Doutorado em Zootecnia (EVZ)

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    Associação e seleção genômica para eficiência alimentar em bovinos Nelore
    (Universidade Federal de Goiás, 2021-02-22) Brunes, Ludmilla Costa; Rey, Fernando Sebastian Baldi;; Lopes, Fernando Brito;; Magnabosco, Cláudio Ulhoa;; Magnabosco, Cláudio Ulhoa; Mascioli, Arthur dos Santos; Carmo, Adriana Santana do; Coelho, Alexandre Siqueira Quedes; Costa, Marcos Fernando Oliveira e
    The aim of this study was to estimate genetic parameters for feed efficiency, growth, reproductive and carcass traits in commercial Nelore cattle herds, and the correlated response between them. It was also aimed perform a study of genomic selection evaluating prediction methods, validation approaches and pseudo-phenotypes, and conduct a weighted single-step genome-wide association study and an enrichment analysis for feed efficiency of feed efficiency related traits. Residual feed intake (RFI), dry matter intake (DMI), feed conversion ratio (FCR), feed efficiency (FE), residual live weight gain (RG), residual intake and live weight gain (RIG), birth weight (BW), weight at 120 (W120), 240 (W240), 365 (W365), and 450 (W450) days of age, scrotal circumference at 365 (SC365) and 450 (SC450) days of age, rib eye area (REA), backfat thickness (BF) and rump fat thickness (RF) were evaluated. The growth, reproductive and carcass traits records from 15,639 Nelore cattle were used. Data from feed efficiency tests carried out between 2011 and 2018, with phenotypic and genotypic information of 4,329 and 3,594 animals, respectively, were considered. The genetic parameters were estimated in a single step approach (ssGBLUP). Six prediction methods of genomic breeding values (GEBVs) were used: ssGBLUP, Bayes A, Bayes B, Bayes Cπ, BLASSO, and Bayes R. Three validation approaches were used: 1) random: the data set was randomly divided into ten subsets and the validation was done in each subset at a time; 2) age: the population was divided into training and validation set based on the year of birth, with the first group consisting of animals born between 2010 and 2016 and the second group born in 2017; 3) genetic breeding value (EBV) accuracy: were divided into two groups, with animals with accuracy above 0.45 considered as the training population, and below 0.45 the validation set. We checked the accuracy and bias of GEBV. The percentage of variance explained by windows of 10 adjacent SNPs was used to identify regions that explained more than 0.5% of the additive genetic variance on each trait. The feed efficiency related traits showed low to moderate heritabilities, ranging from 0.07 to 0.20. Feed efficiency related traits showed low genetic correlations with growth (-0.19 to 0.24), reproductive (-0.24 to 0.27) and carcass (-0.17 to 0.27) traits, except for growth with DMI (0.32 to 0.56) and FE (-0.40). The results showed that the prediction ability were similar between the prediction methods. The low heritability obtained, mainly for FE (0.07±0.03) and FCR (0.09±0.03), limited the GEBVs accuracy, which ranged from low to moderate. The regression coefficient estimates were close to 1, and similar between the prediction methods, validation approaches, and pseudophenotypes. On average and despite low variation (0.0331), the random cross-validation presented the most accurate predictions, ranging from 0.07 to 0.037, than EBV accuracy and age. The prediction ability was higher for phenotype adjusted for fixed effects than for EBV and EBV deregressed (30.0 and 34.3%, respectively). Enrichment analysis by The Database for Annotation, Visualization and Integrated Discovery (DAVID) revealed several functional vias such as neuropeptide signaling pathway (GO:0007218), negative regulation of canonical Wnt signaling pathway (GO:0090090), detection of chemical stimulus involved in sensory perception of bitter taste (GO:0001580), bitter taste receptor activity (GO:0033038), neuropeptide hormone activity (GO:0005184), bile secretion (bta04976), taste transduction (bta0742), and glucagon signaling pathway (bta04922). The selection to improve growth, reproductive and carcass traits would not change RFI, RG, and RIG. On the other hand, DMI, FE and FCR may lead to an increase in body weight, in addition to the selection for FCR may lead to a reduction in carcass yield. The genetic background of feed efficiency related traits are different, which would lead to different genetic responses. The choice of the most adequate selection criterion depends on the production system and goals. Genomic prediction methods can provide a reliable estimate of genomic breeding values for RFI, DMI, RG and RGI, traits that may have higher genetic gain and selection viability than FE and FCR. Enrichment analyzes showed genes associated with in insulin, leptin, glucose, protein and lipid metabolism, energy balance, heat and oxidative stress, zinc finger system, bile secretion, satiety, feed behavior, salivation, digestion and absorption of nutrients. The identification of these genomic regions and their respective genes provide information about genetic basis and biologic regulation for Nelore feed efficiency related traits.
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    Índices microclimáticos e indicativos de estresse térmico em bovinos de corte
    (Universidade Federal de Goiás, 2018-08-13) Karvatte Junior, Nivaldo; Alves, Fabiana Villa;; Miyagi, Eliane Sayuri;; Miyagi, Eliane Sayuri; Almeida, Roberto Giolo de; Santos, Darliane de Castro; Ferro, Diogo Alves da Costa; Ferro, Rafael Alves da Costa
    The 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.
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    O nitrato encapsulado aumenta a eficiência de utilização do suplemento para bovinos de corte em pastejo
    (Universidade Federal de Goiás, 2021-12-14) Figueiredo, Cibelle Borges; Fernandes, Juliano José de Resende;; Silva, Maurícia Brandão da;; Couto, Victor Rezende Moreira;; Couto, Victor Rezende Moreira; Cunha, Paulo Henrique Jorge da; Cabral Filho, Sergio Lucio Salomon; Ribeiro, Marinaldo Divino; Araújo, Rafael Canonenco de
    Encapsulated nitrate has been pointed out as a promising tool for reducing methane production by ruminant animals. The objective was to evaluate, in Chapter 2, the effects of the use of encapsulated nitrate on the performance of beef cattle on pasture in the dry season, dry transition of water and water, and in Chapter 3 the fermentative parameters in in vitro assays using substrates in proportions and similar compositions of the performance experiment. The evaluated treatments were: Control – protein-energy supplement without inclusion of encapsulated nitrate, and EN – protein-energy supplement with inclusion of 50 g of encapsulated nitrate per kg of dry matter. In the performance experiment (Chapter 2), the supplement was given daily at 1.0% of body weight. The leftover concentrate was weighed daily to estimate supplement intake. The animals were weighed every 28 days, and the rate of supplement consumption was also evaluated. There was a reduction in supplement dry matter intake with the inclusion of EN in the supplement in the dry period (P < 0.01) (2.404 to 2.283 kg/day), dry-water transition (P < 0.01) (2.922 kg to 2.496 kg/day), water (P < 0.01) (3.631 to 3.143 kg/day) and total period (P < 0.01) (2.943 to 2.605 kg/day). The average daily gain was not influenced by the inclusion of NE in any of the evaluated periods (P > 0.13). The inclusion of EN resulted in an increase in the feed efficiency of the animals in the dry-water transition period from 0.362 to 0.411 (P < 0.01). In Chapter 3, three experiments were carried out, corresponding to the dry season, dry-water transition and water, in order to evaluate the Control and EN treatments. The evaluation times were zero, three, six, nine, 12, 24 and 48 hours after incubation. Each time was composed of its respective triplicates. In these times, the in vitro degradability of dry matter (IVDDM) and neutral detergent fiber (IVDNDF), ammonia nitrogen (N-NH3), methane and gas production were evaluated. At 24 hours, the production of short-chain fatty acids (SCFA) was evaluated. There was a reduction in methane production from 22.2 to 19.3 mg (P < 0.01) in the dry season. The total incubation time (48 hours) was marked with a 5% reduction in IVDDM with inclusion in EN (741.4 vs 703.9 g/kg) (P < 0.02) in the dry transition season substrate. waters. An increase in the molar proportion of acetate from 14.36 to 20.33 mM/L (P < 0.04) was observed with the inclusion of encapsulated nitrate in the wet season substrate. There was no significant effect of including nitrate in the wet season substrate on IVDDM and IVDNFD (P > 0.06). The inclusion of encapsulated nitrate in the proportion of 50 g/kg of supplement DM increases the feed efficiency of grazing animals, and reduces the methane production with the use of dry season forage.
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    Atividade antimicrobiana de extratos vegetais em frangos de corte de crescimento lento desafiados com Salmonella Heidelberg
    (Universidade Federal de Goiás, 2019-03-08) Mota, Lorena Cunha; Mascarenhas, Alessandra Gimenez;; Leandro, Nadja Susana Mojyca;; Leandro, Nadja Susana Mogyca; Melo, Francislete Rodrigues; Nunes, Romão da Cunha; Café, Marcos Barcellos; Mello, Heloisa Helena de Carvalho
    Two experiments were carried out with the objective of evaluating the antimicrobial activity of native extracts of native species of Brazilian Cerrado. The first experiment was carried out in vitro using seven ethanolic plant extracts native to the Brazilian cerrado (Barbatimão (Stryphnodendron adstringens), Jacaranda (Machaerium villosum), Jenipapo (Genipa americana), Pau-terra (Qualea parviflora), Pau- (Brosimum gaudichaudii), to evaluate the total phenolic compounds, antioxidant activity and antimicrobial activity against Salmonella Heidelberg. The phenolic compounds of the plant extracts were determined by spectroscopy in the visible region, using the Folin-Ciocalteau method. The determination of the antioxidant capacity of the plant extracts was carried out using the ABTS solution free radical sequestration method. The in vitro antimicrobial activity of the seven ethanolic extracts against Salmonella Heidelberg was performed using the disc diffusion method. In the second experiment were performed performance tests, intestinal development, bacteriology and blood biochemistry of slow-growing chickens challenged with Salmonella Heidelberg and treated with woodland plant extract. A total of 432 broiler chickens were used. The roasted red roasted roasted roasted red roasted roe were distributed in six treatments, six replicates and 12 birds per experimental unit. The experimental design was randomized blocks distributed in six treatments: SH + control (birds with challenge + basal ration); SH + EVT (challenged birds + antimicrobial ration), SH + EVPT (control + challenged birds), control (birds without challenge + basal ration), ANT (unchallenged birds + antimicrobial ration) and EVPT challenge + plant extract). Performance, intestinal histomorphometry, specific bacteriology and blood biochemistry were evaluated. The results of the antimicrobial analysis of Salmonella Heidelgerb extracts were submitted to analysis of variance (ANOVA). The data of phenolic compounds and antioxidants were submitted to descriptive analysis. The performance data, histomorphometry and blood biochemistry were submitted to the test of variance. Data from the specific bacteriology were analyzed by descriptive method. The data of phenolic compounds and antioxidants were submitted to descriptive analysis. The ethanolic vegetal extracts varied from 6.48 to 59.81 g EAG / mL of total phenolic compounds and 595 to 1098.33 μmol / L of antioxidant activity. The ethanolic extract of Pau-terra presented moderate antimicrobial activity against Salmonella Heidelberg (halo diameter 9.5%). In the results of the performance evaluation the ANT treatment promoted greater weight gain and higher final weight of the birds and the SH + EVPT treatment influenced in lower weight gain and lower final weight. In the evaluation of the histomorphometry of the segments of the gastrointestinal tract histoformetrium of the chick embryo of slow growth slow crypt depth in the mucosa was higher in the birds submitted to the SH + EVPT treatment and, the lower in the birds submitted to SH + crypt for SH + control birds and reduction in the ratio for SH + EVPT treated birds. The treatments did not influence the studied parameters of the duodenum and jejunum of seven - day - old birds. The SH + EVPT treatment promoted crypt depth increase, and the SH + control treatment reduced crypt depth. In the birds of 42 days of age the treatment promoted EVPT promoted jejunal villus height and SH + control reduced jejunal villus height. In the ilium SH + EVPT treatment promoted villus enlargement and ANT treatment reduced villus height. The SH + control treatment reduced the crypt depth of the ilium and the SH + EVPT treatment increased the crypt depth of the ilium. In bacteriology, 75% of the gastrointestinal tract presented Salmonella Heidelberg at 7 days of age, 58% at 28 days of age and 16.66% at 42 days of age. The concentration of albumin, cholesterol, triglycerides and uric acid was influenced by the treatments. The ethanolic extracts of Barbatimão Jacarandá, Mama-bitch, Jenipapo, Pau-ferro and Murici did not present antimicrobial activity against Salmonella Heidelberg (diameter of halo 5mm). The ethanolic extract of Pau-terra, offered in drinking water, using a concentration of 1: 1000 and supplied once a day to slow-growing chickens does not promote the performance improvement of chickens up to 28 days of age and has no activity antimicrobial activity against Salmonella Heldelberg.
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    Análise multifatorial e preditores para características de importância econômica de matrizes suínas em granja multiplicadora
    (Universidade Federal de Goiás, 2021-09-30) Leal, Guilherme Brunno de Medeiros; Café, Marcos Barcellos;; Antunes, Robson Carlos;; Carmo, Adriana Santana do;; Carmo, Adriana Santana do; Mascarenhas, Alessandra Gimenez; Cadavid, Verónica González; Leite, Carla Daniela Suguimoto; Masciol, Arthur dos Santos
    The present work aimed to investigate the relationship between the productive characteristics and to identify the factors that affect the number of weaned piglets (NLD) per sow/year, the accumulated productivity in kilograms (kg) of weaned piglets (LD) per sow/year and the productive longevity of swine breeders in order to support the selection process of a breeding farm. In chapter 2, factor analyzes were performed in order to understand the relationship between the characteristics and multiple linear regression to identify the main predictor variables for the variables NLD per matrix/year and accumulated productivity in kg of LD per matrix/year. In chapter 3, the females were evaluated as to their longevity, according to two distinct stayability criteria, STAY1 and STAY2, which consider as longevity, respectively, the females that presented the number of live born piglets (NLNV) and kilogram of piglets weaned to the fourth parturition above the herd average. It was identified by the main latent factors that 55% variance between breeders on the farm is explained by the characteristics of maternal ability, piglet viability, fertility and perinatal mortality. The best regression models for prediction explained approximately 66% of the variation both for the NLD traits and for the total weight of weaned piglets adjusted for 21 days (PTD21), evidencing the characteristics number of stillborn piglets (NLNAT), number of dead piglets at birth (NLMN), mean piglet birth weight (PMN) and number of piglets weaned (NLD) with common explanatory factors. It was not possible to obtain a good predictive model for the characteristic mean weight of weaned piglets adjusted to 21 days (PD21) in the present study. The analysis of females by NLNV and PD21 categories indicated that sows that present NLNV below the herd average do not have the potential to exhibit an adequate accumulated production under the evaluated conditions of the farm. The best predictive models for female longevity by STAY1 criteria include age at first mating (IPC) and NLNV and for STAY2 it included only IPC. The prediction model proposed for STAY1 was more efficient (78%) than for STAY2 (55%). Selection for STAY1 can be performed with the NLNV of the first calving, while for STAY2 should preferably be performed later, by the accumulated NLD of the first three calvings. Survival analysis showed that by STAY1, females would be discarded later (8th parturition), when compared to STAY2 (6th parturition).