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Cows and Goats - Artificial insemination (AI)
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Introduction
Is AI for you?
AI is short for artificial insemination. In AI, frozen semen from a sire (buck or bull) is defrosted and inserted into the cervix of a dam (doe or cow) in heat. Animals conceived by AI look and act just like other animals. It is a main means of achieving genetic improvements provided that the semen is of known origin, has undergone performance testing and is of good quality when used. It is not necessary for a small holder farmer to purchase the necessary equipment and learn how to do AI as this would be quite expensive. In Kenya, there are certified AI practioners in almost all regions of the country.
Advantages of AI over natural breeding
There are several advantages of using AI over natural breeding. This includes:
- It eliminates the necessity of keeping one or several bulls/bucks on the farm (depending on herd size). Costs of feeding, housing, separate fencing and labor are eliminated. However, heat detection may be more difficult in the absence of a bull/buck.
- AI can increase the rate of genetic improvement in a herd, as long as superior bulls/bucks are consistently selected. In natural service, the prospective breeder has only the male's pedigree to rely on, whereas AI males should be progeny tested for their transmitting ability of milk and fat percentage, weight gain, type conformation, etc.
- AI allows breeding of different portions of the herd to different males. Young females may be bred to not yet proven but high potential males, while the majority of the herd can be bred to proven high quality males.
- AI permits breeding of many females on one day when synchronization is practiced. No long drives to top males are involved.
- The danger of transmission of diseases or parasites is greatly reduced.
- The time of breeding can be more carefully regulated, and the owner knows exactly when the female was bred, as opposed to pasture servicing by a male that is allowed to run with the herd
- AI induces good recordkeeping of dates of heat, breeding, pedigrees, etc. This will aid in herd improvements and enable the owner to make better culling decisions.
AI in cattle
When can we use AI on cattle?
1.) A heifer is ready for service at 14-18 months2.) Cows resume heat 38th to 42nd day after calving
3.) It is recommended to serve a cow 60 to 90 days after calving
Gestation period is 9.5 months
Calving Interval: Aim at a calf per year per cow
Calving Interval: Aim at a calf per year per cow
Heifers
Most important is how early a cow reaches puberty and what happens next. Puberty in females is defined as the age at the first expressed estrous with ovulation - It should not be considered sexual maturity.
If animals are bred at puberty, a high percentage will have difficulty giving birth. Dairy cows reach puberty at 35% to 45% of their mature weight.
First breeding is only recommended when they are about 55% of their mature weight. (to see how to measure a cows weight with a tape measure please link to Animal Nutrition(link Please))
Age at pubety is affected by both genetic and environmental factors. Genetic factors can be seen by comparing of breeds within a species. Average age at puberty
- European-type dairy cows, 8 to 11 months
- European-type beef cows 10 to 15 months
- Zebu-type cows 17 to 27 months.
Weight at puberty for breeds within a given species depended on the mature size of the breed in question. Jerseys reach puberty at about 8 months and 160 kg, while for Holsteins it's 11months - at optimal feeding regimes.
Environmental factors affecting age at puberty:
- Feeding regimes. A Holstein heifer on a recommeded level of nutrition will reach puberty at about 11 months of age, but if raised from birth on 62% of the recommended level of energy, she will be over 20 months of age at puberty. Feeding above recommeded levels will result in earlier puberty. Holstein heifers fed at 146% of the recommeded level reached puberty at an average of 9.2 months of age as compared to 11 months for controls receiving the recommeded diet. Both problems associated with overconditioning and the extra cost of such a diet make overfeeding undersirable.
- High environmental temperature delays puberty.
- Poor health and poor sanitation in rearing facilities. While adverse environments delay puberty and reduce the mature size of animals, weight at puberty is not greatly affected
Heat detection & timing in cows
Heat occurs during estrous. Estrous is defined as the period of time when the female is receptive to the male and will stand for mating accurate heat detection is the key to a successful artificial insemination program. If you can't catch the cow in heat, it doesn't matter how good the semen is, how careful your thawing procedure, or how skillful your insemination technique. In the figure below, estrous heat occurs approximately 16days after estrous when there is a spike in LH, prolactin and estrogens and a reduction in progesterone.
Hormonal changes in the peripheral plasma during the estrous cycle of the cow. |
NB: The heat period lasts for about 36 hours starting when a cow will let another mount as per drawing below. Optimal serve time is 8 hours after first heat signs. Time between one heat and the next is 21 days on average
Primary signs of a cow on heat:
- Restlessness
- Mounting other cows or standing still while being mounted by other cows
- Clear discharge from vulva
- Drop in milk yield
- Drop in milk yield
- Dilated and enlarged vulva
To improve the success rate of heat detection, set up a specific schedule for observations. Develop the habit of checking cows at specific times each day. Cows show more signs of heat when other activity is minimal - not at milking or feeding time. Cows should be watched at least three times daily. While times vary from farm to farm, most cows can be caught in heat if observations are made:
- Before the morning milking starts.
- In early afternoon.
- After chores are finished in the evening.
For more intensive management, cows must be identified by an ear tag, number brand or a neck chain. You need a diary where all observations on cows can be noted down
Essentially, successful heat detection begins with understanding one simple fact: there is only one sure sign of heat - a cow stands while other animals mount her. As mentioned earlier, this is known as "standing heat"
Weather changes and temperature extremes can cause cows to exhibit estrus differently (or less noticeably). You can't do much about either of those factors, but you should watch even more carefully at those times. Accuracy of detection increases with frequency of observation, but the twice-a-day routine is practical and produces acceptable results.
The average time a female is in standing heat is about 12 to 18 hours; cows usually ovulate (release the egg for fertilization) 25 to 30 hours after first standing. The life of an egg, once released, is six to 10 hours.
On the other side of the fertilization equation, sperm cells have to be in the reproductive tract for about five to six hours before they are capable of fertilization. So, in an ideal world, insemination should take place six to eight hours before ovulation.
Traditionally, cows and heifers are inseminated about 12 hours after they are first observed standing. Those standing in the morning are bred that night; those standing in the evening are held over and then inseminated first thing the next morning. It works well with the twice-a-day routine established for detection.
Secondary Heat Signs:
When you are detecting for estrous, remember the primary sign is standing heat. There are, however, secondary signs you should know and note. They can appear as early as 48 hours before standing heat.
A cow coming into heat may mount other cows, and she may urinate frequently. She may also lay her head over the backs of her herdmates. Nervousness, walking the fence, bawling, spooking, butting other cows and standing while others are lying down are other possible signs. In addition, a cow coming into heat can be off her feed. She may not let her milk down, and her calf may be protesting. The lips of her vulva can also be red and slightly swollen; she may have watery mucous hanging in strings from her vulva. She may pass a lot of mucous, which is most obvious when she is mounting another cow.
Cows in heat, or about to come into heat, tend to congregate. Because mounting activity increases when more than one cow is in heat, it is not a bad idea to keep a cow in the herd that is standing until it's time for her to be inseminated. If you do that, keep in mind that footing must be good.
When a cow is in heat, she's likely to have mud on her rump and sides, as a result of the cows that have been riding her. For the same reason, the hair on her tail-head can be rough and matted (this will be most noticeable after heat - too late to be effective). Often you will have bull calves in the herd attempting to mount her as well.
After heat, her vaginal mucous will be thick and rubbery; one to three days after heat, you may notice a bloody discharge. This is no indication that she is or is not pregnant; it only means she's been in heat. If you failed to observe heat and see a bloody discharge, write down the cow's number and the date in your notebook so you can pay special attention to her in about 15 days.
The Cow Calendar
In livestock enterprise budgeting, it is a good practice to specify the calender of operations; the calender of operations refers to a detailed scheduling of approximate dates when various operations are performed within the calender year, e.g. dates of calving, dates of breeding, dates of deworming, dates of vaccination, dates of branding, dates of castration, dates of weaning, dates of marketing, dates of turning out animals from one pasture to another, etc.
By using below cow calendar-(obtainable from CAIS) - it is quite easy to work out and note down all the relevant data in a diary so one does not get surprised when a cow comes on heat and can help determine when will be a good idea to check the cow for signs of heat.:
Cow Calender |
A cow calendar as the above (sourced from CAIS Kenya - Central Artificial Insemination Station) is a very useful tool in estimating calving dates of cows. The cow calendar consist of two separate but connected discs, the lower disc displaying the days of the year and the upper disc the interval between service date, repeat heat cycles, and calving date. It also shows when a cow should be dried and steamed up (stop milking and start feeding to prepare for normal calving and highest possible milk production). Such calendars can be ordered from CAIS Kenya.
The production cycle can be in three forms:
1.) Weaning-to-weaning: Best, since feeding costs and sales are matched
2.) Calving-to-calving: Not good since accounts will not be balanced.
3.) Breeding-to-breeding: Sales and feeding costs will be mismatched.
1.) Weaning-to-weaning: Best, since feeding costs and sales are matched
2.) Calving-to-calving: Not good since accounts will not be balanced.
3.) Breeding-to-breeding: Sales and feeding costs will be mismatched.
Cow reproductive tract
In summary, the reproductive tract of a cow is composed of the vulva, vestibule, vagina, cervix, uterus and ovaries.
Cow reproduction tract |
Reproductive system and associated parts of the urinary system of the cow as it appears in the natural state (top) and excised (bottom)
Artificial Insemination
After detection of heat, there are three options that follow:
1.) Ignore the signs of heat and thus cow won't breed
2.) Introduce bull for natural service
3.) Inseminate the cow with known semen
Semen is expensive and delicate; hence insemination should be done by a trained and seasoned practitioner. There are several techniques of inseminating cows which include:
Vaginal insemination:
Semen deposition at the mouth of cervix: not usable in artificial insemination because of its low conception rate (CR); require much motile sperm/ insemination.
Cervical insemination:
Semen deposition at 2.5 cm of cervix by use of speculum has 10% lower CR compared with recto-vaginal insemination.Speculum size is 2 to 3 cm in diameter and 35 to 40 cm long; made of metal, glass and plastic materials with pen light or head lamp.
Speculum method for inseminating the cow |
The recto-vaginal technique:
Is the most commonly used method of artificially inseminating (AI) cattle. More difficult to learn, but its superior CR makes it the method of choice. Conception rates are lower for the beginner, but as the technique is mastered CR improves. The basic skills required to perform this technique can be obtained with about 3 days practice under professional instruction and supervision from CAIS. Additional proficiency and confidence come with time and practice. Regardless of whether the inseminator is left or right handed, it is recommended that the left hand be used in the rectum to manipulate the reproductive tract and the right hand be used to manipulate the insemination gun. This is because the rumen or stomach of the cow lays on the left side of the abdominal cavity, displacing the reproductive tract slightly to the right. Thus it may be easier to locate and manipulate the tract with the left hand.
Recto-vaginal method for inseminating the cow |
Simply, the farmer can expect the inseminator to go through the following steps:
a) Washing handsb) Putting on a long plastic glove on the left hand and soaping it up for lubrication
c) Insert left hand into the rectum of the cow
d) Grasp cervix with left hand through rectum;
e) Insert inseminating instrument through vagina;
f) Hold cervix by its posterior end with index and middle fingers and thumb, leaving the other two fingers free to help guide the inseminating instrument;
g) Guide the instrument into the opening of cervix and manipulate the cervix in all directions to pass the instrument through cervix;
h) Move the fingers and thumb forward so that the manipulation is taking place just forward to the end of the instrument;
i) Stop the instrument as soon as it reaches the back end of the cervix, and do not withdraw the instrument, especially when the cow urinates;
j) Deposit semen slowly for 5 seconds.
Failure to get pregnant
AI is not successful every time, so it is common to have to repeat the procedure at least once or twice before the cow becomes pregnant. There may also be complications that causes the cow not to get pregnant such as
Common causes of infertility:
- Retained placenta (link to reproductive problems please)
- Poor feeding (also mineral deficiency - link to animal nutrition)
- Breeding diseases (link to reproductive problems please)
- Difficult calving
AI in goats
Management of breeding does
If fed well goats should become ready to breed from the age of 5 months
Puberty and the pregnancy period
Puberty in females is defined as the age they first expressed estrus with ovulation.It should not be considered sexual maturity.If animals are bred at puberty, a high percentage will have difficulty with giving birth. Most breeds of goats will reach puberty when they are 40% to 50% of their mature weight, but breeding is only recommended when they reach about 65% of their mature weight (hopefully around 5 months of age).
The management of the breeding doe is related to 3 separate physiological stages.
1. The dry period (weaning to mating) - approximately 3 months
2. The pregnancy period (mating to kidding) - approximately 5 months
3. The lactation period (kidding to weaning) - until 2 months into next pregnancy
1. The dry period (weaning to mating) - approximately 3 months
2. The pregnancy period (mating to kidding) - approximately 5 months
3. The lactation period (kidding to weaning) - until 2 months into next pregnancy
The dry period
A doe should be dried off milking at approximately 2 months into next pregnancy. To make sure no mastitis develops during drying off time, strip the goat of her milk in the evening and apply 1 tube dry-goat syringe to each teat (if in doubt call the dairy goat association for good advice). The goat should not be milked again, even if the udder appears to fill. She will now be "dried off" in preparation for her next delivery.
Or you can rely on natural drying off: A dairy goat's milk production will drop at approximately 8 weeks after conception and, by approximately 14 weeks, she may dry herself off. During the dry period the doe recovers from the stresses of the previous pregnancy and lactation. The endocrine system is readjusting to the next service period and pregnancy.
The Pregnancy period
The development of the foetus for the first 3 months of pregnancy is a slow process and no appreciable increase in the food requirement is needed. During the last 4 - 6 weeks before kidding however, the growth of the foetus is sufficiently rapid to deplete the food reserves o the doe. Thus the quantity and quality of the feed given over this period should be sufficient to meet the requirements of the foetus as well as those of the dam in preparation for parturition.
She will need more food to keep herself and the unborn kid growing. By the time she is due to kid she should be receiving as much as you would expect her to need as a milker. The last week prior to kidding, add more bran to her mixture.
At 6 weeks before kidding (16 weeks gestation) there will be a softening around the tail. This is because the pelvic bones are softening in preparation for the birth. The udder will start to expand. At the time of kidding the udder will fill rapidly and harden. If the bag becomes too full, and hard, milk must be taken off or she may develop mastitis and the kid may not be able to suckle.
Good feeding during pregnancy produces greater development of udder tissue and ensures a high milk i potential. A higher level of food offered for the last 2 months of pregnancy has the following advantages:
1. Low doe and kid mortality
2. The kids are given a weight advantage at birth
3. Milk flow in the doe is increased causing a greater live weight gain in the kid and thus a heavier live weight of adult stock.
It is emphasised that during this period there should be no drastic changes of feed. Any change must be done gradually in order to allow adaptation. Water and mineral licks should be provided at all times.
1. Low doe and kid mortality
2. The kids are given a weight advantage at birth
3. Milk flow in the doe is increased causing a greater live weight gain in the kid and thus a heavier live weight of adult stock.
It is emphasised that during this period there should be no drastic changes of feed. Any change must be done gradually in order to allow adaptation. Water and mineral licks should be provided at all times.
During this period pregnant does are housed in large pens. Towards the end of pregnancy, individual does can be confined to pens where the kids are born. Where the floor is made of timber or concrete it is advantageous to use hay to make the doe more comfortable.
The Lactation period
It is highly recommended that goats are kept off the ground on slatted floors and not on a concrete floor as they do not drain properly, are uncomfortable and cold (see housing). After weaning, the does can be divided into two or three groups, and fed according to their condition. With small numbers, the animals can be hand fed individually.
All does should, however, be exposed to a rising level of nutrition, a process referred to as flushing in preparation for pregnancy. Flushing stimulates the number of eggs produced, thus increasing the potential for higher kidding percentages.
Doe Reproductive organs and functions
The doe: The reproductive tract of the mature doe consists of several segments. The ovaries are the primary sex organ and produce the ova (eggs) and secrete the female reproductive hormones (i.e. progesterone and estrogen). The oviducts transport the ova to the uterus and are the site of fertilization. The uterus is the site of embryonic implantation and consists of two uterine horns with a common uterine body. The fetus grows and develops in the uterus during gestation. The uterus is closed to the outside by the cervix, a muscular canal consisting of several cervical folds or rings. The exterior portion of the doe reproductive tract is the vagina which is the site of semen deposition during natural mating; it also supplies a fluid environment to support this process during the appropriate stage of the estrous cycle.
Doe's reproductive tract |
How to detect heat in goats
Heat occurs during estrous. Estrous is defined as the period of time when the female is receptive to the male and will stand for mating. Accurate heat detection is the key to a successful artificial insemination program. If you can?t catch the doe in heat, it doesn?t matter how good the semen is, how careful your thawing procedure, or how skillful your insemination technique.
In the figure below, heat occurs approximately 17-21 days after estrous when there is a spike in FSH,LH and estrogens and a reduction in progesterone.
Hormonal changes in the peripheral plasma during the estrous cycle of the doe |
Fertility process 6-28 hours after the onset of heat *
Signs of heat
The one true sign of estrus or heat is when the doe stands still to be mounted by another goat. This is known as "standing heat". Ovulation occurs an average of 30 to 36 hours after a doe first exhibits standing heat. This is the reason that inseminations should be based on observation of standing heat only and not on the secondary signs of heat.The signs of heat are often mistaken and misunderstood. Classic signs such as restlessness, tail twitching, roughened tail head, dirty flanks, swelling around the vulva, vaginal mucus discharge and the mounting of other animals are often thought of as the main signs of heat, but they are in fact only secondary signs of heat. Secondary signs of heat may indicate that the doe will soon exhibit standing heat, is now exhibiting standing heat or has already gone out of heat. Therefore secondary signs of heat are not reliable.
When to Observe
Animals tend to be more sexually active around morning and evening, which also corresponds to the coolest times of the day. The best times to watch are first thing in the morning before feeding and/or milking and late in the evening after milking and/or feeding have occurred.
Additional Information
Just like with cattle, sexually active goats form sexually active groups. For this reason, individual does can be very hard to catch in heat and must be observed more closely. Once you have caught the does in standing heat, the next important step is to write it down! Do not rely on memory. A small pocket notebook is very handy for this purpose. It only takes a few moments to write down the name or number of the doe and this simple task can help avoid costly mistakes later. It is also a good idea to record the heat dates of all does regardless of whether or not you plan to inseminate them. This will help you to establish their estrus cycle lengths (the average is 21 days) and will also allow you to detect abnormalities quickly so as to minimize unproductive days.
Does should not be inseminated based solely on secondary signs of heat. Does should be observed in a place that allows free mingling but also allows observation of all does at the same time. Optimum reproductive performance is dependent on proper nutrition, including mineral nutrition. Deficiencies in trace minerals such as selenium, copper, zinc and manganese can result in lack of libido (silent heats), reduced conception rates, early embryo deaths, and other reproductive failures.
Does should not be inseminated based solely on secondary signs of heat. Does should be observed in a place that allows free mingling but also allows observation of all does at the same time. Optimum reproductive performance is dependent on proper nutrition, including mineral nutrition. Deficiencies in trace minerals such as selenium, copper, zinc and manganese can result in lack of libido (silent heats), reduced conception rates, early embryo deaths, and other reproductive failures.
Where to get quality semen
Quality tested semen is available from a number of institutions in Kenya, giving farmers a chance of getting good service in the field of AI. Direct importation of semen is also possible for the keen breeder, but can be quite costly for a smallholder farmer especially due to the cost of storage. Goat semen is also commercially available but on small scale.
Imported semen is mainly used by cattle farmers who have pure bred cows and keep them for maximum milk yields or breeding of high quality stock for sale. It is usually more expensive and your local AI provider may not have it readily available. Below some contacts in Kenya:
Cattle semen
1. The Central Artificial Insemination Station (CAIS) provides quality bovine (cattle) semen to the Kenyan market at reasonable prices. (www.cais.co.ke)
American Genetics
2. ABS offers semen from American genetics
P.O.Box 76478-00508, Nairobi, Kenya
Ndama Place, Kabarnet Road,
Tel: +254 (20) 3871692
i. +254 (20) 3868088
Mobile: +254 722 692005
P.O.Box 76478-00508, Nairobi, Kenya
Ndama Place, Kabarnet Road,
Tel: +254 (20) 3871692
i. +254 (20) 3868088
Mobile: +254 722 692005
3. CRI
C/o High Chem Veterinary Ltd
Tel +254 (20) 530744
C/o High Chem Veterinary Ltd
Tel +254 (20) 530744
Nordic Genetics (Sweden and Norway)
4. Fleckvieh genetics E.A ltd supply dual purpose semen.
Website: www.fleckviehgeneticsea.com
2nd floor, Mobil Plaza, Muthaiga Road, Nairobi
Mobile: +254 721 095 555
Website: www.fleckviehgeneticsea.com
2nd floor, Mobil Plaza, Muthaiga Road, Nairobi
Mobile: +254 721 095 555
5. Worlwide sires
Longonot Place, Ground floor Kijabe Street,
P.O.Box 7940-00100, Nairobi, Kenya
Tel: +254 (20) 2245313/4
Mobile: +254 722 509906
Email: info@wwsiresea.co.ke
Longonot Place, Ground floor Kijabe Street,
P.O.Box 7940-00100, Nairobi, Kenya
Tel: +254 (20) 2245313/4
Mobile: +254 722 509906
Email: info@wwsiresea.co.ke
6. Super- sires genetics
Mospa Building, Uganda Rd, Eldoret
P.O.Box 1320, Eldoret, Kenya
Tel: +254 (20) 2027173
Mobile: 0720 872 397
Email: info@ssg.co.ke
Mospa Building, Uganda Rd, Eldoret
P.O.Box 1320, Eldoret, Kenya
Tel: +254 (20) 2027173
Mobile: 0720 872 397
Email: info@ssg.co.ke
Goat Semen
a) Dairy Goat Association of Kenya (DGAK)
Email: m.warui@d-gak.org
Mobile: +254 722685348
Please link to http://www.d-gak.org;
Email: m.warui@d-gak.org
Mobile: +254 722685348
Please link to http://www.d-gak.org;
b) Meru Goat Breeders Association (MGBA);
For Both Goats and Cows, Animal Breeding specialist
For Both Goats and Cows, Animal Breeding specialist
c) Jenan Genetics
P.O.Box 17812-00100 Nairobi
Mobile: +254 732921219
P.O.Box 17812-00100 Nairobi
Mobile: +254 732921219
For the AI technician
N: B- please only allow a trained AI practioner to attend your flock to avoid high health risk that may come about if proper steps are not followed.
Materials needed for artificial insemination
The necessary equipment includes a liquid nitrogen tank, "straws" of semen, tweezers (for removing straws from the tank), a straw cutter, (for cutting off the wax plug keeping the semen in the straw), an open ended glass speculum, a small light (to make the cervix visible), a thermos (for holding warm water to defrost the semen), a thermometer (for measuring the temperature of the water), an insemination gun (A thin metal tube with a plunger to push the semen out of the straw) and disposable plastic sheaths (to hold the straw while in the gun).
Care must be taken in working near liquid nitrogen, since it is -361° F and can cause severe cryogenic burns.
The step by step procedure involves:
1. Restrain the animal to be inseminated. There are several things that should be kept in mind when choosing a location for inseminating cattle. Some of these include safety of both the animal and the inseminator, ease of use, and shelter from adverse weather. A gentle pat on the animal's rump or a soft spoken word as the inseminator approaches will help to avoid startling or surprising the cow.
2. Raise the tail with the right hand and gently massage the rectum with the lubricated glove on the left hand. Place the tail on the back side of the left forearm so it will not interfere with the insemination process. Cup the fingers together in a pointed fashion and insert the left hand in the rectum, up to the wrist.
3. Gently wipe the vulva with a paper towel to remove excess manure and debris. Be careful not to apply excessive pressure which may smear or push manure into the vulva and vagina. With the left hand, make a fist and press down directly on top of the vulva. This will spread the vulva lips allowing clear access to insert the gun tip several inches into the vagina before contacting the vaginal walls.
4. Insert the gun at a 30° upward angle to avoid entering the urethral opening and bladder located on the floor of the vagina. With the gun about 6 to 8 inches inside the vagina, raise the rear of the gun to a somewhat level position and slide it forward.
5. To become a successful inseminator, it is very important to always know where the tip of the insemination gun is located. The walls of the vagina consist of thin layered muscle and loose connective tissue. The insemination gun can be easily felt with the left hand in the rectum. As the breeding gun is inserted into the vagina, keep the gloved hand even with the gun tip. Manure in the rectum can often interfere with the inseminator's ability to palpate the cervix and gun tip. However, it is seldom necessary to remove all the manure from the bowel. Instead, keep the open hand flat against the floor of the rectum, allowing the manure to pass over the top of the hand and arm.
6. With the hand in the rectum, the inseminator may notice colon constrictions or "rings" attempting to force the left arm from the cow. To relax these rings, place two fingers through the center of a ring and massage back and forth. The constriction ring will eventually relax, pass over the hand and arm, and the inseminator can continue the palpation process.
7. Because the reproductive tract is freely movable, cows that have strong rectal and abdominal contractions in response to being palpated may actually push their reproductive tract back into the pelvic cavity. This will cause many folds to form in the vagina. In such cases, the insemination gun can get caught in these folds and little or no progress will be made until they are removed. If the cervix can be located, grasp it and gently push it forward. This will straighten the vagina and the gun should pass freely up to the cervix. The inseminator will note a distinct gristly sensation on the gun when it contacts the cervix.
8. The cervix consists of dense connective tissue and muscle and is the primary landmark for inseminating cattle. It has often been described as having the size and consistency of a turkey neck. The size will vary, however, with post partum interval and age of the animal. The cervix usually has three or four annular rings or folds. The opening into the cervix protrudes back into the vagina.
9. In most cows, the cervix will be located on the floor of the pelvic cavity near the anterior (front) end of the pelvis. In older cows, the cervix may rest slightly over the pelvic bone and down into the abdominal cavity.
10. Once the gun is in contact with the external surface of the cervix, the inseminator is ready to begin threading the cervix over the end of the gun. Place the cervix on or over the insemination gun; the gun is not passed through the cervix. Excessive movement or probing with the insemination gun during this step is seldom productive. The key to mastering this step of the insemination process is knowing how to hold and manipulate the cervix and concentrating on doing the work with the hand inside the cow, not the one holding the gun. When the gun first contacts the cervix, the inseminator will usually find that the tip is in the fornix area directly over the top of the opening of the cervix. If this happens, grasp the external opening to the cervix with the thumb on top and forefingers underneath. This closes the fornix at top and bottom. It is also still important to know the location of the gun tip. This is accomplished by contacting the gun tip with the palm and 3rd and 4th fingers of the hand in the rectum. Use the palm and these two fingers to guide the gun tip to the cervical opening located between the thumb and forefingers. With gentle probing, the opening of the cervix should be located. The inseminator will feel the gun slide forward until it contacts the second cervical ring.
11. Maintain gentle but steady forward pressure on the gun and slide the thumb and forefingers just in front of the gun tip and re-grasp the cervix. Because the cervix is composed of dense connective tissue and muscle, it is difficult to clearly distinguish the gun tip when it is located within this structure. However, the inseminator can determine the approximate location by bending the cervix. Using the flexibility of the wrist, gently twist and bend the cervix until the second ring of the cervix slides over the gun tip. Repeat the process until all the rings have been passed over the gun tip. Remember, the cervix is being placed over the gun, not the gun through the cervix. For the most part, gentle forward pressure is all that is necessary and gun movement should be minimal. When all rings of the cervix have been cleared, the gun should slide forward freely with little resistance. Since the uterine wall is very thin, the inseminator will once again be able to feel the tip of the gun.
12. After properly depositing semen, slowly pull the gun from the reproductive tract. Remove the gloved hand from the rectum. Check the gun tip for signs of blood, infection or semen leakage inside the sheath. Make the necessary notes for future reference and for the local veterinarian. Remove the sheath from the gun and hold it in the gloved hand. Check again to see which bull was used. Remove the glove starting at the top of the arm by turning it inside out trapping manure, the sheath, and dirt inside. Dispose of the used glove in a proper receptacle. Wipe the gun clean and dry and return it to the proper storage location.
Information Source Links
- Barbara Rischkowsky & Dafydd Pilling (editors). (2007). The State of the World?s Animal Genetic Resources for Food and Agriculture. FAO Rome.
- Blowey, R.W. (1986). A Veterinary book for dairy farmers: Farming press limited Wharfedale road, Ipswich, Suffolk IPI 4LG
- Central Artificial Insemination Service: http://www.cais.co.ke
- Force, B. (1999). Where there is no Vet. CTA, Wageningen, The Netherlands. ISBN 978-0333-58899-4.