ARTIFICIAL INSEMINATION
After the collection and evaluation, mostly fresh spermatozoa are inseminated. However, cat semen can be conserved either chilled at 4-5°C for several days or cryopreserved at -196°C for a long period, which makes (inter)national transport and the use of the genetic material of valuable breeding animals possible.
To perform AI successfully in cats, the basic know- ledge of the female genital tract is required. During the estrus, the vestibulum, vagina and cervix measure 20.2
± 3.3, 26.8 ± 3.9 and 1.2 ± 0.1 mm, respectively. The insemination can be performed in the vagina or directly into the uterus. General anesthesia or sedation is required in both cases. Intravaginal AI is performed by inserting a needle (9 cm long - 20 G) with a bulb on the tip or by a nylon probe (9 cm long - 1.5 mm diameter) and a stainless probe (9 cm long - 2 mm dia meter) into the anterior part of the narrow and nondistensible vagina. The animals are in dorsal recumbency (up to 20 minutes after AI) with the hind quarters elevated to improve the transport of the spermatozoa into the uterus.
Intrauterine AI can be obtained by performing a laparotomy and direct injection of the spermatozoa into the uterus of an anesthesized queen by means of a syringe and a small needle. Although this procedure is easy to perform, it is considered invasive and unethical and is therefore prohibited in several countries. Alternatively, several techniques have been described using specific types of transcervical catheters and a speculum (Figure 3), which requires practice to master.successfully applied a transcervical intrauterine technique with the aid of transrectal digital manipulation. The latter technique takes only several minutes to perform but requires an extensive training period.