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1.
Public Health ; 236: 7-14, 2024 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-39154589

RESUMO

OBJECTIVES: This study aimed to comprehensively evaluate Mexico's health system performance from 1990 to 2019 utilising the Health Access and Quality Index (HAQI) as a primary indicator. STUDY DESIGN: A retrospective ecological analysis was performed using data from the Global Burden of Diseases, Injuries and Risk Factors Study (GBD) study and the National Population Council (CONAPO). METHODS: HAQI values for 1990, 2000, 2010, 2015, and 2019 were examined for each state in Mexico and three age groups (young, working, and post-working). Additionally, the marginalisation index was employed to assess inequalities in the HAQI distribution across states. The concentration index of the HAQI for each year was estimated, and the efficiency of states in producing the HAQI was evaluated using a data envelopment approach. RESULTS: Through the analysis of national and subnational data, results indicated an overall improvement in healthcare access and quality during the study period. Although differences in the HAQI value related to state marginalisation decreased from 1990 to 2015, by 2019, the inequality had returned to a level comparable to 2000. Efficiency in producing health (HAQI values) exhibited substantial heterogeneity and fluctuations in the ranking order over time. States such as Nuevo León consistently performed well, while others, such as Guerrero, Chihuahua, Mexico City, and Puebla, consistently underperformed. CONCLUSIONS: The findings from this study emphasise the necessity for nuanced strategies to address healthcare disparities and enhance the overall system performance. The study provides valuable insights for ongoing discussions about the future of Mexico's healthcare system, aiming to inform evidence-based policy decisions and improve the nationwide delivery of healthcare services.

2.
Trop Anim Health Prod ; 51(8): 2175-2180, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31104225

RESUMO

This study used pedigree information and data collected from 1979 to 2012 at the Raeini Cashmere goat breeding station, located in Baft City in Kerman Province in southeastern Iran. Genetic and phenotypic parameters for early reproductive traits of breeding does, including total numbers of kids born at first kidding (LSB1), total numbers of kids weaned at first kidding (LSW1), total birth weight of all kids born at first kidding (LWB1), total weaning weight of all kids weaned at first kidding (LWW1), and age at first kidding (AFK), were estimated using a Bayesian approach via Gibbs sampling. Posterior means for heritability estimates of LSB1, LSW1, LWB1, LWW1, and AFK were statistically significant, with values of 0.12, 0.23, 0.17, 0.15, and 0.46, respectively. Low-to-moderate additive genetic variation was present for the studied reproductive traits. Estimated genetic correlations among LSB1, LSW1, LWB1, and LWW1 were statistically significant and ranged from 0.12 between LWB1 and LWW1 to 0.72 between LSB1 and LSW1. Corresponding phenotypic correlation estimates were also statistically significant and ranged from 0.04 between LWB1 and LWW1 to 0.55 between LSB1 and LSW1. Posterior means of genetic and phenotypic correlations between AFK and other studied traits were statistically significant only for LSB1 and LWB1. For LSB1, LSW1, LWB1, and LWW1, we conclude that genetic and phenotypic improvement in any of these traits in Raeini Cashmere does would favorably influence all of the other traits. However, does that first kidded at younger ages have smaller litters at birth and lower litter birth weights at their first parity.


Assuntos
Peso ao Nascer/genética , Cabras/genética , Tamanho da Ninhada de Vivíparos/genética , Desmame , Animais , Teorema de Bayes , Cruzamento , Feminino , Irã (Geográfico) , Masculino , Idade Materna , Parto , Linhagem , Fenótipo , Gravidez , Reprodução
3.
Soft Matter ; 14(34): 7016-7025, 2018 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-30112557

RESUMO

The rheological properties of a medium can be inferred from the Brownian motion of colloidal tracer particles using the microrheology procedure. The tracer motion can be characterized by the mean-squared displacement (MSD). It can be calculated from the intermediate scattering function determined by Differential Dynamic Microscopy (DDM). Here we show that DDM together with the empirical Cox-Merz rule is particularly suited to measure the steady-shear viscosity, i.e. the viscosity towards zero frequency, due to its ability to provide reliable information on long time and length scales and hence small frequencies. This method, η-DDM, is tested and illustrated using three different systems: Newtonian fluids (glycerol-water mixtures), colloidal suspensions (protein samples) and a viscoelastic polymer solution (aqueous poly(ethylene oxide) solution). These tests show that common lab equipment, namely a bright-field optical microscope, can be used as a convenient and reliable microliter viscometer. Because η-DDM requires much smaller sample volumes than classical rheometry, only a few microliters, it is particularly useful for biological and soft matter systems.

4.
J Anim Breed Genet ; 133(3): 227-37, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26150168

RESUMO

Data from seven generations of a divergent selection experiment designed for environmental variability of birth weight were analysed to estimate genetic parameters and to explore signs of selection response. A total of 10 783 birth weight records from 638 females and 1127 litters in combination with 10 007 pedigree records were used. Each record of birth weight was assigned to the mother of the pup in a heteroscedastic model, and after seven generations of selection, evidence of success in the selection process was shown. A Bayesian analysis showed that success of the selection process started from the first generation for birth weight and from the second generation for its environmental variability. Genetic parameters were estimated across generations. However, only from the third generation onwards were the records useful to consider the results to be reliable. The results showed a consistent positive and low genetic correlation between the birth weight trait and its environmental variability, which could allow an independent selection process. This study has demonstrated that the genetic control of the birth weight environmental variability is possible in mice. Nevertheless, before the results are applied directly in farm animals, it would be worth confirming any other implications on other important traits, such as robustness, longevity and welfare.


Assuntos
Peso ao Nascer , Interação Gene-Ambiente , Camundongos/fisiologia , Animais , Feminino , Masculino , Herança Materna , Camundongos/genética
5.
J Anim Breed Genet ; 131(5): 395-402, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24673743

RESUMO

The most popular use of the Pura Raza Español horse in sport is for dressage competitions. Tests on young sport horses were first established in 2004 in Spain to collect data for the genetic evaluation of this breed's suitability for dressage. The aim of this study was to compare eight different models to find out the most appropriate way to include the rider in the genetic evaluation of dressage. A progressive removal of systematic effects from model was also analysed. A total of 8867 performance records collected between 2004 and 2011 from 1234 horses aged between 4 and 6 years old were used. The final score in the dressage test was used as the performance trait. The pedigree matrix contained 8487 individuals. A BLUP animal model was applied using a Bayesian approach with TM software. The horse's age, gender, travelling time, training level, stud of birth and event were included as systematic effects in all the models. Apart from the animal and residual effects that were present in all models, different models were compared combining random effects such as the rider, match (i.e. rider-horse interaction) and permanent environmental effects. A cross-validation approach was used to evaluate the models' prediction ability. The best model included the permanent environmental, rider and match random effects. As far as systematic effects are concerned, the event or the stud of birth was essential effects needed to fit the data.


Assuntos
Cavalos/genética , Modelos Genéticos , Animais , Teorema de Bayes , Cruzamento , Linhagem , Espanha , Esportes
6.
J Anim Breed Genet ; 130(5): 404-14, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24074177

RESUMO

Data from a divergent experiment for birthweight (BrW) environmental variability were used to estimate genetic parameters for BrW trait and its environmental variability by fitting both homoscedastic (HO) and heteroscedastic (HE) models. A total of 5 475 records of BrW from animals born from inbred dams, and 7 140 pedigree records were used. The heritability of BrW using the model HO was 0.27, with the litter effect much more important, 0.43. The model HE provided a genetic correlation between the trait and its environmental variability that was very high and negative, -0.97, and a high value for the additive genetic variance for environmental variability, suggesting an artefact in the model. The residual skewness was found to be essentially null. A model considering the genetic correlation null was also fitted, and used to obtain the breeding values for the selection process. Moreover, the trait was considered as maternal resulting in similar estimates under the model HO, but more reasonable for the genetic correlation between the trait and its environmental variability of 0.48 with a value of 0.25 for the additive genetic variance regarding environmental variability under the model HE. This led to the conclusion that environmental variability of BrW in mice must be selected via dams. Estimated parameters in a reduced dataset without inbred animals did not substantially change this conclusion.


Assuntos
Peso ao Nascer/genética , Meio Ambiente , Modelos Genéticos , Animais , Feminino , Endogamia , Masculino , Camundongos , Mães
7.
J Anim Breed Genet ; 128(1): 56-63, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21214645

RESUMO

We introduce a simple method to estimate effective population size from increase in coancestry (Δc(jk)) for all pairs of individuals j and k in a reference subpopulation. An increase in pairwise coancestry for any pair of individuals j and k can be defined assuming that a hypothetical mating between them would give an individual with an inbreeding coefficient equal to c(jk), where c(jk) is the coancestry coefficient between the individuals j and k. The equivalent measure to discrete generations value (g(jk)) corresponding to the individual jk can be computed by averaging discrete equivalents generations of its parents (g(j) and g(k)). The mean increase in coancestry for all pairs of individuals in a reference subpopulation can be used to estimate a realized effective population size based on coancestries that would provide information on the effective size of a population under random mating. Performance of the new parameter was tested on simulated and empirical (horse) populations with different mating strategies and population structures. The routines needed to compute the introduced parameters have been included in a new version of the program ENDOG.


Assuntos
Cruzamento/métodos , Cavalos/genética , Modelos Teóricos , Animais , Feminino , Cavalos/fisiologia , Endogamia , Masculino , Linhagem , Densidade Demográfica , Dinâmica Populacional
8.
J Anim Breed Genet ; 128(4): 276-83, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21749474

RESUMO

An experiment with mice was designed to test the relative efficiency of three selection methods that help to minimize the rate of inbreeding during selection. A common house mice (Mus musculus) population was selected for 17 generations to increase the weight gain between 21 and 42 days. The population was split at random into three lines A, B and C where three selection methods were applied: individual selection and random mating, weighted selection with random mating and individual selection with minimum coancestry mating, respectively. There were three replicates for each line. Cumulated selection response was similar in the three lines, but there were differences in the level of inbreeding attained (in percentage): 31.24 (method A), 24.72 (method B) and 27.88 (method C). As consequence, lines B and C (weighted selection and minimum coancestry) showed a lower value of deterioration of fitness traits (the intrauterine mortality and the mortality at birth) than line A (random mating).


Assuntos
Endogamia , Seleção Genética , Aumento de Peso/genética , Animais , Interpretação Estatística de Dados , Feminino , Hibridização Genética , Masculino , Camundongos , Modelos Genéticos
9.
Animal ; 15(5): 100219, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34091274

RESUMO

Addressing the improvement of the textile characteristics is currently required in natural color production of alpaca fiber. This study analyses the possibility of implementing a genetic improvement program aiming to reduce the fiber diameter and the percentage of medullation in natural colors under the incomplete definition of the natural colors of alpaca fiber. The study considers color determination analysis in three separate steps. The first step aimed at finding the values of lightness (L*), red/green axis (a*), yellow/blue axis (b*) of three-dimensional space of color and chroma (C*ab), tone (h*ab) and color difference (ΔE) with mathematical models for the description of the coat color. The second analysis is aimed at estimating genetic parameters of color traits and their correlation with fiber traits (fiber diameter, standard deviations and percentage of medullation - PM). The third step was to determine the potential selection criteria of breeding animals based on the parameters provided by a three-dimensional space values regarding the coat color assignment in alpacas. The colorimetric data were taken using a Chroma meter device analyzing 3 008 records from Huacaya type alpacas, collected between 2018 and 2019. In the first objective of the study, the color traits were subjected to a principal component analysis. The analysis of variance components and the estimation of genetic parameters were carried out using a restricted maximum likelihood procedure. The discriminant analysis was used for the correct assignment of the coat color. The principal component analysis results showed that the L*, a*, b*, h*ab and ΔE values can be grouped into two Principal Components (PC) to describe the color, where the L* value is mainly distributed in PC2, b* is distributed in PC1, while a* is distributed in both components. The heritabilities found were 0.144, 0.128, 0.151, 0.104 and 0.152 for L*, a*, b*, PC1 and PC2. The relevant genetic correlations were between L*-PM (-0.557) and b*-PM (-0.622). The discriminant analysis showed a high percentage of correct assignment in white (99.15%) and black (99.19%) coat colors for Huacaya type alpacas, while for the intermediate colors, the accuracy was lower. The three analyses showed that there is no pure natural color, but a range of color variation. It is better to use the values of the three-dimensional space and within them, the values of L* and b* are potential selection criteria to be included in a genetic improvement program.


Assuntos
Camelídeos Americanos , Colorimetria , Animais , Cor , Colorimetria/veterinária , Fibras na Dieta , Fenótipo
10.
Heredity (Edinb) ; 105(6): 511-9, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20332805

RESUMO

In this study, we show how Y-specific interspersed multilocus microsatellites, which are loci that yield several amplified bands differing in size from the same male individual and PCR reaction, are a powerful source of information for tracing the history of cattle. Our results confirm the existence of three main groups of sires, which are separated by evolutionary time and clearly predate domestication. These three groups are consistent with the haplogroups previously identified by Götherström et al. (2005) using five Y-specific segregating sites: Y1 and Y2 in taurine (Bos taurus) cattle and Y3 in zebu (Bos indicus) cattle. The zebu cattle cluster clearly originates from a domestication process that was geographically and temporally separated from that of taurine clusters. Our analyses further suggest that: (i) introgression of wild sire genetic material into domesticated herds may have a significant role in the formation of modern cattle, including the formation of the Y1 haplogroup; (ii) a putative domestication event in Africa probably included local Y2-like wild sires; (iii) the West African zebu cattle Y-chromosome may have partially originated from an ancient introgression of humped cattle into Africa; and (iv) the high genetic similarity among Asian zebu sires is consistent with a single domestication process.


Assuntos
Bovinos/genética , Evolução Molecular , Impressão Genômica , Repetições de Microssatélites , Cromossomo Y/genética , Animais , Animais Domésticos/genética , Bovinos/classificação , Masculino
11.
Int J Immunogenet ; 37(5): 355-9, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20518842

RESUMO

The purpose of this study was to assess the role of Helicobacter pylori and several genetic polymorphisms in relation to inflammatory bowel disease (IBD). We studied 44 unrelated patients with IBD and 75 subjects with no history of IBD as controls. Using pyrosequencing technology, we identified gene polymorphisms in IL-10, TNF-A, ILB-31, and TLR4. H. pylori status was determined by serology. Individuals homozygous for IL10-592 A or IL10-1082 A genotypes show significantly lower occurrence of IBD (P=0.03 and P<0.01, respectively). Individuals heterozygous at IL10-1082 have significantly increased occurrence of IBD, both ulcerative colitis and Crohn's disease (P<0.01). There was no difference in the prevalence of H. pylori infection between cases and controls. This study provides evidence that variation in IL10 is correlated with IBD occurrence in this Mexican population.


Assuntos
Doenças Inflamatórias Intestinais/epidemiologia , Doenças Inflamatórias Intestinais/genética , Adulto , Idoso , Colite Ulcerativa/epidemiologia , Colite Ulcerativa/genética , Doença de Crohn/epidemiologia , Doença de Crohn/genética , Feminino , Predisposição Genética para Doença , Haplótipos , Infecções por Helicobacter/complicações , Helicobacter pylori , Humanos , Doenças Inflamatórias Intestinais/complicações , Interleucina-10/genética , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Fatores de Risco , Adulto Jovem
12.
J Dairy Sci ; 93(10): 4902-12, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20855025

RESUMO

Influences of inbreeding on daily milk yield (DMY), age at first calving (AFC), and calving intervals (CI) were determined on a highly inbred zebu dairy subpopulation of the Guzerat breed. Variance components were estimated using animal models in single-trait analyses. Two approaches were employed to estimate inbreeding depression: using individual increase in inbreeding coefficients or using inbreeding coefficients as possible covariates included in the statistical models. The pedigree file included 9,915 animals, of which 9,055 were inbred, with an average inbreeding coefficient of 15.2%. The maximum inbreeding coefficient observed was 49.45%, and the average inbreeding for the females still in the herd during the analysis was 26.42%. Heritability estimates were 0.27 for DMY and 0.38 for AFC. The genetic variance ratio estimated with the random regression model for CI ranged around 0.10. Increased inbreeding caused poorer performance in DMY, AFC, and CI. However, some of the cows with the highest milk yield were among the highly inbred animals in this subpopulation. Individual increase in inbreeding used as a covariate in the statistical models accounted for inbreeding depression while avoiding overestimation that may result when fitting inbreeding coefficients.


Assuntos
Bovinos/genética , Endogamia , Lactação/genética , Reprodução/genética , Fatores Etários , Animais , Bovinos/fisiologia , Feminino , Lactação/fisiologia , Leite/metabolismo , Reprodução/fisiologia , Fatores de Tempo
13.
J Chem Phys ; 131(19): 194902, 2009 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-19929071

RESUMO

The effect of particle shape in the small amplitude oscillatory shear behavior of magnetorheological (MR) fluids is investigated from zero magnetic field strengths up to 800 kA/m. Two types of MR fluids are studied: the first system is prepared with spherical particles and a second system is prepared with rodlike particles. Both types of particles are fabricated following practically the same precipitation technique and have the same intrinsic magnetic and crystallographic properties. Furthermore, the distribution of sphere diameters is very similar to that of rod thicknesses. Rod-based MR fluids show an enhanced MR performance under oscillatory shear in the viscoelastic linear regime. A lower magnetic field strength is needed for the structuration of the colloid and, once saturation is fully achieved, a larger storage modulus is observed. Existing sphere- and rod-based models usually underestimate experimental results regarding the magnetic field strength and particle volume fraction dependences of both storage modulus and yield stress. A simple model is proposed here to explain the behavior of microrod-based MR fluids at low, medium and saturating magnetic fields in the viscoelastic linear regime in terms of magnetic interaction forces between particles. These results are further completed with rheomicroscopic and dynamic yield stress observations.

14.
J Anim Breed Genet ; 126(4): 327-32, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19630884

RESUMO

Computation of inbreeding rate (DeltaF) must consider that inbreeding is delayed with one generation with respect to the idealized population when addressed using individual inbreeding coefficients. The expression relating inbreeding in generation t with inbreeding rate F(t) = 1 - (1-DeltaF)(t) should be more correctly written in real animal populations as F(t) = 1 - (1-DeltaF)(t-1), as changes in allele frequencies occur in the equivalent co-ancestries in the previous generation. This simple approach is tested on simulated and real pedigrees thus demonstrating that: (i) the adjusted individual increase in inbreeding becomes stable in populations under random mating while the unadjusted parameter does not; (ii) regression of the unadjusted parameter over generations in pedigrees under random mating is highly significant while after correction it is not significant; and (iii) the variance of the adjusted parameter is reduced with the generations.


Assuntos
Animais Domésticos , Estatística como Assunto/métodos , Animais , Animais Domésticos/genética , Feminino , Endogamia , Masculino , Linhagem , Densidade Demográfica
15.
J Anim Breed Genet ; 126(5): 335-47, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19765160

RESUMO

This research assesses the genetic composition of three Arab-derived Spanish horse breeds as an example to highlight the major shortcomings related to genealogical analyses in open populations and to propose approaches useful to deal with this task. The studbooks of three Spanish Arab (SA)-derived horse breeds, Spanish Anglo-Arab (dAA), Hispano-Arab (dHA) and Spanish Sport Horse (dSSH) and those of their parental breeds SA, Spanish Purebred (SPB) and Thoroughbred (TB), totalling 211 754 individuals, were available. The genealogies of the dAA, dHA and dSSH were analysed not only using the corresponding studbook (breed exclusive dataset) but also including the genealogies of the founders from parental breeds (completed dataset). Coancestry analyses revealed that the present SA-derived populations share more genes with the Arab than with the other parental breeds. Effective population size was computed by accounting for migration rates to obtain an equivalent closed-population effective size ((eq)N(e)) of 39.2 for the dAA, 56.3 for dHA and 114.1 for dSSH. The essayed methodologies were useful for characterising populations involving migration. The consequences of the management of the analysed breeds are discussed. The results emphasize the need to include the complete genealogies of the individuals to attain reliable genealogical parameters.


Assuntos
Cavalos/classificação , Cavalos/genética , Linhagem , Animais , Feminino , Endogamia , Masculino , Oriente Médio/etnologia , Probabilidade , Espanha
16.
Rev Gastroenterol Mex ; 74(4): 366-9, 2009.
Artigo em Espanhol | MEDLINE | ID: mdl-20423770

RESUMO

We report the case of a woman with peritoneal and gastric tuberculosis who presented with clinical and radiologic features mimicking an advanced gastric neoplasia. We emphasize the relevance of including tuberculosis in the differential diagnosis of patients with gastric wall thickness.


Assuntos
Carcinoma/diagnóstico , Neoplasias Peritoneais/diagnóstico , Peritonite Tuberculosa/diagnóstico , Gastropatias/diagnóstico , Gastropatias/microbiologia , Neoplasias Gástricas/diagnóstico , Tuberculose Gastrointestinal/diagnóstico , Idoso , Diagnóstico Diferencial , Feminino , Humanos , Peritônio
17.
Vet Immunol Immunopathol ; 122(3-4): 204-15, 2008 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-18207573

RESUMO

Transmissible spongiform encephalopathies (TSEs) or prion diseases develop as central nervous system (CNS) disorders characterized by extremely long incubation periods. Although TSEs do not go along with inflammatory infiltrates and/or antibody production against the prion protein (PrP(Sc)), the immune system plays an important role in pathogenesis as long as different lymphoid organs (Peyer's patches, lymph nodes and spleen) may facilitate the accumulation and further spread of prions after peripheral exposure. In this work we investigated the changes in lymphoid and dendritic cell (DC) populations as well as the implications of different cytokines during disease progression after experimental oral inoculation of prions in a transgenic mouse model. At different days post-inoculation (dpi), T and B lymphocytes and DC populations from lymphoid organs, blood and brain were analyzed by flow cytometry and immunohistochemistry. Besides time related variations in lymphoid cell numbers due to the aging of the animals significant changes related with the infection were found in mesenteric lymph nodes, peripheral blood leukocytes (PBLs) as well as in spleen, affecting the CD4/CD8 ratio. In contrast, little or no variation was detected in Peyer's Patches or in thymus either associated with aging or the infection status. At individual time points significant differences between infected and control mice were seen in the CD8, CD4 and DC populations, with less evidence of differences in the B cell compartment. Finally, a pro-inflammatory phenotype occurred at early times in the spleen, where the levels of lymphotoxin-beta mRNA were found augmented with respect to controls. Altogether, these results suggest that normal regulation of lymphocyte populations becomes altered along the progression of a prion infection.


Assuntos
Homeostase/fisiologia , Linfócitos/fisiologia , Doenças Priônicas/imunologia , Animais , Células Dendríticas/citologia , Células Dendríticas/fisiologia , Regulação da Expressão Gênica , Predisposição Genética para Doença , Linfócitos/citologia , Tecido Linfoide/citologia , Linfotoxina-beta/genética , Linfotoxina-beta/metabolismo , Camundongos , Camundongos Transgênicos , Proteínas PrPC/genética , Proteínas PrPC/metabolismo , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo
18.
Animal ; 12(1): 20-27, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28633685

RESUMO

Ranking trait was used as a selection criterion for competition horses to estimate racing performance. In the literature the most common approaches to estimate breeding values are the linear or threshold statistical models. However, recent studies have shown that a Thurstonian approach was able to fix the race effect (competitive level of the horses that participate in the same race), thus suggesting a better prediction accuracy of breeding values for ranking trait. The aim of this study was to compare the predictability of linear, threshold and Thurstonian approaches for genetic evaluation of ranking in endurance horses. For this purpose, eight genetic models were used for each approach with different combinations of random effects: rider, rider-horse interaction and environmental permanent effect. All genetic models included gender, age and race as systematic effects. The database that was used contained 4065 ranking records from 966 horses and that for the pedigree contained 8733 animals (47% Arabian horses), with an estimated heritability around 0.10 for the ranking trait. The prediction ability of the models for racing performance was evaluated using a cross-validation approach. The average correlation between real and predicted performances across genetic models was around 0.25 for threshold, 0.58 for linear and 0.60 for Thurstonian approaches. Although no significant differences were found between models within approaches, the best genetic model included: the rider and rider-horse random effects for threshold, only rider and environmental permanent effects for linear approach and all random effects for Thurstonian approach. The absolute correlations of predicted breeding values among models were higher between threshold and Thurstonian: 0.90, 0.91 and 0.88 for all animals, top 20% and top 5% best animals. For rank correlations these figures were 0.85, 0.84 and 0.86. The lower values were those between linear and threshold approaches (0.65, 0.62 and 0.51). In conclusion, the Thurstonian approach is recommended for the routine genetic evaluations for ranking in endurance horses.


Assuntos
Cavalos/genética , Modelos Genéticos , Modelos Estatísticos , Resistência Física , Animais , Cruzamento , Feminino , Cavalos/fisiologia , Masculino , Linhagem , Fenótipo
19.
Animal ; : 1-7, 2018 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-30567623

RESUMO

The alpaca fiber diameter (FD) varies from 18 to 36 µm, being the finer fiber categories highly appreciated. However, the alpaca fiber presents some limitations in the textile industry due to the high incidence of fiber medullation and diameter variability, both reduces the comfort feeling of the garments. Decreasing or even removing medullation could be a possible selection objective in alpaca breeding programs for increasing economic value of the alpaca fiber. Therefore, the present work aimed to estimate genetic parameters regarding medullation traits, as well as the genetic correlations with other economical important traits, to be able to select the appropriate criteria to reduce or remove medullation on alpaca fiber and help to reduce the prickle factor in the garments. The data was collected from 2000 to 2017 and belonged to the Pacomarca experimental farm. There were 3698 medullation records corresponding to 1869 Huacaya and 414 Suri genetic types. The fiber samples were taken from the mid side, and were analyzed in an OFDA 100® device. The traits analyzed were percentage of medullation (PM), medullated fiber diameter (MFD), FD, standard deviation of FD, greasy fleece weight as fiber traits; density, crimp in Huacaya and lock structure in Suri, head conformation, leg coverage as morphological traits; weaning weight and age at first calving as secondary and functional traits. Genetic parameters were estimated via a multitrait restricted maximum likelihood. The heritabilities for PM and MFD were 0.225 and 0.237 in Huacaya genetic type and 0.664 and 0.237 in Suri genetic type, respectively; heritabilities for other traits were moderate for productive and morphological traits, and low to moderate for secondary and functional traits. The genetic correlations PM-FD and MFD-FD were high and favorable in both genetic types, between 0.531 and 0.975; the genetic correlation PM-MFD was 0.121 in Huacaya and 0.427 in Suri. The rest of genetic correlations with other traits were in general moderate and favorable. The repeatabilities were 0.556 and 0.668 for PM, and 0.322 and 0.293 for MFD in Huacaya and Suri genetic types, respectively. As a conclusion, PM was identified to be a good selection criterion, probably combined in an index with FD to reduce prickling factor.

20.
J Dairy Sci ; 90(12): 5744-52, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18024768

RESUMO

Inbreeding depression on female fertility and calving ease in Spanish dairy cattle was studied by the traditional inbreeding coefficient (F) and an alternative measurement indicating the inbreeding rate (DeltaF) for each animal. Data included records from 49,497 and 62,134 cows for fertility and calving ease, respectively. Both inbreeding measurements were included separately in the routine genetic evaluation models for number of insemination to conception (sequential threshold animal model) and calving ease (sire-maternal grandsire threshold model). The F was included in the model as a categorical effect, whereas DeltaF was included as a linear covariate. Inbred cows showed impaired fertility and tended to have more difficult calvings than low or noninbred cows. Pregnancy rate decreased by 1.68% on average for cows with F from 6.25 to 12.5%. This amount of inbreeding, however, did not seem to increase dystocia incidence. Inbreeding depression was larger for F greater than 12.5%. Cows with F greater than 25% had lower pregnancy rate and higher dystocia rate (-6.37 and 1.67%, respectively) than low or noninbred cows. The DeltaF had a significant effect on female fertility. A DeltaF = 0.01, corresponding to an inbreeding coefficient of 5.62% for the average equivalent generations in the data used (5.68), lowered pregnancy rate by 1.5%. However, the posterior estimate for the effect of DeltaF on calving ease was not significantly different from zero. Although similar patterns were found with both F and DeltaF, the latter detected a lowered pregnancy rate at an equivalent F, probably because it may consider the known depth of the pedigree. The inbreeding rate might be an alternative choice to measure inbreeding depression.


Assuntos
Bovinos/genética , Distocia/veterinária , Fertilidade/genética , Endogamia , Animais , Bovinos/fisiologia , Distocia/epidemiologia , Feminino , Fertilidade/fisiologia , Incidência , Gravidez , Taxa de Gravidez , Espanha
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