[Fertility and sterility in domestic animals]

For most of the domestic animals the fertility rate is generally very good. If a uniparous female animal is served during the oestrus period by a male with good sperm quality, the pregnancy rate is 60 to 70%. Among the animals that deliver more than one offspring, in many cases the pregnancy rate even reaches more than 90%. Nevertheless, veterinarians are very frequently consulted for fertility problems in individual animals or in cattle or swine herds. The main causes of subfertility are: Insufficient sperm quality An inseminator with insufficient professional knowledge. The majority of the cows, horses and pigs are inseminated artificially (AI). The insemination is not always carried out by experts. Not the right time for insemination. It especially occurs in animals with weak oestrus symptoms. Venereal infections. In earlier days these infections would occur very often. Due to the application of AI, most of these infections have been eradicated. The malfunctioning of the female genital system, which can be caused by various factors, such as cystic ovarian follicles, endometritis and anatomic abnormalities. The research on reproduction which has been going on during the past ten years in the department of Obstetrics, Reproduction and Herd Health, has been mainly concerned with: Embryo transplantation, in vitro fertilisation and ovum pick up The evaluation of sperm quality Improved freezing methods for both sperm and embryo's The development of new insemination techniques The composition of a new diluent for fresh sperm Cystic ovarian follicles in cows Subfertility in different species of animals Next to the above mentioned study fields, the department is also involved in the research into swine fever, respiratory diseases in pigs, antibiotic resistance in pigs and cattle, mastitis and metabolic problems in cattle and salmonella infections in pigs.