Assessment of different solutions and incubation times in the hypoosmotic swelling test of frozen/thawed semen in Piau boars

The objective of this study was to assess the effect of several solutions and incubation times in the hypoosmotic swelling test in predicting the in vitro quality of the frozen/thawed semen of Piau boars. Four samples of frozen semen from five different Piau boars were used. For the assessment of the hypoosmotic test, three incubation times were used (5, 30 and 60 min) in three different hypoosmotic solutions (BTS at 75 mOsm/Kg, sucrrose at 100 mOsm/Kg and fructose and sodium citrate at 100 mOsm/Kg), thus, samples were submitted to each hypoosmotic solution in three incubation times. The means of sperm motility spermatic vigor and live sperm by supravital staining for the assessed samples were respectively, 37.5 ± 7.2%, 2.8 ± 0.3 and 37.4 ± 7.8% in thawing and 15.5 ± 7.6%, 1.7 ± 0.5 and 22.6 ± 6.6% after 120 mm of thermoresistance test (P < 0.05). There was no difference between the mean values obtained for reactive sperm in the different incubation times and hypoosmotic solutions, and also no interaction between time ans solutions. The results obtained in the resent study demonstrated that quality of frozen/thawed semen, besides offering aliernatives for hypoosmotic solutions and different incubation times in performing the hypoosmotic test to predict the sperm plasmatic membrane quality in boats.

Assessment of different solutions and incubation times in the hypoosmotic swelling test of frozen/thawed semen in Piau boars

The objective of this study was to assess the effect of several solutions and incubation times in the hypoosmotic swelling test in predicting the in vitro quality of the frozen/thawed semen of Piau boars. Four samples of frozen semen from five different Piau boars were used. For the assessment of the hypoosmotic test, three incubation times were used (5, 30 and 60 min) in three different hypoosmotic solutions (BTS at 75 mOsm/Kg, sucrrose at 100 mOsm/Kg and fructose and sodium citrate at 100 mOsm/Kg), thus, samples were submitted to each hypoosmotic solution in three incubation times. The means of sperm motility spermatic vigor and live sperm by supravital staining for the assessed samples were respectively, 37.5 ± 7.2%, 2.8 ± 0.3 and 37.4 ± 7.8% in thawing and 15.5 ± 7.6%, 1.7 ± 0.5 and 22.6 ± 6.6% after 120 mm of thermoresistance test (P < 0.05). There was no difference between the mean values obtained for reactive sperm in the different incubation times and hypoosmotic solutions, and also no interaction between time ans solutions. The results obtained in the resent study demonstrated that quality of frozen/thawed semen, besides offering aliernatives for hypoosmotic solutions and different incubation times in performing the hypoosmotic test to predict the sperm plasmatic membrane quality in boats.(AU)

Relação entre perímetro escrotal e características produtivas e reprodutivas em bovinos de corte: uma revisão / Relationship between scrotal circumference and productive and reproductive traits in beef cattle: a review

Os programas de melhoramento genético visam mudar a herança nas populações pelo aumento dos genes desejáveis ou aumento da frequência de genótipos desejáveis com o objetivo de aumentar a produtividade dos rebanhos. Para tanto, faz-se necessário o conhecimento de parâmetros genéticos (herdabilidades e correlações genéticas) que orientem a escolha dos métodos de seleção. Apesar de a seleção para aumento do perímetro escrotal (PE) não trazer benefício econômico direto, o PE é uma característica que possui herdabilidade de moderada a alta e que é correlacionada com o ganho de peso e com características reprodutivas de fêmeas e machos. O PE se torna, assim, um dos critérios de seleção mais utilizado para eficiência reprodutiva do gado de corte. Esta revisão discute estimativas de herdabilidade e correlações genéticas para PE em bovinos de corte, visando à precocidade reprodutiva e ponderal, além de maior ganho econômico com o rebanho. (AU)

The breeding programs aim changing the genetic heritage of animals by the incorporation of new genes that increase the productivity of herd. Therefore, it is necessary the knowledge of genetic parameters (heritability and genetic correlations) to guide the choice of selection methods. Despite selection for increased scrotal circumference (SC) does not bring direct economic benefits, the SC is a characteristic that has moderate to high heritability, correlated with weight gain and reproductive traits of females and males. The SC thus becomes one of the selections criteria most commonly used for reproductive efficiency of beef cattle. Thus, the objective of this review is to discuss estimates of heritability and genetic correlations for SC in beef cattle, aiming at early reproductive and weight as well as greater economic gain of the herd. (AU)

Relação entre perímetro escrotal e características produtivas e reprodutivas em bovinos de corte: uma revisão / Relationship between scrotal circumference and productive and reproductive traits in beef cattle: a review

Os programas de melhoramento genético visam mudar a herança nas populações pelo aumento dos genes desejáveis ou aumento da frequência de genótipos desejáveis com o objetivo de aumentar a produtividade dos rebanhos. Para tanto, faz-se necessário o conhecimento de parâmetros genéticos (herdabilidades e correlações genéticas) que orientem a escolha dos métodos de seleção. Apesar de a seleção para aumento do perímetro escrotal (PE) não trazer benefício econômico direto, o PE é uma característica que possui herdabilidade de moderada a alta e que é correlacionada com o ganho de peso e com características reprodutivas de fêmeas e machos. O PE se torna, assim, um dos critérios de seleção mais utilizado para eficiência reprodutiva do gado de corte. Esta revisão discute estimativas de herdabilidade e correlações genéticas para PE em bovinos de corte, visando à precocidade reprodutiva e ponderal, além de maior ganho econômico com o rebanho.

The breeding programs aim changing the genetic heritage of animals by the incorporation of new genes that increase the productivity of herd. Therefore, it is necessary the knowledge of genetic parameters (heritability and genetic correlations) to guide the choice of selection methods. Despite selection for increased scrotal circumference (SC) does not bring direct economic benefits, the SC is a characteristic that has moderate to high heritability, correlated with weight gain and reproductive traits of females and males. The SC thus becomes one of the selections criteria most commonly used for reproductive efficiency of beef cattle. Thus, the objective of this review is to discuss estimates of heritability and genetic correlations for SC in beef cattle, aiming at early reproductive and weight as well as greater economic gain of the herd.

Hypoosmotic swelling test in young Nelore bulls classified as sound and unsound for breeding

This work aimed to study the correlations between the physical characteristics of semen, sperm morphology and the biochemical integrity of the plasmatic membrane of raw sperm in young Nelore bulls (Bos taurus indicus). A total of 420 bulls between 18 and 22 months of age were examined for breeding soundness according to the criteria established by the Brazilian College of Animal Reproduction. After physical and morphological evaluation, semen was tested with a hypoosmotic test. To accomplish this, 10 µl of fresh semen was incubated in 1 ml of hypoosmotic solution (150 mOsm/kg) for 60 min at 37°C. After the breeding soundness evaluation, 83% (350/420) of the bulls were classified as sound for breeding. There were no significant differences between the mean testicular biometry, scrotal circumference and the percentage of spermatozoa reactive to the hypoosmotic test (43.9 ± 21.1% vs. 43.6 ± 19.3%) in bulls classified as sound and unsound for breeding (P > 0.05), although there were significant differences between the averages for all physical and morphological aspects of the sperm between the two groups (P 0.05). In this study, the hypoosmotic test was not an efficient predictor of the reproductive potential of young Nelore bulls.

Hypoosmotic swelling test in young Nelore bulls classified as sound and unsound for breeding

This work aimed to study the correlations between the physical characteristics of semen, sperm morphology and the biochemical integrity of the plasmatic membrane of raw sperm in young Nelore bulls (Bos taurus indicus). A total of 420 bulls between 18 and 22 months of age were examined for breeding soundness according to the criteria established by the Brazilian College of Animal Reproduction. After physical and morphological evaluation, semen was tested with a hypoosmotic test. To accomplish this, 10 µl of fresh semen was incubated in 1 ml of hypoosmotic solution (150 mOsm/kg) for 60 min at 37°C. After the breeding soundness evaluation, 83% (350/420) of the bulls were classified as sound for breeding. There were no significant differences between the mean testicular biometry, scrotal circumference and the percentage of spermatozoa reactive to the hypoosmotic test (43.9 ± 21.1% vs. 43.6 ± 19.3%) in bulls classified as sound and unsound for breeding (P > 0.05), although there were significant differences between the averages for all physical and morphological aspects of the sperm between the two groups (P < 0.05). The hypoosmotic test did not correlate with the main characteristics of semen quality (P > 0.05). In this study, the hypoosmotic test was not an efficient predictor of the reproductive potential of young Nelore bulls.(AU)

Aplasia segmentar bilateral do epidídimo na espécie bubalina: relato de caso / A case of bilateral segmental aplasia of the epididymis in a buffalo

Este estudo reporta um bubalino mestiço, com 27 meses de idade, 188 kg de peso de carcaça, sem histórico reprodutivo. Sangue foi coletado para posterior determinação hormonal. Testículos e epidídimos foram avaliados macroscopicamente e microscopicamente. Os testículos apresentaram-se simétricos, caudas dos epidídimos ausentes e cabeças com presença de cistos. Parênquima testicular e mediastino demonstraram edema. Concentrações de testosterona e androstenediona foram de, respectivamente, 9,88 pg/mL e 3,00 ng/mL. Observou-se alto grau de degeneração testicular. Considerando-se a esterilidade do animal, associada à origem genética da patologia, sugere-se que machos acometidos sejam descartados da reprodução.(AU)

This case report involves a slaughtered cross-breed buffalo, age 27 months, carcass weight, 188 kg, without reproductive history. Blood was collected for later hormone determination. Testes and epididymes were evaluated macroscopically and microscopically. The testes were symmetrical. However, the epididymal tails were absent and the epididymal heads had cysts. Testicular parenchyma and mediastinum were swollen. Testosterone and androstenedione concentrations were 9.88 pg/mL and 3.00 ng/mL, respectively. A high degree of testicular degeneration was observed. That this condition causes esterility, coupled with the genetic origin of the disease, it is suggested that affected animals are culled.(AU)

Aplasia segmentar bilateral do epidídimo na espécie bubalina: relato de caso / A case of bilateral segmental aplasia of the epididymis in a buffalo

Este estudo reporta um bubalino mestiço, com 27 meses de idade, 188 kg de peso de carcaça, sem histórico reprodutivo. Sangue foi coletado para posterior determinação hormonal. Testículos e epidídimos foram avaliados macroscopicamente e microscopicamente. Os testículos apresentaram-se simétricos, caudas dos epidídimos ausentes e cabeças com presença de cistos. Parênquima testicular e mediastino demonstraram edema. Concentrações de testosterona e androstenediona foram de, respectivamente, 9,88 pg/mL e 3,00 ng/mL. Observou-se alto grau de degeneração testicular. Considerando-se a esterilidade do animal, associada à origem genética da patologia, sugere-se que machos acometidos sejam descartados da reprodução.

This case report involves a slaughtered cross-breed buffalo, age 27 months, carcass weight, 188 kg, without reproductive history. Blood was collected for later hormone determination. Testes and epididymes were evaluated macroscopically and microscopically. The testes were symmetrical. However, the epididymal tails were absent and the epididymal heads had cysts. Testicular parenchyma and mediastinum were swollen. Testosterone and androstenedione concentrations were 9.88 pg/mL and 3.00 ng/mL, respectively. A high degree of testicular degeneration was observed. That this condition causes esterility, coupled with the genetic origin of the disease, it is suggested that affected animals are culled.

Estimativas de herdabilidades e correlações genéticas entre características reprodutivas em touros da raça Nelore / Genetic correlations and heritability estimates of reproductive traits of Nellore bulls

Foram obtidas estimativas de variância fenotípica, genética e residual, herdabilidades e correlações genéticas para as características reprodutivas em 5.903 animais da raça Nelore. O modelo experimental utilizado foi o método de máxima verossimilhança restrita livre de derivadas. Os valores de herdabilidade foram de 0,24±0,05 para perímetro escrotal aos 450 dias de idade e de 0,37±0,05 aos 21 meses de idade, na ocasião do exame andrológico; de 0,24±0,05 e 0,26±0,05 para comprimento dos testículos esquerdo e direito; de 0,29±0,05 e 0,31±0,05 para largura dos testículos esquerdo e direito; de 0,12±0,04 para formato testicular; de 0,33±0,06 para volume testicular; de 0,11±0,03 para turbilhonamento; de 0,08±0,03 para motilidade e de 0,05±0,02 para vigor espermático; de 0,20±0,04, 0,03±0,02 e 0,19±0,04 para defeitos espermáticos maiores, menores e totais, respectivamente. As características biométricas testiculares apresentaram valores de herdabilidade moderados a altos, enquanto as características seminais valores baixos. Correlações genéticas entre perímetro escrotal com todas as características reprodutivas foram favoráveis, o que sugere o perímetro escrotal como característica de escolha na seleção de touros.(AU)

Estimates of phenotypic, genetics and residual variances for reproductive traits in 5903 Nellore bulls were obtained. The experimental model used was multiple trait derivative-free restricted maximum likelihood. The values obtained for heritability were 0.24±0.05 for scrotal circumference at 450 days of age and 0.37±0.05 at 21 months for age at the time of the breeding soundness evaluation; 0.24±0.05 and 0.26±0.05 for left and right testicle length; 0.29±0.05 and 0.31±0.05 for left and right testicle width; 0.12±0.04 for testicle format; 0.33±0.06 for testicle volume; 0.11±0.03 for gross motility; 0.08±0.03 for individual motility and 0.05±0.02 for spermatic vigor; 0.20±0.04, 0.03±0.02 and 0.19±0.04 for larger defects, smaller defects and total defects, respectively. The values for heritability for testicular biometric characteristics were moderate to high while the seminal characteristics, presented low values. Genetic correlations between scrotal circumference with all the reproductive traits were favorable, suggesting the scrotal circumference as a feature of choice in the selection of bulls.(AU)

Dinâmica folicular ovariana na espécie bubalina / Ovarian follicular dynamics in buffaloes

Considerando o aumento da população mundial de búfalos, pesquisadores do mundo inteiro têm investigado os eventos biológicos envolvidos na foliculogênese dessa espécie, com o intuito de solucionar as dificuldades para a detecção de estro, diminuir o impacto da estacionalidade reprodutiva e aprimorar biotecnologias reprodutivas, como a produção e a manipulação de embriões. Os búfalos são considerados animais sazonais (dias curtos), com duração do ciclo estral variando entre 16 a 33 dias, estro com cerca de cinco a 27 horas e ovulação ocorrendo entre 24 a 48 horas após o início do estro ou seis a 21 horas após o final do estro. O ovário da búfala é ovoide e consideravelmente menor do que o da vaca, apresentando menor número de folículos primordiais e maior taxa de atresia folicular. Os folículos primordiais, primários, secundários e terciários formados no ovário têm em média: 35; 25 a 80; 50 a 100 e 100 a 300 μm de diâmetro, respectivamente. O corpo lúteo, geralmente menor do que o da vaca, pode atingir peso e diâmetro máximo de 2,3 g e de 15 mm, respectivamente, e tem influência negativa no número de folículos superficiais. Os primeiros estudos relacionados ao crescimento folicular em bubalinos registraram a presença de padrões de uma, duas ou três ondas foliculares, propondo, desta forma, que as búfalas apresentam comportamento folicular semelhante ao de vacas, mas com suas peculiaridades. O objetivo desta revisão foi descrever as principais estruturas e os eventos envolvidos na dinâmica folicular ovariana em bubalinos.(AU)

Considering the increasing world population of buffaloes, researchers have been investigating biological events involved in the folliculogenesis of this specie. The main aims are to understand why r the detection of oestrus is difficult in this specie, to reduce the impact of reproductive seasonality in breeding efficiency and to improve the results obtained with the use of reproductive biotechnology, such as production and manipulation of embryos. The buffaloes are considered seasonal animals (short days) with oestrous cycle length ranging from 16 to 33 days, being the oestrous length approximately 5 to 27 hours and the ovulation occurring between 24 to 48 hours after the onset of oestrus or 6 to 21 hours after the end of oestrus. The buffalo ovary is ovoid and considerably smaller than bovine ovaries, showing fewer primordial follicles and higher rate of follicular atresia. The primordial, primary, secondary and tertiary follicles produced in the ovary are on average: 35, 25 to 80, 50 to 100, and 100 to 300 μm in diameter, respectively. The corpus luteum is usually smaller than that of bovine and its maximum weight and diameter are 2.3 g and 15mm, respectively, and has negative influence on the number of superficial follicles. Initial studies focusing follicular growth in buffaloes reported one, two or three follicular waves patterns, suggesting that buffaloes have follicular growth behavior similar to that found in cows, with some specific differences. The purpose of this review is to describe the main structures and events involved in ovarian follicular dynamics in buffaloes.(AU)

Dinâmica folicular ovariana na espécie bubalina / Ovarian follicular dynamics in buffaloes

Considerando o aumento da população mundial de búfalos, pesquisadores do mundo inteiro têm investigado os eventos biológicos envolvidos na foliculogênese dessa espécie, com o intuito de solucionar as dificuldades para a detecção de estro, diminuir o impacto da estacionalidade reprodutiva e aprimorar biotecnologias reprodutivas, como a produção e a manipulação de embriões. Os búfalos são considerados animais sazonais (dias curtos), com duração do ciclo estral variando entre 16 a 33 dias, estro com cerca de cinco a 27 horas e ovulação ocorrendo entre 24 a 48 horas após o início do estro ou seis a 21 horas após o final do estro. O ovário da búfala é ovoide e consideravelmente menor do que o da vaca, apresentando menor número de folículos primordiais e maior taxa de atresia folicular. Os folículos primordiais, primários, secundários e terciários formados no ovário têm em média: 35; 25 a 80; 50 a 100 e 100 a 300 μm de diâmetro, respectivamente. O corpo lúteo, geralmente menor do que o da vaca, pode atingir peso e diâmetro máximo de 2,3 g e de 15 mm, respectivamente, e tem influência negativa no número de folículos superficiais. Os primeiros estudos relacionados ao crescimento folicular em bubalinos registraram a presença de padrões de uma, duas ou três ondas foliculares, propondo, desta forma, que as búfalas apresentam comportamento folicular semelhante ao de vacas, mas com suas peculiaridades. O objetivo desta revisão foi descrever as principais estruturas e os eventos envolvidos na dinâmica folicular ovariana em bubalinos.

Considering the increasing world population of buffaloes, researchers have been investigating biological events involved in the folliculogenesis of this specie. The main aims are to understand why r the detection of oestrus is difficult in this specie, to reduce the impact of reproductive seasonality in breeding efficiency and to improve the results obtained with the use of reproductive biotechnology, such as production and manipulation of embryos. The buffaloes are considered seasonal animals (short days) with oestrous cycle length ranging from 16 to 33 days, being the oestrous length approximately 5 to 27 hours and the ovulation occurring between 24 to 48 hours after the onset of oestrus or 6 to 21 hours after the end of oestrus. The buffalo ovary is ovoid and considerably smaller than bovine ovaries, showing fewer primordial follicles and higher rate of follicular atresia. The primordial, primary, secondary and tertiary follicles produced in the ovary are on average: 35, 25 to 80, 50 to 100, and 100 to 300 μm in diameter, respectively. The corpus luteum is usually smaller than that of bovine and it’s maximum weight and diameter are 2.3 g and 15mm, respectively, and has negative influence on the number of superficial follicles. Initial studies focusing follicular growth in buffaloes reported one, two or three follicular waves patterns, suggesting that buffaloes have follicular growth behavior similar to that found in cows, with some specific differences. The purpose of this review is to describe the main structures and events involved in ovarian follicular dynamics in buffaloes.