The reproductive organs are given below-

1. In male :
Two testicles including the epididymis, vasdeferens and accessory sex glands such as the prostate, Cowper’s gland, seminal vesicles and the penis,

2. In Female :
Two overies, a pair of fallopian tubes and uterus including cervix, vagina and vulva. Mammary glands are also included. The functions of these sexual organs of reproduction are controlled by hormones secreted by the various endocrine glands. The pituitary gland is one of them by which several hormones are secreted and the entire mechanism of endocrine is ruled. It has two chief hormones for reproduction such as-

  • Somatotrophin and
  • Gonadotrophin

Somatotrophin hormone is responsible for growth of all body tissues and so it is called growth hormone and influences mammary gland development. Gonadotrophin hormone is responsible for the development of genital organs and influences both the testes and ovary. It includes two types of hormones as (1) Follicle stimulating hormone i.e. F.S.H. which is responsible for the production of male germ cells i.e. spermatozoa in male and for the formation of Graafian follicle (mature follicle) in female and (2) Luteinising hormone, i.e. L.H. It is often referred to as interstitial cell stimulating hormone, i.e., I.C.S.H. It is responsible for sex desire and functioning of accessory sex apparatus through the hormone testosterone produced by the Leiding cells in the testes. In female, the L.H. in the conjunction with a small quantity of F.S.H. causes rupture and release of the ovum from mature follicle. The released ovum is received in the funnel shaped portion of the fallopian tube and this phenomenon is known as ovulation. Thus, sperm is produced in testes and ovum in ovaries. At the time of sexual union, the sperms are discharged and deposited at the mouth of uterus and taking entrance in the uterus they move to the upper part of the fallopian tube and conjugate with ovum and fertilization takes place within a few minutes. The fertilized ovum starts dividing itself and moves slowly and reaches to the horn of the uterus within 72 to 94 hours being about 16 cells. If by chance, the ovum is not fertilized dies within 8 to 12 hours.

After release of ovum, the vacant place in graafian follicle is filled with blood clots which is gradually transferred into an active endocrine gland known as corpus luteum. It becomes in full form within 10 to 12 days after cessation of oestrus in cow. Now, it acts as an endocrine gland and secretes hormone known as progesterone. This hormone prepares the uterus for reception and implantation of the fertilized ovum and this process is known as nidation. After implantation, the fertilized ovum land this process is known as nidation. After implantation, the fertilized ovum takes a shape of an embryo within about 5 weeks when the placenta begins to develop. The placenta during the foetal life acts as an organ of respiration, nutrition and an endocrine gland. It protects and feeds the foetus and helps in its expulsion. The foetal life lasts in the uterue sor about 282 days in cow and 310 days in buffalo. This period is known as gestation period and it varies according to the species and breeds. The bovine placenta is cotyledonous. The corpus luteum persists in the ovary through out the period of gestation. If conception does not occur, it regresses after about 15 to 17 days of its fertilization and next heat cycle appears within 19 to 21 days in cattle. During pregnancy, the level of oestrogen, the ovary hormone and progesterone, the hormone of corpus luteum, are increased in the blood which help in the development of the mammary gland.
When the foetus is fully developed and becomes ready for expulsion, the progesterone level in the blood is lowered and perhaps it becomes a factor to help in the process of expulsion. The hormone oestrogen, secreted by the ovary causes rhythmic contraction of the uterus. In this way, the oestrogen and progesterone help in the process of parturition. The cervix which remains closed throughout the entire period of gestation, begins to dilate. The uterus starts severe contractions under the influence of oxytocin, the hormone of posterior pituitary gland and the result is the expulsion of the foetus, within 4 to 5 hours. After expulsion of the foetus the, uterus begins to contract rapidly and returns to normal condition within 4 to 5 weeks. The placenta comes out within half an hour to 4-8 hours after parturition. The corpus luteum regresses but if it remains persistent for several months, it causes infertility.
Further, it is better to have some knowledge about the following genetical words which take part in the role of reproduction.

Gonads – are generative glands, i.e. testes and ovary which produce gamates, i.e., ovum and spermatozoa. Testis or Testes or Testicle-is male generative gland or gonad. It lies in the scrotum. It first develops in the abdomen and descends through the inguinal canal into the scrotum. It produces male germ cells or spermatozoa or sperms or gamates. The sperm contains half number of chromosomes.

Ovary – is female generative gland or gonad. It lies suspended in a fold of peritonium from the root of the abdomen. It produces female germ cells ovum or ova or egg or gamates. The ovum contains half number of chromosomes.

Gamates – are ova and spermatozoa. They differ in size and shape but they are alike and each contains half number of chromosomes present in all the body cells that is characteristic of the somatic cells of that species. The ova is produced in the ovary and spermatozoa is produced in testis.

Chromosomes – are microscopic minute bodies within the nucleus of cells which carry genes. The number of chromosomes is constant for any given species. They are usually in the multiple of two having the characters of he species to which the individual belongs. Its haploid number is the basic set found in the gamate, e.g. cow 60, horse 64, sheep 54, dog 78 etc.

Genes – are microscopic minute particles which remain in the chromosomes for determining the characters of each individual inherited from its parents. Every mammalian cell contains about 10,000 genes.

Haploid – is reduced number of chromosomes in the ovum and sperm the basic set (n), i.e. half (diploid) number in the somatic cells which occurs in meiosis i.e. reduction divison in the paired basic set (2n).

Diploid – is paired number of chromosomes, the basic sets (2n), one set from the sire and the other from the dam and this number is found in all somatic cells.
Somatic Cells-are all the cells belonging to the body except the germ cells in the gonads.

Cells – are microscopic units of which all the tissues of animal and plant kingdom are composed. Each cell has a nucleus, i.e. the central body which controls its activities and contains genetical materials, i.e. chromosomes, etc. There are many glands which secrete secrete hormones. They are as below-

1. Gonads are generative glands, i.e. testis and ovary.

  • Testis – secretes testosterone & androgen it helps in development of sex apparatus, sex characters and sex desires i.e. libido.
  • Ovary – secretes oestrogen or oestrin. It helps in the development of genital organs, e.g., teats, vagina, udder, growth of the ovarian follicles, onset of lactation, etc.

2. Corpus leuteum :
secretes progesterone. It helps in preparation of uterus for reception and implantation of fertilizred ovum and development of mammary glands.

3. Pituitary-Secretes

  • Vasopressin -It stimulates the uterus in pregnacy. It acts upon heart and circulation rising blood pressure.
  • Oxytocin – It helps in contraction of the muscles of the uterus. It influences the milk `let down’ mechanism.
  • Protactin – It helps in location i.e. milk secretion.
  • Pituitrin – It is an injection prepared from the posterior lobe. It acts in atony condition of uterus and intestines, pyometra etc.

4. Throid :
secrets thyroxine, i.e. iodine. It helps development of growth, reproduction and lactation.

5. Thyroid – secretes

  • corticosteroid or steroids – It regulates the metabolism of carbohydrate, sodium and potassium level in the body fluid.
  • Cortisone – It helps in relief of arthritis, lameness, inflammation and ketosis, etc.
  • Adrenalin – It helps in checking haemorrhage.
  • Pituitrin – It is an injection prepared from the posterior lobe. It acts in atony condition of uterus and intestines, pyometra etc.

6. Parathyroid : secretes parathyroid. It controls the level of calcium in the blood. Its failure causes spasm and cramps.

7. Pancreas : secretes insulin. It influences digestion and controls the level of blood sugar.


Defination :
A female, by nature, is to produce an offspring. But, when she fails to produce, she is called sterile or infertile and the condition is known as sterility. But the female herself is not responsible for the same because the production of an offspring is a result of conjugation of a male and a female sexual organs, i.e. sexual union. But, the processes of the reproduction are sometimes obstructed due to some changes in the physiological characters and disturbances in th function of the sexual organs by which an offspring is not born. Therefore, it is essential to have some knowledge regarding physiology of reproduction while dealing with sterility


For the cause of sterility, both the male and the female are responsible. The process of reproduction is disturbed by the disturbance in their generative organs. It results in sterility. There may be the following four factors-

  • Congenital abnormalites and defects in hereditary factors.
  • Hormonal deficiency
  • Disease infections
  • Nutritional deficiency

1. Congenital Abnormalities and Defects in Hereditary Factors :
The congenital abnormalities and defects in reproduction are due to some disturbances in the male and the female generative organs caused by lethal or sub-lethal genes, e.g. under developed genital organs, i.e. hypoplasia of testicles or ovaries, absence of uterus or testis, cryptorchidism, i.e. failure of testicles in desceding either one or both from abdomen to scrotum, hermaphroditism, freemortin etc. These defects of sterility are incurable. But, the persistent hymen in female may be treated with minor operation.

2. Hormonal Deficiency :
The hormones of endocrine glands, e.g. hypophysis, i.e. pituitary, gonads, i.e. testis and ovary, thyroid and adrenals are responsible for birth of a progeny. It depends on the coordination of these glands. But, lack of coordination in these glands results in sterility. The deficiency of L.H. in male leads to decrease in sexual desire. The deficiency of F.S.H. may cause disturbance in spern production and development of sex apparatus. The semen of such male will be of poor quality and not suitable for progeny production.
In female, the normal oestrus cycle is disturbed due to incoordintion of the endocrine glands. The other conditions of sterility are described below.

(i) Anaphrodisia – This is a condition of the female animals whose ovaries are small as such follicles are not developed resulting unoestrus and corpus luteum are not palpable in either ovary.
This condition is treated with a subcutanceous injection of 1000 to 1500 I.U. of pregnant mare serum (P.M.S.) which induces oestrus within 3 to 5 days followed by ovulation. But. this treatment is adopted only in such form of sterility in which a corpus luteum is present in the ovaries. Otherwise cystic ovaries or multiple ovulation may result.

(ii) Nymphomania –
It is a condition of uncontrollable sexual desire in female. In some cases, the animal comes in heat at short intervals. It is due to the formation of several comes in heat at short intervals. It is due to the formation of several cysts in the ovary and each time the animal comes in heat. In other cases the heat persists continuously for a longer period and the animal receive of a large cyst or cysts in the ovaries. These conditions are due to the failure of the anterior pituitary gland which becomes unable to secrete sufficient quantity of L.H., and therefore the follicles are not ruptured.
This can be treated by rupture of the cysts with the help of fingers pressure per rectum.
In some cases, the follicle is not ruptured at the end of the heat period with the result that it becomes a large cyst in long standing conditions. In such cases, the heat is commonly suppressed completely but the other symptoms of heat may be seen, such as swelling of vulva, dilated cervix, raised tail head, sank pelvic ligaments and formation of depression or curve line at the root of the tail.
In early stage, the cyst can be ruptured by the digital pressure per rectum. But in long standing cases, when the cyst becomes enlarged and hard, it can be ruptured by puncturing with concealed trocar through vagina.

(iii) Disturbance in Ovulation and Failure in Implantation :
The ovulation is disturbed due to imbalance between oestrogen and progesterone with the result the ovum is either hastened or delayed in passing down the fallopian tube. This affects the occurrence of meeting of the ovum and sperm in the fallopian tube resulting in failure in fertilization. The fertilized ovum usually takes 3 to 4 days to enter the uterine horn. If the entrance is taken place earlier, the fertilized ovum may not get suitable condition for implantation and it dies during the embryonic stage. This condition is not easy to diagnose and so there is no treatment.

(iv) Anoestrus Ovulation or Silent Heat :
Sometimes, the ovary fails to produce sufficient quantity of oestrogen which results ovulation without showing any symptoms of heat. So it is called silent or still heat.

(v) Adrenal Virilism :
Sometimes, the ovary remains undeveloped and clitoris is enlarged due to hyperfunction of adrenal in heifer. It results in viril masculine behaviour. In case of cows the ovaries are often enlarged with lutein cysts. The tough cyst in cow is punctured by concealed trocar.

(iv) Persistent Corpus Luteum :
Sometimes, the corpus luteum does not regress and remains present for longer period. It causes anoestrus for several months. It is ruptured by fingers pressure through the rectum. After rupture of the persistent corpus luteum, the animal comes in heat within 2 to 6 days. But it requires very care in putting pressure because the pressure may injure the ovary. It is also to be kept in mind that the animal may be pregnant in the presence of corpus luteum and the animal does not come in heat. If it is ruptured in the presence of pregnancy, the animal may abort.

(iv) Persistent Corpus Luteum :
Sometimes, the corpus luteum does not regress and remains present for longer period. It causes anoestrus for several months. It is ruptured by fingers pressure through the rectum. After rupture of the persistent corpus luteum, the animal comes in heat within 2 to 6 days. But it requires very care in putting pressure because the pressure may injure the ovary. It is also to be kept in mind that the animal may be pregnant in the presence of corpus luteum and the animal does not come in heat. If it is ruptured in the presence of pregnancy, the animal may abort.
In this way, hormaturely due to deficiency in secretion of progesterone, i.e. hormonal imbalance.
In this way, hormone therapy is used in the infertility or sterility where the reasons are hormonal. But sometimes it causes several complications in slight mistake because all the glands of endocrine are closely related. It is also understood that hormonal disturbances are mostly genetical in orign. In the world test, it is found that a liberal use of oestrogen or progesterone for conception and abortion is harmful. Its wrong use (misuse) may cause under developed and abnormal birth of a progeny. It also affects badly the uterus and the animal may lose the potency for embryo development. Therefore, one should be very careful in sue of hormonal thrapy and its use should be avoided as far as possible.

3. Disease Infection ;
The entrance of infective organisms into the genital tract causes pathological condtions resulting in decreased fertility in both males and females, e.g., Brucellosis, Vibriosis, Trichomoniasis, Epidicdymitis, Vaginitis etc. These organisms cause inflammation in the genital tract, Vaginits etc. These organisms cause inflammation in the genital tract. In brucellosis, orchitis (inflammation of testes) and vesicultis (inflammation of seminal vesicle) are commonly observed. In females, this infection often results in abortion and placenta is retained several times.
In case of vibriosis and trichomoniasis, the clinical symptoms are not obvious and no pathological changes in the genital tract are readily detected. The only symptoms commonly observed is frequent infertile services. The only symptoms commonly observed is frequent infertile services. The infection is transmitted during coitus. The oestrus cycles in the infected females are usually longer ranging from 30 to 40 days. There is undetected early embryonic death. Abortion also occurs during advanced stage of pregnancy but the incidence of such abortion is not high as brucellosis.
The infections of genital tract commonly occur during the calving time and after parturition.
The infections may cause vaginitis in the vagina, cervicitis in cervix, methritis and endometritis in uterus, salpingitis in fallopian tubes, oophoritis in ovaries. In many cases, this condition may occur with the contaminated hands and instrument used at the time of dystocia and retention of placenta.
These conditions, the vagina and cervix should be swabbed with the stock solution of lugol’s solution prepared as below. It gives good result

4. Nutritional Deficiency :
Nutritions food is very important for development land functioning of the genital organs. The deficient nutrients or lack of proteins, vitamins and minerals may cause sterility or infertility. A deficiency of proteins causes obstruction in the formation of spermatozoa. The oestrus cycle is distrurbed in lack of vitamin A.A deficiency of calcium and phosphorus also causes infertility. A deficiency of vitamin E also causes infertility and conception does not occur. Sometimes, it is also found that the infertility is caused by fatness both in male and female because the functions of the testes and ovaries are impaired by fat deposition in the gonads. Therefore, the rich food and inadequate exercise are contributory factors in sterility. A severe debility and emaciation due to infectionus diseases or malnutrition or food may lead to anoestrus and disturbance in sperm production affecting fertility.


Causes :

  • Genital diseases, e.g., vaginitis, cervicitis, metritis, cystic ovary, trichomoniasis, etc.
  • Imbalance of hormones.
  • Deficiency of vitamin A and E.
  • Mineral deficiency.
  • Malnutrition.
  • Faulty artificial insemination.
  • Acidic condition of genitals.
  • Underdeveloped genital organs.