कृत्रिम गर्भाधान: किसानों के लिए उपयोगी सुझाव
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 and proper place with the help of instruments i.e A.I gun. 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.
Signs of heat
There are various signs of heat which can be seen by farmers mainly because they are the care taker of animals and can judge their animal. Different signs are present in different animals; sometimes one is present in an animal but absent in other.
- The animal will be in excited condition. The animal will be restless and nervous.
- The animal will be bellow frequency. This is the main sign which farmer think is the basic sign but not present all the time.
- Clear mucous discharge will be seen from the vulva, sometimes it will be string like the mucous will be seen stick to the near the pasts of valva. Clear ropy mucous discharge is the basic sign of heat.
- The animals which are in heat will lick other animals and smelling other animals.
- The animals will try to mount other animals.
- The animals will standstill when other animal try to mount. This period is known as standing heat. This extends 14-16 hours.
- Frequent urination will be observed.
- Swelling of the vulva will be seen.
- The tail can be in raised position.
- Milk production will be slightly decreased.
- The animal might reduce the intake of feed.
- On Palpation uterus will be turgid and the cervix will be opened.
Proper Timing of Insemination for Maximum Conception
Females go into heat once every ~21 days. Conception rate is lower when animal are bred prior to mid estrus. Maximal conception is obtained when cows are inseminated between mid estrus and the end of standing estrus. This time period is when the female ovulates, sending an ovum out to the fallopian tube to await fertilization from sperm from a bull.
In cows estrus may last from 10 to 24 hours and in buffalo estrus lasts from 6 to 12 hours. Success in insemination timing is depends upon a good heat detection. In field heat detection is responsibility of farmer. A successful heat detection and subsequent proper timing of insemination will increase reproductive efficiency. Practical recommendation for timing of insemination are:
Buffalo showing estrus
Should be inseminated
Same Day Evening
Next Day Morning
Cows showing estrus
Should be inseminated
Next day Morning
Next day afternoon
Steps for doing A.I
The following steps should be followed while doing A.I. Please also consider using an experienced certified AI technician to AI your animal. These people are better to use than training yourself to do it.
- Watch your animal for signs of estrus as discussed earlier. Physiological, behavioural and physical signs of heat which last for 24-36 hours. Most heat periods start or end around dusk or dawn.
- Handle the animal in calm way with proper handling practices, without irritating animal.
- If doing AI outside, it is best to do it on sunny warm days, not when the weather is rainy or windy or even stormy. If you have a facility that is set up inside a shed or barn, so much the better.
Preparations Prior to Insemination
- Prepare a water bath that is between 90 to 95 degrees Fahrenheit (or 34 to 35 degrees Celsius) in a thermos. Use a thermometer for better accuracy.
- Identify which canister contains the semen you need.
- Remove the canister from its storage location to the centre of the tank. Lift the canister just high enough into the neck region of the tank to grasp the desired cane of semen. Keep the tops of the canister or canes no higher than the frost line, or two to three inches from the top of the tank.
- Grasp the desired cane then immediately lower the canister to the tank floor. Keep the cane as low inside the tank as possible while removing the straw of semen with tweezers. Never take semen straw with bare hand. You only have 10 seconds to take the semen straws out.
- Shake the straw to remove excess liquid nitrogen (nitrogen quickly goes into a gaseous state when exposed to air and warmer temperatures) otherwise it can burst the semen straw when put in water bath.
- Immediately place it the prepared thermos of water and keep it in there for 40 to 45 seconds. This process is known as thawing.
- Get your AI gun ready by having it pre-assembled (this should be done before/after you prep the thermos with warm water. If it's cold outside, warm the tip. Rubbing a paper towel on the rod also helps warm it up. If it's hot outside, keep it in a cool place. The AI gun should not be extremely hot or cold to the touch.
- Remove the straw from the thermos and wipe it dry with a paper towel. It should be completely dry before you do anything else with it. The flick should move the bubble to the end you are holding.
- Put the straw in the rod. Use sharp scissors or specially designed straw-cutter scissors should be used, and cut in the area that the air bubble is located.
- Wrap the AI gun in a clean dry paper towel or protective sheath and tuck it in your clothing close to your body to both transport it to the animal and to maintain a constant temperature.
- Artificially Inseminating the Female Bovine. Move the tail so it's on top of your left forearm or tie it up so it will not interfere with the AI process. Raise the tail with one hand (preferably the right) and with the other (which should be gloved and lubricated), gently reach inside the cow to clean out any faeces that may interfere with the process of feeling for and inserting the AI gun into the animal’s vagina. Clean the vulva with a clean paper towel or rag to remove excess manure and debris.
- Take the gun out of your jacket or overalls, unwrap it, then insert it at a 30 degree angle into the cow's vulva. This is so that you avoid going into the urethral opening into the bladder.
- With your left hand in the rectum of the cow (which should have been there to begin with), feel with your finger tips through the wall of the rectum and vagina the location of the end of the AI gun until you reach the cervix.
- Grasp the cervix with the hand in the rectum of the cow (like you would hold a bar that is below your hand) and hold it steady while you thread the rod into and through the cow's cervix.
- When the rod is all the way through the cervix, check the location with your index finger. The rod should be only 1/2 to 1/4 of an inch into the uterus.
- Slowly depress the plunger at the end where your right hand is so that 1/2 or is deposited.
- Recheck the location of the semen to make sure you are in the cow's uterus and not in any of her "blind spots" (see tips below), and deposit the other half of the straw's contents.
- Slowly remove the AI gun, your hand and arm from inside the cow. Check for any blood, infection or semen "feedback" from inside the sheath.
- Recheck the straw to see if you used the right bull semen for the cow.
- Dispose the straw, glove, and towels in the proper place.
- Clean the AI gun if necessary.
- Record breeding information on any record keeping system you have on hand.
Points to keep in mind while inseminating
- Semen Straw should not come in contact with water or scissors while cutting the tip of straw, as water changes ph of semen.
- Inseminating equipment should avoid contact with lubricants at all time, because most lubes are spermicidal.
- Take your time while breeding of animal. Never be in hurry while inseminating the animal as rushing around causes far more mistakes than taking things calmly and slowly.
- Liquid nitrogen is the best solution to use to keep semen cold and keep them for a long time.
- Always keep inseminating equipment clean, warm and dry.
- Never let the end of the AI gun goes very far past the cervix, otherwise infection or puncture of the uterine wall may occur.
- Always keep the end of the pipette UP at a 30 degree angle, not down, to avoid going into the bladder.
- Use your fingers to help move and locate the AI gun down the animal's vagina. Avoid two particular blind spots as you get closer to the cow's cervix.
- There is a blind circular pouch that joins to the backward-facing cervix. This pocket surrounds the entire dome-shaped rear of the cervix
- The cervix also is not a straight-and-narrow passage way. It contains finger-like projections that cause the passageway to be crooked. They also cause dead-ends or blind pockets that can cause problems animal.
Myths about artificial insemination among farmers:
- Farmers think that conception rate is less than natural service.
- Bellowing is the only heat sign.
- While animal in silent heat cannot be inseminated.
ADVANTAGES OF AI:
- Increased efficiency of bull usage: During natural breeding, a male deposit much more semen than is theoretically needed to produce a pregnancy. In addition, natural breeding is physically stressful. Both of these factors limit the number of natural mating a male can make. However, collected semen can be diluted and extended to create hundreds of doses from a single ejaculate. Also, semen can be easily transported; allowing multiple females in different geographical locations to be inseminated simultaneously, and semen can be stored for long periods of time, meaning that males can produce offspring long after their natural reproductive lives end.
- Increased potential for genetic selection: Because artificial insemination allows males to produce more offspring, fewer males are needed. Therefore, one can choose only the few best males for use as parents, increasing the selection intensity. Furthermore, because males can have more offspring, their offspring can be used in a progeny test program to more accurately evaluate the genetic value of the male. Finally, individual farmers can use artificial insemination to increase the genetic pool with which his or her animals can be mated, potentially decreasing effects of inbreeding.
- Decreased Costs: Male animals often grow to be larger than females and can consume relatively larger amounts of feed. Also, male animals are often more strong, powerful, and potentially ill-mannered and thus require special housing and handling equipment.
- Increased safety for animals and farmers: As mentioned, male animals can become large and aggressive. These factors mean that maintaining a bull on a farm may be dangerous. Also, because of the relatively larger size of adult males than females, natural mating is more likely to result accidents and injury to either the cow or the bull than is artificial insemination.
- Reduced disease transmission: Natural mating allows for the transfer of venereal diseases between males and females. It prevents the spread of certain diseases and sterility due to genital diseases e.g: contagious abortion, vibriosis etc. Some pathogens can be transmitted in semen through artificial insemination, but the collection process allows for the screening of disease agents. Collected semen is also routinely checked for quality, which can help avoid problems associated with male infertility. By regular examination of semen after collection and frequent checking on fertility make early detection of interior males and better breeding efficiency is ensured.
- It makes possible the mating of animals with great differences in size without injury to either of the animal.
- It is helpful to inseminate the animals that are refusing to stands or accept the male at the time of oestrum.-
- It helps in maintaining the accurate breeding and cawing records.
- It increases the rate of conception.
- Old, heavy and injured sires can be used.
- Improving production traits in cattle operation;
- When combined with estrus synchronization, a shorter calving season can be achieved, resulting in a more consistent, uniform calf crop.
- For the commercial cattleman, this could mean increased weaning weights, improved post-weaning performance, enhanced carcass value and more productive replacement heifers.
DISADVANTAGES OF ARTIFICIAL INSEMINATION
- It can be more laborious and additional the cost of implementing a program.
- Requires well-trained operations and special equipment.
- Requires more time than natural services.
- Necessitates the knowledge of the structure and function of reproduction on the part of operator.
- Improper cleaning of instruments and in sanitary conditions may lead to lower fertility.
- Market for bulls will be reduced, while that for superior bull is increased.
- Male animals instinctively detect the females that are in the correct status for conception.
- With artificial insemination the detection work falls on the responsibility of the farmer. Poor detection results in decreased rates of fertility.
- Increasing the number of offspring per male has selective advantages only if the best males can be accurately determined. Otherwise this process only decreases the genetic variability in a population. Increasing the number of offspring per male always reduces the gene pool. The benefits of more intense selection must be balanced against the negative effects of decreased variation.
- Typically, an AI program would require more intensive management of the cowherd. To be successful, a producer should have a sound nutrition program (cows in good body condition), good records, an effective herd health program, adequate working facilities, accurate estrus detection and a well-trained AI technician. Poor management in one or more of these areas could result in lower success rates.
- The cost of implementing an AI program can be variable, depending on the method of estrus synchronization used, cost of semen and whether an AI technician is hired or the producer performs the inseminations. Recent studies indicate that several estrus synchronization/AI programs cost less than natural service, especially with the increased costs of bull replacement and bull maintenance.
- In the past, the greatest demand on time and labour came from “heat” detection. However, new estrus synchronization protocols allow producers to successfully inseminate cows at a predetermined, fixed time, resulting in pregnancy rates similar to those achieved with estrus detection. This eliminates the need to “heat” detect.
1 Deepak Mehta and 2. Divya Sethi
1 Veterinary Surgeon, Department of Animal Husbandry and Dairying, Haryana
2 Research Scholar Department of Foods and Nutrition, I.C. College of Home Science,
Chaudhary Charan Singh Haryana Agricultural University, Hisar, Haryana