Adriano Carvalho Costa

Efeito do uso de óleo na dieta sobre a lipogênese e o perfil lipídico de tilápias-do-nilo

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-Knotts 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.

Desempenho produtivo de Brycon orthotaenia em tanques-rede sob diferentes densidades de estocagem

The objective of this study was to determine the stocking density of matrinxa (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 matrinxa (Brycon orthotaenia) up to 120 fish m -3 represent the best productive performance.

Deposition of bodily chemical components in the carcass of tilapia (oreochromis sp.) strains

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) 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.

Determinação do sexo em catfish de canal ( Ictalurus punctatus) utilizando endoscopia

A identificacao precoce do sexo em peixes e um procedimento importante para o desenvolvimento de estrategias que facilitem o manejo no plantel de reprodutores. A endoscopia pode ser utilizada para essa identificacao, embora em peixes seu uso ainda seja restrito. Diante disso, o objetivo deste trabalho foi validar o uso do endoscopio rigido via poro urogenital para determinacao do sexo do catfish de canal (Ictalurus punctatus). O equipamento utilizado foi um endoscopio 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 endoscopio via poro genital e, logo em seguida, eutanaziados para confirmacao do sexo. Amostras de tecido gonadal foram coletadas para avaliacao histologica do estadio de maturacao e confirmacao do sexo. Os resultados mostraram que dos 60 peixes examinados, 57 tiveram confirmacao positiva do sexo via endoscopia, o que corresponde a 95% da amostra. A utilizacao da endoscopia para determinacao do sexo em I. punctatus via poro genital e viavel.

Sulfated Polysaccharides in Diets for Nile tilapia (Oreochromis niloticus) in theInitial Growth Phase

This study had the objective of evaluating the performance of Nile tilapia, in initial growth phase, with the supplementation of fucoidan, extracted from brown algae, at 30 days of rearing. The experiment was conducted for a period of 30 days. We used 216 Nile tilapia fingerlings distributed in to twelve 60 liter tanks, in a completely randomized design, totalizing four treatments and tree replicates. The fingerlings were supplemented with powdered sulfated polysaccharide extract at the levels of 0%, 0.5%, 1.0% and 1.5%. During the experimental period, two samplings were performed (initial and final) to measure zootechnical performance, muscle histology and blood plasma chromatography. The data were submitted to analysis of variance at a level of significance of 5%. The performance variables muscle fiber diameter frequency and fucose plasmatic concentration were not significant among the treatments (P>0.05). It was possible to identify fucose in the blood plasma of the animals, proving its efficiency in breaking the α-(1-3) bonds of the polysaccharide, thus absorbing this component. The histological analysis showed that there was a higher percentage of hypertrophic growth of the muscle fibers, given that, in all treatments, the diameter class >50 μm prevailed (P<0.05). In conclusion, the sulfated polysaccharide fucoidan, used in diets for Oreochromis niloticus with 30 days of rearing, was not effective in increasing performance parameters and muscle growth.

69 AGE AT PUBERTY AND REPRODUCTIVE DEVELOPMENT OF LAMBS FED SUNFLOWER CAKE

The objective of this study was to evaluate the effects of lipid inclusion, represented by sunflower cake (SC), on the performance, age at puberty, ovarian follicular development, and metabolic panel of prepubertal lambs. Thirty-five crossbred Santa Ines lambs were used [initial body weight (BW) 21.5 ± 1.6 kg and age 138 ± 3 days]. Four SC inclusions were tested: 0% SC, n = 9; 15% SC, n = 9; 30% SC, n = 9; and 45% SC, n = 8, within the dry matter of the diet. The diets were offered to the lambs until they reached 43.6 ± 0.8 kg; after reaching this BW they were slaughtered. Dry matter intake and performance were analysed. The number of follicles, the diameter of the larger follicle, and the total cholesterol serum concentration were evaluated one day before slaughtering. The serum progesterone concentration was analysed every 6 days after the animals reached 30 kg. Puberty was determined when the progesterone concentration reached = 1 ng mL–1 for the first time. The animals were randomly confined in individual pens. To study the significant variable and its effects on the treatments, regression analysis was performed. The number of follicles visualised in the ovary through ultrasound and after slaughtering was analysed by Proc Genmod. Spearman correlation coefficient of the number of follicles obtained through the in vivo ultrasound technique and by the count of follicles in the ovary postmortem. SAS software was used (SAS Institute Inc., Cary, NC, USA). Daily dry matter intake (1.3 ± 0.5, 1.4 ± 0.5, 1.3 ± 0.5, and 1.3 ± 0.6 kg) and weight gain (0.19 ± 0.02, 0.23 ± 0.02, 0.19 ± 0.02, and 0.18 ± 0.02 kg) in the treatments of 0, 15, 30, and 45% of SC, respectively, presented no significant differences (P > 0.05). Total cholesterol serum concentration linearly increased (y = 73.1784 + 0.7206x), (R2 = 0.8477; P   0.05), whereas the number of follicles = 3 mm of diameter was correlated (r = 0.56; P  5 mm (0.5 ± 0.3, 0.7 ± 0.3, 0.8 ± 0.2, and 0.6 ± 0.3), and the diameter of the largest follicle (0.45 ± 0.03, 0.45 ± 0.04, 0.43 ± 0.03, and 0.40 ± 0.04 cm) verified through ultrasound, age at puberty (204 ± 11, 211 ± 13, 211 ± 13, 196 ± 11, 218 ± 11 days), and the weight at puberty (33.5 ± 1.5, 33.5 ± 1.7, 32.2 ± 1.5, and 33.5 ± 1.5 kg) in the treatments 0, 15, 30, and 45% SC, respectively, did not differ (P > 0.05), although the progesterone concentration presented a linear increase (y = 1.4783 + 0.02826x; P   3 mm (0.91 ± 0.2, 0.91 ± 0.2, 0.97 ± 0.2, and 0.88 ± 0.2) did not differ (P > 0.05). In conclusion, the use of SC in the lamb’s diet positively affected the progesterone concentration and the development of follicles <3 mm of diameter, which presented an optimal level at 23.4% SC inclusion.

Influence of Photoperiod over Morphometric and Hematological Parameters of Juvenile Piracanjubas (Brycon orbygnianus)

The aim of this study was to evaluate morphometric and hematological parameters of juveniles Piracanjubas treated with two distinct photoperiod. Twenty nine fish with 100 g, in a factorial design were performed in 18 h light:6 h dark (18L:6D) and 6L:18D two different photoperiod, and morphometric and hematological parameters were evaluated at 45 d and 90 d after photoperiod treatment. Benzocaine 1% was used for euthanasia. Fish were weighed and measured, so as visceral fat, liver and gonads. Hematocrit, total count of white cells, lymphocytes and neutrophils were counted. Results showed that there was no significant relationship between bodyweight and standard length. Significant interaction (P = 0.00018) had been found between the fat index (FI) and gonado-somatic index (GSI) and the photoperiod and time. At 90 d, the fish kept in 18L:6D had a lower rate of fat than the fish kept in 6L:18D (P < 0.05). The GSI was higher in the group 6L:18D compared with the 18L:6D (P < 0.005). There was no interaction between photoperiod and period of treatment for total leukocyte count, however with 90 d, the total leukocyte count was decreased (P < 0.05). Moreover, decrease of the hematocrit from 58.1% to 46.9% and an increase of lymphocytes from 31.5% to 43.5% had been found in fish kept in 18L:6D after 90 d (P < 0.05). Fish kept in 6L:18D presented an increase in segmented neutrophils and lymphocytes (P < 0.05). It is concluded that photoperiod maintained at 6L:18D for Piracanjubas permits a greater gonadal development and an amount of immune cells over the photoperiod maintained in 18L: 6D.

RENDIMENTO E COMPOSIÇÃO CORPORAL DE BRYCON ORTHOTAENIA ESTOCADOS EM TANQUES-REDE SOB DIFERENTES DENSIDADES

A ciencia sobre a composicao bromatologica do pescado no cenario mercadologico se torna imprescindivel, uma vez que o consumidor esta atento cada vez mais com o produto de melhor qualidade nutricional e com seu processamento, que ira determinar a qualidade do produto, os rendimentos e cortes comerciais. Dessa forma, o objetivo deste trabalho foi avaliar a composicao bromatologica e os rendimentos corporais de Brycon orthotaenia estocados em tanques-rede sob diferentes densidades. O experimento foi realizado em delineamento inteiramente casualizado, utilizando 5.280 juvenis, os quais foram distribuidos em 16 tanques-rede de 4m³ em quatro densidades de estocagem (45, 70, 95, 120 juvenis/m³) e quatro repeticoes. Durante o periodo experimental os peixes foram alimentados ate a saciedade aparente com racao comercial de 40% de proteina bruta. Ao final do experimento foi realizada a despesca total dos tanques-rede, sendo os peixes insensibilizados por meio da seccao da medula. Em seguida, 10% dos peixes de cada tanque-rede foram pesados e dessecados para obtencao dos rendimentos corporais, e moidos para o estudo da composicao bromatologica. Os dados obtidos foram submetidos ao teste de Lilliefors para verificacao da normalidade. Posteriormente, os dados foram submetidos a analise de variância e regressao linear, optando-se pela equacao de melhor ajuste aos dados. Nao foram observadas diferencas significativas entre os tratamentos para o rendimento corporal e composicao bromatologica. Avaliando os resultados, pode-se concluir que a densidade de estocagem de Brycon orthotaenia ate 120 peixes/m³, nao representou efeitos negativos sobre o rendimento corporal e composicao bromatologica dos peixes.

1-MCP nos aspectos fisiológicos e na qualidade pós-colheita de maçãs Eva durante o armazenamento refrigerado

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.