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Navegando Programa de Pós-graduação em Zootecnia por Assunto "Adaptability"
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Item Índices microclimáticos e indicativos de estresse térmico em bovinos de corte(Universidade Federal de Goiás, 2018-08-13) Karvatte Junior, Nivaldo; Alves, Fabiana Villa; http://lattes.cnpq.br/1153061642306224; Miyagi, Eliane Sayuri; http://lattes.cnpq.br/5838290185532582; Miyagi, Eliane Sayuri; Almeida, Roberto Giolo de; Santos, Darliane de Castro; Ferro, Diogo Alves da Costa; Ferro, Rafael Alves da CostaThe objective was to use microclimatic indexes and to propose indicators of thermal stress in beef cattle to evaluate animal production systems. For that, two experiments were carried out: (i) using infrared thermography to evaluate microclimate and thermal comfort in silvopastoral systems; and (ii) evaluating the physiological adaptability of beef cattle in feedlot and pasture submitted to thermal stress. The first experiment was conducted at the Empresa Brasileira de Pesquisa Agropecuária, in Campo Grande, Mato Grosso do Sul, from June 2015 to February 2016. The evaluations were carried out in two silvopastoral systems with different densities and spatial arrangements of cultivated and native trees, from 08h to 16h, with intervals of one hour between evaluations. Infrared radiation emissions of temperature (°C) and humidity (%) of the canopy and pasture surface were recorded, in the shadow projection and in the full sun. At the same time, the microclimatic parameters were evaluated and the main thermal comfort indeces were subsequently calculated. Variations of canopy and pasture temperature and humidity were observed, with direct influences on microclimate and animal thermal comfort. The greatest fluctuations occurred during the summer and at noon with substantial improvements in the environment under the canopy. The Principal Components Analysis extracted two components in order of their importance to explain 70.6% of the total variance observed between the variables. Moderate and strong correlations (r ≥ 0.63; or, r ≤ 0.80) showed positive linear effects (R²adj ≥ 0.40, or, ≤ 0.63) between thermography, microclimate and thermal comfort indeces. The results show that temperatures and humidities of canopy and pasture surfaces can be continuously monitored using infrared thermal imagers, making it a potential tool (r ≥ 0.53; or, r ≤ 0.78) for microclimate prediction and thermal comfort in silvopastoral systems. The second experiment was conducted on farms located in Civitella Paganico, Grosseto province, Italy, in partnership with Università di Pisa (Italy), from May to September 2017, using 60 animals (20 Aubrac, 20 Maremmano and 20 ½ Maremmano x ½ Piemontês) divided into two production systems (confinement and pasture). Cortisol in the hair, physiological variables (rectal, hair and skin temperatures, cardiac and respiratory frequency) and hematological variables (complete blood count) were evaluated. No effects of production system were observed (P> 0.05). However, the effects of genetic groups, the evaluation period and the interaction between genetic groups and production systems significantly affected (P <0.05) all evaluated parameters. The crossbreed genetic group had the highest concentrations of cortisol during the whole experimental period, favoring the greater variations in the physiological parameters and being more susceptible to chronic stress. Non-invasive methods, such as the sampling of hairs on animals and the application of infrared thermography for the evaluation of production systems, contribute to the advancement of scientific research in several areas of knowledge.Item Marcadores moleculares na identificação de corridas de homozigose e endogamia nas raças curraleiro pé-duro e pantaneiro(Universidade Federal de Goiás, 2021-11-25) Santos, Marcelo Fernandes dos; Magnabosco, Claudio Ulhoa; http://lattes.cnpq.br/1852112832119187; Rey, Fernando Sebastián Baldi; http://lattes.cnpq.br/2142265309634106; Carmo, Adriana Santana do; http://lattes.cnpq.br/0782572407995106; Carmo, Adriana Santana do; Freitas, Thais Miranda Silva; Leite, Carla Daniela SuguimotoThe runs of homozygosity (ROHs) can be used to estimate more accurate population parameters and genomic regions under selection in different species and breeds. Therefore, this approach can be used in locally adapted breeds to identify genes of economic interest and estimate autozygosity, enabling the optimization of selection and mating strategies and mitigating their extinction risk. The objective of this work is to identify and characterize the ROHs present in locally adapted breeds Curraleiro Pé-Duro (CPD) and Pantaneiro (PANT) in order to identify genes under selection and estimate their inbreeding coefficient (FROH). The ROHs were identified in 126 and 35 animals of the CPD and PANT breeds, respectively, with data from 54,000 SNP markers. For the identification of ROHs, the following criteria were used: a) sliding window of 50 SNPs, b) minimum number of 100 consecutive SNPs in each ROH, c) minimum length of 1 Mb, c) maximum interval between homozygous consecutive SNPs of 0, 5 Mb, d) maximum of five SNPs with absent genotypes, 1083 and 140 ROHs were found in the CPD and PANT breeds, respectively, and that the predominant pattern of ROHs in the studied breeds are those of medium to long size, which demonstrates recent events of autozygosity. Six islands of homozygosity were identified in both breeds on autosomal chromosomes 6, 8, 10, 13, 14 and 17. Genes and QTLs previously related to traits of interest are located in the segments found, highlighting QTLs associated with production and quality traits of milk (57%), as those involved in the content of proteins such as caseins and genes associated with the immune system, such as the genes of the beta defensin family. The estimated inbreeding coefficient showed that both breeds have low autozygosity (2-4%), which differs from what is expected for populations with a reduced genetic base such as those studied. The present work identified six homozygous islands in common in the Curraleiro Pé-Duro and Pantaneiro breeds, located in genomic regions previously reported to be associated with characteristics of economic interest, such as disease resistance and milk protein content, which can be considered candidate regions the selection. The inbreeding coefficient estimated based on the ROHs showed that inbreeding is low (2 to 4%) in the studied populations, diverging from what was expected in small populations.Item Identificação de assinaturas de seleção e variações no número de cópias em bovinos da raça Curraleiro Pé-Duro(Universidade Federal de Goiás, 2020-02-27) Teixeira, Ana Lúcia Coutinho; Mascioli, Arthur dos Santos; http://lattes.cnpq.br/6557055478323026; Carmo, Adriana Santana do; http://lattes.cnpq.br/0782572407995106; Carmo, Adriana Santana do; Hellmeister Filho, Paulo; Freitas, Thais Miranda SilvaThe use of new molecular technologies in animal production has grown significantly in recent years, as it allows us to understand the genetic architecture of the traits of interest. Thus, the present work aimed to identify the selection signatures and the copy number variations (CNVs) present in Curraleiro Pé-Duro (CPD), in order to identify genes related to the productive and adaptive capacity of this breed. For this purpose, Illumina® BovineHD BeadChip genotypes of 120 CPD cattle from 20 different properties were used. For selection signature detection, the quality control of SNPs was performed based on the SNP and sample call rate equal to or greater than 90% and SNPs with minor allelic frequency less than 3% using the software Plink. The construction of chromosomal haplotypes was performed using the Beagle software. Signatures were identified by the following methodologies: Haplotype Integration Score (iHS), Extended Haplotype Homozygosis (EHH) and Long Range Haplotype Test (LRH). The identification of CNVs was performed using PennCNV software, adjusting the Guanine and Cytosine (GC) content of a 500 base pair (bp) genomic window. Quality control was performed using LRR standard deviation less than 0.3, BAF standard deviation less than 0.01 and wave factor less than 0.05, samples with more than 150 CNVs and markers smaller than 5,000 bp has been removed. The identification of selection signatures proved to be effective in identifying genomic regions associated with production traits, and they are mainly related to adaptability, as they are related to thermotolerance and disease resistance. CNVs are in regions of the genome that harbor genes related to thermotolerance, reproduction and negative energy balance. The results found in both studies reinforce regions of the BTA 20 chromosome as potential candidates for the selection of these characteristics.