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ABSTRACT OF PROFESSOR MATTHEW OLUGBENGA OYEYEMI INAUGURAL LECTURE

ABSTRACT OF PROFESSOR MATTHEW OLUGBENGA OYEYEMI INAUGURAL LECTURE

The inaugural lecture reports my academic contributions mainly in the field of Andrology which is an aspect of Theriogenology. The title; Spermatozoa: Staff of offence and defence emanated from the fact that spermatozoa when properly guided and guarded will fertilize viable ova would result in conception and thereafter offspring. The offspring will then serve as food and financial security which are ‘keys’ to defence or serve as security guards (dogs) which typify offence.
The roles of the testicles in spermatogenesis in different animals should be properly understood before using spermatozoa from them for natural or artificial insemination. The scrotum with external insults (examples are ticks infestation, warts, encrustations and mange) will have its thermoregulatory functions compromised leading to subsequent adherence of the scrotum to the testicles, testicular flabbiness or degeneration.
During spermatozoa transit, sperm cells move through the three segments of the epididymis. There are four major occurrences in the epididymis while the spermatozoa are in transit. The first is: - the transport of developing sperm cells from the testicles to the vas deferens. The second is the concentration of the spermatozoa by absorption of surplus fluids. The third is maturation of the developing spermatozoa while the fourth is the storage of viable sperm cells in the epididymal tail.
In artificial insemination where semen would be pre-collected using any of the collection methods, the forms and shapes of the penis of different species of animals must be understood and careful attention paid to it. The dog, bear, seal, bat and rodent have a special bone in the penis which helps maintain erection. In some animals (e.g. bull, ram and boar), the penis has an ‘S’ shaped bend that allows it to fold up outside period of erection.
Semen characteristics are the qualities of any ejaculate that identifies spermatozoa with the breed and the species. Semen characteristics are important traits of reproductive behaviour in farm and domestic animals. These characteristics are influenced by a number of factors such as breed, age, time and method of collection, system of rearing and scrotal circumference among others.
The nutritional level of male animals has an important and lasting effect on fertility. It is thus recommended that male animals should be fed on balanced and adequate quality ration so as to maintain normal reproductive performance.
It is therefore recommended that to improve and sustain livestock production, the expertise of the animal Andrologist is essentially vital.