Genetic relationship, inbreeding and generation interval in registered Gir cattle in Brazil

Queiroz, S. A.; Lôbo, Raysildo Barbosa

doi:10.1111/j.1439-0388.1993.tb00734.x

Cited by 12 publications

(10 citation statements)

References 16 publications

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“…A longer GI than that found in this study was reported for Gir cattle (8.02 years) in Brazil (Q ueiroz and L ôbo 1993) and for Wakwa cattle (8.67 years) in Cameroon (T awah et al 1994). However, this is still relatively long when compared with the overall average of 4.36 years (M rode 1988) from several beef cattle selection experiments, though this is largely from temperate breeds.…”

Section: Resultscontrasting

confidence: 59%

Estimates of genetic and environmental trends of growth traits in Boran cattle

Haile‐Mariam

Philipson

1996

J Animal Breeding Genetics

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Summary Data from a Boran cattle breeding scheme, run by the Ministry of Agriculture in Ethiopia, were analysed by separating the genetic and environmental trends in growth traits. The data used included weight records at birth (BW), weaning (WW), and as yearlings (YW), for animals born between 1959 and 1985. The mean generation interval calculated was 6.75 years. In a 24‐year actual selection period, 3.29 generations of selection occurred, during this time inbreeding increased, to an average of 1.7% in animals born in 1985. The regressions of estimated direct and maternal breeding value on year of birth were −0.002 and 0.003 kg, 0.32 and 0.02 kg, and 0.22 and −0.005 kg, for BW, WW, and YW respectively. The aggregate breeding value, which is the sum of the maternal and direct breeding values, showed an increase of 0.34 and 0.21 kg per year for WW and YW, respectively. Whereas the maternal environmental trends were slight, the variation in the direct environmental effects was the greatest. Generally, a less marked annual genetic trend was shown, when breeding values were regressed on generation coefficients than on year of birth. Despite the good opportunity for selection, that was demonstrated by the more than 50 kg difference between the maximum and minimum breeding values for WW and YW, the maximum genetic gain in aggregate breeding value was only 0.2% of the mean WW per year. This limited response was due to the high level of genetic antagonism between direct and maternal effects, and also to problems in running the selection scheme, for example, selection on phenotypic performance alone and relatively long generation intervals. Zusammenfassung Genetische und umweltbedingte Trends von Wachstumseigenschaften bei Boran Rindern Die Daten des Boran Zuchtprojektes des äthiopischen Landwirtschafsministeriums wurden zur Trennung genetischer und umweltbedingter Trends analysiert, und zwar Geburts‐ (BW), Absatz‐ (WW) und Jährlingsgewicht (YW) der zwischen 1959 und 1985 geborenen Tiere. Das mittlere Generationsintervall war 6,75 Jahre, so daß in der 24 Jahresperiode 3,29 Generationen abgelaufen sind, während welchen der Inzuchtgrad auf 1,7% bei den 1985 geborenen Tieren angestiegen ist. Regression geschätzter direkter und maternaler Zuchtwerte auf Geburtsjahr waren −0,002 und 0,003 kg für BW, 0,32 und 0,02 für WW ond 0,22 und −0,005 kg für YW. Die Summe beider Zuchtwerte, aggregierter Zuchtwert, ist damit um 0,34 und 0,21 kg für WW und YW angestiegen. Der Umwelttrend für maternale Wirkungen war gering, der für direkte zeigte große Variabilität. Der jährliche genetische Trend war geringer, wenn die Regression auf Generation statt Geburtsjahr bezogen wurde. Trotz guter Selektionsmöglichkeit, wie sie durch die mehr als 50 kg weite Spanne zwischen höchsten und neidrigsten Zuchtwerten für WW und YW deutlich wird, war der maximale Zuchtforschritt im Gesamtzuchtwert nur 0,2 % des jährlichen WW Durchschnittes. Dieser begrenzte Erfolg ist auf genetischen Antagonismus zwischen direkten und maternalen Wirkungen zurückzuführen, abe...

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Section: Resultscontrasting

confidence: 59%

Estimates of genetic and environmental trends of growth traits in Boran cattle

Haile‐Mariam

Philipson

1996

J Animal Breeding Genetics

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“…Esses valores foram superiores aos estimados por Queiroz & Lôbo (1993), na raça Gir, e denotam a necessidade de se monitorarem os acasalamentos entre os animais dessa raça, para evitar acasalamentos entre indivíduos aparentados e restringir os acasalamentos entre parentes, pela fixação Tabela 2. Média da integralidade (I) do pedigree, até a sexta geração, por ano de nascimento de bovinos da raça Brahman.…”

Section: Resultsunclassified

Variabilidade genética da raça Brahman no Brasil detectada por meio de análise de pedigree

Faria¹,

Queiroz

Vozzi³

et al. 2010

Pesq. agropec. bras.

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Resumo -O objetivo deste trabalho foi analisar a variabilidade genética da raça Brahman no Brasil, por meio da análise de 15.851 pedigrees. O arquivo de dados foi dividido em dois períodos : 1998-2001 e 2002-2005. A variabilidade genética foi avaliada por parâmetros baseados na probabilidade de origem do gene: número efetivo de ancestrais, número efetivo de fundadores, número efetivo de genomas remanescentes e coeficientes de parentesco e de endogamia. Os valores encontrados quanto ao número de fundadores mostraram que a população está em expansão, embora o número efetivo de fundadores tenha diminuído de um período para outro. Os resultados foram diferentes em relação ao número de ancestrais e genomas remanescentes, que apresentaram crescimento de 23% nos períodos avaliados. O coeficiente de endogamia diminuiu nos períodos estudados, porém o coeficiente de parentesco "inter se" cresceu. Poucos ancestrais apresentaram grande contribuição genética para a população, o que evidencia a utilização de poucos indivíduos na reprodução. A raça Brahman, no Brasil, encontra-se em expansão, caracterizada pela diminuição do coeficiente de endogamia e aumento nos números efetivos de fundadores e de genótipos remanescentes. Entretanto, a variabilidade genética da raça mostra aumento do parentesco "inter se" e grande concentração do patrimônio genético de poucos indivíduos na população.Termos para indexação: coeficiente de parentesco, endogamia, número efetivo de ancestrais, número efetivo de fundadores, número efetivo de genomas remanescentes. Genetic variability detection in Brahman cattle in Brazil trough pedigree analysisAbstract -This work aimed to analyse the genetic variability of Brahman breed in Brazil, through the analysis of 15,851 pedigrees. The data file was divided into two periods: 1998-2001 and 2002-2005. The genetic variability was evaluated by the following parameters, based on the probability of gene origin: number of ancestors, effective number of founders, effective number of remaining genomes, and the relationship and inbreeding coefficients. The values for the number of founders showed that the population is expanding, although the effective number of founders has been reduced from one period to the other. The results were different for the number of ancestors and the remaining genomes, which grew by 23% in the studied periods. The inbreeding coefficient decreased in the studied periods, but the "inter se" relationship coefficient increased. Few ancestors showed great genetic contribution to the population, which indicates the use of small number of individuals in the reproduction. Brahman breed population in Brazil is expanding, characterized by the decreasing of the inbreeding coefficients and the increasing of the effective number of ancestors and remaining genotypes. Nevertheless, the breed genetic variability shows increasing "inter se" relationships and a great concentration of gene heritage of few individuals in the population.Index terms: relationship coefficient, inbreeding, effective number of an...

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“…Those imported animals were first consumed for beef cattle purpose, and some breeders started to use them for milk production. Gyr animals have been intensely applied as the basis for crosses with taurine dairy breeds due to its rusticity and greater tolerance to the tropical environment [ 22 ]. The mating between imported animals invariably led to a steep increase in inbreeding rate in the population, resulting in genetic gains and fixation of favorable alleles.…”

Section: Introductionmentioning

confidence: 99%

Assessment of runs of homozygosity islands and estimates of genomic inbreeding in Gyr (Bos indicus) dairy cattle

et al. 2018

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BackgroundRuns of homozygosity (ROH) are continuous homozygous segments of the DNA sequence. They have been applied to quantify individual autozygosity and used as a potential inbreeding measure in livestock species. The aim of the present study was (i) to investigate genome-wide autozygosity to identify and characterize ROH patterns in Gyr dairy cattle genome; (ii) identify ROH islands for gene content and enrichment in segments shared by more than 50% of the samples, and (iii) compare estimates of molecular inbreeding calculated from ROH (FROH), genomic relationship matrix approach (FGRM) and based on the observed versus expected number of homozygous genotypes (FHOM), and from pedigree-based coefficient (FPED).ResultsROH were identified in all animals, with an average number of 55.12 ± 10.37 segments and a mean length of 3.17 Mb. Short segments (ROH1–2 Mb) were abundant through the genomes, which accounted for 60% of all segments identified, even though the proportion of the genome covered by them was relatively small. The findings obtained in this study suggest that on average 7.01% (175.28 Mb) of the genome of this population is autozygous. Overlapping ROH were evident across the genomes and 14 regions were identified with ROH frequencies exceeding 50% of the whole population. Genes associated with lactation (TRAPPC9), milk yield and composition (IRS2 and ANG), and heat adaptation (HSF1, HSPB1, and HSPE1), were identified. Inbreeding coefficients were estimated through the application of FROH, FGRM, FHOM, and FPED approaches. FPED estimates ranged from 0.00 to 0.327 and FROH from 0.001 to 0.201. Low to moderate correlations were observed between FPED-FROH and FGRM-FROH, with values ranging from −0.11 to 0.51. Low to high correlations were observed between FROH-FHOM and moderate between FPED-FHOM and FGRM-FHOM. Correlations between FROH from different lengths and FPED gradually increased with ROH length.ConclusionsGenes inside ROH islands suggest a strong selection for dairy traits and enrichment for Gyr cattle environmental adaptation. Furthermore, low FPED-FROH correlations for small segments indicate that FPED estimates are not the most suitable method to capture ancient inbreeding. The existence of a moderate correlation between larger ROH indicates that FROH can be used as an alternative to inbreeding estimates in the absence of pedigree records.Electronic supplementary materialThe online version of this article (10.1186/s12864-017-4365-3) contains supplementary material, which is available to authorized users.

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Genetic relationship, inbreeding and generation interval in registered Gir cattle in Brazil

Cited by 12 publications

References 16 publications

Estimates of genetic and environmental trends of growth traits in Boran cattle

Estimates of genetic and environmental trends of growth traits in Boran cattle

Variabilidade genética da raça Brahman no Brasil detectada por meio de análise de pedigree

Assessment of runs of homozygosity islands and estimates of genomic inbreeding in Gyr (Bos indicus) dairy cattle

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