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Abduch NG, Reolon HG, Ligori VA, Silva RMDO, Veríssimo CJ, Paz CCP, Stafuzza NB. Resistance to natural tick infestation varies with age and coat and hair traits in a tropically adapted beef cattle breed. Vet Parasitol Reg Stud Reports 2024; 50:101017. [PMID: 38644040 DOI: 10.1016/j.vprsr.2024.101017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 03/28/2024] [Accepted: 03/29/2024] [Indexed: 04/23/2024]
Abstract
Rhipicephalus (Boophilus) microplus causes considerable livestock production losses. Knowledge of the traits that influence tick resistance contributes to the development of breeding strategies designed to improve herd productivity. Within this context, this study evaluated the resistance of Caracu, a tropically adapted cattle breed, to R. microplus. Tick count, hair length, coat thickness, and coat color were evaluated in 202 naturally tick-infested females (cows and heifers) over a period of 18 months. Blood samples were collected from all animals during the winter season for hematological analysis. Data were analyzed using Pearson correlations, generalized linear models, and principal component analysis. Correlation coefficients of tick count with coat color, coat thickness, and hair length were estimated within each season. Hematological parameters were only included in the winter season analysis and were analyzed by the restricted maximum likelihood method using log-transformed data. No differences in blood parameters were observed between animals with and without ticks. However, tick count was negatively correlated with erythrocytes (-0.29) and hematocrit (-0.24) and positively correlated with mean corpuscular hemoglobin (0.21) and mean corpuscular hemoglobin concentration (0.25). These findings suggest that higher tick counts lead to a decrease in erythrocytes but also to an increase in the amount of hemoglobin per erythrocyte, which could reduce the damage caused by low erythrocyte levels due to tick hematophagy, delaying or preventing anemia. Although tick infestation on pasture was demonstrated by the infestation of all staff members during herd management, none of the animals exhibited high tick counts, providing evidence of resistance of Caracu animals to R. microplus. Tick infestation was influenced by age class (cows > heifers), season (spring and summer > fall and winter), coat thickness (>1.5 mm > <1.5 mm), and hair length (>6 mm > <6 mm). Three components were extracted by principal component analysis, which accounted for 69.46% of data variance. The findings of this study will contribute to the development of efficient strategies aimed at reducing economic losses due to tick infestation and could be applied in animal breeding to select for tick resistance traits, reducing chemical control strategies and consequently improving sustainable livestock production.
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Affiliation(s)
- Natalya Gardezani Abduch
- Department of Genetics, Ribeirao Preto Medical School (FMRP), University of Sao Paulo (USP), Ribeirao Preto, SP 140349-900, Brazil.
| | | | - Viviane Andrade Ligori
- Beef Cattle Research Center, Animal Science Institute (IZ), Sertaozinho, SP 14160-900, Brazil.
| | | | - Cecília José Veríssimo
- Sao Paulo Agency of Agribusiness and Technology, Animal Science Institute (IZ), Nova Odessa, SP 13380-011, Brazil.
| | - Claudia Cristina Paro Paz
- Department of Genetics, Ribeirao Preto Medical School (FMRP), University of Sao Paulo (USP), Ribeirao Preto, SP 140349-900, Brazil; Sustainable Livestock Research Center, Animal Science Institute, Sao Jose do Rio Preto, SP 15130-000, Brazil
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Freitas LA, Savegnago RP, Alves AAC, Stafuzza NB, Pedrosa VB, Rocha RA, Rosa GJM, Paz CCP. Genome-enabled prediction of indicator traits of resistance to gastrointestinal nematodes in sheep using parametric models and artificial neural networks. Res Vet Sci 2024; 166:105099. [PMID: 38091815 DOI: 10.1016/j.rvsc.2023.105099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 11/15/2023] [Accepted: 11/19/2023] [Indexed: 01/01/2024]
Abstract
This study aimed to assess the predictive ability of parametric models and artificial neural network method for genomic prediction of the following indicator traits of resistance to gastrointestinal nematodes in Santa Inês sheep: packed cell volume (PCV), fecal egg count (FEC), and Famacha© method (FAM). After quality control, the number of genotyped animals was 551 (PCV), 548 (FEC), and 565 (FAM), and 41,676 SNP. The average prediction accuracy (ACC) calculated by Pearson correlation between observed and predicted values and mean squared errors (MSE) were obtained using genomic best unbiased linear predictor (GBLUP), BayesA, BayesB, Bayesian least absolute shrinkage and selection operator (BLASSO), and Bayesian regularized artificial neural network (three and four hidden neurons, BRANN_3 and BRANN_4, respectively) in a 5-fold cross-validation technique. The average ACC varied from moderate to high according to the trait and models, ranging between 0.418 and 0.546 (PCV), between 0.646 and 0.793 (FEC), and between 0.414 and 0.519 (FAM). Parametric models presented nearly the same ACC and MSE for the studied traits and provided better accuracies than BRANN. The GBLUP, BayesA, BayesB and BLASSO models provided better accuracies than the BRANN_3 method, increasing by around 23% for PCV, and 18.5% for FEC. In conclusion, parametric models are suitable for genome-enabled prediction of indicator traits of resistance to gastrointestinal nematodes in sheep. Due to the small differences in accuracy found between them, the use of the GBLUP model is recommended due to its lower computational costs.
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Affiliation(s)
- L A Freitas
- University of Sao Paulo, Department of Genetics, Ribeirão Preto, São Paulo 14049-900, Brazil; University of Wisconsin, Department of Animal and Dairy Sciences, Madison 53706, USA.
| | - R P Savegnago
- Michigan State University, Department of Animal Science, MI 48864, USA.
| | - A A C Alves
- University of Wisconsin, Department of Animal and Dairy Sciences, Madison 53706, USA.
| | - N B Stafuzza
- Sustainable Livestock Research Center, Animal Science Institute, São José do Rio Preto, São Paulo 15130-000, Brazil
| | - V B Pedrosa
- State University of Ponta Grossa, Ponta Grossa, Paraná 84030-900, Brazil.
| | - R A Rocha
- State University of Ponta Grossa, Ponta Grossa, Paraná 84030-900, Brazil.
| | - G J M Rosa
- University of Wisconsin, Department of Animal and Dairy Sciences, Madison 53706, USA.
| | - C C P Paz
- University of Sao Paulo, Department of Genetics, Ribeirão Preto, São Paulo 14049-900, Brazil; Sustainable Livestock Research Center, Animal Science Institute, São José do Rio Preto, São Paulo 15130-000, Brazil.
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Gama MPM, Savegnago RP, Ventura HT, Pereira MA, Freitas LA, Paz CCP, El Faro L. Estimates of genetic parameters, principal components and cluster analysis for milk yield and body weight in Guzera cattle. Anim Prod Sci 2022. [DOI: 10.1071/an20041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
ContextThe estimation of genetic parameters for traits related to the production of milk, beef or both may assist in defining the selection criteria and objectives of the breeding program, as well as in the identification and selection of genetically superior animals.AimsThe objectives of this study were to estimate genetic parameters for body weight and 305-day milk yield of Guzera cattle and to perform cluster analysis on the basis of estimated breeding values for these traits, to identify groups of animals that could be selected for the production of beef, milk or dual purpose.MethodsBody weights (N=253 012) of males and females were ecorded at 120 days of age (BW120), at weaning (WW), at 365 days (BW365), at yearling stage (YW) and at 24 months (BW24), and 6237 complete lactations (MY305) of 4723 cows were used to estimate the genetic parameters. The bi-trait animal models included direct additive genetic, maternal permanent environmental and temporary random effects for body weights and additive genetic, permanent environmental and temporary environmental random effects for MY305. The fixed effects for all the traits were contemporary group and age of cow at calving.Key resultsThe estimates of heritability ranged from 0.14±0.01 for WW to 0.23±0.01 for MY305. The genetic correlations between body weights at different ages and milk yield were positive and ranged from 0.27±0.11 to 0.38±0.19. Two principal components explained 86.74% of the total genetic variance among the traits.ConclusionsCluster analysis identified four different clusters and showed that the Guzera breed had bulls with different genetic patterns that permits genetic selection for beef, milk or dual purpose.ImplicationsThe genetic correlations of the present study suggest that selection to increase milk yield will lead to a slight genetic gain in the same direction for body weight at different ages, in contrast to reports from some other studies.
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Araujo FM, Meola J, Rosa-E-Silva JC, Paz CCP, Ferriani RA, Nogueira AA. Increased expression of ID2, PRELP and SMOC2 genes in patients with endometriosis. ACTA ACUST UNITED AC 2017; 50:e5782. [PMID: 28678915 PMCID: PMC5496152 DOI: 10.1590/1414-431x20175782] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 05/09/2017] [Indexed: 02/02/2023]
Abstract
Endometriosis is a benign, estrogen-dependent disease with symptoms such as pelvic pain and infertility, and it is characterized by the ectopic distribution of endometrial tissue. The expression of the ID2, PRELP and SMOC2 genes was compared between the endometrium of women without endometriosis in the proliferative phase of their menstrual cycle and the eutopic and ectopic endometrium of women with endometriosis in the proliferative phase. Paired tissue samples from 20 women were analyzed: 10 from endometrial and peritoneal endometriotic lesions and 10 from endometrial and ovarian endometriotic lesions. As controls, 16 endometrium samples were collected from women without endometriosis in the proliferative phase of menstrual cycle. Analysis was performed by real-time polymerase chain reaction (PCR). There was no significant difference between gene expression in the endometrium of women with and without endometriosis. The ID2 gene expression was increased in the most advanced stage of endometriosis and in ovarian endometriomas, the PRELP was more expressed in peritoneal lesions, and the SMOC2 was highly expressed in both peritoneal and endometrioma lesions. Considering that the genes studied participate either directly or indirectly in cellular processes that can lead to cell migration, angiogenesis, and inappropriate invasion, it is possible that the deregulation of these genes caused the development and maintenance of ectopic tissue.
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Affiliation(s)
- F M Araujo
- Departamento de Ginecologia e Obstetrícia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - J Meola
- Departamento de Ginecologia e Obstetrícia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - J C Rosa-E-Silva
- Departamento de Ginecologia e Obstetrícia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - C C P Paz
- Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - R A Ferriani
- Departamento de Ginecologia e Obstetrícia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - A A Nogueira
- Departamento de Ginecologia e Obstetrícia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
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Albuquerque RS, Morais R, Reis AN, Miranda MS, Dias EAR, Monteiro FM, Paz CCP, Nichi M, Kawai GKV, Della'Aqua CPF, Papa FO, Viana RB, Gimenes LU. Comparison of two methods of seminal plasma removal on buffalo (Bubalus bubalis) sperm cryopreservation. Reprod Domest Anim 2017; 52:905-910. [DOI: 10.1111/rda.12992] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 04/04/2017] [Indexed: 11/27/2022]
Affiliation(s)
- RS Albuquerque
- Departamento de Medicina Veterinária Preventiva e Reprodução Animal; Universidade Estadual Paulista; Jaboticabal Brasil
| | - R Morais
- Central de Biotecnologia da Reprodução Animal; Universidade Federal do Pará; Castanhal Brasil
| | - AN Reis
- Central de Biotecnologia da Reprodução Animal; Universidade Federal do Pará; Castanhal Brasil
| | - MS Miranda
- Central de Biotecnologia da Reprodução Animal; Universidade Federal do Pará; Castanhal Brasil
| | - EAR Dias
- Centro APTA Bovinos de Corte; Instituto de Zootecnia; Sertãozinho Brasil
| | - FM Monteiro
- Centro APTA Bovinos de Corte; Instituto de Zootecnia; Sertãozinho Brasil
| | - CCP Paz
- Centro APTA Bovinos de Corte; Instituto de Zootecnia; Sertãozinho Brasil
| | - M Nichi
- Departamento de Reprodução Animal; Universidade de São Paulo; São Paulo Brasil
| | - GKV Kawai
- Departamento de Reprodução Animal; Universidade de São Paulo; São Paulo Brasil
| | - CPF Della'Aqua
- Departamento de Reprodução Animal e Radiologia Veterinária; Universidade Estadual Paulista; Botucatu Brasil
| | - FO Papa
- Departamento de Reprodução Animal e Radiologia Veterinária; Universidade Estadual Paulista; Botucatu Brasil
| | - RB Viana
- Instituto da Saúde e Produção Animal; Universidade Federal Rural da Amazônia; Belém Brasil
| | - LU Gimenes
- Departamento de Medicina Veterinária Preventiva e Reprodução Animal; Universidade Estadual Paulista; Jaboticabal Brasil
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Coutinho CC, Mercadante MEZ, Jorge AM, Paz CCP, El Faro L, Monteiro FM. Growth curves of carcass traits obtained by ultrasonography in three lines of Nellore cattle selected for body weight. Genet Mol Res 2015; 14:14076-87. [PMID: 26535722 DOI: 10.4238/2015.october.29.27] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The effect of selection for postweaning weight was evaluated within the growth curve parameters for both growth and carcass traits. Records of 2404 Nellore animals from three selection lines were analyzed: two selection lines for high postweaning weight, selection (NeS) and traditional (NeT); and a control line (NeC) in which animals were selected for postweaning weight close to the average. Body weight (BW), hip height (HH), rib eye area (REA), back fat thickness (BFT), and rump fat thickness (RFT) were measured and records collected from animals 8 to 20 (males) and 11 to 26 (females) months of age. The parameters A (asymptotic value) and k (growth rate) were estimated using the nonlinear model procedure of the Statistical Analysis System program, which included fixed effect of line (NeS, NeT, and NeC) in the model, with the objective to evaluate differences in the estimated parameters between lines. Selected animals (NeS and NeT) showed higher growth rates than control line animals (NeC) for all traits. Line effect on curves parameters was significant (P < 0.001) for BW, HH, and REA in males, and for BFT and RFT in females. Selection for postweaning weight was effective in altering growth curves, resulting in animals with higher growth potential.
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Affiliation(s)
- C C Coutinho
- Faculdade de Medicina Veterinária e Zootecnia, Fazenda Experimental Lageado, Universidade Estadual "Júlio de Mesquita Filho", Botucatu, SP, Brasil
| | - M E Z Mercadante
- Centro APTA Bovinos de Corte, Instituto de Zootecnia, Sertãozinho, SP, Brasil
| | - A M Jorge
- Faculdade de Medicina Veterinária e Zootecnia, Fazenda Experimental Lageado, Universidade Estadual "Júlio de Mesquita Filho", Botucatu, SP, Brasil
| | - C C P Paz
- Centro APTA Bovinos de Corte, Instituto de Zootecnia, Sertãozinho, SP, Brasil
| | - L El Faro
- Centro APTA Bovinos de Corte, Instituto de Zootecnia, Sertãozinho, SP, Brasil
| | - F M Monteiro
- Centro APTA Bovinos de Corte, Instituto de Zootecnia, Sertãozinho, SP, Brasil
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Da Broi MG, Malvezzi H, Paz CCP, Ferriani RA, Navarro PAAS. Follicular fluid from infertile women with mild endometriosis may compromise the meiotic spindles of bovine metaphase II oocytes. Hum Reprod 2013; 29:315-23. [PMID: 24166595 DOI: 10.1093/humrep/det378] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
STUDY QUESTION What is the potential impact of follicular fluid (FF) from infertile women with mild endometriosis (ME) on oocyte quality, especially on nuclear maturation and the meiotic spindle? SUMMARY ANSWER FF from infertile women with ME may compromise nuclear maturation and the meiotic spindles of in vitro matured bovine oocytes. WHAT IS KNOWN ALREADY Controversial studies have suggested that impaired oocyte quality may be involved in the pathogenesis of endometriosis-related infertility. Moreover, some studies have demonstrated alterations in the composition of FF from infertile women with endometriosis. However, to date no study has evaluated the effect of FF from infertile women with ME on the genesis of meiotic oocyte anomalies. STUDY DESIGN, SIZE, DURATION We performed an experimental study. Samples of FF were obtained from February 2009 to February 2011 from 22 infertile women, 11 with ME and 11 with tubal or male factors of infertility (control group), who underwent ovarian stimulation for ICSI at our university IVF Unit. From March 2011 to February 2012 we performed in vitro maturation (IVM) experiments using immature bovine oocytes as described below. PARTICIPANTS/MATERIALS, SETTING, METHODS FF free of blood and containing a mature oocyte was obtained from 22 infertile women during oocyte retrieval for ICSI. Immature bovine oocytes underwent IVM in the absence of FF (No-FF) and in the presence of four concentrations (1, 5, 10 and 15%) of FF from infertile women without endometriosis (C-FF) and with ME (ME-FF). Eleven replicates were performed, each one using FF from a control patient and a patient with ME. Each FF sample was used in only one experiment. After 22-24 h of IVM, oocytes were denuded, fixed and immunostained for morphological visualization of microtubules and chromatin by confocal microscopy. MAIN RESULTS AND THE ROLE OF CHANCE A total of 1324 cumulus-oocyte complexes were matured in vitro. Of these, 1128 were fixed and 1048 were analyzed by confocal microscopy. The percentage of meiotically normal oocytes was significantly higher for oocytes that underwent IVM in the absence of FF (No-FF; 76.5%) and in the presence of 1% (80.9%), 5% (76.6%), 10% (75%) and 15% (76.2%) C-FF than in oocytes that underwent IVM in the presence of 1% (44.4%), 5% (36.7%), 10% (45.5%) and 15% (51.2%) ME-FF (P < 0.01). No differences were observed among FF concentrations within each group. When the four concentrations from each group were pooled, the number of oocytes in metaphase I stage was significantly higher in the ME-FF (50 oocytes) than in the C-FF (29 oocytes) group and the percentage of meiotic abnormalities was significantly higher when oocytes were matured with ME-FF (55.8%) than with C-FF (23.1%), P < 0.01. LIMITATIONS, REASONS FOR CAUTION Owing to the strict selection criteria for FF donors, this study had a small sample size (11 cases and 11 controls), and thus further investigations using a large cohort of patients are needed to confirm these results. In addition, data obtained from studies using animal models may not necessarily be extrapolated to humans and studies evaluating in vivo matured oocytes from infertile women with ME are important to confirm our results. WIDER IMPLICATIONS OF THE FINDINGS Our results open new insights into the pathogenic mechanisms of infertility related to mild endometriosis, suggesting that FF from infertile women with mild endometriosis may be involved in the worsening of oocyte quality of these women. STUDY FUNDING/COMPETING INTEREST(S) This study was supported by the National Council for Scientific and Technological Development (CNPq), Brazil. The authors declare no conflicts of interest.
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Affiliation(s)
- M G Da Broi
- Human Reproduction Division, Department of Gynecology and Obstetrics, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, SP, Brazil
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Abstract
Considerable effort has been invested in searching for less invasive methods of diagnosing endometriosis. Previous studies have indicated altered levels of the CALD1 gene (encoding the protein caldesmon) in endometriosis. The aims of our study were to investigate whether average CALD1 expression and caldesmon protein levels are differentially altered in the endometrium and endometriotic lesions and to evaluate the performance of the CALD1 gene and caldesmon protein as potential biomarkers for endometriosis. Paired biopsies of endometrial tissue (eutopic endometrium) and endometriotic lesions (ectopic endometrium) were obtained from patients with endometriosis to evaluate CALD1 gene expression and caldesmon protein levels by real-time PCR and Western blot analysis, respectively. In addition, immunostaining for caldesmon to determine cellular localization was also performed. Endometrium from women without endometriosis was used as a control. Increased CALD1 expression and caldesmon levels were detected in the endometriotic lesions. The electrophoretic profile of caldesmon by Western blot analysis was clearly different between the control group (endometrium of women without endometriosis) and the group of women with endometriosis (eutopic endometrium and endometriotic lesions). Caldesmon expression as determined by immunostaining showed no variation among the cell types in endometriotic lesions and eutopic endometrium. Stromal cells marked positively in eutopic endometrium from control patients and in the endometriotic lesions. The presence of caldesmon in the endometrium of patients with and without endometriosis permitted diagnoses with 95% sensitivity (specificity 100%) and 100% sensitivity (specificity 100%) for the disease and for minimal to mild endometriosis in the proliferative phase of the menstrual cycle, respectively. In the secretory phase, minimal to mild endometriosis was detected with 90% sensitivity and 93.3% specificity. Caldesmon is a possible predictor of endometrial dysregulation in patients with endometriosis. A potential limitation of our study is the fact that other endometrial diseases were not excluded, and therefore prospective studies are needed to confirm the potential of caldesmon as a biomarker exclusively for endometriosis.
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Affiliation(s)
- Juliana Meola
- Department of Gynecology and Obstetrics, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
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Andrade PC, Grossi DA, Paz CCP, Alencar MM, Regitano LCA, Munari DP. Association of an insulin-like growth factor 1 gene microsatellite with phenotypic variation and estimated breeding values of growth traits in Canchim cattle. Anim Genet 2008; 39:480-5. [PMID: 18637878 DOI: 10.1111/j.1365-2052.2008.01755.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A population of 1398 Canchim (CA) cattle was genotyped to assess the association of an insulin-like growth factor 1 (IGF1) gene microsatellite with phenotypic variation and estimated breeding values of pre-weaning, weaning and post-weaning growth traits. After an initial analysis, the IGF1 genotype only had a significant effect (P < 0.05) on birth weight (BW) and weaning weight adjusted to 240 days (WW240). For these two traits, direct and maternal breeding values were estimated using the restricted maximum likelihood (reml). Two analyses were carried out. In the first (Model I), all fixed effects were fitted. In the second (Model II), the fixed effect of the IGF1 genotype was omitted. The estimated genetic and phenotypic components of variance were similar for every trait in both models. For Model I, estimated direct and maternal heritabilities were 0.26 and 0.16 for BW and 0.23 and 0.14 for WW240 respectively. The genetic and phenotypic correlations between BW and WW240 were 0.38 and 0.38 (Model I) and 0.19 and 0.38 (Model II) respectively. Fifty animals were classified according to their direct and maternal breeding values for both traits. Spearman rank-order correlation between animal rankings in the two models was used to assess the effect of including the IGF1 genotype in the model. Non-significant values from this correlation were indicative of a difference in breeding value rankings between the two approaches. The IGF1 gene was found to be associated with phenotypic variation and breeding values in the early phase of growth.
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Affiliation(s)
- P C Andrade
- Departamento de Ciências Exatas, UNESP, Faculdade de Ciências Agrárias e Veterinárias, Jaboticabal, SP 14884-900, Brazil
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