| dc.description.abstract | The application of assisted reproductive technologies play an important role
in sheep breeding. The genetical progress, selection and preservation can be
provided by these methods quickly and more effectively. The ewes should be
synchronized by intravaginal devices containing progesterone-like hormone
before the artificial insemination. The insemination can be vaginal, deep cervical,
transcervical and laparoscopic, depending on the deposition of the sperm. The
laparoscopic technique is a minimal invasive method in which two one cm wide
skin incisions are needed where the trocars pierce through the abdominal wall
and we can inject the sperm into the uterus. This technique is used worldwide in
sheep breeding with good efficiency (40-80% pregnancy rate, depending on the
protocol, season, breed, age) so this is the most successful way for inseminating
with frozen sperm but it needs expensive equipment and high level of knowledge
and the ewes need to be sedated before the procedure. The frozen sperm can
be used by transcervical technique as well where the insemination catheter
is going through the cervix and the sperm is injected into the uterine cavity.
This method is not widely spread and used in farm conditions because of the
anatomy of the sheep cervix, which is narrow, closed and it is hard to penetrate it
with a catheter. The successful use of the transcervical method depends also on
the protocol, breed, age, number of lambings and the anatomy of the external
os. Because of the limits of this technique, it is not widely used in the practice,
although it has a lot of benefits, and due to animal health and welfare aspects
(no need for sedation and starvation, no postoperative complications, no need
for antibiotic), developing of the transcervical technique is a good possibility for
research in sheep reproduction. | en_US |
