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RESUMO As raças taurinas de origem ibérica Limonero e Carora (Bos primigenius taurus) possuem o fenótipo de pelo curto, liso e com baixa densidade folicular, o que confere a esses animais maior tolerância térmica e melhor produtividade em regiões quentes. Diferentes mutações associadas a esse fenótipo foram descritas no gene do receptor de prolactina PRLR, localizado no cromossomo bovino BTA20. Uma mutação recentemente encontrada é a substituição do nucleotídeo C por T, SNP 39136666 (p. R497*), no exon 11, que gera um códon de parada e, consequentemente, uma menor isoforma desse receptor. Neste trabalho, desenvolveu-se um protocolo rápido e de baixo custo para detecção desse SNP, utilizando-se a técnica de tetra-primer ARMS-PCR. Assim, foi possível detectar essa mutação nas raças brasileiras de origem ibérica localmente adaptadas: Caracu, Crioulo Lageano, Mocho Nacional e Pantaneiro. O alelo T foi mais frequente na raça Caracu (80%), enquanto o alelo C foi mais frequente na raça Crioulo Lageano (84%). Essa simples metodologia pode ser usada para genotipar esse SNP e ajudar na aplicação dessas informações moleculares em programas de melhoramento focados na tolerância térmica em bovinos taurinos e seus mestiços.

Rhipicephalus microplus causes huge losses in cattle. Host genetic background greatly affects the immune efficiency in resistance or susceptibility to tick infestation, which is one of the many factors that play a role on that trait. We performed a systematic review of genome-wide association studies (GWAS) for tick resistance in cattle resulting in 1353 candidate genes for post-GWAS analyses. From those, genes showing possible structural variants from the bovine genome were classified by the Variant Effect Predictor from Ensembl. Ninety-two candidate genes showed potential structural variants in 5' UTR and coding region and were used for functional annotation. Enriched biological processes (e.g. regulation of eosinophil chemotaxis, RIG-I signalling pathway and monocyte differentiation) and candidate genes (e.g. DAPK2, PUM1, ACIN1, INPP5D) linked with immune system function were identified and thus associated with tick resistance. Besides, gene-transcription factors (TFs) networks were obtained from TFs associated with immune system (FOXO3, PPARG, STAT3, NFKB1, GATA3 and ARNT) and the candidate genes associated with tick resistance in cattle highlighted (e.g. OR4L1, PNP, LRRIQ1, GIMAP8, MYO6, MEP1A and LRFN2). Thus, promising candidate genes with a possible functional role for tick resistance in cattle are presented for further in vitro and/or in vivo analyses. Made available in DSpace on 2022-07-25T13:20:05Z (GMT). No. of bitstreams: 1 Candidate-genes-for-tick-resistance-in-cattle.pdf: 1963506 bytes, checksum: b97dc4a9f2a268ebd1d7f0d2f8ecec48 (MD5) Previous issue date: 2022

Cattle population history, breeding systems, and geographic subdivision may be reflected in runs of homozygosity (ROH), effective population size (Ne), and linkage disequilibrium (LD) patterns. Thus, the assessment of this information has become essential to the implementation of genomic selection on purebred and crossbred cattle breeding programs. In this way, we assessed the genotype of 19 cattle breeds raised in Brazil belonging to taurine, indicine, synthetic crossbreds, and Iberian-derived locally adapted ancestries to evaluate the overall LD decay patterns, Ne, ROH, and breed composition. We were able to obtain a general overview of the genomic architecture of cattle breeds currently raised in Brazil and other tropical countries. We found that, among the evaluated breeds, different marker densities should be used to improve the genomic prediction accuracy and power of genome-wide association studies. Breeds showing low Ne values indicate a recent inbreeding, also reflected by the occurrence of longer ROH, which demand special attention in the matting schemes to avoid extensive inbreeding. Candidate genes (e.g., ABCA7, PENK, SPP1, IFNAR1, IFNAR2, SPEF2, PRLR, LRRTM1, and LRRTM4) located in the identified ROH islands were evaluated, highlighting biological processes involved with milk production, behavior, rusticity, and fertility. Furthermore, we were successful in obtaining the breed composition regarding the taurine and indicine composition using single-nucleotide polymorphism (SNP) data. Our results were able to observe in detail the genomic backgrounds that are present in each breed and allowed to better understand the various contributions of ancestor breeds to the modern breed composition to the Brazilian cattle.

The objective of this work was to evaluate the effects of breed and heterosis on the estimates of genetic parameters of 305-day milk yield (305MY), by fitting milk yield data to the Wood, Mixed Log, Morgan, and Wilmink non-linear models. A total of 258,891 test-day milk yield records of 37,965 Holstein (H), Gyr (G), and Girolando (1/2 H, 1/4 H, 3/4 H, 3/8 H, 5/8 H and 7/8 H genetic groups) cows from 1840 herds were collected in the state of Minas Gerais, Brazil, in the period of 1998 to 2014. The pedigree file included 36,640 animals, 3677 bulls and 24,472 cows. The genetic parameters were obtained by one-character analysis using the AIREMLF90 software. The heritability estimates of 305MY, and of 305MY fitted to the different nonlinear models ranged from 0.14 to 0.20. Most genetic groups had heterosis effect, with the greatest effects for 305MY on 1/2 H (1/2 Holstein × 1/2 Gyr) cows, presenting a milk yield of 1112.73 kg higher than the average of their parents. The results indicate that most genetic groups of Girolando present heterosis effect for 305MY estimated through nonlinear models, and the possibility of obtaining moderate genetic gains when these animals are subjected to selection procedures.HIGHLIGHTS The use Girolando cows in production systems in Brazil has shown positive results of production. This greater productive efficiency may be because of heterosis on the production and adaptation of these animals. The effect of breed and heterosis can be included in traditional models for the improvement of selection.

Knowledge of lactation curves in dairy cattle is essential for understanding the animal production in milk production systems. Genomic prediction of lactation curves represents the genetic pattern of milk production of the animals in the herd. In this context, we made genomic predictions of lactation curves through genome-wide selection (GWS) to characterize the genetic pattern of lactation traits in Girolando cattle based on parameters estimated by nonlinear mixed effects (NLME) models. Data of 1,822 milk control records from 226 Girolando animals genotyped for 37,673 single nucleotide polymorphisms were analyzed. Nine NLME models were compared to identify the equation with the best fit. The lactation traits estimated by the best model were submitted to GWS analysis, using the Bayesian LASSO method. Then, based on the genomic estimated breeding values (GEBVs) obtained, genomic predictions of lactation curves were constructed, and the genetic parameters were calculated. Wood's equation showed the best fit among the evaluated models. Heritabilities ranged from 0.09 to 0.29 for the seven lactation variables (initial production, rates of increase and decline, lactation peak, time to peak yield, persistence and total production). The correlations among GEBVs ranged from -0.85 to 0.98. The concordances between the best animals selected according to the selected traits were greater when the correlations between GEBVs for these traits were also high. Consequently, the methodology allowed us to identify the best nonlinear model and to construct the genetic lactation curves of a Girolando cattle population, as well as to assess the differences between animals and the association between lactation variables. Made available in DSpace on 2021-08-13T17:00:23Z (GMT). No. of bitstreams: 1 Genomic-prediction.pdf: 1063909 bytes, checksum: 77039067fba1eeecda481e6a6fa74c74 (MD5) Previous issue date: 2021

Bos taurus taurus and Bos taurus indicus cattle subspecies present different capabilities in coping with situations of elevated temperatures, the latter being more tolerant to heat stress. Thus, some breeding programs crossed these subspecies to produce a high producing yet heat-tolerant breed (Girolando). Nineteen Holstein (H100) and 19 Girolando cows [(½ Holstein × Gir (H50) and ¾ Holstein × Gir (H75)] with similar milk production were used in a six-day experiment to evaluate the consequences of heat stress due to shade deprivation on their physiological, blood and milk traits. Cows were exposed to a non-shaded environment between morning (06:00h; GMT -3:00) and evening milking (14:30h; GMT -3:00) with access to water ad libitum. Procedures were conducted before morning and evening milkings. Physiological parameters related to mechanisms of heat dissipation were measured, as well as the milk composition. Blood traits were evaluated. The temperature-humidity index (THI) was calculated. Statistical procedures included analysis of variance, correlation, and principal factors. THI was elevated during the trial and negatively impacted physiological, milk, and blood parameters in H100, H75, and H50. Alterations in physiology, milk stability, milk composition, and blood traits were more pronounced in H100. Holstein cows presented changes in physiological parameters in a more pronounced manner and in some milk and blood traits related to the reduced capability of this breed in dealing with elevated THI. The similarity in milk production levels excludes this parameter as a justification for differences in heat tolerance, with genetic composition being the main reason for these results. Made available in DSpace on 2021-11-25T12:04:23Z (GMT). No. of bitstreams: 1 Elevated-temperature-humidity.pdf: 761551 bytes, checksum: 0e2950a57ff402580f102316e5cd8df9 (MD5) Previous issue date: 2021

The objective of this study was to estimate the components of variance and genetic parameters of test-day milk yield in first lactation Girolando cows, using a random regression model. A total of 126,892 test-day milk yield (TDMY) records of 15,351 first-parity Holstein, Gyr, and Girolando breed cows were used, obtained from the Associação Brasileira dos Criadores de Girolando. To estimate the components of (co) variance, the additive genetic functions and permanent environmental covariance were estimated by random regression in three functions: Wilmink, Legendre Polynomials (third order) and Linear spline Polynomials (three knots). The Legendre polynomial function showed better fit quality. The genetic and permanent environment variances for TDMY ranged from 2.67 to 5.14 and from 9.31 to 12.04, respectively. Heritability estimates gradually increased from the beginning (0.13) to mid-lactation (0.19). The genetic correlations between the days of the control ranged from 0.37 to 1.00. The correlations of permanent environment followed the same trend as genetic correlations. The use of Legendre polynomials via random regression model can be considered as a good tool for estimating genetic parameters for test-day milk yield records. Made available in DSpace on 2021-08-12T15:01:11Z (GMT). No. of bitstreams: 1 Estimation-genetic.pdf: 283041 bytes, checksum: 4e38ef5410ebe3066df90abfed20d0e7 (MD5) Previous issue date: 2021

The objective of this study was to estimate the breed, heterosis, and recombination effects on different components of the lactation curve of Girolando cattle. The dataset used consisted of 12,121 purebred cows of Holstein (H) and Gyr (G) breeds, and six H×G crossbred cows (Girolando). The model used presents random effects of herd and cow, regression coefficient associated with linear effect of proportion of H breed, regression coefficient associated with the linear effect of heterosis between H and G breeds, regression coefficient associated with the linear effect of recombination between H and G breeds, and random effect of residual. Dijkstra?s (DJ), Nelder's (ND), Wilmink's (WL), and Wood's (WD) models were tested to fit production records of these different genetic groups. These models were then tested according to evaluation criteria of quality of fit (AIC, BIC, and RMSE), and the two best models (WD and WL) were chosen for estimation of 305-day milk yield (MY305), peak yield, time to peak, and persistency of milk yield. The breed effect was significant for all traits and components of the lactation curve. The heterosis effect was significant for all traits, and was more significant for MY305 (945.62±79.17 kg). Peak yield was the component of lactation curve that presented the most significant heterosis effect, partially explaining the heterosis effect (12 to 21%) found for MY305. The recombination effect was positive only for lactation period and time to peak of lactation in Girolando cows. Made available in DSpace on 2021-08-10T19:02:05Z (GMT). No. of bitstreams: 1 Breed-heterosis.pdf: 400315 bytes, checksum: ae446e63b554054361c8ef882a6dd141 (MD5) Previous issue date: 2021

Made available in DSpace on 2020-12-12T01:38:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-09-11 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) BACKGROUND: The cattle introduced by European conquerors during the Brazilian colonization period were exposed to a process of natural selection in different types of biomes throughout the country, leading to the development of locally adapted cattle breeds. In this study, whole-genome re-sequencing data from indicine and Brazilian locally adapted taurine cattle breeds were used to detect genomic regions under selective pressure. Within-population and cross-population statistics were combined separately in a single score using the de-correlated composite of multiple signals (DCMS) method. Putative sweep regions were revealed by assessing the top 1% of the empirical distribution generated by the DCMS statistics. RESULTS: A total of 33,328,447 biallelic SNPs with an average read depth of 12.4X passed the hard filtering process and were used to access putative sweep regions. Admixture has occurred in some locally adapted taurine populations due to the introgression of exotic breeds. The genomic inbreeding coefficient based on runs of homozygosity (ROH) concurred with the populations' historical background. Signatures of selection retrieved from the DCMS statistics provided a comprehensive set of putative candidate genes and revealed QTLs disclosing cattle production traits and adaptation to the challenging environments. Additionally, several candidate regions overlapped with previous regions under selection described in the literature for other cattle breeds. CONCLUSION: The current study reported putative sweep regions that can provide important insights to better understand the selective forces shaping the genome of the indicine and Brazilian locally adapted taurine cattle breeds. Such regions likely harbor traces of natural selection pressures by which these populations have been exposed and may elucidate footprints for adaptation to the challenging climatic conditions. São Paulo State University (Unesp) School of Agricultural and Veterinarian Sciences Animal Breeding and Genetics Group Department of Animal Sciences University of Goettingen, Albrecht-Thaer-Weg 3 Center for Integrated Breeding Research University of Goettingen, Albrecht-Thaer-Weg 3 National Council for Scientific and Technological Development (CNPq) Embrapa Dairy Cattle Embrapa Beef Cattle São Paulo State University (Unesp) School of Agricultural and Veterinarian Sciences

A biópsia embrionária associada à genotipagem permite a obtenção de informações genômicas antes mesmo da transferência dos embriões. Neste estudo, foram avaliadas amostras biopsiadas de blastocistos bovinos transferidos para receptoras (n=47), sob a hipótese de que a raça (Gir ou Girolando), o estádio embrionário (blastocisto ou blastocisto expandido) e a competência para estabelecimento de prenhez (positiva ou negativa) afetariam a quantidade e a qualidade do DNA da amostra obtida. O DNA foi extraído, amplificado, quantificado por eletroferograma e genotipado. O parâmetro call rate (CR) foi adotado para mensurar a qualidade da genotipagem. Obteve-se concentração de DNA de 86,07±171,66ng/μL e CR 0,73±0,17. O CR não variou em função da quantidade de DNA nas amostras. As variáveis raça e estádio embrionário não influenciaram a concentração de DNA, nem o CR. Houve efeito da prenhez sobre o CR (P=0,0187), mas, como houve maior CR nas amostras provenientes do grupo prenhez negativa, não foi possível associar esse parâmetro à qualidade embrionária. Concluiu-se que a raça e a qualidade embrionária não afetam os parâmetros aqui estudados em amostras embrionárias, ou seja, embriões com maiores chances de implantação não refletem alta qualidade nas amostras de biópsia genotipadas. Made available in DSpace on 2021-08-16T19:00:26Z (GMT). No. of bitstreams: 1 Quantificacao-DNA.pdf: 746488 bytes, checksum: 0de1fdf609f6152f7fb47e24ffd04119 (MD5) Previous issue date: 2020

In dairy farm animals, one the most important goal of the selection is the improvement of milk yield and composition. Several studies have demonstrated that the candidate genes of the kappa-casein (CSN3) and Beta- lactoglobulin (Beta-LG) are associated with milk yield, milk quality and health traits in dairy animals. Therefore the aim of this study was to detect polymorphisms in CSN3 and Beta-LG genes and its association with milk yield in up to 305 days (305MY) and predicted transmission capacity (PTA) for 305MY in Girolando cattle. Totally, 138 bulls and 729 cows (n=867) were sampled. The genotypes of both genes were obtained by the PCR-RFLP method using HinfI and HaeIII enzymes for CSN3 and Beta-LG genes, respectively. Statistical results revealed two alleles A and B for both genes. The genotypes and alleles more frequents for CSN3 and Beta-LG genes were respectively: AA (0.7324) and A (0.8558), and AB (0.4827) and A (0.5017). The x 2 test revealed that the two loci were at Hardy- Weinberg equilibrium (p0.05). The allele variants of Beta-LG and CSN3 might be more investigated before include them into future breeding schemes designed for Girolando dairy cattle with objective of improving milk traits as milk yield in up to 305 days (305MY) and predicted transmission capacity (PTA) for 305MY. RESUMO - Em rebanhos leiteiros, um dos objetivos mais importantes da seleção é a melhoria da produção e composição do leite. Vários estudos demonstraram que os genes candidatos da kappa-caseína (CSN3) e da Beta-lactoglobulina (Beta-LG) estão associados à produção de leite, qualidade do leite e características de saúde em animais leiteiros. Portanto, o objetivo deste estudo foi detectar polimorfismos nos genes CSN3 e Beta-LG e avaliar possíveis associações desses polimorfismos com a produção de leite em até 305 dias (305MY) e a capacidade de transmissão prevista (PTA) de leite em bovinos da raça Girolando. No total, 138 touros e 729 vacas (n = 867) foram amostrados. A genotipagem foi realizada pelo método PCR-RFLP utilizando as enzimas HinfI e HaeIII para os genes CSN3 e Beta-LG, respectivamente. Os resultados estatísticos revelaram dois alelos A e B para ambos os genes. Os genótipos e alelos mais frequentes para os genes CSN3 e Beta-LG foram respectivamente: AA (0,7324) e A (0,8558) e AB (0,4827) e A (0,5017). O teste x2 revelou que os dois loci estavam em equilíbrio de Hardy-Weinberg (p 0,05). Portanto, as variantes alélicas identificadas nos genes ?-LG e CSN3 devem ser mais investigadas antes de serem incluídas nos programas de melhoramento desenhados para bovinos leiteiros Girolando objetivando melhorar as características do leite analisadas no presente estudo. Made available in DSpace on 2019-12-30T18:13:12Z (GMT). No. of bitstreams: 1 RrevBrasSPAMartaGenetic.pdf: 131332 bytes, checksum: b33cda6d68a0a1b815ecb7811a132abe (MD5) Previous issue date: 2019

Made available in DSpace on 2018-12-11T17:14:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-08-23 Background: Beef cattle breeding programs in Brazil have placed greater emphasis on the genomic study of reproductive traits of males and females due to their economic importance. In this study, genome-wide associations were assessed for scrotal circumference at 210d of age, scrotal circumference at 420d of age, age at first calving, and age at second calving, in Canchim beef cattle. Data quality control was conducted resulting in 672,778 SNPs and 392 animals. Results: Associated SNPs were observed for scrotal circumference at 420d of age (435 SNPs), followed by scrotal circumference at 210d of age (12 SNPs), age at first calving (six SNPs), and age at second calving (four SNPs). We investigated whether significant SNPs were within genic or surrounding regions. Biological processes of genes were associated with immune system, multicellular organismal process, response to stimulus, apoptotic process, cellular component organization or biogenesis, biological adhesion, and reproduction. Conclusions: Few associations were observed for scrotal circumference at 210d of age, age at first calving, and age at second calving, reinforcing their polygenic inheritance and the complexity of understanding the genetic architecture of reproductive traits. Finding many associations for scrotal circumference at 420d of age in various regions of the Canchim genome also reveals the difficulty of targeting specific candidate genes that could act on fertility; nonetheless, the high linkage disequilibrium between loci herein estimated could aid to overcome this issue. Therefore, all relevant information about genomic regions influencing reproductive traits may contribute to target candidate genes for further investigation of causal mutations and aid in future genomic studies in Canchim cattle to improve the breeding program. Universidade Federal da Paraíba (UFPB) Departamento de Zootecnia Fast Genetics Beef Improvement Opportunities (BIO) University of Guelph Centre for Genetic Improvement of Livestock (CGIL) Department of Animal and Poultry Science Universidade Estadual Paulista (Unesp) Departamento de Ciências Exatas Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista (Unesp) Departamento de Zootecnia Núcleo de Pesquisa e Conservação de Cervídeos Faculdade de Ciências Agrárias e Veterinárias Federal University of Lavras (UFLA) Department of Animal Science Federal University of São Carlos (UFSCar) Department of Genetics and Evolution Embrapa Agricultural Informatics Embrapa Dairy Cattle Embrapa Southeast Livestock Universidade Estadual Paulista (Unesp) Departamento de Ciências Exatas Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista (Unesp) Departamento de Zootecnia Núcleo de Pesquisa e Conservação de Cervídeos Faculdade de Ciências Agrárias e Veterinárias

Made available in DSpace on 2018-11-28T07:23:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-03-21 Embrapa (Brazil) Genomic Selection in Dairy Cattle in Brazil Embrapa (Brazil) National network for development of innovative genomic strategies applied to animal breeding, conservation and production (PI - ARC) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Whole-genome re-sequencing, alignment and annotation analyses were undertaken for 12 sires representing four important cattle breeds in Brazil: Guzerat (multi-purpose), Gyr, Girolando and Holstein (dairy production). A total of approximately 4.3 billion reads from an Illumina HiSeq 2000 sequencer generated for each animal 10.7 to 16.4-fold genome coverage. A total of 27,441,279 single nucleotide variations (SNVs) and 3,828,041 insertions/deletions (InDels) were detected in the samples, of which 2,557,670 SNVs and 883,219 InDels were novel. The submission of these genetic variants to the dbSNP database significantly increased the number of known variants, particularly for the indicine genome. The concordance rate between genotypes obtained using the Bovine HD BeadChip array and the same variants identified by sequencing was about 99.05%. The annotation of variants identified numerous non-synonymous SNVs and frameshift InDels which could affect phenotypic variation. Functional enrichment analysis was performed and revealed that variants in the olfactory transduction pathway was over represented in all four cattle breeds, while the ECM-receptor interaction pathway was over represented in Girolando and Guzerat breeds, the ABC transporters pathway was over represented only in Holstein breed, and the metabolic pathways was over represented only in Gyr breed. The genetic variants discovered here provide a rich resource to help identify potential genomic markers and their associated molecular mechanisms that impact economically important traits for Gyr, Girolando, Guzerat and Holstein breeding programs. Univ Estadual Paulista, Dept Ciencias Exatas, Fac Ciencias Agrarias & Vet, Sao Paulo, Brazil Embrapa Informat Agr, Campinas, SP, Brazil Embrapa Recursos Genet & Biotecnol, Brasilia, DF, Brazil Iowa State Univ, Dept Anim Sci, Ames, IA USA Embrapa Gado Leite, Juiz De Fora, MG, Brazil Univ Fed Minas Gerais, Dept Biol Geral, Belo Horizonte, MG, Brazil ARS, USDA, Anim Genom & Improvement Lab, Beltsville, MD USA Univ Estadual Paulista, Dept Ciencias Exatas, Fac Ciencias Agrarias & Vet, Sao Paulo, Brazil Embrapa (Brazil) Genomic Selection in Dairy Cattle in Brazil: SEG 02.09.07.008.00.00 Embrapa (Brazil) National network for development of innovative genomic strategies applied to animal breeding, conservation and production (PI - ARC): SEG 01.11.07.002.00.00 CNPq: PVE 407246/2013-4 FAPEMIG: CVZ PPM 00395/14 FAPESP: 15/08939-0

The objective of this work was to determine whether the random regression model using linear splines (RRMLS) is suitable to estimate the genetic parameters for productive and reproductive traits of a multiple-breed dairy cattle population, as well as to investigate the effect of the genetic group of the progeny on the genetic merit of the sire. The multiple-trait model (MTM) and the RRMLS with one knot fitted for every genetic group were used to obtain the genetic parameters. Records of 1/2 Holstein + 1/2 Gyr (1/2HG), 5/8 Holstein + 3/8 Gyr (5/8HG), and 3/4 Holstein + 1/4 Gyr (3/4HG) crossbreed dams were considered. The RRMLS showed better fitting. The additive and residual variances estimated by the MTM and the RRMLS were similar. Heritability varied from 0.20 to 0.33 for age at first calving, from 0.09 to 0.22 for first lactation length, and from 0.15 to 0.35 for first lactation 305-day milk yield, according to the genetic composition of the dams. The RRMLS is suitable to estimate the genetic parameters for productive and reproductive traits of multiple-breed dairy cattle populations. The genetic merit of the sires is affected by the genetic group of the progeny by which they are evaluated. Made available in DSpace on 2017-12-23T23:34:33Z (GMT). No. of bitstreams: 1 Cnpgl2017PABGenetic.pdf: 426369 bytes, checksum: d2acd3973422b1fe120386e4bb35bcd9 (MD5) Previous issue date: 2017-12-22 Título em português: Análise genética de características produtivas e reprodutivas em populações multirraciais de bovinos leiteiros.

Made available in DSpace on 2017-11-20T23:31:34Z (GMT). No. of bitstreams: 1 Cnpgl2017RevBrasZootInfrared.pdf: 1742584 bytes, checksum: 140e37615fe7436aac110ed6a92a7b29 (MD5) Previous issue date: 2017-11-20

Made available in DSpace on 2018-12-11T17:31:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-02-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The aim of this study was to evaluate the level of introgression of breeds in the Canchim (CA: 62.5% Charolais-37.5% Zebu) and MA genetic group (MA: 65.6% Charolais-34.4% Zebu) cattle using genomic information on Charolais (CH), Nelore (NE), and Indubrasil (IB) breeds. The number of animals used was 395 (CA and MA), 763 (NE), 338 (CH), and 37 (IB). The Bovine 50SNP BeadChip from Illumina panel was used to estimate the levels of introgression of breeds considering the Maximum likelihood, Bayesian, and Single Regression method. After genotype quality control, 32,308 SNPs were considered in the analysis. Furthermore, three thresholds to prune out SNPs in linkage disequilibrium higher than 0.10, 0.05, and 0.01 were considered, resulting in 15,286, 7,652, and 1,582 SNPs, respectively. For k = 2, the proportion of taurine and indicine varied from the expected proportion based on pedigree for all methods studied. For k = 3, the Regression method was able to differentiate the animals in three main clusters assigned to each purebred breed, showing more reasonable according to its biological viewpoint. Analyzing the data considering k = 2 seems to be more appropriate for Canchim-MA animals due to its biological interpretation. The usage of 32,308 SNPs in the analyses resulted in similar findings between the estimated and expected breed proportions. Using the Regression approach, a contribution of Indubrasil was observed in Canchim-MA when k = 3 was considered. Genetic parameter estimation could account for this breed composition information as a source of variation in order to improve the accuracy of genetic models. Our findings may help assemble appropriate reference populations for genomic prediction for Canchim-MA in order to improve prediction accuracy. Using the information on the level of introgression in each individual could also be useful in breeding or crossing design to improve individual heterosis in crossbred cattle. Departamento de Ci�ncias Exatas Universidade Estadual Paulista (Unesp) Faculdade de Ci�ncias Agrarias e Veterinarias Beef Improvement Opportunities (BIO) Departamento de Ci�ncias Basicas Universidade de S�o Paulo (USP) Faculdade de Zootecnia e Engenharia de Alimentos (FZEA) Departamento de Zootecnia Universidade Estadual Paulista (Unesp) Faculdade de Ci�ncias Agrarias e Veterinarias Embrapa Southeast Livestock Embrapa Agricultural Informatics Faculdade de Agronomia e Medicina Veterin�ria Universidade de Passo Fundo Embrapa Dairy Cattle Department of Agricultural Food and Nutritional Science University of Alberta Lacombe Research and Development Centre Agriculture and Agri-Food Canada, 6000 C and E Trail Department of Animal and Poultry Science University of Guelph Centre for Genetic Improvement of Livestock (CGIL) Departamento de Ci�ncias Exatas Universidade Estadual Paulista (Unesp) Faculdade de Ci�ncias Agrarias e Veterinarias Departamento de Zootecnia Universidade Estadual Paulista (Unesp) Faculdade de Ci�ncias Agrarias e Veterinarias CAPES: 02663/09-0 CNPq: 449564/2014-2

RESUMO - O objetivo neste estudo foi avaliar a estrutura genética da população de bovinos da raça Girolando no Brasil. Analisou-se o arquivo de pedigree de 26.969 animais, composto de 3.031 machos e 23.938 fêmeas. O nível de conteúdo de informação do pedigree na geração atual foi 61%, mostrando ser de qualidade moderada. O coeficiente de endogamia médio e o coeficiente de relação médio da população Girolando foram 0,11 e 0,13%, respectivamente. O tamanho efetivo da população, considerando a geração completa traçada, foi 188, acima do nível crítico. Do total de 9.457 ancestrais que contribuíram para a população de referência, 457 explicaram 50% da variabilidade genética da população. O número efetivo de fundadores foi 551 e o de ancestrais 393. O intervalo médio de geração foi de 5,26 anos, sendo ligeiramente maior nas trilhas gaméticas mãe-filho e pai-filha. A partir dos coeficientes estimados, pode-se concluir que a endogamia nos rebanhos da raça Girolando foi de pequena magnitude e que as práticas de acasalamento foram adequadas durante o período avaliado. No entanto, é importante continuar com o monitoramento desses coeficientes a fim de prevenir perda de variabilidade genética. ABSTRACT - The aim of this study was to evaluate the population structure of Girolando cattle in Brazil. The pedigree file contained 26,969 individuals, from which 3,031 were males and 23,938 were females. The average level of completeness of the pedigree in the current generation was of reasonable quality (61%). Inbreeding and average relatedness coefficients were low: 0.11 and 0.13%, respectively. Estimates of effective population size considering the full generations traced was 188, which is above the critical level range. The number of ancestors that contributed to the reference population was 9,457 animals, from which 457 explained 50% of the genetic variability of the population. The effective number of founders and the effective number of ancestors in this population were, respectively, 551 and 393. The average generation interval was 5.26 years, slightly higher in genetic pathways dam-son and sire-daughter. The inbreeding in the Girolando breed was of small magnitude, indicating that the current practices of mating were adequate during the study period. However, it is important to continue monitoring these coefficients in order to prevent loss of genetic variability.

Made available in DSpace on 2014-12-03T13:08:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-04-14Bitstream added on 2014-12-03T13:23:21Z : No. of bitstreams: 1 WOS000336970400107.pdf: 784251 bytes, checksum: 64e08e6e41d1cf9590f0c3af2df34a38 (MD5) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) University of Guelph Studies are being conducted on the applicability of genomic data to improve the accuracy of the selection process in livestock, and genome-wide association studies (GWAS) provide valuable information to enhance the understanding on the genetics of complex traits. The aim of this study was to identify genomic regions and genes that play roles in birth weight (BW), weaning weight adjusted for 210 days of age (WW), and long-yearling weight adjusted for 420 days of age (LYW) in Canchim cattle. GWAS were performed by means of the Generalized Quasi-Likelihood Score (GQLS) method using genotypes from the BovineHD BeadChip and estimated breeding values for BW, WW, and LYW. Data consisted of 285 animals from the Canchim breed and 114 from the MA genetic group (derived from crossings between Charolais sires and 1/2 Canchim + 1/2 Zebu dams). After applying a false discovery rate correction at a 10% significance level, a total of 4, 12, and 10 SNPs were significantly associated with BW, WW, and LYW, respectively. These SNPs were surveyed to their corresponding genes or to surrounding genes within a distance of 250 kb. The genes DPP6 (dipeptidyl-peptidase 6) and CLEC3B (C-type lectin domain family 3 member B) were highlighted, considering its functions on the development of the brain and skeletal system, respectively. The GQLS method identified regions on chromosome associated with birth weight, weaning weight, and long-yearling weight in Canchim and MA animals. New candidate regions for body weight traits were detected and some of them have interesting biological functions, of which most have not been previously reported. The observation of QTL reports for body weight traits, covering areas surrounding the genes (SNPs) herein identified provides more evidence for these associations. Future studies targeting these areas could provide further knowledge to uncover the genetic architecture underlying growth traits in Canchim cattle. UNESP Univ Estadual Paulista, Dept Ciencias Exatas, Fac Ciencias Agr & Vet, Sao Paulo, Brazil Univ Guelph, Dept Anim & Poultry Sci, CGIL, Guelph, ON N1G 2W1, Canada BIO, Guelph, ON, Canada Semex Alliance, Guelph, ON, Canada Fed Univ Lavras UFLA, Dept Anim Sci, Lavras, MG, Brazil Fed Univ Sao Carlos UFSCar, Dept Genet & Evolut, Sao Paulo, Brazil Embrapa Southeast Livestock, Sao Paulo, Brazil Embrapa Agr Informat, Sao Paulo, Brazil Embrapa Dairy Cattle, Juiz De Fora, MG, Brazil Embrapa Beef Cattle, Campo Grande, MS, Brazil UNESP Univ Estadual Paulista, Dept Ciencias Exatas, Fac Ciencias Agr & Vet, Sao Paulo, Brazil CNPq: 142053/2010-4 CAPES: 5285-11-9

Background: Meat quality involves many traits, such as marbling, tenderness, juiciness, and backfat thickness, all of which require attention from livestock producers. Backfat thickness improvement by means of traditional selection techniques in Canchim beef cattle has been challenging due to its low heritability, and it is measured late in an animal?s life. Therefore, the implementation of new methodologies for identification of single nucleotide polymorphisms (SNPs) linked to backfat thickness are an important strategy for genetic improvement of carcass and meat quality. Results: The set of SNPs identified by the random forest approach explained as much as 50% of the deregressed estimated breeding value (dEBV) variance associated with backfat thickness, and a small set of 5 SNPs were able to explain 34% of the dEBV for backfat thickness. Several quantitative trait loci (QTL) for fat-related traits were found in the surrounding areas of the SNPs, as well as many genes with roles in lipid metabolism. Conclusions: These results provided a better understanding of the backfat deposition and regulation pathways, and can be considered a starting point for future implementation of a genomic selection program for backfat thickness in Canchim beef cattle.

El núcleo de formación del ecotipo Mantiqueira perteneciente al Instituto de Zootecnia, SP, Brasil, fue creado en 1952 con 50 animales originados a partir de cruzamientos ocurridos entre la raza Frisona y el ganado Criollo de la región de la Sierra de Mantiqueira, SP. Estos animales presentan características morfológicas bien definidas, buena producción lechera y adaptabilidad a los sistemas tradicionales de producción. Se analizó el pedigrí de 2070 animales, correspondientes a 1920 vacas, hijas de 150 sementales, con el objetivo de evaluar la variabilidad genética a través de la genealogía y estimar la frecuencia media de endogamia por generación. Made available in DSpace on 2022-08-11T17:19:51Z (GMT). No. of bitstreams: 1 Estimacion-de-la-variabilidad-genetica-atraves-de-la-genealogia-en-el-ganado.pdf: 26596 bytes, checksum: 017c1268926d2abb0ed920af588cef2d (MD5) Previous issue date: 2007

A identificação de QTLs (Quantitative trait lócus) visa auxiliar os programas de melhoramento permitindo a seleção de características economicamente importantes. Neste trabalho a associação entre o marcador ILSTS011 do cromossomo 14 de bovinos e a característica peso ao nascimento (PN), foi investigada em uma população de 294 animais provenientes dos cruzamentos entre as raças Gir e Holandês, produzidos na Embrapa Gado de Leite. A genotipagem do marcador ILSTS011 foi feita através do sequenciador automático. Os resultados da análise de substituição de alelos deste marcador sobre PN sugerem efeito negativo de um alelo que originou-se nesta população da raça Gir. Made available in DSpace on 2015-02-11T08:51:24Z (GMT). No. of bitstreams: 1 Binder1.pdf: 1515297 bytes, checksum: f0f0df836a66b6b84e645f84aae2a149 (MD5) Previous issue date: 2004-07-15