Animals go through what is described as an “estrus” cycle or “heat” humans go through a menstrual cycle. Apart from other hormonal variations one significant difference between humans and animals is that the female sex hormone, estrogen, which increases just before ovulation in animals is the trigger factor for their sex drive. This hormone is responsible for producing eggs. In other words animals do not desire to have sex unless there is an egg to be fertilized in the female’s womb. In humans however, sexual desire is much more complex and is not driven by the female sex hormone estrogen, but by the male sex hormone testosterone. This is unique in the animal kingdom and it is specially a human phenomenon. The small amount of testosterone that the female makes is enough to generate a sexual drive in her it is only few females that recognize the slight increase in testosterone around the ovulation to enable them deliberately initiate sex at the appropriate time to get pregnant.
From sociolgical studies the fact that humans make lover facing each other indicates a communication system of direct sexual interest and development of love, permanent mating and a family system. On the contrary, throughout the animal kingdom, the female squats in her position of “heat” and the male mounts on top of her facing her rear end. The animals never get to look at each other and they do not need to know each other or get emotionally involved for intercourse to take place. In other words, for animals, sex is not about ’emotions but is purely for procreation. For humans, however, having sex is about expressing emotions and not just for the purpose of having babies. This makes us less reproductively efficient.
The reproductive system of the human male is also highly inefficient. Most male animals produce about 25 million sperms per day per gram of testicular tissue. Humans produce only 4 million sperms per day per gram of testicular tissue. Only the gorilla, the cheetah and the goose produce less sperm per gram of testicular tissue than us! To illustrate the importance of sperm per gram of testicular tissue the average bull ejaculates about 10 billion sperms whereas the average fertile man ejaculate would contain between 1 to 5 billion sperms. This means that the average bull in a single ejaculate produces thirty to one hundred times that of the average man. The bull’s sperm will also move three times the speed of the human sperm, in a perfectly straight line, with virtually no abnormal, weak or deformed sperms. A man whose ejaculate has 60% of the sperms moving is lucky. Studies on sperm population find that up to 40% of a man’s sperms are abnormal.
Take the pig to really show superior animal fertility! The pig ejaculates an entire pint of sperm on having sex with the sow its orgasm will take a full half hour. Compare this to a mere 120 seconds for most men. In addition the pig has little screw like grooves on the end of its penis that fits into a similar groove in the cervix of the female. This guaranties that no sperm will leak during intercourse. The amount of sperm in a single pig’s ejaculate is about four hundred times higher than the sperm in a single human ejaculate, and none is lost. In most animals the sperm cells as they mature from stage to stage are arranged in perfect order. This is not so in humans whose sperm cells mature in a helter-skelter fashion according to histologists.
Why is the human sperm count so poor?
Several factors have been blamed for the low sperm count in men. Stress. It has been well documented that modern life can have a negative impact on reproduction. Many sperm banks in Europe, America and here in Lagos get medical students or other professional students to donate their sperms. It is not unusual for good donors with high sperm counts on one occasion to have a poor sperm count on the next occasion if the donor is having an
exam. There was a case in the University of California where a donor’s sperm count went literally to zero. It was only a close interview that revealed that this student was going through a bout of depression thinking that his life was falling apart. There are cases of infertility with low sperm count from the husband. When the couple goes on vacation the wife gets pregnant because of the change in the environment, which removes the male stress factor.
Hazardous substances. There are several factors in the environment that have a terrible effect on the sperm. To make the situation worse many documented, researched 0r accounted for. In a village in China for instance in the early 1920s they discovered that fertility was on the decline and the women were not getting pregnant. Suddenly in the 1930s the sterility was reversed and the people started having children again. The villagers through that the curse placed on them had been lifted It was later that they realized that the sterility was due to a change in cooking oil. The use of a cheap crude cottonseed oil for cooking created the sterility in the men. It was found that the crude extract has a chemical called gossypols that causes male sterility and is now being used as a male contraceptive. A good number of these have been discovered by accident while there are several out there that are yet to be discovered. There are possibly many herbs or fruits that contain gossypol- like substances that the Nigerian population eats and we do not know about.
Sexually Transmitted Disease. Research shows that about 10 percent of human infertility is caused by tubule obstruction, and this is usually, although not always caused by infectious diseases transmitted sexually. One-third of African men are sterile because of epididymal obstruction caused by sexually transmitted disease
For example gonorrhoea causes irreversible tubule blockage. This type of infertility caused by sexual transmitted disease requires the most complex medical treatment, which includes new methods of assisted conception or reproductive technology.
Human Destiny and Fertility. 25 percent of infertile is partly due to some of the reasons given above. The remaining couples suffering from infertility that cannot be explained need not be pessimistic. The new infertility technologies of IV, GIFT, ICSI and microsurgery with TESA can help most if not all infertile couples conceive.