2. Semen deposition

In the cow, the best fertility can be obtained with the recto-vaginal technique. A gloved hand is inserted into the rectum of the cow and used to pick up the cervix by means of the gloved hand in the rectum. Sufficient practice is necessary before an individual becomes proficient at this technique. Some kind of nonirritating lubricant to the anal region prior to insertion of the cupped hand through the anal musculature is advisable.

Insertion of the inseminating tube into the vagina should be started with the tip pointed upward at an angle of 20-30 degrees. This avoids the possibility of having the tip enter the blind pouch or urethral opening. The gloved hand in the rectum should be used to follow the tip of the inseminating tube as it is gently pushed into the vagina, for the tube will serve as a guide in locating the cervix and in the anterior portion of the cervix is recommended.


The highest rate of conception is obtained by inseminating deep into the cervix. Except under certain conditions, insemination into the uterus has no advantage over cervical insemination. On the other hand it carries the risk of infection into the uterus, trauma or termination of pregnancy if the animal in heat happens to be already pregnant. In general routine work, intra-uterine insemination is not recommended.

The quantity of semen to be used for insemination depends on the quality of semen sample and the rate of dilution. For obtaining best insemination results, 1.0 ml of diluted semen should contain a minimum of 10 million viable, progressively motile spermatozoa. It has been observed that sperm concentration as low as 500 million per mililiter will give as good fertility results as more concentrated ones, provided the semen is diluted on the basis of number of motile spermatozoa or more per mililiter. In artificial insemination, it is the number of healthy mobile spermatozoa that is of greater consequence than the quantity of semen used.


For obtaining high conception rate the time of ovulation should synchronize with the presence of active sperm in the fallopian tubes. The highest rates are obtained by inseminating cows in the middle or the end of the heat period. A moderately high conception rate may also be obtained when insemination is performed 6 hours after the termination of heat.

Care and Training of Sire

In natural and A.I. services, the desired results can be obtained only when the sire is maintained in a good breeding condition. An otherwise excellent sire unless it is allowed the opportunity for full development of its inheritance with respect to type, size and breeding abilities, may have to be discarded, resulting in the loss of valuable germplasm.

The feed requirements of a young, growing animal are different from those of full grown sire. The latter requires proportionately larger quantities of total digestible nutrients, good quality protein, minerals and vitamins for the proper development of tissues and normal functioning of the various systems of the body, including that of reproduction. Over-feeding and excessive conditioning should be avoided. Fatness in the breeding sire is likely to impair fertility. Several workers have reported deleterious effects on fertility because of excessive protein in the feed.

Turning the bulls out on a good pasture is an excellent practice, I. for it provides not only nutrition but also exercise for them. It is r very important that the bulls are housed in cool quarters with ample supply of cool water for drinking. Experiments have repeatedly demonstrated the deleterious effects of warm temperature on semen quality. In temperate countries, a young bull under proper management is fit for light service at one year of age. Except for rare cases, bulls in India do not become sexually mature before two years of age.

When bulls are to be used for semen collection, it is more convenient to train than for such use while they are young. They should be docile and free from vices. They may at first be allowed to serve for males in heat, the same site being used for mating and preferably by the same attendant thereby avoiding any psychological disturbance that might be caused to the bull at the time of training. Before long he becomes familiar with the entire procedure and anticipates services when brought to the site. An anoestrus cow or even a dummy can at this stage be substituted for the oestrus female and, if an A V is now provided, most bulls and buffalo bulls will readily mount and serve it.

Bulls for artificial insemination should mount the female reasonably quickly, but excessive quickness is not desirable. Improvements in the quantity and quality of semen generally results when sire is allowed some pre-service activities. The frequency of semen collection from a good sire will have to be determined with due regard to the desirability of making full use of the sire over as many years as possible. After being repeatedly used, bulls differ greatly in their capacity to produce good quality semen. Some bulls can stand more frequent collections than others without loss of semen quality. The usual practice in A.I. centres is to make not more than two collections in a week.

A sire sowing decline in semen quality or sex drive should be allowed sufficient sexual rest to enable it to regain its vigour and capacity of semen production. Sex drive, however, is not an index of quality of the semen that a bull will produce. A vigorous bull may be completely sterile. Travel or transport of the sire from one place to another often affects both the sex desire and the semen quality. A bull should, therefore, be rested for about a fortnight or more before semen samples are obtained from it for evaluation.