Loading...
Publication
Studies on equine sperm cryopreservation : fundamental and applied aspects
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| Resumo, Índice, Introdução | 518.01 KB | Adobe PDF | ||
| Documento Principal | 791.23 KB | Adobe PDF |
Advisor(s)
Abstract(s)
Nos últimos anos, verifica-se um aumento na utilização de sémen criopreservado na inseminação artificial na indústria equina. Contudo, o potencial de fertilização do sémen criopreservado nos equinos é menor do que o de outras espécies domésticas, especialmente nos bovinos. Vários estudos têm sido realizados com a utilização de diferentes curvas e meios de congelação, com o objectivo de melhorar a qualidade do sémen equino após a criopreservação; contudo, ainda não existe um protocolo ideal para todos os casos. Assim sendo, o objectivo desta tese de doutoramento foi melhorar a criopreservação de sémen equino. A nossa hipótese foi a de que a adição de antioxidantes (α-tocoferol e ácido ascórbico) no meio de congelação e o uso de diferentes curvas de congelação (CCs) poderão aumentar as taxas de sobrevivência do sémen equino. Foram realizados estudos fisiológicos e metabólicos do sémen, a fim de compreender os mecanismos pelos quais a criopreservação pode alterar a função espermática, e melhorar a qualidade esta metodologia. Como também, pretendeu-se provar que a fertilização in vitro (FIV) heteróloga pode predizer o potencial fertilizante do sémen, validando um novo protocolo de FIV heteróloga utilizando oócitos bovinos com zona pelúcida (ZP) intacta e sémen equino. [...]
ABSTRACT: The use of frozen stallion spermatozoa for artificial insemination is increasing in the equine industry. Unfortunately, the fertilizing capacity of cryopreserved stallion semen is generally considered to be lower than that of some other domestic species, especially that of dairy cattle. Several different freezing regimes with new protocols and extenders have been designed and published to improve the quality of post-thaw equine semen; however, no ideal protocol for all cases exists. Therefore, the aim of the research presented in this thesis was to improve stallion cryopreservation. It has been hypothesized that the addition of antioxidants (α-tocopherol and ascorbic acid) in the freezing extender and the use of different freezing rates (FRs) might yield increased cryosurvival of spermatozoa. Sperm's physiological and metabolic studies were also evaluated, in order to understand the mechanisms by which cryopreservation can alter sperm function, and to improve the quality of post-thaw equine semen. Moreover, the study also aimed to prove that the heterologous in vitro fertilization (IVF) can predict male fertility, validating a new approach for a heterologous IVF assay using bovine oocytes with zona pellucida (ZP) intact and equine sperm. [...].
ABSTRACT: The use of frozen stallion spermatozoa for artificial insemination is increasing in the equine industry. Unfortunately, the fertilizing capacity of cryopreserved stallion semen is generally considered to be lower than that of some other domestic species, especially that of dairy cattle. Several different freezing regimes with new protocols and extenders have been designed and published to improve the quality of post-thaw equine semen; however, no ideal protocol for all cases exists. Therefore, the aim of the research presented in this thesis was to improve stallion cryopreservation. It has been hypothesized that the addition of antioxidants (α-tocopherol and ascorbic acid) in the freezing extender and the use of different freezing rates (FRs) might yield increased cryosurvival of spermatozoa. Sperm's physiological and metabolic studies were also evaluated, in order to understand the mechanisms by which cryopreservation can alter sperm function, and to improve the quality of post-thaw equine semen. Moreover, the study also aimed to prove that the heterologous in vitro fertilization (IVF) can predict male fertility, validating a new approach for a heterologous IVF assay using bovine oocytes with zona pellucida (ZP) intact and equine sperm. [...].
Description
Tese de Doutoramento, Ciências Agrárias, especialidade em Reprodução Animal, 25 de Junho de 2015, Universidade dos Açores.
Keywords
Antioxidantes Equinos Criopreservação Fertilização in vitro Heteróloga Antioxidants Cryopreservation Freezing Rates Heterologous in vitro Fertilization
Citation
Franco, Joanna Sousa de Vasconcelos. "Studies on equine sperm cryopreservation: fundamental and applied aspects". 2016. 135 p.. (Tese de Doutoramento em Ciências Agrárias, especialidade em Reprodução Animal). Angra do Heroísmo: Universidade dos Açores, 2014 [Consult. Dia Mês Ano]. Disponível em www:<http://hdl.handle.net/10400.3/3927>.