Correlations between Breast Yield and Morphometric Traits in Broiler Pure Lines

Broiler pure lines are valuable breeding species and morphometric traits are advantageous for the selection of breast yield since they could be applied practically and without any negative impact on welfare. In this study, live weight (LW), carcass weight and ratio (CW and CR), breast weight and ratio (BW and BR), abdominal fat weight and ratio (AFW and AFR), morphometric traits such as breast width, length and index (BWD, BL and BI) were investigated in broiler pure lines. The research material consisted of 3 dam (A1, A2 and A3) and 2 sire (B1, B2) pure lines of 42 days of age. LW, CW, BW, AFW, AFR, BR, BL, BWD and BI values were different between the two lines (p 0.05). LW, CW, BW and BI were higher in sire lines. The relationship between breast weight and index were also higher in sire and dam lines than the relationships between breast width and length separately (in sire lines: BWD: 0.73; BL: 0.79; BI: 0.79, in dam lines: BWD: 0.79; BL: 0.74; BI: 0.84). In addition, high r 2 values were determined in regression equations for BW estimation in dam and sire lines (0.836 and 0.857, respectively). Because of the significant correlations between breast yield and its morphometric traits, it is seen that more feasible, ease of measurement, protection of breeding resources and welfare. It is thought that the use of breast index which shows a higher correlation compared to these traits will increase selection efficiency instead of using breast width and length separately.(AU)

Correlations between Breast Yield and Morphometric Traits in Broiler Pure Lines

Broiler pure lines are valuable breeding species and morphometric traits are advantageous for the selection of breast yield since they could be applied practically and without any negative impact on welfare. In this study, live weight (LW), carcass weight and ratio (CW and CR), breast weight and ratio (BW and BR), abdominal fat weight and ratio (AFW and AFR), morphometric traits such as breast width, length and index (BWD, BL and BI) were investigated in broiler pure lines. The research material consisted of 3 dam (A1, A2 and A3) and 2 sire (B1, B2) pure lines of 42 days of age. LW, CW, BW, AFW, AFR, BR, BL, BWD and BI values were different between the two lines (p 0.05). LW, CW, BW and BI were higher in sire lines. The relationship between breast weight and index were also higher in sire and dam lines than the relationships between breast width and length separately (in sire lines: BWD: 0.73; BL: 0.79; BI: 0.79, in dam lines: BWD: 0.79; BL: 0.74; BI: 0.84). In addition, high r 2 values were determined in regression equations for BW estimation in dam and sire lines (0.836 and 0.857, respectively). Because of the significant correlations between breast yield and its morphometric traits, it is seen that more feasible, ease of measurement, protection of breeding resources and welfare. It is thought that the use of breast index which shows a higher correlation compared to these traits will increase selection efficiency instead of using breast width and length separately.

Successful Identification of Duck Genome Region Determining Desirable Uniformity of Meat Performance Traits

ABSTRACT The objective of this study was to identify genome regions determining duck meat performance traits with possible small variation. In total, 368 crossbred ducks of F2 generation obtained from two parental lines: Pekin-type ducks of Polish origin (A55) and Pekin-type ducks of French origin (GL-30) were recorded. The following seven traits were analyzed: body weight, breast muscle weight, leg muscle weight, water holding capacity in the breast and leg muscles, and color lightness L* of the breast and leg muscles. All birds (including parental and F1 generations) were genotyped (29 microsatellite markers). Means and coefficients of variation (CV) were calculated for 28 full-sibs (four sires by six dams and one sire by four dams). Number of progeny per full-sib group ranged from 7 to 17. The multivariate cluster analysis using grouping by k-means algorithm was used on transformed data. The multivariate cluster analysis gave two clusters: first group with 10 full-sibs and second one with 18 families. Differences among half-sibs in the CV of the recorded traits were determined. It should be noted that one out of five sire groups showed statistically significant differences from the other ones. Moreover, the CVs in this group were smaller. The analysis of microsatellite markers indicated three alleles from three loci were present only in the superior sire group. The obtained results indicate a promising opportunity of effective selection for improving carcass technological quality using molecular markers.(AU)

Successful Identification of Duck Genome Region Determining Desirable Uniformity of Meat Performance Traits

ABSTRACT The objective of this study was to identify genome regions determining duck meat performance traits with possible small variation. In total, 368 crossbred ducks of F2 generation obtained from two parental lines: Pekin-type ducks of Polish origin (A55) and Pekin-type ducks of French origin (GL-30) were recorded. The following seven traits were analyzed: body weight, breast muscle weight, leg muscle weight, water holding capacity in the breast and leg muscles, and color lightness L* of the breast and leg muscles. All birds (including parental and F1 generations) were genotyped (29 microsatellite markers). Means and coefficients of variation (CV) were calculated for 28 full-sibs (four sires by six dams and one sire by four dams). Number of progeny per full-sib group ranged from 7 to 17. The multivariate cluster analysis using grouping by k-means algorithm was used on transformed data. The multivariate cluster analysis gave two clusters: first group with 10 full-sibs and second one with 18 families. Differences among half-sibs in the CV of the recorded traits were determined. It should be noted that one out of five sire groups showed statistically significant differences from the other ones. Moreover, the CVs in this group were smaller. The analysis of microsatellite markers indicated three alleles from three loci were present only in the superior sire group. The obtained results indicate a promising opportunity of effective selection for improving carcass technological quality using molecular markers.

IMPACTO DA DISTRIBUIÇÃO DE NÚMERO DESIGUAL DE PROGÊNIES POR REPRODUTOR NA AVALIAÇÃO GENÉTICA DE ANIMAIS, EM AMBIENTES COM PRESENÇA DE HETEROGENEIDADE DE VARIÂNCIA AMBIENTAL

Abstract A progeny test representing the milk yield was simulated to evaluate the effect of heterogeneity of environmental variance on genetic evaluation of sires in situations of unequal number of progeny per sire between herds, eliminating, at random, daughters per sires in environments of low and high environmental variability. In all situations involving loss of information in the environment of lower environmental variability, there was larger overestimation of the residual variance component, resulting in lower estimates of heritability. On the other hand, the decrease in the amount of information of herds from high environmental variability led to greater overestimation of additive genetic variance and lower overestimation of environmental variance. Although there were alterations in breeding values regarding sires, Spearman and Pearson correlations between breeding values, in all situations, were higher than 0.90. The uneven number of progeny per sire in the presence of heterogeneity of environmental variance led to the overestimation of variance components and changes in absolute breeding values of the sires, without, however, changing the classification values.

Resumo Foi simulado um teste de progênie com o objetivo de avaliar o efeito da heterogeneidade de variância ambiental sobre a avaliação genética de reprodutores, em situações de número desigual de progênie por reprodutor entre rebanhos. A situação do número desigual de progênie por reprodutor foi representada eliminando-se, de forma aleatória, o número de progênies por reprodutor em ambientes de baixa e alta variabilidade ambiental. Nas situações que envolveram perda de informação no ambiente de menor variabilidade ambiental, houve maiores superestimações na estimação da variância residual, ocasionando menores estimativas de herdabilidade. Por outro lado, quando se diminuiu a quantidade de informação proveniente de rebanhos de alta variabilidade ambiental, houve maior superestimação da variância genética aditiva e menor superestimação da variância ambiental. Embora tenham ocorrido alterações na magnitude dos valores genéticos para os reprodutores, as correlações de Spearman e Pearson entre os valores genéticos dos mesmos, em todas as situaçãoes, foram maiores do que 0,90. O número desigual de progênie por reprodutor na presença de heterogeneidade de variância ambiental provoca superestimação das estimativas de componentes de variância e valores absolutos de predição de valores genéticos dos reprodutores, sem, contudo, alterar a classificação dos mesmos.

Combination of commercially available molecular assays and culture based methods in diagnosis of tuberculosis and drug resistant tuberculosis

ABSTRACT Early diagnosis of tuberculosis is of major clinical importance. Among 4733 clinical specimens collected from 3363 patients and subjected to Ziehl-Neelsen microscopy, 4109 were inoculated onto Lõwenstein-Jensen slants and 3139 in Bactec/9000MB. Polymerase Chain Reaction (PCR) was performed in 3139 specimens, whereas, a genotypic assay was directly applied in 93 Mycobacterium tuberculosis complex PCR-positive for isoniazid and rifampicin resistance detection specimens (GenoType MTBDRplus). Recovered M. tuberculosis isolates (64) as well as, 21 more sent from Regional Hospitals were tested for antimycobacterial resistance with a phenotypic (manual MGIT-SIRE) and a genotypic assay (GenoType MTBDRplus). PCR in the clinical specimens showed excellent specificity (97.4%) and accuracy (96.8%), good sensitivity (70.4%), but low positive predictive value (40.3%). MGIT-SIRE performed to M. tuberculosis did not confer a reliable result in 16 isolates. Of the remaining 69 isolates, 15 were resistant to streptomycin, seven to isoniazid, seven to ethambutol and five to rifampicin. GenoType MTBDRplus correctly detected isoniazid (seven) and rifampicin-resistant M. tuberculosis strains (five), showing an excellent performance overall (100%). Susceptibility results by the molecular assay applied directly to clinical specimens were identical to those obtained from recovered isolates of the corresponding patients. Combining molecular and conventional methods greatly contribute to early diagnosis and accurate susceptibility testing of tuberculosis.(AU)

Impacto da distribuição de número desigual de progênies por reprodutor na avaliação genética de animais, em ambientes com presença de heterogeneidade de variância ambiental / Impact of the uneven distribution of the number of progenies by sires in the genetic evaluation of animals in environments with presence of heterogeneity of environmental variance

A progeny test representing the milk yield was simulated to evaluate the effect of heterogeneity of environmental variance on genetic evaluation of sires in situations of unequal number of progeny per sire between herds, eliminating, at random, daughters per sires in environments of low and high environmental variability. In all situations involving loss of information in the environment of lower environmental variability, there was larger overestimation of the residual variance component, resulting in lower estimates of heritability. On the other hand, the decrease in the amount of information of herds from high environmental variability led to greater overestimation of additive genetic variance and lower overestimation of environmental variance. Although there were alterations in breeding values regarding sires, Spearman and Pearson correlations between breeding values, in all situations, were higher than 0.90. The uneven number of progeny per sire in the presence of heterogeneity of environmental variance led to the overestimation of variance components and changes in absolute breeding values of the sires, without, however, changing the classification values.

Foi simulado um teste de progênie com o objetivo de avaliar o efeito da heterogeneidade de variância ambiental sobre a avaliação genética de reprodutores, em situações de número desigual de progênie por reprodutor entre rebanhos. A situação do número desigual de progênie por reprodutor foi representada eliminando-se, de forma aleatória, o número de progênies por reprodutor em ambientes de baixa e alta variabilidade ambiental. Nas situações que envolveram perda de informação no ambiente de menor variabilidade ambiental, houve maiores superestimações na estimação da variância residual, ocasionando menores estimativas de herdabilidade. Por outro lado, quando se diminuiu a quantidade de informação proveniente de rebanhos de alta variabilidade ambiental, houve maior superestimação da variância genética aditiva e menor superestimação da variância ambiental. Embora, tenham ocorrido alterações na magnitude dos valores genéticos para os reprodutores, as correlações de Spearman e Pearson entre os valores genéticos dos mesmos, em todas as situações, foram maiores do que 0,90. O número desigual de progênie por reprodutor na presença de heterogeneidade de variância ambiental provoca superestimação das estimativas de componentes de variância e valores absolutos de predição de valores genéticos dos reprodutores, sem, contudo, alterar a classificação dos mesmos.

Impacto da distribuição de número desigual de progênies por reprodutor na avaliação genética de animais, em ambientes com presença de heterogeneidade de variância ambiental / Impact of the uneven distribution of the number of progenies by sires in the genetic evaluation of animals in environments with presence of heterogeneity of environmental variance

A progeny test representing the milk yield was simulated to evaluate the effect of heterogeneity of environmental variance on genetic evaluation of sires in situations of unequal number of progeny per sire between herds, eliminating, at random, daughters per sires in environments of low and high environmental variability. In all situations involving loss of information in the environment of lower environmental variability, there was larger overestimation of the residual variance component, resulting in lower estimates of heritability. On the other hand, the decrease in the amount of information of herds from high environmental variability led to greater overestimation of additive genetic variance and lower overestimation of environmental variance. Although there were alterations in breeding values regarding sires, Spearman and Pearson correlations between breeding values, in all situations, were higher than 0.90. The uneven number of progeny per sire in the presence of heterogeneity of environmental variance led to the overestimation of variance components and changes in absolute breeding values of the sires, without, however, changing the classification values.(AU)

Foi simulado um teste de progênie com o objetivo de avaliar o efeito da heterogeneidade de variância ambiental sobre a avaliação genética de reprodutores, em situações de número desigual de progênie por reprodutor entre rebanhos. A situação do número desigual de progênie por reprodutor foi representada eliminando-se, de forma aleatória, o número de progênies por reprodutor em ambientes de baixa e alta variabilidade ambiental. Nas situações que envolveram perda de informação no ambiente de menor variabilidade ambiental, houve maiores superestimações na estimação da variância residual, ocasionando menores estimativas de herdabilidade. Por outro lado, quando se diminuiu a quantidade de informação proveniente de rebanhos de alta variabilidade ambiental, houve maior superestimação da variância genética aditiva e menor superestimação da variância ambiental. Embora, tenham ocorrido alterações na magnitude dos valores genéticos para os reprodutores, as correlações de Spearman e Pearson entre os valores genéticos dos mesmos, em todas as situações, foram maiores do que 0,90. O número desigual de progênie por reprodutor na presença de heterogeneidade de variância ambiental provoca superestimação das estimativas de componentes de variância e valores absolutos de predição de valores genéticos dos reprodutores, sem, contudo, alterar a classificação dos mesmos.(AU)

Seminal factors influencing return to estrus in female pigs following artificial insemination

Tests were applied to extended, chilled boar semen to further define those factors associated with return to estrus in inseminated female pigs (sows and gilts). Females were each inseminated twice with the same batch of extended chilled single-sire semen that was concurrently assessed at the Charles Sturt University Andrology Laboratory (CSUAL) in Australia. Semen traits tested were pH, clump score and temperature while sperm morphology assessment included abnormal heads, acrosomes, midpieces, tails and retained cytoplasmic droplets. Sperm motility and concentration were tested using a computerized sperm analyser (CASA) system. Female return types were categorised as early, early regular, early irregular, late regular and late. Depending on the type of variable of interest, statistical analyses used linear mixed models or generalised linear models. Terms included in the models were dam line, sire line, parity, insemination season, return type, individual boars and inseminators. Of 1205 inseminated females, 894 (74.2%) farrowed, 3 (0.2%) aborted and 308 (25.6%) showed different types of return to estrus. The fixed variables dam-line, sire-line and parity were significantly (P < 0.05, P < 0.05 and P < 0.001 respectively) associated with female return type, although inseminator and insemination season were not. Of the semen/sperm traits tested, the acrosomal defects that were significantly associated (P < 0.05) with female return-type were morphologically abnormal acrosomes and percent intact acrosomes while cytoplasmic droplets, normal morphology and bacterial score also influenced return type (P < 0.05). There were also correlations between sperm factors such as abnormal sperm tails, motility and velocity and sow parity. In conclusion, sperm morphologic assessment, in particular of the acrosome region, was useful in predicting female returns to estrus.

Seminal factors influencing return to estrus in female pigs following artificial insemination

Tests were applied to extended, chilled boar semen to further define those factors associated with return to estrus in inseminated female pigs (sows and gilts). Females were each inseminated twice with the same batch of extended chilled single-sire semen that was concurrently assessed at the Charles Sturt University Andrology Laboratory (CSUAL) in Australia. Semen traits tested were pH, clump score and temperature while sperm morphology assessment included abnormal heads, acrosomes, midpieces, tails and retained cytoplasmic droplets. Sperm motility and concentration were tested using a computerized sperm analyser (CASA) system. Female return types were categorised as early, early regular, early irregular, late regular and late. Depending on the type of variable of interest, statistical analyses used linear mixed models or generalised linear models. Terms included in the models were dam line, sire line, parity, insemination season, return type, individual boars and inseminators. Of 1205 inseminated females, 894 (74.2%) farrowed, 3 (0.2%) aborted and 308 (25.6%) showed different types of return to estrus. The fixed variables dam-line, sire-line and parity were significantly (P < 0.05, P < 0.05 and P < 0.001 respectively) associated with female return type, although inseminator and insemination season were not. Of the semen/sperm traits tested, the acrosomal defects that were significantly associated (P < 0.05) with female return-type were morphologically abnormal acrosomes and percent intact acrosomes while cytoplasmic droplets, normal morphology and bacterial score also influenced return type (P < 0.05). There were also correlations between sperm factors such as abnormal sperm tails, motility and velocity and sow parity. In conclusion, sperm morphologic assessment, in particular of the acrosome region, was useful in predicting female returns to estrus.(AU)

Estabilidade e adaptabilidade de touros Tabapuã para característica de desempenho em função do índice de rebanhos / Stability and adaptability analysis of Tabapuã bulls for performance traits according to the herd level

Com o objetivo de estudar a estabilidade e a adaptabilidade de bovinos da raça Tabapuã para a característica peso aos 120 dias efeito materno, empregou-se metodologias de regressão linear. As análises incluíram as diferenças esperadas nas progênies de cinco reprodutores em quatro rebanhos, localizados nos estados da Bahia (rebanhos 1 e 2), Paraná (rebanho 3) e Minas Gerais (rebanho 4). Os resultados mostraram que o desempenho dos touros depende, em grande parte, da variabilidade genética das matrizes para a característica estudada nos diferentes rebanhos, o que permite a recomendação de reprodutores específicos para cada rebanho. As análises de adaptabilidade e estabilidade discriminaram diferenças de desempenho nos rebanhos e identificaram touros perfeitamente adaptados e estáveis, touros com adaptação geral, com adaptação específica a ambientes favoráveis e desfavoráveis.(AU)

In order to study the stability and adaptability of Tabapuã cattle for the characteristic weight at 120 days of maternal effect, we used methods based on linear regression. The analysis included differences in the expected progeny of five sire sin herds located in four farms in the states of Bahia, (herds 1and 2), Paraná (herd 3) and Minas Gerais (herd 4). The results show that the performance of bulls depend largely on the genetic variability of the matrices for different characteristics in herds studied, allowing the recommendation of a specific breeding herd. Analyses of adaptability and stability discriminated performance differences in herds. Bulls were identified as adapted and perfectly stable, bulls with general adaptation, and with specific adaptation to favorable and unfavorable environments.(AU)

Perfil genético das linhagens de touros leiteiros Holandês e Jersey disponíveis no Brasil / Genetic profile of Holstein and Jersey dairy bull lines available in Brazil

As raças de bovinos de leite Holandesa e Jersey estão entre as mais prevalentes no Brasil. Para avaliar as diferenças entre as PTAs (habilidades de transmissão preditas) destas raças e suas linhagens, foram coletadas informações de 385 touros Holandês e 82 touros Jersey disponibilizados por nove empresas comercializadoras de sêmen no Brasil. Três diferentes linhagens de cada raça foram encontradas. O método dos modelos lineares generalizados foi utilizado para a comparação entre linhagens e entre raças. As duas linhagens da raça Holandesa mais prevalentes apresentaram as maiores PTAs médias para produção de leite (1.061,04 libras e 975,32 libras) e as menores PTAs para a porcentagem de sólidos no leite (de -0,05% a -0,0003%)(AU)

The Holstein and Jersey dairy cattle breeds are among the most prevalent in Brazil. To evaluate differences among the PTAs (predicted transmitting abilities) of these breeds and their lines, data were collected on 385 Holstein bulls and 82 Jersey sires with semen commercially available from nine Brazilian companies. Three different sire lines for each breed were found. The general linear models method was used for the comparison among lines and between breeds. The two most prevalent lines of Holstein breed presented higher average PTAs for milk yield (1,061.04 pounds and 975.32 pounds) and lower PTAs for percentage of milk solids (from -0.05% to -0.0003%)(AU)

Perfil genético das linhagens de touros leiteiros Holandês e Jersey disponíveis no Brasil / Genetic profile of Holstein and Jersey dairy bull lines available in Brazil

As raças de bovinos de leite Holandesa e Jersey estão entre as mais prevalentes no Brasil. Para avaliar as diferenças entre as PTAs (habilidades de transmissão preditas) destas raças e suas linhagens, foram coletadas informações de 385 touros Holandês e 82 touros Jersey disponibilizados por nove empresas comercializadoras de sêmen no Brasil. Três diferentes linhagens de cada raça foram encontradas. O método dos modelos lineares generalizados foi utilizado para a comparação entre linhagens e entre raças. As duas linhagens da raça Holandesa mais prevalentes apresentaram as maiores PTAs médias para produção de leite (1.061,04 libras e 975,32 libras) e as menores PTAs para a porcentagem de sólidos no leite (de -0,05% a -0,0003%)

The Holstein and Jersey dairy cattle breeds are among the most prevalent in Brazil. To evaluate differences among the PTAs (predicted transmitting abilities) of these breeds and their lines, data were collected on 385 Holstein bulls and 82 Jersey sires with semen commercially available from nine Brazilian companies. Three different sire lines for each breed were found. The general linear models method was used for the comparison among lines and between breeds. The two most prevalent lines of Holstein breed presented higher average PTAs for milk yield (1,061.04 pounds and 975.32 pounds) and lower PTAs for percentage of milk solids (from -0.05% to -0.0003%)

Structure and geographic distribution of the Santa Inês sheep flock in the Piauí state / Estrutura e distribuição geográfica do rebanho de ovinos Santa Inês no Estado do Piauí

This study was carried out to evaluate the effects of heterogeneity of residual variance on genetic evaluation of cattle raised on pasture from Amazônia Bioma, Brazil. Adjusted weights at weaning weight (205 days of age) were sorted in three phenotypic classes: low (less than average weight), medium (between the average and the average plus one standard deviation) and high (greater than average plus one standard deviation). There was increased of genetic additive direct and residual variances to the extent that increased phenotypic classes. The heritabilities for low, medium and high phenotypic classes were 0.27, 0.33 and 0.26, respectively. These estimates suggest that mass selection could result in genetic gain on breeding program that use weaning weight as a selection criteria. Genetic correlations between the low and medium, low and high, and medium and high phenotypic classes were 0.82, 0.35 and 0.72, respectively. The estimate of correlation of the breeding values of sire shown effect of the heterogeneity of phenotypic variance on the prediction of animals breeding values. There was a major variability for the breeding values of sires at high phenotype class. Thus, we suggested the identification and selection of sires with the highest breeding values for weaning weight, according with environment in which these animals are being raised.(AU)

Objetivou-se descrever o quantitativo, distribuição e estrutura do rebanho de ovino da raça Santa Inês no estado do Piauí. Foram analisados dados de registros genealógicos da raça Santa Inês, mantidos pela Associação Brasileira de Criadores de Ovinos (ARCO), referentes ao período de 1992 a 2012. Foram realizadas análises estatísticas descritivas de modo a conhecer como o rebanho Santa Inês está estruturado. Foi realizada a classificação do rebanho quanto a sua estrutura organizacional, determinada com base na origem e uso dos reprodutores, utilizando-se o programa ENDOG. v.4.8. O registro dos animais da raça Santa Inês, no Piauí, teve inicio em 1990, e a maior representatividade foi verificada no período de 1993 a 2001. Quanto à estrutura dos rebanhos, 56,8% foram classificados como rebanhos multiplicadores (estrato intermediário da pirâmide) e 43,2% como rebanhos comerciais (base da pirâmide), sendo que não se observou nenhum rebanho núcleo e nem isolado. A falta de rebanhos núcleo da raça no Estado pode ser uma das causas da redução do número de animais registrados nos últimos anos no Piauí.(AU)

Structure and geographic distribution of the Santa Inês sheep flock in the Piauí state / Estrutura e distribuição geográfica do rebanho de ovinos Santa Inês no Estado do Piauí

This study was carried out to evaluate the effects of heterogeneity of residual variance on genetic evaluation of cattle raised on pasture from Amazônia Bioma, Brazil. Adjusted weights at weaning weight (205 days of age) were sorted in three phenotypic classes: low (less than average weight), medium (between the average and the average plus one standard deviation) and high (greater than average plus one standard deviation). There was increased of genetic additive direct and residual variances to the extent that increased phenotypic classes. The heritabilities for low, medium and high phenotypic classes were 0.27, 0.33 and 0.26, respectively. These estimates suggest that mass selection could result in genetic gain on breeding program that use weaning weight as a selection criteria. Genetic correlations between the low and medium, low and high, and medium and high phenotypic classes were 0.82, 0.35 and 0.72, respectively. The estimate of correlation of the breeding values of sire shown effect of the heterogeneity of phenotypic variance on the prediction of animals breeding values. There was a major variability for the breeding values of sires at high phenotype class. Thus, we suggested the identification and selection of sires with the highest breeding values for weaning weight, according with environment in which these animals are being raised.

Objetivou-se descrever o quantitativo, distribuição e estrutura do rebanho de ovino da raça Santa Inês no estado do Piauí. Foram analisados dados de registros genealógicos da raça Santa Inês, mantidos pela Associação Brasileira de Criadores de Ovinos (ARCO), referentes ao período de 1992 a 2012. Foram realizadas análises estatísticas descritivas de modo a conhecer como o rebanho Santa Inês está estruturado. Foi realizada a classificação do rebanho quanto a sua estrutura organizacional, determinada com base na origem e uso dos reprodutores, utilizando-se o programa ENDOG. v.4.8. O registro dos animais da raça Santa Inês, no Piauí, teve inicio em 1990, e a maior representatividade foi verificada no período de 1993 a 2001. Quanto à estrutura dos rebanhos, 56,8% foram classificados como rebanhos multiplicadores (estrato intermediário da pirâmide) e 43,2% como rebanhos comerciais (base da pirâmide), sendo que não se observou nenhum rebanho núcleo e nem isolado. A falta de rebanhos núcleo da raça no Estado pode ser uma das causas da redução do número de animais registrados nos últimos anos no Piauí.

Modelos lineares generalizados mistos na avaliação genética da prenhez precoce na raça Nelore / Generalized linear mixed models on genetic evaluation of early pregnancy in Nellore breed

Utilizaram-se os modelos lineares generalizados com as funções de ligação probit e logit na avaliação da prenhez precoce, e observaram-se os efeitos na variabilidade genética e na seleção de reprodutores quando diferentes idades são adotadas na definição dessa característica. A prenhez precoce foi estudada aos 15 (PP15) e 21 meses (PP21). Correlações entre os valores genéticos preditos e a porcentagem de touros em comum, considerando 10% dos touros com maiores valores genéticos (TOP10), entre a classificação dos modelos com função de ligação logit e probit e em cada modelo entre PP15 e PP21, foram calculadas. As herdabilidades para PP15 e PP21 foram próximas entre os modelos, exceto para PP15 utilizando a função de ligação probit. Aquelas entre os modelos e a TOP/10 foram altas. Os critérios de Akaike e Bayesiano apresentaram-se semelhantes entre os modelos. As correlações entre PP15 e PP21 e a TOP10, considerando o mesmo modelo, foram de média magnitude.(AU)

This study aimed to use the generalized linear models with probit and logit link function to evaluate early pregnancy, and to observe the effects on genetic variability and on sire selection when different ages are adopted in the definition of this trait. Early pregnancy was studied at 15 (EP15), and 21 (EP21) months. The analysis was done in R software. Pearson correlations (PC), between genetic predicted values and percentage of bulls in common considering only 10% of bulls with higher genetic values (TOP 10), between classification by logit and probit models and in each model among EP15 and EP21, were calculated. The heritability for EP15 and EP21 were close between models, except for EP15 using probit link function. PC and TOP10 among models were high. The Akaike and Bayesian criteria reported was similar between models. TOP10, considering the same model, among EP15-EP21 were moderated between EP15-EP21.(AU)

Genotype-environment interaction in the genetic analysis for weaning weight in Nelore cattle using bayesian approach - doi: 10.4025/actascianimsci.v33i2.8469 / Interação genótipo-ambiente na análise genética do peso ao desmame de bovinos Nelore sob enfoque bayesiano - doi: 10.4025/actascianimsci.v33i2.8469

The objective was to evaluate the interactions of genotype-environment effects on the components of (co)variance estimates and the prediction of breeding values for weaning weight in Nelore cattle, using a Bayesian approach. Records of 16,644 weaning weights were used from cattle distributed in ten ranches across six Brazilian states. The genetic parameters were estimated under an animal model considering Bayesian statistics. To verify genotype-environment interaction effects, we analyzed the following matrix model: without the inclusion of genotype-environment interaction effects, and with the inclusion of genotype-environment interaction effects, which considered the effect of sire-year, sire-herd, and both effects. In general, the results suggest that the inclusion of genotype-environment interaction in genetic analysis for weight at weaning tends to alter the estimates of genetic and environment (co)variances. The Spearman correlations between the breeding values were above 97%, indicating practically no change in the classification of animals evaluated. It can be inferred that the interaction effects of sire-year and sire-herd do not change the animals rank, and if not included in the genetic evaluation, the selection based on predictions of breeding values for weaning weight will not be affected.

Objetivou-se avaliar os efeitos das interações genótipo-ambiente sobre as estimativas de componentes de (co)variâncias e predição dos valores genéticos para o peso ao desmame de bovinos Nelore, sob enfoque bayesiano. Foram utilizados 16.644 registros de pesos ao desmame de bovinos provenientes de dez rebanhos participantes do Programa Nelore Brasil. Os parâmetros genéticos foram estimados sob modelo animal, considerando a estatística bayesiana. Para verificar o efeito da interação genótipo-ambiente, foram analisados os seguintes modelos matriciais: sem a inclusão dos efeitos de interação genótipo-ambiente; com a inclusão dos efeitos de interação genótipo-ambiente, em que se considerou o efeito de touro-ano, touro-rebanho e ambos os efeitos. De modo geral, verifica-se que a inclusão da interação genótipo-ambiente na análise genética para o peso ao desmame, tende a alterar as estimativas de (co)variâncias genéticas e ambientais. As correlações de Spearman entre os valores genéticos foram acima de 97%, indicando que, praticamente, não houve mudança na classificação dos animais avaliados. Pode se inferir que os efeitos de interação touro-ano e touro-rebanho não alteram as classificações dos animais, e a não-inclusão destes efeitos na avaliação genética, não afetam a seleção baseada nas predições dos valores genéticos para o peso ao desmame.

Interação genótipo-ambiente na análise genética do peso ao desmame de bovinos Nelore sob enfoque bayesiano / Genotype-environment interaction in the genetic analysis for weaning weight in Nelore cattle using bayesian approach

Objetivou-se avaliar os efeitos das interações genótipo-ambiente sobre as estimativas de componentes de (co)variâncias e predição dos valores genéticos para o peso ao desmame de bovinos Nelore, sob enfoque bayesiano. Foram utilizados 16.644 registros de pesos ao desmame de bovinos provenientes de dez rebanhos participantes do Programa Nelore Brasil. Os parâmetros genéticos foram estimados sob modelo animal, considerando a estatística bayesiana. Para verificar o efeito da interação genótipo-ambiente, foram analisados os seguintes modelos matriciais: sem a inclusão dos efeitos de interação genótipoambiente; com a inclusão dos efeitos de interação genótipo-ambiente, em que se considerou o efeito de touro-ano, touro-rebanho e ambos os efeitos. De modo geral, verifica-se que a inclusão da interação genótipo-ambiente na análise genética para o peso ao desmame, tende a alterar as estimativas de (co)variâncias genéticas e ambientais. As correlações de Spearman entre os valores genéticos foram acima de 97%, indicando que, praticamente, não houve mudança na classificação dos animais avaliados. Pode se inferir que os efeitos de interação touro-ano e touro-rebanho não alteram as classificações dos animais, e a não-inclusão destes efeitos na avaliação genética, não afetam a seleção baseada nas predições dos valores genéticos para o peso ao desmame.

The objective was to evaluate the interactions of genotype-environment effects on the components of (co)variance estimates and the prediction of breeding values for weaning weight in Nelore cattle, using a Bayesian approach. Records of 16,644 weaning weights were used from cattle distributed in ten ranches across six Brazilian states. The genetic parameters were estimated under an animal model considering Bayesian statistics. To verify genotype-environment interaction effects, we analyzed the following matrix model: without the inclusion of genotype-environment interaction effects, and with the inclusion of genotype-environment interaction effects, which considered the effect of sire-year, sire-herd, and both effects. In general, the results suggest that the inclusion of genotype-environment interaction in genetic analysis for weight at weaning tends to alter the estimates of genetic and environment (co)variances. The Spearman correlations between the breeding values were above 97%, indicating practically no change in the classification of animals evaluated. It can be inferred that the interaction effects of sire-year and sire-herd do not change the animals rank, and if not included in the genetic evaluation, the selection based on predictions of breeding values for weaning weight will not be affected.

Efeito da idade sobre as principais características andrológicas de touros Brangus-Ibagé criados extensivamente no estado do Mato Grosso do Sul - Brasil / Effect of age on the andrological characteristics of Brangus-Ibagé bulls extensively reared in Mato Grosso do Sul state - Brazil

Bull fertility is extremely important for beef cattle production systems and has a multiplier impact on the economical and zootechnical indexes of the herd. Bulls raised in tropical conditions may present varied seminal characteristics due to, among other causes, different management practices and quality of pastures. Another factor that influences the semen characteristics is the age of the sire. The reproductive potential of bull evaluated through the andrological exam aims to ensure the semen quality and to improve the herd reproductive efficiency. The aim of this study was to evaluate the main semen parameters of Brangus- Ibagé bulls extensively reared in eastern Mato Grosso do Sul state and to verify the effect of age on the andrological characteristics analyzed. It was also evaluated the correlation between age, scrotal circumference, and physical and morphological sperm characteristics produced by the Brangus bulls.[...]

Efeito da idade sobre as principais características andrológicas de touros Brangus-Ibagé criados extensivamente no estado do Mato Grosso do Sul - Brasil / Effect of age on the andrological characteristics of Brangus-Ibagé bulls extensively reared in Mato Grosso do Sul state - Brazil

Bull fertility is extremely important for beef cattle production systems and has a multiplier impact on the economical and zootechnical indexes of the herd. Bulls raised in tropical conditions may present varied seminal characteristics due to, among other causes, different management practices and quality of pastures. Another factor that influences the semen characteristics is the age of the sire. The reproductive potential of bull evaluated through the andrological exam aims to ensure the semen quality and to improve the herd reproductive efficiency. The aim of this study was to evaluate the main semen parameters of Brangus- Ibagé bulls extensively reared in eastern Mato Grosso do Sul state and to verify the effect of age on the andrological characteristics analyzed. It was also evaluated the correlation between age, scrotal circumference, and physical and morphological sperm characteristics produced by the Brangus bulls.[...](AU)