Ribeirão Preto, Brazil
Ribeirão Preto, Brazil

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Laureano M.M.M.,Federal University of Amazonas | Bignardi A.B.,São Paulo State University | El Faro L.,Polo Regional Centro Leste | Cardoso V.L.,Polo Regional Centro Leste | And 2 more authors.
Animal | Year: 2012

Genetic parameters for test-day milk flow (TDMF) of 2175 first lactations of Holstein cows were estimated using multiple-trait and repeatability models. The models included the direct additive genetic effect as a random effect and contemporary group (defined as the year and month of test) and age of cow at calving (linear and quadratic effect) as fixed effects. For the repeatability model, in addition to the effects cited, the permanent environmental effect of the animal was also included as a random effect. Variance components were estimated using the restricted maximum likelihood method in single- and multiple-trait and repeatability analyses. The heritability estimates for TDMF ranged from 0.23 (TDMF 6) to 0.32 (TDMF 2 and TDMF 4) in single-trait analysis and from 0.28 (TDMF 7 and TDMF 10) to 0.37 (TDMF 4) in multiple-trait analysis. In general, higher heritabilities were observed at the beginning of lactation until the fourth month. Heritability estimated with the repeatability model was 0.27 and the coefficient of repeatability for first lactation TDMF was 0.66. The genetic correlations were positive and ranged from 0.72 (TDMF 1 and 10) to 0.97 (TDMF 4 and 5). The results indicate that milk flow should respond satisfactorily to selection, promoting rapid genetic gains because the estimated heritabilities were moderate to high. Higher genetic gains might be obtained if selection was performed in the TDMF 4. Both the repeatability model and the multiple-trait model are adequate for the genetic evaluation of animals in terms of milk flow, but the latter provides more accurate estimates of breeding values. © Copyright The Animal Consortium 2011.


Bignardi A.B.,São Paulo State University | El Faro L.,Polo Regional Centro Leste | Torres Junior R.A.A.,Embrapa Gado de Corte | Cardoso V.L.,Polo Regional Centro Leste | And 2 more authors.
Genetics and Molecular Research | Year: 2011

We analyzed 152,145 test-day records from 7317 first lactations of Holstein cows recorded from 1995 to 2003. Our objective was to model variations in test-day milk yield during the first lactation of Holstein cows by random regression model (RRM), using various functions in order to obtain adequate and parsimonious models for the estimation of genetic parameters. Test-day milk yields were grouped into weekly classes of days in milk, ranging from 1 to 44 weeks. The contemporary groups were defined as herd-test-day. The analyses were performed using a single-trait RRM, including the direct additive, permanent environmental and residual random effects. In addition, contemporary group and linear and quadratic effects of the age of cow at calving were included as fixed effects. The mean trend of milk yield was modeled with a fourth-order orthogonal Legendre polynomial. The additive genetic and permanent environmental covariance functions were estimated by random regression on two parametric functions, Ali and Schaeffer and Wilmink, and on B-spline functions of days in milk. The covariance components and the genetic parameters were estimated by the restricted maximum likelihood method. Results from RRM parametric and B-spline functions were compared to RRM on Legendre polynomials and with a multi-trait analysis, using the same data set. Heritability estimates presented similar trends during mid-lactation (13 to 31 weeks) and between week 37 and the end of lactation, for all RRM. Heritabilities obtained by multi-trait analysis were of a lower magnitude than those estimated by RRM. The RRMs with a higher number of parameters were more useful to describe the genetic variation of test-day milk yield throughout the lactation. RRM using B-spline and Legendre polynomials as base functions appears to be the most adequate to describe the covariance structure of the data. © FUNPEC-RP.


Bignardi A.B.,São Paulo State University | El Faro L.,Polo Regional Centro Leste | Santana M.L.,Federal University of Mato Grosso | Rosa G.J.M.,University of Wisconsin - Madison | And 4 more authors.
Livestock Science | Year: 2012

The objective of this paper is to model variations in test-day milk yields of first lactations of Holstein cows by RR using B-spline functions and Bayesian inference in order to fit adequate and parsimonious models for the estimation of genetic parameters. They used 152,145 test day milk yield records from 7317 first lactations of Holstein cows. The model established in this study was additive, permanent environmental and residual random effects. In addition, contemporary group and linear and quadratic effects of the age of cow at calving were included as fixed effects. Authors modeled the average lactation curve of the population with a fourth-order orthogonal Legendre polynomial. They concluded that a cubic B-spline with seven random regression coefficients for both the additive genetic and permanent environment effects was to be the best according to residual mean square and residual variance estimates. Moreover they urged a lower order model (quadratic B-spline with seven random regression coefficients for both random effects) could be adopted because it yielded practically the same genetic parameter estimates with parsimony. © 2012 Elsevier B.V.


Bignardi A.B.,São Paulo State University | El Faro L.,Polo Regional Centro Leste | Rosa G.J.M.,University of Wisconsin - Madison | Cardoso V.L.,Polo Regional Centro Leste | And 3 more authors.
Journal of Dairy Science | Year: 2012

A total of 46,089 individual monthly test-day (TD) milk yields (10 test-days), from 7,331 complete first lactations of Holstein cattle were analyzed. A standard multivariate analysis (MV), reduced rank analyses fitting the first 2, 3, and 4 genetic principal components (PC2, PC3, PC4), and analyses that fitted a factor analytic structure considering 2, 3, and 4 factors (FAS2, FAS3, FAS4), were carried out. The models included the random animal genetic effect and fixed effects of the contemporary groups (herd-year-month of test-day), age of cow (linear and quadratic effects), and days in milk (linear effect). The residual covariance matrix was assumed to have full rank. Moreover, 2 random regression models were applied. Variance components were estimated by restricted maximum likelihood method. The heritability estimates ranged from 0.11 to 0.24. The genetic correlation estimates between TD obtained with the PC2 model were higher than those obtained with the MV model, especially on adjacent test-days at the end of lactation close to unity. The results indicate that for the data considered in this study, only 2 principal components are required to summarize the bulk of genetic variation among the 10 traits. © 2012 American Dairy Science Association.


Goncalves P.S.,Instituto Agronomico | Junior E.J.S.,Agencia Paulista de Tecnologia dos Agronegocios APTA | Martins M.A.,University of Sao Paulo | Moreno R.M.B.,University of Sao Paulo | And 2 more authors.
Pesquisa Agropecuaria Brasileira | Year: 2011

The objective of this work was to evaluate the performance of 15 clones of the IAC 500 series of Hevea brasiliensis, developed at Instituto Agronômico (IAC), over a 12-year period, in the northwest region of São Paulo State, Brazil. The 15 new clones evaluated are primary clones obtained from selected ortets within half-sib progenies. The clone RRIM 600, of Malaysian origin, was used as the control. Dry rubber yield performance over a four-year period, mean girth at the tenth year, girth increment before and during tapping, thermal properties of the natural rubber produced and other characters of the laticiferous system were evaluated. Forty percent of the clones were superior in comparison to the control for yield. Clone IAC 500 recorded the highest yield (66.81 g per tree per tapping) over four years of tapping, followed by IAC 502 (62.37 g per tree per tapping), whereas the control recorded 48.71 g per tree per tapping. All selected clones were vigorous in growth. The natural rubber from this IAC clones showed thermal stability up to 300°C. No differences were observed in the thermal behavior of rubber among the IAC series and the RRIM 600 clones. The clones IAC 500, IAC 501, IAC 502, IAC 503 and IAC 506 are the more promising for small-scale plantations, due to growth and yield potential.


Vilela M.,Federal University of Lavras | Moraes J.C.,Federal University of Lavras | Alves E.,Federal University of Lavras | Santos-Cividanes T.M.,Polo Regional Centro Leste | And 2 more authors.
Revista Colombiana de Entomologia | Year: 2014

Integrated pest management (IPM) strategies include factors that induce host plant resistance. Silicon may increase plant resistance to attack by insect pests. In a greenhouse, two sugarcane cultivars RB72454 (moderately resistant) and SP801842 (susceptible), treated and untreated with silicon (Si) were infested with adult Diatraea saccharalis (Lepidoptera: Crambidae) and checked after 60 days. The accumulation of silicon increased in the susceptible cultivar, resulting in a silicon content that was not significantly different than that of the untreated moderately resistant cultivar. The number of holes in the susceptible cultivar grown in silicon-treated soil was similar to that of the moderately resistant cultivar. Silicon application promotes cuticle thickening and the accumulation of crystals on the leaf stomata. © 2014 The American Society for Cell Biology.


Lara R.I.R.,Polo Regional Centro Leste | Perioto N.W.,Polo Regional Centro Leste | Perioto N.W.,São Paulo State University
Acta Amazonica | Year: 2016

Hemerobiidae (Insecta, Neuroptera) is a cosmopolitan clade that comprises about 600 described species distributed into 26 genera. Since the publication of revisions to Hemerobius, Megalomus, Nusalala and Nomerobius, new records have been added in literature and taxonomic modifications have occurred at the genus level. The aim of this study was to update a checklist of Hemerobiidae species from Brazil and of specimens deposited at Coleção de Invertebrados do Instituto Nacional de Pesquisa da Amazônia (INPA), Manaus, Brazil; in order to summarize the geographical data of species in Brazilian states and in the Neotropical Region and to present new distributional data. The INPA collection holds 19 nominal species (55.2% of the all specimens identified at species level) of hemerobiids into eight genera and six subfamilies, mainly from the Neotropical Region; the remaining studied specimens were identified to the genus level. Megalomus marginatus is reported for the first time in Brazil and Nusalala dispar in Ecuador. Moreover, ten new records for the Brazilian states are presented: two to Nusalala tessellata and Hemerobius, and one each to Megalomus impudicus, Notiobiella maculata, Sympherobius ariasi, Megalomus, Nusalala and Sympherobius. © 2016, Instituto Nacional de Pesquisas da Amazonia. All rights reserved.


Venturini G.C.,São Paulo State University | Grossi D.A.,São Paulo State University | Ramos S.B.,São Paulo State University | Cruz V.A.R.,São Paulo State University | And 5 more authors.
Genetics and Molecular Research | Year: 2012

We estimated genetic parameters for egg production in different periods by means of random regression models, aiming at selection based on partial egg production from a generation of layers. The production was evaluated for each individual by recording the number of eggs produced from 20 to 70 weeks of age, with partial records taken every three weeks for a total of 17 periods. The covariance functions were estimated with a random regression model by the restricted maximum likelihood method. A model composed of third-order polynomials for the additive effect, ninth-order polynomials for the permanent environment, and a residual variance structure with five distinct classes, was found to be most suitable for adjusting the egg production data for laying hens. The heritability estimates varied from 0.04 to 0.14. The genetic correlations were all positive, varying from 0.10 to 0.99. Selection applied in partial egg production periods will result in greater genetic profit for the adjacent periods. However, as the distance in time between periods increases, selection becomes less efficient. Selection based on the second period (23 to 25 weeks of age), where greater heritability was estimated, would note benefit the final egg-laying cycle periods. ©FUNPEC-RP.


Sesana R.C.,São Paulo State University | Bignardi A.B.,São Paulo State University | Borquis R.R.A.,São Paulo State University | El Faro L.,Polo Regional Centro Leste | And 5 more authors.
Journal of Animal Breeding and Genetics | Year: 2010

The objective of this work was to estimate covariance functions for additive genetic and permanent environmental effects and, subsequently, to obtain genetic parameters for buffalo's test-day milk production using random regression models on Legendre polynomials (LPs). A total of 17 935 test-day milk yield (TDMY) from 1433 first lactations of Murrah buffaloes, calving from 1985 to 2005 and belonging to 12 herds located in São Paulo state, Brazil, were analysed. Contemporary groups (CGs) were defined by herd, year and month of milk test. Residual variances were modelled through variance functions, from second to fourth order and also by a step function with 1, 4, 6, 22 and 42 classes. The model of analyses included the fixed effect of CGs, number of milking, age of cow at calving as a covariable (linear and quadratic) and the mean trend of the population. As random effects were included the additive genetic and permanent environmental effects. The additive genetic and permanent environmental random effects were modelled by LP of days in milk from quadratic to seventh degree polynomial functions. The model with additive genetic and animal permanent environmental effects adjusted by quintic and sixth order LP, respectively, and residual variance modelled through a step function with six classes was the most adequate model to describe the covariance structure of the data. Heritability estimates decreased from 0.44 (first week) to 0.18 (fourth week). Unexpected negative genetic correlation estimates were obtained between TDMY records at first weeks with records from middle to the end of lactation, being the values varied from -0.07 (second with eighth week) to -0.34 (1st with 42nd week). TDMY heritability estimates were moderate in the course of the lactation, suggesting that this trait could be applied as selection criteria in milking buffaloes. © 2010 Blackwell Verlag GmbH.


Santana M.L.,Federal University of Mato Grosso | Pereira R.J.,Federal University of Mato Grosso | Bignardi A.B.,Federal University of Mato Grosso | El Faro L.,Polo Regional Centro Leste | And 2 more authors.
Livestock Science | Year: 2014

The Gir cattle breed (Bos indicus) is an important genetic resource for milk production throughout the tropics. The small number of Gir animals introduced in Brazil, rapid dissemination of this breed recently, and the intensification of selection practices could contribute to increase of inbreeding level and reduce genetic diversity in this population. The population was analyzed in terms of pedigree completeness level, inbreeding coefficient, coancestry, generation interval, effective population size, effective number of founders and ancestors, among others. Despite the low mean inbreeding (around 2%), minor problems were identified in the population structure of the Brazilian Gir cattle, e.g., trend of narrower bottlenecks in the pedigree in recent years. The effective population sizes based on inbreeding (94) or coancestry (165.9) as well as the effective number of ancestors (76) and founders (143) were relativity high. The major subdivision of the Gir breed was observed between 1993 and 2002 (dairy and dual-purpose herds, wide use of within-herd matings). In this period the level of inbreeding remained at a higher level, there was a small increase in coancestry and the number of equivalent subpopulations was approximately 6. After 2002, there was genetic exchange between subpopulations, reduction in the average inbreeding, pronounced increase in the average coancestry, and the number of equivalent subpopulations was about 2. Furthermore, it was found that the mean generation interval of the population tended to increase in recent years (around 9 years). About 2.3% of genetic diversity has been lost since the first generation of founders. Based on the effective population size, number of equivalent subpopulations, inbreeding, coancestry, and loss of genetic diversity, the Gir population is still highly structured, but there is ample room for artificial selection. The results regarding the effective number of founders and ancestors in the present population demonstrate the existence of bottlenecks in the pedigree and indicate the need for population structure monitoring. Nevertheless, the Brazilian Gir breed can perfectly face a breeding program with high selection intensity. © 2014 Elsevier B.V.

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