Correlation of sexual maturity stage with testicular echotexture in young Nellore bulls / Correlation of sexual maturity stage with testicular echotexture in young Nellore bulls

Background: Ultrasound images depend on the relative density of the tissues to be examined. During the period of sexual maturity, the cellular content and changes in the secretion of liquids from the genital organs assist in the identification of development changes. However, the establishment of normal ultrasound parameters for testicular dimensions and the characterization of normal testicular images are necessary to permit more detailed studies related to degenerative and pathological conditions of bovine testes. The objective of this study was to evaluate the pattern of echogenicity of the testicular parenchyma in young Nellore bulls at different stages of sexual maturity. Materials, Methods & Results: The sample consisted of 405 young Nellore bulls between 21 and 33 months of age. All of the animals were evaluated for breeding soundness examination and ultrasound examination of the testes. All of the images were transferred to the computer with the help of Image J software for further analysis. To correlate the several intensities of pixel resolutions with sexual maturity stage and to study the pattern of testicular parenchyma echogenicity of the animals, the bulls were subdivided in three age classes: 1) 21 to 25.9 months, 2) 26 to 29.9 months, and 3) 30 to 33 months. Additionally, according to the physical and morphological semen features, the animals were classified

Background: Ultrasound images depend on the relative density of the tissues to be examined. During the period of sexual maturity, the cellular content and changes in the secretion of liquids from the genital organs assist in the identification of development changes. However, the establishment of normal ultrasound parameters for testicular dimensions and the characterization of normal testicular images are necessary to permit more detailed studies related to degenerative and pathological conditions of bovine testes. The objective of this study was to evaluate the pattern of echogenicity of the testicular parenchyma in young Nellore bulls at different stages of sexual maturity. Materials, Methods & Results: The sample consisted of 405 young Nellore bulls between 21 and 33 months of age. All of the animals were evaluated for breeding soundness examination and ultrasound examination of the testes. All of the images were transferred to the computer with the help of Image J software for further analysis. To correlate the several intensities of pixel resolutions with sexual maturity stage and to study the pattern of testicular parenchyma echogenicity of the animals, the bulls were subdivided in three age classes: 1) 21 to 25.9 months, 2) 26 to 29.9 months, and 3) 30 to 33 months. Additionally, according to the physical and morphological semen features, the animals were classified

Correlation of sexual maturity stage with testicular echotexture in young Nellore bulls / Correlation of sexual maturity stage with testicular echotexture in young Nellore bulls

Background: Ultrasound images depend on the relative density of the tissues to be examined. During the period of sexual maturity, the cellular content and changes in the secretion of liquids from the genital organs assist in the identification of development changes. However, the establishment of normal ultrasound parameters for testicular dimensions and the characterization of normal testicular images are necessary to permit more detailed studies related to degenerative and pathological conditions of bovine testes. The objective of this study was to evaluate the pattern of echogenicity of the testicular parenchyma in young Nellore bulls at different stages of sexual maturity. Materials, Methods & Results: The sample consisted of 405 young Nellore bulls between 21 and 33 months of age. All of the animals were evaluated for breeding soundness examination and ultrasound examination of the testes. All of the images were transferred to the computer with the help of Image J software for further analysis. To correlate the several intensities of pixel resolutions with sexual maturity stage and to study the pattern of testicular parenchyma echogenicity of the animals, the bulls were subdivided in three age classes: 1) 21 to 25.9 months, 2) 26 to 29.9 months, and 3) 30 to 33 months. Additionally, according to the physical and morphological semen features, the animals were classified

Background: Ultrasound images depend on the relative density of the tissues to be examined. During the period of sexual maturity, the cellular content and changes in the secretion of liquids from the genital organs assist in the identification of development changes. However, the establishment of normal ultrasound parameters for testicular dimensions and the characterization of normal testicular images are necessary to permit more detailed studies related to degenerative and pathological conditions of bovine testes. The objective of this study was to evaluate the pattern of echogenicity of the testicular parenchyma in young Nellore bulls at different stages of sexual maturity. Materials, Methods & Results: The sample consisted of 405 young Nellore bulls between 21 and 33 months of age. All of the animals were evaluated for breeding soundness examination and ultrasound examination of the testes. All of the images were transferred to the computer with the help of Image J software for further analysis. To correlate the several intensities of pixel resolutions with sexual maturity stage and to study the pattern of testicular parenchyma echogenicity of the animals, the bulls were subdivided in three age classes: 1) 21 to 25.9 months, 2) 26 to 29.9 months, and 3) 30 to 33 months. Additionally, according to the physical and morphological semen features, the animals were classified

Estimation of genetic parameters in an F2 swine population / Estimação de parâmetros genéticos de uma população F2 de suínos

The aim of this work was to estimate genetic parameters for carcass, carcass cuts, meat quality and performance traits in an F2 swine population (Piau x commercial strain) in order to understand the inheritance of the traits and the association among them. Heritability estimates and genetic correlations were obtained using univariate and bivariate animal models, respectively, and (co)covariance components were obtained by means of restricted maximum likelihood analyses using the software MTDFREML. The heritability estimates using single trait model ranged from 0.10 to 0.43 for carcass, 0.07 to 0.47 for carcass cuts, 0.14 to 0.40 for meat quality and 0.18 to 0.86 for performance traits. The genetic correlation estimates using bi-trait model were high for several traits, showing that they are controlled by the same genes or linked genes. These results suggest that a better understanding of the genetic correlation among the traits, as well as, the quantitative trait loci position can be obtained by mapping studies in this population.

Objetivou-se estimar parâmetros genéticos de características de carcaça, cortes de carcaça, qualidade de carne e desempenho de suínos em uma população F2 (Piau x linhagem comercial), para melhor se compreender a herança e a associação entre essas características. Para obter as estimativas de herdabilidades e correlações genéticas foi utilizado um modelo animal unicaracterístico e bicaracterístico, respectivamente, e os parâmetros foram estimados a partir dos componentes de variância e covariância, obtidos pelo método da máxima verossimilhança restrita por meio do programa MTDFREML. As herdabilidades estimadas, em modelo unicaracterístico, variaram de 0,10 a 0,43 para o grupo de características de carcaça, de 0,07 a 0,47 para cortes de carcaça, de 0,14 a 0,40 para qualidade de carne e de 0,18 a 0,86 para características de desempenho. As correlações genéticas estimadas em modelo bicaracterístico foram altas para algumas características, o que pode ser indicativo de que estas são controladas pelos mesmos genes ou genes ligados. Estudos futuros de mapeamento dos locos de características quantitativas, nesta população permitirão uma melhor compreensão das causas das correlações genéticas existentes entre as características, bem como determinar em qual região cromossômica localiza-se os locos de características quantitativas.

Estimação de parâmetros genéticos de uma população F2 de suínos

The aim of this work was to estimate genetic parameters for carcass, carcass cuts, meat quality and performance traits in an F2 swine population (Piau x commercial strain) in order to understand the inheritance of the traits and the association among them. Heritability estimates and genetic correlations were obtained using univariate and bivariate animal models, respectively, and (co)covariance components were obtained by means of restricted maximum likelihood analyses using the software MTDFREML. The heritability estimates using single trait model ranged from 0.10 to 0.43 for carcass, 0.07 to 0.47 for carcass cuts, 0.14 to 0.40 for meat quality and 0.18 to 0.86 for performance traits. The genetic correlation estimates using bi-trait model were high for several traits, showing that they are controlled by the same genes or linked genes. These results suggest that a better understanding of the genetic correlation among the traits, as well as, the quantitative trait loci position can be obtained by mapping studies in this population.

Objetivou-se estimar parâmetros genéticos de características de carcaça, cortes de carcaça, qualidade de carne e desempenho de suínos em uma população F2 (Piau x linhagem comercial), para melhor se compreender a herança e a associação entre essas características. Para obter as estimativas de herdabilidades e correlações genéticas foi utilizado um modelo animal unicaracterístico e bicaracterístico, respectivamente, e os parâmetros foram estimados a partir dos componentes de variância e covariância, obtidos pelo método da máxima verossimilhança restrita por meio do programa MTDFREML. As herdabilidades estimadas, em modelo unicaracterístico, variaram de 0,10 a 0,43 para o grupo de características de carcaça, de 0,07 a 0,47 para cortes de carcaça, de 0,14 a 0,40 para qualidade de carne e de 0,18 a 0,86 para características de desempenho. As correlações genéticas estimadas em modelo bicaracterístico foram altas para algumas características, o que pode ser indicativo de que estas são controladas pelos mesmos genes ou genes ligados. Estudos futuros de mapeamento dos locos de características quantitativas, nesta população permitirão uma melhor compreensão das causas das correlações genéticas existentes entre as características, bem como determinar em qual região cromossômica localiza-se os locos de características quantitativas.

Estimation of genetic parameters in an F2 swine population / Estimação de parâmetros genéticos de uma população F2 de suínos

The aim of this work was to estimate genetic parameters for carcass, carcass cuts, meat quality and performance traits in an F2 swine population (Piau x commercial strain) in order to understand the inheritance of the traits and the association among them. Heritability estimates and genetic correlations were obtained using univariate and bivariate animal models, respectively, and (co)covariance components were obtained by means of restricted maximum likelihood analyses using the software MTDFREML. The heritability estimates using single trait model ranged from 0.10 to 0.43 for carcass, 0.07 to 0.47 for carcass cuts, 0.14 to 0.40 for meat quality and 0.18 to 0.86 for performance traits. The genetic correlation estimates using bi-trait model were high for several traits, showing that they are controlled by the same genes or linked genes. These results suggest that a better understanding of the genetic correlation among the traits, as well as, the quantitative trait loci position can be obtained by mapping studies in this population.

Objetivou-se estimar parâmetros genéticos de características de carcaça, cortes de carcaça, qualidade de carne e desempenho de suínos em uma população F2 (Piau x linhagem comercial), para melhor se compreender a herança e a associação entre essas características. Para obter as estimativas de herdabilidades e correlações genéticas foi utilizado um modelo animal unicaracterístico e bicaracterístico, respectivamente, e os parâmetros foram estimados a partir dos componentes de variância e covariância, obtidos pelo método da máxima verossimilhança restrita por meio do programa MTDFREML. As herdabilidades estimadas, em modelo unicaracterístico, variaram de 0,10 a 0,43 para o grupo de características de carcaça, de 0,07 a 0,47 para cortes de carcaça, de 0,14 a 0,40 para qualidade de carne e de 0,18 a 0,86 para características de desempenho. As correlações genéticas estimadas em modelo bicaracterístico foram altas para algumas características, o que pode ser indicativo de que estas são controladas pelos mesmos genes ou genes ligados. Estudos futuros de mapeamento dos locos de características quantitativas, nesta população permitirão uma melhor compreensão das causas das correlações genéticas existentes entre as características, bem como determinar em qual região cromossômica localiza-se os locos de características quantitativas.