 10 and 50mg L-1, fruit showed more yellow, evidenced best action of 1-MCP at low concentrations. Fruit that have not undergone the treatments showed a higher ratio of soluble solids and acidity, thus demonstrating increased metabolic activity.

O estudo foi realizado com o objetivo de verificar quais medidas e razões morfométricas estão mais diretamente relacionadas com os rendimentos corporais da tilápia do Nilo, Oreochromis niloticus, em duas classes de peso. Foram analisados os dados de 257 exemplares de tilápia divididos em duas categorias de peso: p1 = 400 a 599 g e p2 = 600 a 900 g. As medidas morfométricas comprimento padrão (CP), comprimento da cabeça (CC), altura do corpo (AC) e largura do corpo (LC), e as razões entre estas medidas (CC / CP, AC / CP, LC / CP, LC / CC, LC / AC, CC / AC) foram avaliadas. Os rendimentos corporais calculados foram: carcaça (RCAR), filé (RFILE) e cabeça (RCAB). Os dados foram inicialmente submetidos ao procedimento 'stepwise' para eliminar os problemas de multicolinearidade entre as variáveis morfométricas, em seguida, as correlações entre as variáveis dependentes (rendimentos corporais) e as variáveis independentes (medidas e razões morfométrica) foram calculados. Posteriormente estas correlações foram desdobradas em efeitos diretos e indiretos por meio de análise de trilha e as contribuições diretas e indiretas de cada variável foram quantificadas percentualmente. A razão morfométrica LC / CC, para ambas as classes de peso, foi a variável mais altamente correlacionada e com o maior efeito direto sobre RFILE e RCAB, mostrando ser a variável morfométrica estudada mais importante para determinação das características de carcaça da tilápia.

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.

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.

Sex identification in fish is an important practice for the development of broodstock management strategies. Endoscopy can be used for sex identification, although in fish, it is still restricted. Therefore, the objective of this study was to validate the use of rigid endoscope via the urogenital pore to determine the sex of the catfish (Ictalurus punctatus afinesque, 1818). The equipment used was a Multi-Purpose Rigid ™ 30º endoscope, with 2.7 mm in diameter and 18 cm in length. We examined 60 fish weighing between 86 and 1032 grams, in which the endoscope was introduced via the genital pore and then immediately euthanized to confirm the sex. Gonadal tissue samples were collected for histological assessment of maturation stage and sex confirmation. The results showed that of the 60 fish examined, 57 had positive sex confirmation by endoscopy, corresponding to 95% of the sample. The results show that it is feasible the use of endoscopy for sex determination in catfish via genital pore.

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.