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1.
Anim. Reprod. (Online) ; 18(4): e20210084, 2021. tab, graf
Artigo em Inglês | LILACS-Express | VETINDEX | ID: biblio-1355647

Resumo

Abstract The present study aimed to investigate the effects of a combination of progesterone with different doses of E-17β on following end points: (1) ovarian follicular dynamics and emergence of a new follicular wave, and (2) superovulatory response and embryo yield. In Experiment 1, 28 ewes were randomly divided into four groups (n = 7) to receive either 2.0 mg, 1.0 mg, 0.5 mg or none E-17β one day after insertion of a progesterone device. The different doses of estradiol similarly delayed the moment of follicular emergence (overall mean = 3.1 ± 1.0 days vs. control group = 0.86 ± 1.0 days; P < 0.01), but the emergence of the new wave showed greater synchronization with the 0.5 mg dosage of E-17β. In Experiment 2, sixty-two donor ewes received an internal progesterone release device (day -1) for 7 d and 1 d after the insertion of this device (day 0) were allocated randomly to receive 0.5 mg of E-17β or only the vehicle (control group). Superstimulation was initiated on day 3 with the administration of 133 mg of pFSH in eight decreasing doses. Contrary to expectations, the protocol with the administration of 0.5 mg E-17β did not improve the percentage of donors with > 2 CL, the number of CL and the production of embryos (P > 0.05). It was concluded that the combination of progesterone and 0.5 mg E-17β was more efficient in synchronizing the emergence of the new follicular wave, however this approach seems to be unnecessary in ewe's superovulation programs.

2.
Anim. Reprod. ; 18(1): e20200776, 2021. tab, graf
Artigo em Inglês | VETINDEX | ID: vti-765796

Resumo

The aim of this study was to use estrus synchronization protocols to favor fixed-time artificial insemination and consequently fixed-time embryo collection, and increase embryo production using eCG, in gits. In a cross over design, nine Piau breed gilts were subjected to 18 days of oral progesterone; P4 group did not receive any further; GnRH group received 25µg of GnRH 104 hours after the final application of P4; and eCG+GnRH group received 1000IU of eCG 24 hours after the final P4 in addition to GnRH for subsequent embryo collection, that was performed six days after first AI, by laparotomy. Artificial insemination was performed after 12 and 24 hours of estrus in P4 group, and 128 and 144 hours in GnRH and eCG+GnRH groups. The number of CL (8.6±3.9; 8.3±2.1; 26.7±15.0) and anovulatory follicles (4.3±3.7; 3.9±3.9; 17.2±9.5) was higher in the eCG+GnRH gilts (P<0.05). However, the use of 1000 IU of eCG reduced (P<0.05) the number of total structures (5.2±3.6; 5.1±3.1; 1.7±2.7), viable embryos (5.0±3.5; 4.8±3.3; 0.4±0.7), freezable embryos (3.6±3.4; 3.3±3.8; 0.1±0.3) and recovery rate (63.7±38.9; 58.6±24.7; 5.38±9.5). P4 and GnRH protocols were effective in the production and recovery of embryos. However, the use of 1000 IU of eCG, 24 hours after P4, was not effective in promoting the production of embryos, although the animals had superovulated.(AU)


Assuntos
Animais , Feminino , Suínos/anatomia & histologia , Suínos/fisiologia , Inseminação Artificial , Ovulação , Eletrocardiografia , Hormônio Liberador de Gonadotropina , Sincronização do Estro/métodos
3.
Anim. Reprod. ; 18(4): e20210084, 2021. ilus, tab, graf
Artigo em Inglês | VETINDEX | ID: vti-765788

Resumo

The present study aimed to investigate the effects of a combination of progesterone with different doses of E-17β on following end points: (1) ovarian follicular dynamics and emergence of a new follicular wave, and (2) superovulatory response and embryo yield. In Experiment 1, 28 ewes were randomly divided into four groups (n = 7) to receive either 2.0 mg, 1.0 mg, 0.5 mg or none E-17β one day after insertion of a progesterone device. The different doses of estradiol similarly delayed the moment of follicular emergence (overall mean = 3.1 ± 1.0 days vs. control group = 0.86 ± 1.0 days; P < 0.01), but the emergence of the new wave showed greater synchronization with the 0.5 mg dosage of E-17β. In Experiment 2, sixty-two donor ewes received an internal progesterone release device (day -1) for 7 d and 1 d after the insertion of this device (day 0) were allocated randomly to receive 0.5 mg of E-17β or only the vehicle (control group). Superstimulation was initiated on day 3 with the administration of 133 mg of pFSH in eight decreasing doses. Contrary to expectations, the protocol with the administration of 0.5 mg E-17β did not improve the percentage of donors with > 2 CL, the number of CL and the production of embryos (P > 0.05). It was concluded that the combination of progesterone and 0.5 mg E-17β was more efficient in synchronizing the emergence of the new follicular wave, however this approach seems to be unnecessary in ewes superovulation programs.(AU)


Assuntos
Animais , Feminino , Ovinos/anatomia & histologia , Ovinos/fisiologia , Sincronização do Estro , Superovulação , Estradiol
4.
R. bras. Saúde Prod. Anim. ; 22: e2122022021, 2021. ilus, tab, graf
Artigo em Inglês | VETINDEX | ID: vti-32048

Resumo

Animals in subtropical regions can be exposed to periods of thermal stress. Locally adapted breeds are especially important in this context, but these have little information available in their natural environments. The aim of this study was to assess whether season affects thermal comfort and physiological responses to increased temperatures of two breeds of bulls in a subtropical climate. Four Angus and four Crioulo Lageano bulls were used in this study. Body and testicles measurements, skin pigmentation and thickness, hair number, length and pigmentation, respiratory rate, panting score, rectal temperature and haematological profile were recorded on three occasions in summer and winter, morning and afternoon. The surface temperature of the flank, eye and scrotum were obtained by infrared thermography. Hair coat colour was determined by CIELAB method. Thermal comfort indexes were calculated from meteorological data. Statistical analysis included analyses of variance, correlations and a partial least squares regression in determining which traits were the most important in thermal adaptability. External morphology of the bulls was important for explaining physiological changes in both seasons, but their contribution was greater in summer. Bulls experienced moderate heat stress in summer, which led to significant physiological responses, which were more pronounced in Angus bulls. The main differences in thermal adaptation found between breeds were the hair coat characteristics and respiratory rate. Despite using different mechanisms to cope with environmental challenges, all bulls were able to maintain optimal testicular thermoregulation as well as systemic normothermia throughout the seasons, showing good adaptation to the climate conditions.(AU)


Animais em regiões subtropicais podem ser expostos ao estresse térmico. As raças localmente adaptadas são especialmente importantes nesse contexto, mas possuem pouca informação disponível em seus ambientes naturais. O objetivo deste estudo foi avaliar se a estação afeta o conforto térmico e as respostas fisiológicas ao aumento da temperatura de duas raças de touros em clima subtropical. Quatro touros Angus e quatro Crioulo Lageano foram utilizados neste estudo. As medidas do corpo e testículos, pigmentação e espessura da pele, número, comprimento e pigmentação de pêlos, frequência respiratória, escore ofegante, temperatura retal e perfil hematológico foram registradas no verão e inverno, manhã e tarde. A temperatura da superfície do flanco, olho e escroto foi obtida por termografia infravermelho. Os índices de conforto térmico foram calculados a partir de dados meteorológicos. A análise estatística incluiu análises de variância, correlações e uma regressão parcial de mínimos quadrados para determinar quais características foram as mais importantes na adaptabilidade térmica. A morfologia externa dos touros foi importante para explicar as mudanças fisiológicas nas duas estações, mas sua contribuição foi maior no verão. Os touros sofreram estresse térmico moderado no verão, o que levou a respostas fisiológicas significativas, que foram mais pronunciadas na Angus. As principais diferenças de adaptação térmica encontradas entre as raças foram as características do pêlo e a frequência respiratória. Apesar de usar diferentes mecanismos para lidar com os desafios ambientais, todos os touros foram capazes de manter a termorregulação testicular ideal e a normotermia, mostrando boa adaptação às condições climáticas.(AU)


Assuntos
Animais , Bovinos , Bovinos/anormalidades , Bovinos/fisiologia , Fenômenos Fisiológicos , Regulação da Temperatura Corporal , Transtornos de Estresse por Calor , Resposta ao Choque Térmico
5.
Rev. bras. saúde prod. anim ; 22: e2122022021, 2021. ilus, tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1493891

Resumo

Animals in subtropical regions can be exposed to periods of thermal stress. Locally adapted breeds are especially important in this context, but these have little information available in their natural environments. The aim of this study was to assess whether season affects thermal comfort and physiological responses to increased temperatures of two breeds of bulls in a subtropical climate. Four Angus and four Crioulo Lageano bulls were used in this study. Body and testicles measurements, skin pigmentation and thickness, hair number, length and pigmentation, respiratory rate, panting score, rectal temperature and haematological profile were recorded on three occasions in summer and winter, morning and afternoon. The surface temperature of the flank, eye and scrotum were obtained by infrared thermography. Hair coat colour was determined by CIELAB method. Thermal comfort indexes were calculated from meteorological data. Statistical analysis included analyses of variance, correlations and a partial least squares regression in determining which traits were the most important in thermal adaptability. External morphology of the bulls was important for explaining physiological changes in both seasons, but their contribution was greater in summer. Bulls experienced moderate heat stress in summer, which led to significant physiological responses, which were more pronounced in Angus bulls. The main differences in thermal adaptation found between breeds were the hair coat characteristics and respiratory rate. Despite using different mechanisms to cope with environmental challenges, all bulls were able to maintain optimal testicular thermoregulation as well as systemic normothermia throughout the seasons, showing good adaptation to the climate conditions.


Animais em regiões subtropicais podem ser expostos ao estresse térmico. As raças localmente adaptadas são especialmente importantes nesse contexto, mas possuem pouca informação disponível em seus ambientes naturais. O objetivo deste estudo foi avaliar se a estação afeta o conforto térmico e as respostas fisiológicas ao aumento da temperatura de duas raças de touros em clima subtropical. Quatro touros Angus e quatro Crioulo Lageano foram utilizados neste estudo. As medidas do corpo e testículos, pigmentação e espessura da pele, número, comprimento e pigmentação de pêlos, frequência respiratória, escore ofegante, temperatura retal e perfil hematológico foram registradas no verão e inverno, manhã e tarde. A temperatura da superfície do flanco, olho e escroto foi obtida por termografia infravermelho. Os índices de conforto térmico foram calculados a partir de dados meteorológicos. A análise estatística incluiu análises de variância, correlações e uma regressão parcial de mínimos quadrados para determinar quais características foram as mais importantes na adaptabilidade térmica. A morfologia externa dos touros foi importante para explicar as mudanças fisiológicas nas duas estações, mas sua contribuição foi maior no verão. Os touros sofreram estresse térmico moderado no verão, o que levou a respostas fisiológicas significativas, que foram mais pronunciadas na Angus. As principais diferenças de adaptação térmica encontradas entre as raças foram as características do pêlo e a frequência respiratória. Apesar de usar diferentes mecanismos para lidar com os desafios ambientais, todos os touros foram capazes de manter a termorregulação testicular ideal e a normotermia, mostrando boa adaptação às condições climáticas.


Assuntos
Animais , Bovinos , Bovinos/anormalidades , Bovinos/fisiologia , Fenômenos Fisiológicos , Regulação da Temperatura Corporal , Transtornos de Estresse por Calor , Resposta ao Choque Térmico
6.
Artigo em Inglês | LILACS-Express | VETINDEX | ID: biblio-1493902

Resumo

ABSTRACT Animals in subtropical regions can be exposed to periods of thermal stress. Locally adapted breeds are especially important in this context, but these have little information available in their natural environments. The aim of this study was to assess whether season affects thermal comfort and physiological responses to increased temperatures of two breeds of bulls in a subtropical climate. Four Angus and four Crioulo Lageano bulls were used in this study. Body and testicles measurements, skin pigmentation and thickness, hair number, length and pigmentation, respiratory rate, panting score, rectal temperature and haematological profile were recorded on three occasions in summer and winter, morning and afternoon. The surface temperature of the flank, eye and scrotum were obtained by infrared thermography. Hair coat colour was determined by CIELAB method. Thermal comfort indexes were calculated from meteorological data. Statistical analysis included analyses of variance, correlations and a partial least squares regression in determining which traits were the most important in thermal adaptability. External morphology of the bulls was important for explaining physiological changes in both seasons, but their contribution was greater in summer. Bulls experienced moderate heat stress in summer, which led to significant physiological responses, which were more pronounced in Angus bulls. The main differences in thermal adaptation found between breeds were the hair coat characteristics and respiratory rate. Despite using different mechanisms to cope with environmental challenges, all bulls were able to maintain optimal testicular thermoregulation as well as systemic normothermia throughout the seasons, showing good adaptation to the climate conditions.


RESUMO Animais em regiões subtropicais podem ser expostos ao estresse térmico. As raças localmente adaptadas são especialmente importantes nesse contexto, mas possuem pouca informação disponível em seus ambientes naturais. O objetivo deste estudo foi avaliar se a estação afeta o conforto térmico e as respostas fisiológicas ao aumento da temperatura de duas raças de touros em clima subtropical. Quatro touros Angus e quatro Crioulo Lageano foram utilizados neste estudo. As medidas do corpo e testículos, pigmentação e espessura da pele, número, comprimento e pigmentação de pêlos, frequência respiratória, escore ofegante, temperatura retal e perfil hematológico foram registradas no verão e inverno, manhã e tarde. A temperatura da superfície do flanco, olho e escroto foi obtida por termografia infravermelho. Os índices de conforto térmico foram calculados a partir de dados meteorológicos. A análise estatística incluiu análises de variância, correlações e uma regressão parcial de mínimos quadrados para determinar quais características foram as mais importantes na adaptabilidade térmica. A morfologia externa dos touros foi importante para explicar as mudanças fisiológicas nas duas estações, mas sua contribuição foi maior no verão. Os touros sofreram estresse térmico moderado no verão, o que levou a respostas fisiológicas significativas, que foram mais pronunciadas na Angus. As principais diferenças de adaptação térmica encontradas entre as raças foram as características do pêlo e a frequência respiratória. Apesar de usar diferentes mecanismos para lidar com os desafios ambientais, todos os touros foram capazes de manter a termorregulação testicular ideal e a normotermia, mostrando boa adaptação às condições climáticas.

7.
Anim. Reprod. (Online) ; 14(4): 1034-1042, Oct.-Dec. 2017. tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1461299

Resumo

The aim of this research was to evaluate pubertal development characteristics of Crioulo Lageano breed bulls (n = 10) using morphometric measurements and semen analysis, to identify factors that can be used to estimate age at puberty in this locally adapted breed. Monthly measurement of body weight and fortnightly measurement of scrotal circumference, chest girth, testicular length, width, thickness, and volume were recorded for each of the 10 Crioulo Lageano breed bulls, which were between 10 and 20 months old. During this period, semen samples were collected every two weeks using electro ejaculation method and analyzed physically and morphologically. The ages of the appearance of first spermatozoa in the ejaculate (FSE), the first motile spermatozoa in the ejaculate (FSEM), seminal puberty (PUB) and total detachment between glans penis and prepuce (DPP) were ascertained. Crioulo Lageano bulls reached puberty at 14.1 ± 2.0 months old with lower weight and larger testicles than those of other bovine breeds. Similarly, the period from FSEM to PUB was shorter and the period from FSE to FSEM was longer than those reported for other breeds. The most important characteristics studied in order to estimate puberty age in Crioulo Lageano bulls were the measures of testicular length, width, and volume. These parameters can be used as criteria to select young bulls as sires.


Assuntos
Animais , Bovinos , Bovinos/anatomia & histologia , Bovinos/crescimento & desenvolvimento , Técnicas Reprodutivas/classificação , Técnicas Reprodutivas/veterinária , Peso Corporal
8.
Anim. Reprod. ; 14(4): 1034-1042, Oct.-Dec. 2017. tab, graf
Artigo em Inglês | VETINDEX | ID: vti-18209

Resumo

The aim of this research was to evaluate pubertal development characteristics of Crioulo Lageano breed bulls (n = 10) using morphometric measurements and semen analysis, to identify factors that can be used to estimate age at puberty in this locally adapted breed. Monthly measurement of body weight and fortnightly measurement of scrotal circumference, chest girth, testicular length, width, thickness, and volume were recorded for each of the 10 Crioulo Lageano breed bulls, which were between 10 and 20 months old. During this period, semen samples were collected every two weeks using electro ejaculation method and analyzed physically and morphologically. The ages of the appearance of first spermatozoa in the ejaculate (FSE), the first motile spermatozoa in the ejaculate (FSEM), seminal puberty (PUB) and total detachment between glans penis and prepuce (DPP) were ascertained. Crioulo Lageano bulls reached puberty at 14.1 ± 2.0 months old with lower weight and larger testicles than those of other bovine breeds. Similarly, the period from FSEM to PUB was shorter and the period from FSE to FSEM was longer than those reported for other breeds. The most important characteristics studied in order to estimate puberty age in Crioulo Lageano bulls were the measures of testicular length, width, and volume. These parameters can be used as criteria to select young bulls as sires.(AU)


Assuntos
Animais , Bovinos , Bovinos/anatomia & histologia , Bovinos/crescimento & desenvolvimento , Técnicas Reprodutivas/classificação , Técnicas Reprodutivas/veterinária , Peso Corporal
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