Genetic parameters for worm resistance in Santa Inês sheep using the Bayesian animal model.

OBJECTIVE: The objective of this study was to estimate the genetic parameters for worm resistance (WR) and associated characteristics, using the linear-threshold animal model via Bayesian inference in single- and multiple-trait analyses. METHODS: Data were collected from a herd of Santa Inês breed sheep. All information was collected with animals submitted to natural contamination conditions. All data (number of eggs per gram of feces [FEC], Famacha score [FS], body condition score [BCS], and hematocrit [HCT]) were collected on the same day. The animals were weighed individually on the day after collection (after 12-h fasting). The WR trait was defined by the multivariate cluster analysis, using the FEC, HCT, BCS, and FS of material collected from naturally infected sheep of the Santa Inês breed. The variance components and genetic parameters for the WR, FEC, HCT, BCS, and FS traits were estimated using the Bayesian inference under the linear and threshold animal model. RESULTS: A low magnitude was obtained for repeatability of worm-related traits. The mean values estimated for heritability were of low-to-high (0.05 to 0.88) magnitude. The FEC, HCT, BCS, FS, and body weight traits showed higher heritability (although low magnitude) in the multiple-trait model due to increased information about traits. All WR characters showed a significant genetic correlation, and heritability estimates ranged from low (0.44; single-trait model) to high (0.88; multiple-trait model). CONCLUSION: Therefore, we suggest that FS be included as a criterion of ovine genetic selection for endoparasite resistance using the trait defined by multivariate cluster analysis, as it will provide greater genetic gains when compared to any single trait. In addition, its measurement is easy and inexpensive, exhibiting greater heritability and repeatability and a high genetic correlation with the trait of resistance to worms.

SSR and ISSR markers in assessing genetic diversity in Gallus gallus domesticus: a quantitative analysis of scientific production / Marcadores SSR e ISSR na avaliação da diversidade genética em Gallus gallus domesticus: uma análise quantitativa da produção científica

ABSTRACT: Poultry meat is a major source of animal protein in the world. Research indicates a high inbreeding rate derived from a relative absence of heterozygous subpopulations of chicken from different suppliers. Molecular markers can provide information for the genetic basis of chicken consumed in rural areas and help establishing a chicken database for product quality and warranty. The bibliometric research, comprises between 1994 and 2018, from five previously selected databases: Google Scholar, PubMed, ScienceDirect, Scopus and Web of Science, using the following descriptors: 'microsatellites', 'SSR', 'ISSR', 'genetic variability' and 'genetic diversity', all of them coupled to 'chicken' and/or 'birds' results in 66 scientific publications. The publications were then categorized according to their titles to the use of ISSR or SSR markers. They were also addressed by countries according first author cited. The publications data appointed that countries with the height production of poultry meat and hens are the most interested in the genetic diversity study of these species. The SSR markers, due to its more specific characteristic, are more frequently applied to genetic diversity assignment, compared to ISSR.

RESUMO: A carne de frango é uma das principais fontes de proteína animal do mundo. Pesquisas indicam uma alta taxa de endogamia derivada de uma relativa ausência de subpopulações heterozigotas de frango de diferentes fornecedores. Marcadores moleculares podem fornecer informações para a base genética de frango consumido em áreas rurais, e ajudar a estabelecer um banco de dados de frango para qualidade e garantia do produto. A pesquisa bibliométrica compreende entre 1994 e 2018, a partir de cinco bancos de dados selecionados anteriormente: Google Scholar, PubMed, ScienceDirect, Scopus e Web of Science, usando os seguintes descritores: 'microssatélites', 'SSR', 'ISSR', 'variabilidade genética' e 'diversidade genética', todos eles associados a resultados de 'galinha' e / ou 'aves' o que resultou em 66 publicações científicas. As publicações foram então categorizadas de acordo com seus títulos para o uso de marcadores ISSR ou SSR. Eles também foram abordados pelos países, segundo o primeiro autor citado. Os dados das publicações obtidas apontam que os países com grande produção de carnes de frangos são os mais interessados no estudo da diversidade genética dessas espécies. Os marcadores SSR, devido à sua característica mais específica, são frequentemente aplicados à atribuição de diversidade genética, em comparação com o ISSR.

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.

Associaçäo entre o California Mastitis Test e a Contagem de Células Somáticas na avaliaçäo da saúde da glândula mamária caprina / Relationship between California Mastitis Test and Somatics Cells Count in the avaliation of the healthy mammary gland in goats

A correlaçäo entre os resultados do California Mastitis Test (CMT) e da Contagem de Células Somáticas (CCS) foi estudada em 68 cabras das raças Anglo-Nubiana, Pardo Alpina e Saanen. Os dados foram coletados quinzenalmente, durante sete meses, realizando-se a CCS em amostras de leite bacteriologicamente negativas. Os resultados mostraram uma correlaçäo positiva e significativa (p < 0,05) entre os testes avaliados, com um coeficiente de r = 0,63. Quando os testes foram correlacionados com a produçäo de leite, observou-se uma correlaçäo negativa e significativa (p < 0,05) de r = -0,27 e r = -0,28 para o CMT e a CCS, respectivamente. Na associaçäo das reaçöes do CMT com a CCS obtiveram-se médias de 0,78 x 10(6) céls/ml para as reaçöes negativas (N, T e 1+) e média de 5,32 x 10(6) céls/ml para as reaçöes positivas (2+ e 3+). Os resultados indicam que, para evitar resultados falso-positivos, outros testes diagnósticos deveräo ser usados juntamente com o CMT, para se avaliar a saúde da glândula mamária caprina