Structure and genetic relationships between Brazilian naturalized and exotic purebred goat domestic goat (Capra hircus) breeds based on microsatellites

The genetic relationships and structure of fourteen goat (Capra hircus) populations were estimated based on genotyping data from 14 goat populations (n = 410 goats) at 13 microsatellite loci. We used analysis of molecular variance (AMOVA), principal component analysis (PCA) and F statistics (F IS, F IT and F ST) to evaluate the genetic diversity (Ho, He and ad) of the goats. Genetic distances between the 14 goat populations were calculated from allelic frequency data for the 13 microsatellite markers. Moderate differentiation was observed for the populations of the undefined breeds (including the Anglo-Nubian-M breed), the naturalized Brazilian breeds (Moxotó, Canindé), the exotic purebred breeds (Alpine, Saanen, Toggenbourg and Anglo-Nubian) and the naturalized Brazilian Graúna group. Our AMOVA showed that a major portion (88.51 percent) of the total genetic variation resulted from differences between individual goats within populations, while between-populations variation accounted for the remaining 11.49 percent of genetic variation. We used a Reynolds genetic distance matrix and PCA to produce a phenogram based on the 14 goat populations and found three clusters, or groups, consisting of the goats belonging to the undefined breed, the naturalized breeds and the exotic purebred breeds. The closer proximity of the Canindé breed from the Brazilian state of Paraíba to the Graúna breed from the same state than to the genetically conserved Canindé breed from the Brazilian state of Ceará, as well as the heterozygosity values and significant deviations from Hardy-Weinberg equilibrium suggests that there was a high number of homozygotes in the populations studied, and indicates the importance of the State for the conservation of the local breeds. Cataloguing the genetic profile of Brazilian goat populations provides essential information for conservation and genetic improvements programs.

Genetic diversity between herds of Alpine and Saanen dairy goats and the naturalized Brazilian Moxotó breed

Brazilian naturalized goat breeds are adapted to the semiarid conditions prevalent in the Northeast region of the country (which has the largest Brazilian goat heard) and represent an as yet uninvestigated source of genetic diversity. Currently, imported goat breeds are crossed with Brazilian naturalized goat breeds, endangering the genetic potential of the naturalized breeds. We used 11 microsatellite markers to determine the genetic diversity among imported (non-naturalized) dairy Alpine and Saanen goats and naturalized Brazilian Moxotó goats. We genotyped 292 goats from three herds (one private, one from the University of Minas Gerais and the Moxotó conservation herd from Embrapa Caprinos) and found that the general heterozygosity was 0.6952 for Alpine, 0.7043 for Saanen and 0.4984 for Moxotó goats. The number of alleles ranged from 5 (INRA005) to 11 (BM3205), with an average of 7 alleles per locus in the imported breeds and 3.5 alleles per locus in the Moxotó breed. Mean differentiation between populations was higher for herds (F ST S = 0.0768) than for breeds (F ST P = 0.0263), indicating similarity between the imported breeds and the existence of crosses between them. Nei's genetic distance was highest between the Moxotó breed and the imported breeds. These indicate that further studies using these molecular markers would be fruitful.

Ocorrência de tetas supranumerárias em caprinos sem raça definida do Estado do Ceará, Brasil / Occurrence of supernumerary teats in no-described goats from Ceará State, Brazil

A caprinocultura nordestina é principalmente produtora de carne, mas a espécie caprina é por excelência produtora de leite. As características da glândula mamária não devem ser negligenciadas, fazendo-se seleção contra tetas defeituosas de matrizes e reprodutores. Foram amostrados 485 caprinos sem raça definida (SRD) em 21 rebanhos no Estado do Ceará, em 1991. Em cada uma das microrregiões homogêneas do Estado, foram amostrados na razão de 0,05 por cento dos caprinos existentes (IBGE, 1988), em um ou mais rebanhos. Dentro do rebanho, a escolha dos animais se deu ao acaso. Todos os machos amostrados eram inteiros. No conjunto do Estado, observou-se que 27 por cento dos animais (n=131) apresentavam tetas supranumerárias: acessórias (não fundidas) ou papilas mamárias duplas (fundidas). Nas diversas mesorregiões do Ceará, os percentuais de animais com defeitos desta natureza, foram de 26,8 por cento no Nordeste, 26,6 por cento no Centro-Leste e 31,6 por cento no Sul. Do total de animais defeituosos, 62,9 por cento apresentavam uma teta acessória de cada lado, 29,6 por cento uma teta acessória em apenas um dos lados, 4,5 por cento mais de uma teta acessória de um ou ambos os lados; 3,0 por cento apresentavam papila mamária dupla em um ou ambos os lados. Apresentaram algum dos defeitos mencionados 16,7 por cento dos machos adultos (n=24), 25,4 por cento dos machos de recria (n= 63), 33,3 por cento das fêmeas de recria (n=72) e 26,7 por cento das fêmeas adultas examinadas (n=326). O número de animais defeituosos não difere entre mesorregiões, entre sexos ou entre faixas etárias (p>0,05). Concluiu-se que é alto o percentual de animais defeituosos e que os criadores devem ser orientados quanto à importância e o modo de seleção de matrizes e reprodutores para estes parâmetros.