Proper Artificial Insemination Technique in Cattle for Optimum Conception and Pregnancy

Proper Artificial Insemination Technique in Cattle for Optimum Conception and Pregnancy

Artificial insemination (AI) has revolutionized the cattle industry by providing an effective means of breeding to improve genetic traits and increase the reproductive efficiency of cattle herds. When performed with precision and care, AI can yield high conception rates and successful pregnancies. However, achieving optimum results in cattle AI requires a thorough understanding of the process, proper technique, and attention to various factors that influence successful conception and pregnancy. In this comprehensive article, we will delve into the key aspects of AI in cattle, from selecting suitable candidates to the actual insemination process, and highlight the importance of proper technique for achieving successful outcomes.

The artificial insemination is one of the most important reproductive techniques which have been most popular in veterinary practice. The artificial insemination is universally accepted for genetic improvement of the animals especially cows and buffaloes. The recto-vaginal method is most common method to inseminate the cows/buffaloes. This technique brought tremendous improvement in milk production through selection of good quality bulls of high genetic merit for milk production. So, to increase the conception rate, there must be proper knowledge of proper insemination techniques. This chapter provides an idea about proper use of different equipments related to A.I. and proper techniques of insemination for successful conception and pregnancy.

EQUIPMENTS INVOLVED IN ARTIFICIAL INSEMINATION

I) Semen Storage Tank

ü This is made of aluminum body and is a tank within a larger tank suspended over a narrow neck. The space in between the two tanks is a vacuum.

ü Semen Storage tank should not be kept in cemented floor as acid from the floor may corrode the aluminum body and result in microscopic holes that destroys the vacuum and the insulating property of the tank is lost. This type of tank should ideally be kept on a wooden platform.

ü If dew accumulates at the neck of a filled semen storage tank, then it indicates vacuum loss and such a tank should be rejected.

ü Newly purchased semen storage tank should be evaluated for evaporation rate by daily measurement of liquid nitrogen level with a measuring stick.

II) Canisters Canisters are cylindrical stainless steel containers with long handle that hangs from the mouth of the tank. Semen straws are placed in plastic goblets those are kept within the canisters. Generally, six canisters are provided for a semen storage tank. When the semen storage tank is filled with liquid nitrogen these canisters are completely dipped in liquid nitrogen.

III)Frozen Semen Straws These are plastic straws with a factory seal end with two cotton plugs and PVC in between them and a heat seal end that is sealed ultrasonically after the straws are being filled with semen. The straws are filled with extended bovine semen except at the heat seal end where there is an air gap.

IV) Artificial Insemination Gun This is a stainless steel tube with a piston and a barrel. The semen is inserted into the barrel of the gun. One ‘O’ ring is also provided with the gun so as to lock the sheath in it.

V) Artificial Insemination Sheath This is a sterile plastic cover that is put over the metal body of the gun. The sheath has a green or yellow plastic insert that holds the cut end of the straw preventing the semen from back flowing into the gun.

VI) Tweezer Forceps These are long forceps for taking a straw out of the tank.

STEPS IN ARTIFICIAL INSEMINATION

1. Animal Preparation Manure should be removed completely from the rectum of the cow to be inseminated. The tail and the peri-vaginal area should be cleaned thoroughly with water and should be wiped dry.

2. Taking a Frozen Semen Straw out from the Storage Tank The canister holding the straws should be lifted no farther up than the frost line at the neck of the tank and the semen straws should be taken out with the help of tweezer forceps. The frost line is an area at the neck of the tank below which is covered by a layer of frost. This is the danger zone above which there is an abrupt increase in temperature that can result in significant damage to the straws.

3. Thawing After taking a straw out of the tank, it should be dipped in a thermos containing water at 37º C for 30 seconds. After thawing the straw should be taken out of the water and wiped dry with a tissue paper towel. This is important as any contact of the semen with outside water, once the lab seal end of the straw is cut open, may lead to death of the spermatozoa.

4. Loading the AI Gun

ü Before loading the semen straw into the barrel of the AI gun, the piston should be retracted out of the gun the length of the straw. Thawed semen straws should be inserted into the AI gun at the factory seal end (cotton-PVC-cotton).

ü The lab seal end of the straws should be cut with a pair of scissors at right angle to the straw. Deviation from the right angle leads to mis-aligned fit in the sheath resulting in backflow of semen.

ü The cut end of the straw should be fitted nicely into the green/yellow insert of the sheath and then the sheath should be glided gently over the gun, except at the upper end where the ‘O’ ring should pass over the sheath. The split upper end of the sheath should touch the head of the gun and then the ‘O’ ring should be tightened over the split end of the sheath.

ü AI sheath with a plastic cover over them is ideal. These minimize the uterine contamination with vaginal pathogens.

5. Artificial Insemination

ü Once a frozen semen straw is thawed, it should be inseminated within 5 minutes.

ü The cow should be secured firmly in a trevis and one animal attendant should hold the tail away.

ü Well lubricated gloved hand should be inserted into the rectum and the cervix should be held firmly.

ü Then the loaded gun should be inserted through the vulva in an upward direction to prevent it from entering the urethral orifice.

ü After the gun passes through the vestibule it should be held horizontally and the cervix should be pull forward with the rectal hand so as to straighten the vaginal folds should the gun lodge in these folds

ü Once the gun reaches the cervix, the protective thin plastic cover over the sheath should be pulled back and the posterior end of the cervix should be held firmly with the rectal hand so as to obliterate the blind pouch ‘fornix vagina’ thus ensuring that the gun enters the internal os cervix.

ü The cervix is a cartilaginous structure at the neck of the uterus that contains three to five annular rings. As the gun enters the os cervix and passes through the first ring, a gritty sensation can be felt.

ü At this stage the cervix should be moved in all directions so as to enable it to glide it over the gun. Too much force should not be applied on the gun as the idea is to glide the cervix over the gun and not to push the gun through the cervix.

ü If too much forced is applied on the gun there is every possibility to slip through the cervical annular ring and forcefully tear the uterine wall, thus jeopardizing the life of the animal.

ü Once the gun passes through the cervix, it should be advanced no farther than the body of the uterus and this can be checked by palpation with the index finger.

ü Finally, the semen should be deposited at the body of uterus by pressing the piston of the AI gun.

ü Once the insemination is completed it is good practice to massage the clitoris as it enhances the conception rate. Measurement of Liquid Nitrogen Level in the Semen Storage Tank This is performed by a plastic or wooden meter scale. The scale is first dipped completely to the bottom of the storage tank and kept for two minutes. It is then taken out and gently swung in the air. This results in a white frost line to develop in the scale. The upper level of the frost line denotes the level of liquid nitrogen in the storage tank. Ideally frozen semen straws should be completely dipped in liquid nitrogen. Therefore, the liquid nitrogen level in the tank should be checked periodically.

Selection of Candidates

Before delving into the AI technique, it is essential to choose suitable candidates for artificial insemination. Proper selection is crucial for optimizing the chances of conception and a successful pregnancy.

Considerations for Selection

1. Breeding Goals: Determine the breeding objectives and goals. AI is particularly useful for improving genetic traits, so choose candidates whose genetic lineage aligns with these objectives.
2. Age and Health: Select animals that are in good health and within the appropriate age range for AI. Young heifers are generally more fertile, while older cows may have a reduced conception rate.
3. Reproductive Health: Ensure that candidates are free from reproductive health issues, such as uterine infections, as these can hinder conception.
4. Estrus Synchronization: Estrus synchronization can help optimize the timing of AI. This process involves manipulating the estrous cycle of cattle to facilitate AI when they are most fertile.
5. Sperm Selection and Handling

The quality of sperm and proper handling techniques are pivotal in achieving a successful AI outcome.

Sperm Selection

1. Sperm Quality: Choose high-quality semen from reputable suppliers. Semen should have a high sperm concentration and motility, and a low level of abnormalities.
2. Genetic Traits: Select semen from bulls that possess desirable genetic traits related to the breeding objectives.
3. Semen Handling
4. Thawing Procedure: Follow the recommended thawing procedure provided by the semen supplier. Rapid and uneven thawing can damage sperm cells.
5. Semen Temperature: Maintain the semen at the appropriate temperature throughout the process. Sperm should be kept at a temperature close to the body heat of cattle.
6. Avoid Contamination: Practice strict hygiene to avoid contamination during semen handling. Contaminants can compromise sperm quality and fertility.

III. Estrus Detection

Effective estrus detection is vital to ensure that AI is performed at the most opportune moment during the cow’s reproductive cycle.

Behavioral Signs

1. Mounting Behavior: Observing mounting behavior by the cow, especially when she stands still when mounted by other cows or attempts to mount other cows, is a reliable sign of estrus.
2. Tail Head and Vulvar Swelling: Swelling of the tail head and vulva is a physical sign of estrus.
3. Mucus Discharge: The presence of clear, stringy mucus discharge from the vulva is indicative of estrus.
4. Technological Aids

Various technologies, such as heat detection patches and electronic monitoring systems, are available to assist in estrus detection, making it more efficient and accurate.

AI Technique

Proper technique during the insemination process is crucial for optimizing conception and pregnancy rates.

Equipment Preparation

1. Semen Gun: Ensure that the AI technician uses a clean and properly lubricated semen gun. Lubricants should be sperm-friendly and should not harm sperm cells.
2. Gloves: Wear disposable, sterile gloves to minimize the risk of contamination during the procedure.
3. Speculum: Use a clean, properly sized speculum to gain access to the cow’s cervix.
4. Rectal Palpation

Before AI, a rectal palpation is often performed to confirm the cow’s reproductive status, check for any reproductive abnormalities, and position the cervix correctly.

Insemination Procedure

1. Cervical Insertion: Gently insert the speculum into the cow’s vagina and guide it to the cervix. This should be done carefully to avoid causing injury or stress to the animal.
2. Cervical Manipulation: After reaching the cervix, manipulate it gently with the speculum to locate the cervical opening.
3. Semen Deposition: Once the cervix is properly located, deposit the semen into the uterus using the semen gun. The procedure should be done slowly and steadily to minimize the risk of injury.
4. Post-Insemination Care
5. Uterine Massage: Following insemination, gently massage the uterus to distribute the semen and improve its chances of fertilizing the egg.
6. Rest and Recovery: Ensure that the cow is given adequate rest and access to water and food to aid in post-insemination recovery.
7. Timing and Synchronization

Timing is crucial in AI to ensure that insemination aligns with the cow’s fertile period.

Estrus Synchronization

When using estrus synchronization protocols, it is essential to follow the timing guidelines precisely to optimize the chances of conception.

Timing of Insemination

Insemination should ideally take place during the cow’s peak fertility, which typically occurs 12-18 hours after the onset of estrus.

Pregnancy Diagnosis

Pregnancy diagnosis is a critical step to confirm the success of AI and identify any animals that may need to be re-inseminated.

Timing of Diagnosis

Pregnancy diagnosis can typically be performed around 30-60 days after AI. It can be done through various methods, including rectal palpation, ultrasound, or blood tests.

Repeat Insemination

In cases where pregnancy is not confirmed, a repeat insemination can be scheduled, taking into consideration the cow’s estrous cycle.

VII. Health and Nutrition

Proper health and nutrition management of cattle are crucial in achieving successful conception and maintaining a healthy pregnancy.

1. Nutrition
2. Balanced Diet: Ensure that cattle receive a well-balanced diet that meets their nutritional requirements. Proper nutrition is essential for reproductive health.
3. Adequate Body Condition: Cattle should maintain an appropriate body condition score, as excessive body fat or being underweight can negatively impact reproductive success.
4. Disease Management
5. Vaccinations: Implement a vaccination program to protect cattle from diseases that can affect reproduction, such as brucellosis.
6. Parasite Control: Manage internal and external parasites, as parasitic infestations can affect cattle’s overall health and reproduction.

VIII. Environmental Considerations

The environment in which cattle are raised can also impact their reproductive success.

Housing and Comfort

Ensure that cattle have access to comfortable and clean housing. Stress due to environmental factors can negatively affect fertility.

Climate and Seasonality

Consider the climate and seasonality when planning AI. Cold weather, extreme heat, or adverse weather conditions can influence the success of AI.

Record-Keeping

Maintaining comprehensive records is crucial for tracking the success of AI and the reproductive history of individual animals.

Estrus and AI Records

Accurate records of estrus observations, AI dates, and semen used are essential for monitoring the success of AI.

Pregnancy Records

Keep detailed records of pregnancy diagnosis results, which will help in planning for calving and identifying animals that may need re-insemination.

Ethical Considerations

Responsible AI practices also

In conclusion, the proper knowledge of instruments and their handling related to artificial insemination and A.I. technique is most important to optimize conception/ pregnancy in cows/buffaloes.

Compiled  & Shared by- This paper is a compilation of groupwork provided by the

Team, LITD (Livestock Institute of Training & Development)

 Image-Courtesy-Google

 Reference-On Request.

Proper Artificial Insemination Technique in Cattle for Optimum Conception and Pregnancy

Proper Artificial Insemination Technique in Cattle for Optimum Conception and Pregnancy

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