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| Author(s): |
Sidnei Nunes de Oliveira
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Botucatu. 2016-07-06. |
| Institution: | Universidade Estadual Paulista (Unesp). Faculdade de Medicina Veterinária e Zootecnia. Botucatu |
| Defense date: | 2016-05-03 |
| Advisor: | Frederico Ozanam Papa |
| Abstract | |
The penis is the copulatory organ and in the stallion it is classified as cavernous muscle and the cavernous spaces are filled with blood during erection. In the testicles occurs sperm production, that are transported through the rete testis to the epididymis, where they will suffer maturation, fertilizer capacity and will be stored until ejaculation. The accessory sex glands are responsible for the expelled fluids during ejaculation, named seminal plasma that are mixed with sperm cells and form the ejaculate. Each of these glands are responsible for a certain secretion that will divide equine semen into three distinct fractions: pre-sperm fraction, produced by the prostate and bulbourethral glands; rich fraction in sperm, produced by epididymal secretions and liquids from ampoules of the vas deferens; post-sperm fraction or poor fraction, consisting of sperm remaining in the urethral canal and liquids produced by the seminal vesicles, the gel. During the physiological process of mating, several events occur named erection, in which the stud is excited by stimuli emission which is characterized by the release of sperm into the pelvic urethra followed by ejaculation with the expulsion of semen, relaxation and gathering the penis. Typically, horse semen collections are performed in the conventional way, with a closed artificial vagina, where all the fractions are mixed. Each stud has individual characteristics related to the maintenance of sperm cells during the cryopreservation, these characteristics may be related to production of seminal plasma and to the components that form it as well. What is known is that there is a negative effect played by the seminal plasma components mainly produced by the seminal vesicles, to the sperm during cryopreservation process, however, these factors are still unknown. Several hypotheses are suggested such as the production’s reduction of lipids and proteins and the types of ions present in each fraction of the ejaculate. Knowing this, the fractional collection may be beneficial to sperm, considering that the first fractions do not have contact with seminal plasma produced by the seminal vesicles. This work aims to review the semen fraction harvest in stallions, as well as its benefits for the sperm cells to be submitted to cryopreservation. (AU) | |
| FAPESP's process: | 14/00354-0 - Effect of fractioned collection on sperm kinetics and viability of cooled and frozen stallion sêmen |
| Grantee: | Sidnei Nunes de Oliveira |
| Support Opportunities: | Scholarships in Brazil - Master |