Navegando por Autor "Glória, Leonardo Siqueira"
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Item Accessing marker effects and heritability estimates from genome prediction by Bayesian regularized neural networks(Livestock Science, 2016-09) Glória, Leonardo Siqueira; Cruz, Cosme Damião; Vieira, Ricardo Augusto Mendonça; Resende, Marcos Deon Vilela de; Lopes, Paulo Sávio; Silva, Fabyano Fonseca e; Siqueira, Otávio H. G. B. Dias deRecently, there is an increasing interest on semi- and non-parametric methods for genome-enabled prediction, among which the Bayesian regularized artificial neural networks (BRANN) stand. We aimed to evaluate the predictive performance of BRANN and to exploit SNP effects and heritability estimates using two different approaches (relative importance-RI, and relative contribution-RC). Additionally, we aimed also to compare BRANN with the traditional RR-BLUP and BLASSO by using simulated datasets. The simplest BRANN (net1), RR-BLUP and BLASSO methods outperformed other more parameterized BRANN (net2, net3, … net6) in terms of predictive ability. For both simulated traits (Y1 and Y2) the net1 provided the best h2 estimates (0.33 for both, being the true h2=0.35), whereas RR-BLUP (0.18 and 0.22 for Y1 and Y2, respectively) and BLASSO (0.20 and 0.26 for Y1 and Y2, respectively) underestimated h2. The marker effects estimated from net1 (using RI and RC approaches) and RR-BLUP were similar, but the shrinkage strength was remarkable for BLASSO on both traits. For Y1, the correlation between the true fifty QTL effects and the effects estimated for the SNPs located in the same QTL positions were 0.61, 0.60, 0.60 and 0.55, for RI, RC, RR-BLUP and BLASSO; and for Y2, these correlations were 0.81, 0.81, 0.81 and 0.71, respectively. In summary, we believe that estimates of SNP effects are promising quantitative tools to bring discussions on chromosome regions contributing most effectively to the phenotype expression when using ANN for genomic predictions.Item Assessment of genome-wide prediction by using Bayesian regularized neural networks(Universidade Federal de Viçosa, 2015-05-25) Glória, Leonardo Siqueira; Silva, Fabyano Fonseca e; http://lattes.cnpq.br/4040549227019212Recently there is an increase interest to use nonparametric methods, such as artificial neural networks (ANN). In animal breeding, an especial class of ANN called Bayesian Regularized Neural Network (BRNN) has been preferable since it not demands a priori knowledge of the genetic architecture of the characteristic as assumed by the most used parametric methods (RR-BLUP, Bayes A, B, Cπ, BLASSO). Although BRNN has been shown to be effective for genomic enable prediction. The aim of the present study was to apply the ANN based on Bayesian regularization to genome-enable prediction regarding simulated data sets, to select the most relevant SNP markers by using two proposed methods, to estimate heritabilities for the considered traits, and to compare the results with two traditional methods (RR-BLUP and BLASSO). The simplest Bayesian Regularized Neural Network (BRNN) model gave consistent predictions for both traits, which were similar to the results obtained from the traditional RR-BLUP and BLASSO methods. The SNP importance identification methods based on BRNN proposed here showed correlation values (0.61 and 0.81 for traits 1 and 2, respectively) between true and estimated marker effects higher than the traditional BLASSO (0.55 and 0.71, respectively for traits 1 and 2) method. With respect to h 2 estimates (assuming 0.35 as true value), the simplest BRNN recovered 0.33 for both traits, thus outperforming the RR-BLUP and BLASSO, that, in average, estimated h 2 equal to 0.215.Item Intake, total apparent digestibility, and microbial efficiency of sheep fed pineapple waste silage in different planes of nutrition(Brazilian Journal of Animal Science, 2022-03-04) Cordeiro, Camila da Conceição; Fernandes, Alberto Magno; Oliveira, Tadeu Silva de; Camilo, Michele Gabriel; Baffa, Danielle Ferreira; Glória, Leonardo Siqueira; Bernardo, Sarah Ellen EduardoThe study aimed to nutritionally evaluate the silage of pineapple crop waste in sheep feeding in different planes of nutrition (L). We used eight growing sheep and four male castrated adults, in individual metabolic cages distributed in a switchback design with two treatments and three periods. The treatments were the different planes of nutrition: L = MEI⁄Mm, MEI⁄1.5Mm, and MEI⁄2.5Mm, in which L = MEI/Mm, MEI is the energy amount of the feed intake and Mm is the maintenance. We performed a digestibility trial of the diet composed of silage of pineapple crop waste, ground corn, and soybean meal. Data were analyzed using regression analysis. Nutrient intake behaved linearly according to the increase in the L, except for organic matter, which presented a quadratic behavior. Planes of nutrition did not affect protein and fiber digestible fractions. However, digestible fractions of fat and non-fibrous carbohydrates (NFC) increased with L. The indigestible fractions displayed a quadratic behavior with an increase in the L. Regarding the microbial synthesis efficiency, we observed a linear decrease with the increase in L. Thus, the silage of pineapple crop waste is a feed very rich in NFC. Besides, silage of pineapple crop waste presented a good alternative roughage during forage shortages. Diet inclusion of 2.5x the maintenance does not compromise the sheep performanceItem Multi-trait and repeatability models for genetic evaluation of litter traits in pigs considering different farrowings(Revista Brasileira de Saúde e Produção Animal, 2016-10) Costa, Edson Vinícius; Ventura, Henrique Torres; Figueiredo, Elsio Antônio Pereira; Silva, Fabyano Fonseca e; Glória, Leonardo Siqueira; Godinho, Rodrigo Mezêncio; Resende, Marcos Deon Vilela de; Lopes, Paulo SávioWe aimed to compare multi-trait and repeatability models to estimate genetic parameters for the traits number of piglets born alive (NBA) and alive at 3 week of age (NP3), litter weight at birth (LW0) and at 3 week of age (LW3), and mean piglet weight at birth (MW0) and at 3 week of age (MW3), considering the first three farrowings of Landrace sows. Heritability (h2) estimates showed an increasing pattern up to the third farrowing for LW0 and MW3. For NBA, NP3, LW3, and MW0 h2 increased from the first to the second and decreased from the second to the third farrowing. In general, heritability estimated in the repeatability model was lower than the mean of the estimates in the multi-trait model. The traits LWO, MW0, and MW3 presented high genetic correlation among different farrowings (0.961–0.997), while NBA, NP3, and LW3 (0.092–0.986) presented irregular values among farrowings. The corrected Akaike information criterion shows that the repeatability model is not indicated for almost all of the studied traits. These results indicate that the multi-trait model is recommended for genetic evaluation of the traits number of piglets born alive and alive at 3 week of age, litter weight and mean piglet weight at birth and 3 week of age, in different farrowings, as different traits.Item Polymorphism in the BIEC2-808543 locus and its association with growth curve in Brasileiro de Hipismo horse breed(Brazilian Journal of Animal Science, 2021-11-18) Costa, Érica Cristina Xisto da; Vieira, Ricardo Augusto Mendonça; Glória, Leonardo Siqueira; Soares, Maria Amélia MenckOur objective was to evaluate whether the single nucleotide polymorphism (SNP) BIEC2-808543, identified in some horse breeds, also occurs in the Brasileiro de Hipismo (BH) breed. In addition, we verified if this SNP is related to the growth curve profile of these animals for the variables body mass, height at withers, and height at croup, using nonlinear mixed models. For the DNA isolation, we collected blood samples from 167 young BH horses. We obtained the genotypes of these animals using the polymerase chain reaction-restriction fragment length polymorphism technique. For the association studies of this polymorphism with the growth curve in foals, we selected three traits: body mass, height at withers, and height at croup. Polymorphism C/T exists in BH horses and is significantly associated with the evaluated traits. Animals that presented the TT genotype were smaller and lighter when compared with animals of the CT and CC genotypes. By the Akaike information criterion, the model that best described the growth curve for the body mass variable is the Brody model associated with the power of the mean variance function. For the height at withers variable, the best-fit model was von Bertalanffy, adjusted without polymorphism effect in parameter b, associated with the asymptotic variance. For the height at croup trait, the model that best described the growth curve was Brody model, associated with asymptotic variance. This polymorphism represents a good molecular marker. Nonlinear models are promising for describing growth curves in horses, particularly by the possibility of associating SNP effects to model parametersItem Simulation of diets for dairy goats and growing doelings using nonlinear optimization procedures(Revista Brasileira de Zootecnia, 2016-08-03) Glória, Leonardo Siqueira; Abreu, Matheus Lima Corrêa; Rocha, Norberto Silva; Oliveira, Tadeu Silva de; Gomes, Raphael dos Santos; Rohem Júnior, Nardele Moreno; Bendia, Laila Cecília Ramos; Fernandes, Alberto MagnoThe objective of this study was to simulate total dry matter intake and cost of diets optimized by nonlinear programming to meet the nutritional requirements of dairy does and growing doelings. The mathematical model was programmed in a Microsoft Excel(r) spreadsheet. Increasing values of body mass and average daily weight gain for growing doelings and increasing body mass values and milk yield for dairy does were used as inputs for optimizations. Three objective functions were considered: minimization of the dietary cost, dry matter intake maximization, and maximization of the efficiency of use of the ingested crude protein. To solve the proposed problems we used the Excel(r) Solver(r) algorithm. The Excel(r) Solver(r) was able to balance diets containing different objective functions and provided different spaces of feasible solutions. The best solutions are obtained by least-cost formulations; the other two objective functions, namely maximize dry matter intake and maximize crude protein use, do not produce favorable diets in terms of costs.