Biodiversity studies are more efficient when large numbers of breeds belonging to several countries are involved, as they allow for an in-depth analysis of the within- and between-breed components of genetic diversity. A set of 21 microsatellites was used to investigate the genetic composition of 24 Creole goat breeds (910 animals) from 10 countries to estimate levels of genetic variability, infer population structure and understand genetic relationships among populations across the American continent. Three commercial transboundary breeds were included in the analyses to investigate admixture with Creole goats. Overall, the genetic diversity of Creole populations (mean number of alleles = 5.82 ± 1.14, observed heterozygosity = 0.585 ± 0.074) was moderate and slightly lower than what was detected in other studies with breeds from other regions. The Bayesian clustering analysis without prior information on source populations identified 22 breed clusters. Three groups comprised more than one population, namely from Brazil (Azul and Graúna; Moxotó and Repartida) and Argentina (Long and shorthair Chilluda, Pampeana Colorada and Angora-type goat). Substructure was found in Criolla Paraguaya. When prior information on sample origin was considered, 92% of the individuals were assigned to the source population (threshold q ≥ 0.700). Creole breeds are well-differentiated entities (mean coefficient of genetic differentiation = 0.111 ± 0.048, with the exception of isolated island populations). Dilution from admixture with commercial transboundary breeds appears to be negligible. Significant levels of inbreeding were detected (inbreeding coefficient > 0 in most Creole goat populations, P < 0.05). Our results provide a broad perspective on the extant genetic diversity of Creole goats, however further studies are needed to understand whether the observed geographical patterns of population structure may reflect the mode of goat colonization in the Americas.

RESUMO -Objetivou-se com este trabalho verificar a utilização de 27 microssatélites para caracterização genética das raças caprinas nativas do Brasil. Foram coletadas amostras de pêlos de 332 animais das raças Moxotó (60), Canindé (50), Serrana Azul (55), Marota (68), Repartida (52) Genetic characterization of Brazilian native breeds of goats using 27 markers microsatellitesABSTRACT -This study aimed to evaluate 27 microsatellites for genetic characterization of Brazilian native goats using samples of hair collected from 332 animals of the Moxotó, Canindé, Serrana Azul, Marota, Repartida and Graúna breeds.Twenty-seven microsatellites were selected, amplified by polymerase chain reaction (PCR). The amplified products were submitted to electrophoreses in poliacrylamide gel using an ABI 377XL automatic sequencer. The number of alleles ranged between three (MAF209) and twenty-three (CSSM66). Averages of expected and observed heterozigosity were respectively 0,672 and 0,582. Except for the marker MAF209 (PIC: 0,042), all the analyzed microsatellites were informative. The polymorphism of all microsatellites indicate their hability in identifying genetic variability of Brazilian native breeds of goats.Key Words: goats, genetic conservation, molecular markers, genetic variability IntroduçãoAs raças caprinas nativas do Brasil estão localizadas na Região Nordeste, onde os animais são criados em sistemas extensivo e semi-extensivo para produção de carne, pele e leite. São animais bem adaptados à região semi-árida e resistentes a doenças e parasitas. Porém, são poucos os trabalhos realizados com esses animais, ameaçados de extinção. Para minimizar esse problema, um programa de conservação foi estruturado e uma de suas prioridades é o estudo da caracterização genética desses patrimônios genéticos.Segundo Gama (2004), a variabilidade genética total das espécies é representada pela contribuição das variabilidades inter e intra-raciais. Verifica-se, portanto, a importância de se medir a variabilidade genética dos animais, visto que a conservação dos recursos genéticos está efetivamente relacionada à manutenção das variabilidades inter-racial (evita a extinção das raças) e intra-racial (evita a erosão genética).A caracterização genética com o uso de marcadores moleculares tem demonstrado ser uma ferramenta eficaz para quantificação da diversidade genética de animais domésticos. Os marcadores genéticos são loci que apre-

Brazilian goat breeds are believed to derive mainly from animals brought by Portuguese settlers since the 16th century. We used microsatellite markers in a sample of 436 animals to study genetic variability and differentiation of the six Portuguese (PT) and six Brazilian (BR) goat breeds currently recognized in the two countries. These breeds were also compared with an outgroup represented by a sample of Alpine (ALP) goats. The effective number of alleles and allelic richness were slightly higher in PT than in BR breeds. The global F(ST) was nearly 0.11 when PT and BR breeds were considered, with a mean pairwise F(ST) of about 0.03 among PT breeds, 0.07 among BR breeds and 0.15 between PT and BR breeds. The dendrogram illustrating relationships between populations and the correspondence analysis indicate the existence of two very distinct clusters, corresponding to the countries of origin of the breeds studied, which are nearly equidistant from the Alpine outgroup. The analysis with structure confirmed the separation between PT and BR breeds but suggests that some BR breeds, especially Graúna and Canindé, may share a common ancestry with PT breeds. The divergence observed between PT and BR breeds may result from founder effects and genetic drift but could also reflect the introduction in Brazil of goats originating from other regions, e.g., West Africa.

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RESUMO. Este estudo objetivou avaliar os custos de produção, receitas e rentabilidade da atividade leiteira de seis sistemas de produção de leite bovino no Cariri paraibano. Foi objetivo, também, identificar os componentes que exerceram maior influência sobre os custos finais da atividade por meio dos resultados econômicos e indicadores técnicos de desempenho econômico. Para a realização das análises econômicas, os produtores foram divididos em dois grupos, em função do vínculo com a Cooperativa, sendo sócios e nãosócios. A receita bruta da atividade foi suficiente para cobrir os custos operacionais efetivos e totais nas propriedades 1, 2, 3 e 5. Os itens que compõem o custo operacional efetivo de produção do leite foram responsáveis por porcentuais superiores a 60% em todas as propriedades analisadas. O valor superior recebido pelo grupo de produtores sócios da Cooperativa, para o litro de leite comercializado, tem possibilitado investimentos tecnológicos na atividade e, consequentemente, aumento da produtividade nessas propriedades.Palavras-chave: bovinocultura leiteira, eficiência econômica, sistemas de produção.ABSTRACT. Economic analysis of the milk production in the cariri region of the Paraíba State. This study aimed to evaluate the costs of production, revenue and profitability of six milk production systems in Paraíba State, Brazil and to identify major variables related to the final cost of milk through the economic results and indicators of economic performance. In order to carry out the economic analysis, farmers were grouped into two clusters, depending on the link to a cooperative, i.e., members and non-members. The gross revenue was sufficient to cover total and operating costs in the farms 1, 2, 3 and 5. The items that make up the operational cost of milk production accounted for percentages above 60% in all these farms. The higher value received by the cluster of producers comprised by members of the cooperative for a gallon of milk has allowed investments in technology leading to productivity increase in these farms.