IMPORTANCE OF ARTIFICIAL INSEMINATION IN BOVINE

IMPORTANCE OF ARTIFICIAL INSEMINATION IN BOVINE

Monika Rani, Deepak kumar Tiwari

¹Monika Rani [PhD Scholar, Department of Veterinary Surgery and Radiology, Mumbai Veterinary College, Parel- 400012 monikajangra3535@gmail.com ]

²Assistant Professor, Department of Veterinary Surgery and Radiology, Lala Laj Pat Rai University of Veterinary and Animal Sciences (LUVAS), Hisar 125001 dr.deepaktiwari@gmail.com

INTRODUCTION

High-quality production as well as good reproduction are two necessary elements for making the dairy farming a profitable one. To improve the reproductive capabilities, several new reproductive technologies have been introduced. One of the most important reproductive technologies used by the dairy sector is artificial insemination using cryopreserved semen for genetic improvement and production enhancement of dairy animals. It is very much evident how this technology has affected the economic advancement of industrialised countries. However, the potential of this technology has not been fully exploited in several countries, including India.  It is a well-known fact that farmers can overcome significant challenges in managing a bull for breeding of their animals by utilising cryopreserved semen in artificial insemination technology.

What is Artificial insemination (AI)

It is a technique in which semen is collected from the male, processed, stored and artificially deposited into the female genital tract at right place and right time for the purpose of conception. It is one of the important technique responsible for genetic improvement in farm animals. Besides cattle and buffalo, boar and buck semen can be frozen and utilized but AI is used on limited basis in horses and sheep.

Procedure of Artificial insemination in cattle

Source: https://www.change.org/p/nz-government-ban-animal-artificial-insemination

THAWING OF SEMEN STRAW

Lift the neck plug of the LN2 container. Precool the forceps in the liquid nitrogen vapour for 5-10 seconds. Then, lift the canister from the neck and move it to its opposite edge. Now, the body of the canister will come to centre. Lift the canister to the level of neck to identify and lift the straw by forceps. The whole operation of lifting of canister and removal of straw should be done as fast as possible i.e. within 5-10 seconds. Otherwise immerse the canister into the liquid nitrogen. Immediately after removing the semen straw give a jerk to remove the liquid nitrogen on the straw and also to avoid popping of the seal. If the straw is having cracks or broken or defective seals the straw should be discarded. Then, put the semen straw in a water bath of 37⁰C for 30 seconds and straw should be completely submerged in water. The thawing water and container should be clean. Thaw the semen straw either in horizontal or vertical manner and after the thawing remove the straw and wipe with cotton to remove all the water on the surface of the straw. Under no circumstances, thawed semen should be used beyond 15 minutes.

LOADING OF AI GUN (FRENCH STRAW)

Remove the straw from the thawing tray using fingers and dry it with tissue paper. Check the

name of the bull printed on the straw. If the wrong straw has been selected it must be discarded. Never replace a thawed straw in liquid nitrogen. Pull back the plunger of the AI gun. Holding the straw by the end, to avoid damage to the semen through temperature shocks, insert the manufacturer’s end into the gun as far as it will go. There is an in-built stop preventing it going too far. Prepare to cut off the laboratory end of the straw using thoroughly cleaned and dried the scissors/straw cutter. Hold the loaded gun vertically at eye level and using clean sharp scissors make a horizontal cut just below the laboratory seal end. The cut must be at right angle to the straw so that a perfect seal occurs between the straw and the sheath. Place a sheath over the barrel of the gun. Handle and touch only the split end of sheath to keep the other end clean. Push the sheath through the central hole of the locking ring, twist it down on the conical seal of the gun and place O-ring over the sheath. Seal between the sheath and the gun is essential otherwise semen will leak into the gun. Press the plunger of the gun until the semen is just visible at the end of the gun. This reduces the stretching of fingers needed during handling of the loaded gun. Now, loaded AI gun is ready to inseminate the animals.

TECHNIQUE OF AI

1) Cervical Insemination using speculum method

2) Recto-vaginal method

1). Cervical insemination using speculum method:

This is older method and AI is performed with the help of vaginal speculum after cleaning the external genitalia of the cow/buffalo. With the aid of light, a long insemination pipette about 1 ml of liquid semen is introduced and deposited into the external os of the cervix.

Disadvantages

1. It is fairly satisfactory but requires frequent cleaning and disinfection of the speculum or use of a different speculum on each cow.
2. When large number of cows are inseminated the sterilization of speculum sometimes will become problem.

iii. Chances of injury and infection of vagina and cervix will lower the fertility.

2). Recto-vaginal method:

It is more effective and widely adopted method. This recto-vaginal method is performed in animals in standing position. The animal is restrained properly in a service crate. The perineal region of the animal is cleaned to remove the dung and dirt. The inseminator’s hand is covered with disposable rubber sleeve. The lubrication is done with non-irritant soap or liquid paraffin and the hand is passed into the rectum. The dung inside the rectum is removed by back racking. Frequent removal of hand from the rectum while removing dung should be avoided because it will lead to ballooning of the rectum. Vulva and vulval lips are carefully wiped or if necessary, washed and then wiped dry with cotton or a paper towel. The cervix is grasped with gloved hand and the external os is located. If the external os is hard to locate, the cervix may be hold by the fingers and the thumb is placed over the external os. The vulval lips are widened apart by an attendant and the insemination gun is inserted through the vulva and vagina and into the external os of the cervix. If folds of vaginal wall interfere, the cervix is pulled or pushed forwarded to straighten the lumen of the vagina. By manipulation of the cervix with the hand in the rectum, the insemination catheter is passed just through the annular rings of the cervix. The frozen thawed semen is deposited into the body of the uterus. Semen is expelled slowly. A common error is to penetrate the catheter beyond the body of the uterus into the uterine horns.

Advantages of recto-vaginal technique of insemination

1. Deposition of semen at proper site is ensured without loss of semen.
2. Chances of infection are minimized and fertility rate is high compared to speculum method.

iii. Injury/bleeding caused while using speculum is avoided in this method.

1. Estrum is confirmed while examining the animal per rectum.
2. Inseminating pregnant animal is also avoided because the rectal palpation of genital organs rules out pregnancy.

Artificial insemination by Recto-vaginal method

ADVANTAGES OF ARTIFICIAL INSEMINATION OVER NATURAL SERVICE

1. Genetic Improvement: Genetic improvement is faster in AI than natural mating.
2. Control of venereal diseases: The bulls used for semen collection are tested for various diseases. Secondly, the bulls do not come in direct contact with females, so chances of transmission of venereal disease are very less.
3. Easy transportation: The preserved semen of a genetically superior bull can be transported from one corner of world to another with low cost as compared to bull.
4. Effective use of superior bull: Through AI elite bulls can be used effectively. Normally a bull under natural mating system can serve 100 females in one year and the same bull can cover 600 to 800 cows by single ejaculation after dilution, up to 30,000 females/year through AI. For example, if a bull is used for 2 collections per week and one ejaculation has 6 ml volume with 1000 million sperms/ml. Then total sperms harvested are 6,00,000 million (2 x 6ml x 109 x 50 weeks = 6×1011). Considering 20 million sperm concentration per straw 30,000 AI can be performed by one bull per year (i.e. 6×1011/20×106 =30,000).
5. Economical: AI technique is economical than rearing a bull. The charges taken by bull owner for natural mating are quite higher than charges of AI.
6. It facilitates progeny testing of sires.
7. Breeding records: Correct breeding records can be maintained in AI programme for all the animals of a herd.
8. Maximum utilization of elite germplasm: The semen used for AI is evaluated before and after freezing which is not possible in natural mating. Secondly it allows maximum utilization on elite/quality germplasm.
9. Monitoring reproductive health of female: At the time of AI, the cow is examined per-rectally which may reveal anatomical or pathological defects.
10. Overcoming differences in size of animals: If a female is comparatively smaller in size and bull is heavy, then natural mating may not be possible but in AI there is no such problem.
11. Use of bulls with physical inability: Genetically superior bulls with good quality semen if having problems in joints, bones etc. can be subjected to Electroejeculation for semen collection.
12. Cryopreservation of quality semen: Semen can be preserved for longer periods and even after the death of the bull, semen can be utilized for AI programme. Secondly, the germplasm of wild animals and endangered species can also be preserved.
13. Avoidance of poor quality semen dissemination: At the time of semen collection, semen is evaluated and poor quality semen producing bulls are rejected, thus it avoids dissemination of poor quality semen.

LIMITATIONS

1. It requires costly equipments.
2. It requires well trained personnel at lab as well as field level.
3. Easy transfer of diseases if bull is not screened properly i.e. improper breeding soundness examination.
4. The availability of liquid nitrogen is not so good in the country.
5. Level of liquid nitrogen should be checked regularly otherwise all the spermatozoa will die.
6. Improper cleaning of the equipments and poor hygiene at the time of AI may lead to conception failure.
7. Faulty AI in pregnant animals may lead to abortion.

CONCLUSION

A calf crop obtained by artificial insemination approaches around 80 percent, compared to 40 to 65 percent under natural breeding conditions, suggests that artificial insemination has a practical application in cattle farming. The ability to keep records on every cow through artificial insemination allowed non-breeders to be recognized and discarded.

REFERENCES

Physiology of Reproduction and Artificial Insemination of Cattle (1978). 2^nd Edition, authored by G. W. Salisbury, N. L. Van Demark and J. R. Lodge.

Veterinary Reproduction and Obstetrics (2019). 10th edition, authored by David E. Noakes, Timothy J. Parkinson and Gary C.W. England.

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