FEMALE REPRODUCTIVE TRACT
Sexual
Maturity and Ovulation
Eggs or ova form in the ovary, developing from sex cells called oogonia.
At the time of sexual maturity, these cells stop dividing and develop
into primary oocytes.
This is usually about 5 to 8 months of age.
This is the beginning of the estrous cycle.
The estrous cycle of the pig is not dependent on feeding such as in the
cow. The gilt will begin to cycle at about five months of age.
The estrous cycle lasts an average of 21 days with an average of 48 hours
of “standing heat” and the female ovulates between 10 and 25 eggs.
The actual ovulation is between 36 and 48 hours after the onset of dead
standing heat in the female. When the sow and/or the gilt go “out of heat,”
it is not advised to try to inseminate then, for it is too late.
The single most important factor in a successful artificial insemination
program is heat detection. This
factor cannot be stressed enough. Plain
and simple heat detection is the difference between the most successful and
least successful programs. When
trouble shooting problems time after time heat detection and timing are the
problem. Sows must be checked for heat morning and night during the
days when they are expected to be cycling.
After a female is detected in heat the following insemination times are
recommended:
Sows
24 and 36 hours
Gilts
12 and 24 hours
Two inseminations are recommended because studies show as much as a 20% increase in conception rates with two services instead of one. An increase in number born alive is also noted. If conception rates are good but number born alive is lower than naturally serviced sows, then try increasing the insemination times. Many people inseminate too early because they are afraid they will miss the sow and she will go out of heat but with good heat detection and a solid knowledge of your herd, you can wait comfortably until the correct time. Your herd may vary from the normal, and fine tuning on your part may be necessary.
Heat Detection
Sows weaned from three to six weeks should start their heat period within 4 to 7 days after the baby pigs are removed. This is an excellent time to breed sows because of natural heat synchronization.
Estrus Pattern
The broad pattern of estrus or heat is always the same
Indications of heat sometimes starts 4 days ahead, especially gilts.
Some indications are:
Swelling of vulva
Nosing and smelling
Attempting to ride
Roaring noises
Aggressive behavior
Heat Check
Check sows or gilts twice a day, morning and evening ---- not at feeding time or during a lot of activity
Have a boar in a pen next to the gilts or sow to be bred.
Use boar if possible to check for standing heat.
Insemination
Swine AI methods are easier than the procedure for cattle because of the anatomical differences between the species. The method can be easily learned with a little determination and practice.
The essential equipment needed is an insemination catheter. The Golden Pig and Blue Foam are popular foam catheters on the market. Spirettes include the steriizable Melrose and the disposable Melrose. There is also the small plastic pipette that has 30 degree angle 3/4" from end.
Stimulate sow or gilt throughout insemination, keeping her attention on mating by using combination of back pressure, rubbing her underline, using your knee gently on her side, and communicating with a boar. Stimulation will also occur with the insemination itself.
Due to the length of the horns of the uterus, it is necessary that the proper uterine contractions be present for fertilization of the eggs. This can be achieved if the sow is aware th she is being bred and is best accomplished by the presence of a boar or a herdsman using tender loving care to stimulate the sow.
Keep activities that may be upsetting to the animals as limited as possible.
Puberty - Estrus and Ovulation
| Age at puberty | Age at puberty |
| Age at puberty | Age at puberty |
| Duration of Estrus | 1 - 5 days (2 day avg.) |
| Interval of Estrus | 16 - 25 days (21 day avg.) |
| Weaning to Estrus | 3 - 8 days (5 day avg.) |
| Time of ovulation | 36 - 48 hours (from onset of estrus |
| Eggs produced - gilts | 10 - 15 |
| Eggs produced - sows | 18 - 25 |
Faulty heat detection methods - not checking twice a day - checking at feeding time or during movement of pigs
Hot weather tress - Temperatures above 85 degrees F.- high humidity
Silent heat - ovulation occurs with no visible signs of heat
Sickness - disease - fever
Nutritional - lack of protein or energy
Social tress - fighting overcrowding, etc.
Instructions for fresh boar semen
Storage and Usage
Keep bottles in Styrofoam contqiner and store in a place that holds the temperature at about 60 degrees to 64 degrees F ( 16 degrees to 18 degrees C). A basement or other underground storage usually stays in an acceptable temperature range. DO NOT GET TOO COLD! Small, efficient electrical coolers such as our "Cold Hold" are available for constant temperature storage. Semen will settle to bottom, therefore it needs to be put back in solution by slowly rotating (mix) the bottkle of semen genly twice daily during the storage period.
Life Expectancy
This semen is normally useful for three to seven days when properly rotated and stored at the recommended temperature.
Insemination Procedure
Observe sows for heat morning and night, preferably not at feeding time. Sows should be inseminated with fresh semen the first 12 to 24 hours after standing heat is observed and the second time 12 to 24 hours later.
During cold weather, keep the liquid semen in a warm container during transport from the storage place to the site of insemination.
Sows and gilts may stand better uring insemination if you moe a boar into the adjacent pen just before insemination.
Infertility Checklist
File this sheet of questions where you can find it, then if you have or suspect trouble with fertility in your herd, answer the following questions on a separate sheet for you benefit first and for whomever you go to for help
Females
Are you hand-breeding, pen-breeding, or using artificial insemination?
Are you confinement-breeding or pasture-mating?
Are they pregnant?
If they are not pregnant, are they cycling regularly?
Are there boar in close proximity to the cycling females?
How do you check for heat?
When are you breeding in relation to the onset of standing heat?
Do you mate each female to one or to boars?
If you are pen-mating, how many females do you put with each boar an are the boars rotated?
What is you average litter size for gilts and sows?
What is the average number of stillborn pgs and mummies per litter?
Have any females been sick, if so , in what way and when?
Do you have the records needed to answer these questions?
Males
Was the boar raised in total isolation, with other boars, or in contact with gilts and boars?
Has the boar had a semen check to see if sperm are present?
How many females had the boar settled this breeding period and last?
How many females are you expecting the boar to cover in three weeks' time?
Have you actually observed the boar attain coupling with a female?
Have the boars been exposed to temperatures above 90 degrees F three days or more, or had a rectal temperature of 102 degrees F or more within the last three months?
Does he have any physical impairments that reduce his ability to coup0le successfully, i.e. inability to maintain an erection, penis ties, malformed penis, abnormal growth on penis, etc.?
Has he developed any bad habits such as backing away while attempting to mate?
If a new boar, id you get him from a farm, sale barn, or show sale?
How long was the new boar allowed to rest on your farm before starting to use him?