1000 resultados para Bovino de corte - Melhoramento genético - Crescimento
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Este estudo visou avaliar a variabilidade e distância genética dentro de uma população-base de melhoramento genético de Eucalyptus grandis. A avaliação da variabilidade genética tem como objetivos principais analisar a base genética da população-base e montar um banco de dados marcadores moleculares da população em análise. Essa população é formada por 327 indivíduos, principalmente das procedências de Coff's Harbour, Atherton e Rio Claro. Devido à heterozigosidade natural dessa população, ela pode ser dividida em diversas subpopulações, de acordo com a latitude e longitude de origem; e dentro de subpopulações, em função do grau de melhoramento genético já realizado do material analisado no Brasil. Isso permitiu avaliar quanto da variabilidade detectada dentro da população-base foi devido a esses fatores: procedência e grau de melhoramento. A aplicação da técnica RAPD permitiu avaliar 70 locos polimórficos, que foram analisados utilizando-se o coeficiente de Jaccard, o que resultou em matrizes de similaridade genética entre os indivíduos. Os dados de similaridade genética posteriormente foram submetidos à análise estatística. Osdados indicaram que a população-base apresenta ampla base genética, com média de similaridade genética de 0,328. O subgrupo denominado Região 3, composto por material selvagem da macrorregião de Atherton, juntamente com material de APS da macrorregião de Coff's Harbour, foi um dos que mais contribuíram para a ampla base genética da população-base. Foi possível detectar diferença estatística entre as populações selvagens das procedências de Atherton e Coff's Harbour, assim como entre essas procedências e a de Rio Claro.
Resumo:
Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff) agente causal da murcha-de-curtobacterium em feijoeiro (Phaseolus vulgaris), é um patógeno vascular de difícil controle. A doença foi detectada pela primeira vez no Brasil na safra das águas de 1995, no Estado de São Paulo. Por se tratar de uma doença de difícil controle, a resistência genética tem sido a melhor opção. O objetivo deste trabalho foi avaliar a reação de genótipos de feijoeiro à murcha-de-curtobacterium, frente a 333 acessos pertencentes ao banco de germoplasma de feijoeiro do Instituto Agronômico de Campinas (IAC). Oportunamente, foram selecionados genótipos de feijoeiro altamente resistentes e suscetíveis, com a finalidade de comparar a colonização de Cff no vaso do xilema a partir da visualização sob microscopia eletrônica de varredura. Os resultados da triagem da resistência genética em genótipos de feijoeiro indicaram a existência de variabilidade genética nas amostras dos 333 genótipos avaliados, ao isolado de Cff Feij 2634. Os materiais foram classificados em 4 grupos de resistência: 29 genótipos (8,7%) comportaram-se como altamente resistentes, 13 genótipos (3,9%) como resistentes, 18 genótipos (5%) como moderadamente resistentes e 273 genótipos (81%) suscetíveis. A partir dos resultados obtidos, cerca de 18% dos genótipos de feijoeiros, desde altamente resistentes à moderadamente resistentes, poderão ser úteis para o programa de melhoramento genético como fonte de genes para resistência a Cff. Através da microscopia eletrônica de varredura, foram observadas em genótipos altamente resistentes, várias aglutinações da bactéria envolvidas por filamentos e estruturas rendilhadas sob pontuações da parede do vaso do xilema, não verificados em genótipos suscetíveis, o que sugere a ativação de mecanismos de defesa estruturais e bioquímicos nas plantas resistentes.
Resumo:
Devido a grande importância da cultura de Eucalyptus no Brasil, empresas do setor florestal têm buscado através de programas de melhoramento genético, reduzir as perdas de produção e atender a demanda do mercado de papel e celulose. Um exemplo, é a busca por genes de resistência a doenças, principalmente a ferrugem causada por Puccinia psidii Winter, que resulta em redução da produtividade em plantas altamente suscetíveis. No presente trabalho, mudas de Eucalyptus pertencentes a uma geração F1, provenientes do cruzamento controlado entre parentais híbridos E. grandis X E. urophylla, sendo eles resistente e suscetível, foram inoculadas com Puccinia psidii em casa de vegetação e acompanhadas até o aparecimento dos sintomas da ferrugem. Foram classificadas, em dois grupos: resistentes (ausência de sintomas) e suscetíveis (presença de sintomas e esporulação). As amostras de DNA foram comparadas com o uso de marcadores moleculares associado ao método de BSA (Bulked Segregant Analysis). O polimorfismo entre os grupos foi geneticamente relacionado ao loco que determina a característica de resistência ou sucetibilidade. Dentre os 720 primers testados, 19 foram polimórficos, porém, apenas o marcador AK 01 manteve-se presente, quando testado em todos os indivíduos da população, mostrando-se a uma distância genética estimada de 20 cM em repulsão ao gene de resistência.
Resumo:
No melhoramento genético de espécies florestais, uma população base ou indivíduos superiores pré-selecionados tem importância fundamental para a manutenção do programa. Indivíduos de melhores procedências e de ampla base genética propiciam a obtenção de ganhos de forma contínua. O objetivo deste trabalho foi avaliar a diversidade genética em duas populações-núcleo de Eucalyptus grandis. Foram avaliados 39 indivíduos, sendo 19 pertencentes à população 1 e 20, à população 2, utilizando-se 14 primers microssatélite. Os fragmentos foram identificados e analisados a partir dos programas GeneScan e Genotyper, utilizando-se um sequenciador automático ABI Prism 3100. O número de alelos encontrados para cada primer variou de cinco a 15 para a população 1 e, de 8 a 18 para a população 2. A heterozigosidade estimada foi maior na população 2, 0,869, contra 0,843 na população 1. A média da distância genética entre os indivíduos da população 1 foi 0,6220 e na população 2 foi 0,6112. Com a caracterização molecular dos indivíduos destas populações foi construído um banco de dados que permitirá, a partir dos parâmetros de genética de populações, monitorar esses programas de melhoramento em diferentes ciclos de seleção.
Resumo:
Brazil is one of the major centers of diversity for polyploid cotton plants; these plants belong to the genus Gossypium, which has three known species: G. hirsutum, G. barbadense and G. mustelinum. The Northeast is the only region where the three species occur, the last group being endemic. Northeast s cotton plants can be important sources of variability for genetic breeding. It is believed that great part of local diversity is being lost, due to economic, political, cultural and agricultural problems. In an attempt to mitigate this loss and delineate conservation strategies it is necessary to know how the species are found where they occur. The objective was to characterize and determine how plants are maintained in situ in the states of Maranhão, Piauí, Ceará, Rio Grande do Norte and Paraíba at the beginning of the XXI century. The in situ characterization of G. hirsutum and G. barbadense was conducted through structured interviews with the cotton plants owners and through the analysis of the environment. The data were collected during expeditions undertaken between the years 2004 to 2005. Twenty-two plants were collected in the state of Paraíba, forty-four in the state of Rio Grande do Norte, one hundred and forty-six in the state of Ceará, forty in the state of Maranhão and ninety-one plants in the state of Piauí. All plants collected in the states of Paraíba and Rio Grande do Norte belonged to moco type. Moco cotton plants also predominated in the other states, representing 92%, 62% and 78% of plants collected in Ceará, Piauí and Maranhão, respectively. The other cotton plants collected belong to the species G. barbadense. The cotton plants were found in situ as dooryard plants, roads side, feral populations, cultivation or local varieties. Great part were dooryard plants (45.2%), being major in Piauí and Maranhão. Cultivation predominated in Ceará; in Rio Grande do Norte feral populations were the most frequent and, in Paraíba, local varieties. The maintenance of moco plants is related, mainly, to the phytotherapic domestic use (20.9%) and to confection of lamp wicks (29.7%). Few inhabitants in Paraíba, Rio Grande do Norte, Piauí and none in Maranhão used harvest the plants, storage the seeds or gin; however, in Ceará, 40.5% of owners affirmed that they harvested and commercialized the fiber. It was found that the maintenance of species is dependent of the fragile cultural habits of local inhabitants, therefore the maintenance in situ is not a suitable way to conservation of genetic resources. The efforts must be directed to the continuity of collections, maintenance and characterization ex situ
Resumo:
We analyzed the quality of raw milk from eight dairy farms in Rio Grande do Norte stored in a cooling tank , in order to evaluate methods for determining somatic cell counts (SCC). The Somaticell® kit and a portable Direct Cell Counter (DCC) were compared with each other and with the MilkoScanTM FT+ (FOSS Denmark), which uses Fourier Transform Infrared (FTIR) spectroscopy). Direct cell counter data were processed for somatic cell scores (log-transformed somatic cell count) and analyzed with the SAS®, statistical package , Statistical Analysis System, (SAS, INSTITUTE, 1998). Comparison of means and correlation of somatic cell scores were conducted using Pearson s correlation coefficient and the Tukey Test at 1 %. No significant difference was observed for comparison of means. The correlation between somatic cell scores was significant, that is, 0.907 and 0.876 between the MilkoScanTM FT+ and the Somaticell® kit and Direct Cell Count (DCC) respectively, and 0.943 between the Somaticell® kit and Direct Cell Count (DCC). The methods can be recommended for monitoring the quality of raw milk kept in a cooling tank in the production unit
Resumo:
The aim of this study was to evaluate and characterize phenotypically goats with different levels of resistance to gastrointestinal nematodes. For a period of 93 days, 60 F2 goats originated from ½ Saanen and ½ Anglo- nubian animals were kept in the same area of pasture. Every seven days, feces and blood were collected for eggs per gram counts of feces (EPG) and cultures of feces and to determinate the number of eosinophils, packed cell volume and total plasma protein, respectively. On the same day, the animals were weighed and submitted to body score condition and FAMACHA method to worm control. Based on the average of EPG, the twelve animals with the highest average (susceptible group) and the twelve animals with the lowest average of EPG (resistant group) were selected, slaughtered and necropsied to recovery, counting andparasites identification. The resistant animals present lower EPG mean (P <0.0001) and 4.7 folder less parasites than susceptible animals. The resistant group presented higher mean packed cell volume (26.48%) and total plasma protein (6.24 g / dl) than susceptible one (24,04% e 5,82g/dl, respectively). The average number of eosinophils was similar in both groups The Haemonchus sp. was the most prevalent in the culture of feces, followed by Trischostrongylus sp. and Oesophagostomum sp.. The counting of nematodes in the abomasum of susceptible group was higher than in resistant one. The species identified were H. contortus in abomasums and T. colubriformis in small intestine. It can be concluded that EPG, packed cell volume and total plasma protein were useful phenotypic markers to identify animals as resistant and susceptible to gastrointestinal nematodes infections
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Resumo:
The objective of this study was to identify DNA polymorphisms at the genes leptin, β-lactoglobulin and pituitary-specific transcription factor in three genetic groups of Holstein x Guzerat dairy cows and investigate the relationship between their genotypes and the composition and quality of milk of dairy cows. Samples were collected in August 2009, being 113 blood samples from lactating crossbred cows and 58 milk samples. For analysis of DNA polymorphisms blood samples were collected, analyzed later in the Genetic Laboratory affiliated to the Zootechny Institute of São Paulo and individual milk samples were collected according to standards established by the laboratory of Management Program of Northeast Dairy Herds (PROGEN), at Federal Rural University of Pernambuco (UFRPE) for analysis of milk composition and quality. The characterization of genotypes was performed by PCR-RFLP, for which were designed specific primers for each studied gene and restriction enzymes Kpn2I, HaeIII and HinfI that cut the DNA of the following genes: leptin, β-lactoglobulin and a PIT, respectively. The leptin estimate genotypic frequence were CC 0.112, TT 0.225 and CT 0.661, for β-lactoglobulin were AA 0.136, AB 0.323 and BB 0.539, and for PIT were ++ 0.655, -- 0.311 and +- 0.032. The results show that the population is in Hardy-Weinberg disequilibrium for leptin, β-lactoglobulin and a PIT due to excess of heterozygotes in the population, however, as these genes are associated with the milk production it is considered that the animals have genetic potential for milk production in the Brazilian semi-arid conditions. Through the characterization of the studied herd there were not found implications of the polymorphism of leptin, β-lactoglobulin and PIT in the composition and quality of milk from cows in the different genetic groups 1/2, 3/4 and 7/8 Holstein x Guzerat. Key words: β-lactoglobulin, crossbred cows, leptin, PCR-RFLP, PIT1, semi-arid.
Resumo:
The present study was conducted to evaluate the intake and digestibility of diets containing increasing levels of byproduct of cashew in sheep. The animals were distributed in a completely randomized design were evaluated in four levels (0%, 20%, 40%, 60%) by product of cashew with four replicates, making up 16 observations. The indicator used was the Purified Lignin and Enriched - LIPE ®. The scorer was orally administered directly into the mouth of the animals, in the form of capsules 250mg/animal/dia for a period of two days and five days of adaptation samples being the same supplied with the aid of a hose polyethylene and a device allowing the release of the capsule in the esophagus of sheep. With the estimate made by the indicator LIPE was observed a reduction for DM, OM, CP, NDF, EE, NFC and MM along the inclusion of byproduct of cashew. The results of nutrient digestibility were not satisfactory with the inclusion of byproduct of cashew, reducing linearly with the inclusion of the diets. The use of increasing levels of byproduct of cashew in the diets of sheep did not provide satisfactory results, it is not feasible to use the animals studied in this experiment
Resumo:
This study aimed to evaluate the performance and profitability of Canindé goats kept under semi-intensive management in mix farming system. 84 animals were used, being 81 does e three bucks.. The means of fertility rate at parturition, prolificacy and percentages of pregnant, kid survival and reproductive rate were compared by Tukey test at significance level of 5.0%. The kid weights from birth to weaning were submitted to variance analysis considering sex and birth type and the means were compared by Tukey test at 5.0% of significance. The percentages of fertility rate by ultrassographic were 91.36 and parturition 74.84. The prolificacy was 1.53. Independently of sex the mortality rate of kids from birth to weaning was 12.3. The average weights of offspring were 2.11 and 1.92 kg and 6.74 and 6.84 kg for male and female offspring at birth and weaning, in this order. The average weights of kids, meaning PN, P28, P56, P63, in the first season of kidding were 2.11 ± 0.46 kg, 3.63 ± 1.04 kg, 5.96 ± 158 kg and 6.74 ± 1.79 kg. There was significant differences (P<0,05) only to birth weight of kids sons of buck 135. However, the fertility at parturition for first and second breeding seasons (BS) were 87.65 and 62.96, respectively (P<0.05). The prolificacy was 1.58 and 1.47 to first and second BS in this order. The percentages of offspring survival from birth to weaning, to first and second BS were 92.86 and 80.00, respectively. From the first BS the reproduction rate was 1.28 while in the second was 0.74. After weaning the duration of lactation was 104 days to first breeding parturition and 38 days in the second one. The total milk production was 853.50 kg. The kids weight gain was influenced by season of year, wet and dry and buck (P<0.05). Were concluded that the seasons of year when breeding season and parturition occur strongly affected the productive performance and profitability of production system
Resumo:
The control of gastrointestinal nematodes of small ruminants is usually done with anthelmintics. However, due to the emergence of ever-increasing parasite resistance to these drugs, looking up an alternative control parasites. One of this is sought in pasture management, as these are the sources of animals` infection by L3 infective larvae of helminths. The aim of this study was to evaluate the performance of sheep to natural infections by gastrointestinal nematodes grazing Panicum maximum cv. Massai and cv. Aruana, and Brachiaria brizantha cv. Piatã and cv. Marandu. The work was conducted from May to August-2011 with 48 male sheeps SRD versus Santa Inês breed. The animals were naturally infected with gastrointestinal nematodes, and maintained in four different cultivars of tropical forage grasses, naturally contaminated with eggs and larvae of gastrointestinal nematodes. Each week the animals were phenotypically characterized by parasitological examinations (eggs per gram of feces - EPG, and feces culture), hematological (packed cell volume PCV, and blood eosinophil count) method to evaluate the Famacha© colorof ocular mucosa, and the measures of body condition score and weight. In pastures was made the recovery of infective larvae in order to determine the quantity of L3 present in the pasture. The experimental design was a randomized completed block with two replications and before the entry of animals in the paddocks, they have been wormed. The experiment was ended when the animals reached 32.0 kg liveweight, and then were slaughtered and autopsies performed for the recovery and identify parasites of the abomasum, small intestine and large intestine. Results were subjected to analysis of variance, t test and Tukey`s test. The animals kept on pastures of Marandu grass had lower EPG counts, higher percentage of packed cell volume and higher average weight; those who remained in the Piatã pasture had lower eosinophil counts per microliter of blood. About the Famacha©, the highest prevalence was Famacha 2, and the body condition score ranged between 2 and 3. The results of feces cultures and recovery of larvae on pastures showed the presence of larvae of Trichostrongylus sp., and at the necropsy too. This way, it was concluded that the grass cultivars influences the sheep parasite load; the Famacha, together with EPG and packed cell volume are important indicators for use in controlling gastrointestinal nematode infections. The Trichostrongylus sp. was the most prevalent parasite in sheep during the rainy season
Resumo:
The main specie of marine shrimp raised at Brazil and in the world is Litopenaeus vannamei, which had arrived in Brazil in the `80s. However, the entry of infectious myonecrosis virus (IMNV), causing the infectious myonecrosis disease in marine shrimps, brought economic losses to the national shrimp farming, with up to 70% of mortality in the shrimp production. In this way, the objective was to evaluate the survival of shrimps Litopenaeus vannamei infected with IMNV using the non parametric estimator of Kaplan-Meier and a model of frailty for grouped data. It were conducted three tests of viral challenges lasting 20 days each, at different periods of the year, keeping the parameters of pH, temperature, oxygen and ammonia monitored daily. It was evaluated 60 full-sib families of L. vannamei infected by IMNV in each viral challenge. The confirmation of the infection by IMNV was performed using the technique of PCR in real time through Sybr Green dye. Using the Kaplan-Meier estimator it was possible to detect significant differences (p <0.0001) between the survival curves of families and tanks and also in the joint analysis between viral challenges. It were estimated in each challenge, genetic parameters such as genetic value of family, it`s respective rate risk (frailty), and heritability in the logarithmic scale through the frailty model for grouped data. The heritability estimates were respectively 0.59; 0.36; and 0.59 in the viral challenges 1; 2; and 3, and it was also possible to identify families that have lower and higher rates of risk for the disease. These results can be used for selecting families more resistant to the IMNV infection and to include characteristic of disease resistance in L. vannamei into the genetic improvement programs
Resumo:
Given the significant share of food costs of poultry production, it is necessary to use strategies and techniques to maximize the utilization and biological value of the components of the diets, keeping constant or improving animal performance. In this context, seeking partial substitution of corn and the best use of the constituents of the diet, the present study aimed to evaluate the effects of inclusion of cashew pomace dehydrated (BCD) and enzyme complex (EC) in the diet on performance and quality eggs of Japanese quails. A total of 200 Japanese quail at 87 days of age, in 25 cages in a completely randomized design in a factorial 2 x 2 + 1 (two levels of cashew bagasse x two levels of enzymes) + control diet without cashew bagasse totaling five treatments with five replicates of eight birds each repetition. The experiment lasted 84 days, divided into four periods of 21 days. The treatments consisted of T1-Ration Control, T2-ration with 7.5% without EC BCD, T3-ration with 7.5% BCD with CE, T4-Ration with 15% BCD without EC and T5-Feed with 15% of BCD with EC. The enzyme complex (EC) is used fermentation product of Aspergillus niger, and cashew bagasse was obtained from the juice industry, passed through drying and crushing process for producing the bran. The performance and egg quality of quails, and performance variables: feed intake (FI), feed conversion ratio per dozen eggs (CAKDZ) and egg mass (CAMO), egg production (OP% bird / day), average egg weight (PMO) and egg mass (MO), and variables were egg quality, specific gravity (SG), Haugh unit (HU), yolk index, and the relationships between components eggs (%albumen,% yolk and %shell). Data were analyzed with the Statistical SAEG (2007). The 7.5 and 15% of cashew bagasse, independent of the enzyme complex decreased feed intake and improved the average egg weight. The two levels with the addition of EC showed significant differences for feed conversion by egg mass. The 7.5 with the addition of enzyme complex obtained the lowest average feed conversion per dozen eggs. The inclusion of up to 15% of cashew bagasse dehydrated with or without addition of enzyme complex in the diet of Japanese quails not interfere in the internal and external quality of eggs. The 7.5 and 15% BCD without added enzyme complex gave better means for specific gravity. Under conditions in which the experiment was conducted, it can be stated that the inclusion of up to 15% of cashew bagasse dehydrated with added enzyme complex feeding quail is economically viable, with the level of 7.5% with the addition of complex enzyme presented the best economic indices