Artificial insemination is the technique in which semen with living sperms is collected from the male and introduced into female reproductive tract at proper time with the help of instruments. This has been found to result in a normal offspring. In this process, the semen is inseminated into the female by placing a portion of it either in a collected or diluted form into the cervix or uterus by mechanical methods at the proper time and under most hygienic conditions.
Artificial insemination is not merely a novel method of bringing about impregnation in females. Instead, it is a powerful tool mostly employed for livestock improvement. In artificial insemination the germplasm of the bulls of superior quality can be effectively utilized with the least regard for their location in faraway places. By adoption of artificial insemination, there would be considerable reduction in both genital and non-genital diseases in the farm stock.
ADVANTAGES OF ARTIFICIAL INSEMINATION
There are several advantages by artificial insemination over natural mating or servicing.
1. There is no need of maintenance of breeding bull for a herd; hence the cost of maintenance of breeding bull is saved.
2. It prevents the spread of certain diseases and sterility due to genital diseases. i.e.: contagious abortion, vibriosis.
3. By regular examination of semen after collection and frequent checking on fertility make early detection of interior males and better breeding efficiency is ensured.
4. The progeny testing can be done at an early age.
5. The semen of a desired size can be used even after the death of that particular sire.
6. The semen collected can be taken to the urban areas or rural areas for insemination.
7. 7 it makes possible the mating of animals with great differences in size without injury to either of the animal.
8. It is helpful to inseminate the animals that are refuse to stands or accept the male at the time of oestrum.
9. It helps in maintaining the accurate breeding and cawing records.
10. It increases the rate of conception.
11. It helps in better record keeping.
12. Old, heavy and injured sires can be used.
DISADVANTAGES OF A.I:
1. Requires well-trained operations and special equipment.
2. Requires more time than natural services.
3. Necessitates the knowledge of the structure and function of reproduction on the part of operator.
4. Improper cleaning of instruments and in sanitary conditions may lead to lower fertility.
5. If the bull is not properly tested, the spreading of genital diseases will be increased.
6. Market for bulls will be reduced, while that for superior bull is increased.
THE TECHNOLOGY OF DEEP FREEZING BUFFALO SEMEN
Semen from genetically superior bulls are collected using artificial vagina (42-48°C)
Semen Evaluation
Collected semen will be evaluated visually (color, pH, volume) and microscopically (motility, concentration, morphology)
Ejaculated semen with good color and with 60% and above motility are diluted with an equal volume of extender initially at 28-32°C
The extended semen is cooled to 15-20°C then to 2-7°C. this procedure is done to protect the sperm from cold shock. Table 1 shows the composition of the extender used in the laboratory.
Table 1. Composition of Extender
Buffer
| |
Tris hydroxymethyl aminomethane
|
3.028g
|
Citric acid monohydrate
|
1.675g
|
Fructose
|
1.25g
|
Raffinose
|
2.7g
|
Distilled water
|
100 ml
|
(dissolve the chemicals then bring to boil in water bath for 10-15 minutes)
| |
Extender (100ml)
| |
Buffer solution
|
73ml
|
Egg yolk (20%)
|
20ml
|
Glycerol (7%)
|
7ml
|
Penicillin
|
0.03mg/100ml
|
Streptomycin
|
1mg/ml
|
Final Dilution
Remaining volume of extender will be added once the initially diluted semen reaches 2-7 C. (Concentration of sperm after dilution is approximately 100 million per ml)
Filling and Sealing
Extended semen is filled in 0.5 ml capacity straw bearing the bull name, number and date of processing for identification
Equilibrium
Strawed semen is maintained at 2-7°C in cooling chamber for at least 4 hours. During this time, the spermatozoa acquire the ability to survive freezing because the glycerol form complexes with water
Freezing
After equilibration the semen in straw is frozen in liquid nitrogen vapor for 5-7 minutes, after which they are immersed into liquid nitrogen at -196°C. (use of a simple rapid freezer, FHK, FA1652 is the most common in the country)
Post Freezing Evaluation
Frozen semen samples from each bull are thawed and the percentage of cells exhibiting normal progressive movement is assessed. (Percent post thaw mortality must be at least 30% or approximately about 15 million motile sperm per dose)
Storage
All frozen semen from each ejaculate that passed the post freezing evaluation will then be transferred to the designated storage tanks assigned for each bull
Distribution
The stored frozen semen is always available for disposal to AI technicians
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