1. Female's progesterone level. The female's progesterone level ranges between 0 at the beginning of her season/cycle and 65 at the end of her season/cycle. Ovulation of the egg occurs when the progesterone level is 5.0. The egg needs 2 days to mature before fertilization can occur.
2. Type of breeding. There are 4 types of breedings that can take place. 1. Natural breeding between the male and female. 2. Artificial insemination using fresh semen collected and inserted into the female's vagina immediately after collection usually done by the vet. 3. Chilled semen usually shipped to the vet office that is qualified to do either or both a trans cervical insemination or surgical insemination by placing the semen where the fallopian tubes meet the uterus. Chilled semen last 24 to 72 hours. 4. Frozen semen usually the vet performs the surgical insemination by placing the semen directly in the uterus (recommended) within 12 to 24 hours after collection.
Thus, you see the timing of ovulation receptive to fertilization and longevity of the semen based upon the type of breeding influence a successful pregnancy or not.
Your female who should be at least 2 years of age in accordance with various German shepherd club standards. Equally important is the good health of the female. She should be examined by your vet to determine that she is in good health particularly if she did not conceive at a prior breeding. The following test should be done to rule our underlying causes that could prevent pregnancy: culture and sensitivity, thyroid, lyme disease, mycoplasma, and brucellosis. The vet can treat any positive results in time to have a healthy female in time for her season.
Next, you should decide on the type of breeding from above that you will use that is usually dictated by the availability of where the male is located because the viability of the sperm is anywhere from as little as 12 hours to 7 days based upon the type of breeding. Additionally, the sperm requires approximately 7 hours after ejaculation to "capacitate" in order to fertilize the egg.
Next, you should start progesterone testing on the 1st day you notice her show (blood) to determine where she is in her season/cycle, and count that as day 1 depending on the progesterone level normally less than 0.1. Her progesterone level usually will start low, e.g. less than 0.1 and than slowly rise and than advance rapidly after 2.5. So it is important to test daily after 2.5 or at least 2 days later in order to identify when her level reaches 5.0. The 5.0 level can be extropolated from my spreadsheet/chart to clearly identify when her progesterone level was 5.0. I recommend using a vet's office that can provide the progesterone results the same day or within 24 hours of the blood draw for testing. Obviously, timing becomes important once the progesterone level reaches 2.5 or higher. Remember the egg requires 2 days to mature before fertilization can take place, so this is your buffer to still have a successful breeding should the progesterone level surge past 5.0, but you will need my recommendation for timing based upon the type of breeding in order to maximize your opportunity for a successful pregnancy.
Next, having determine when her progesterone level was 5.0 you should have already determined the type of breeding to be done, arranged with the vet if the vet's services are required, and arranged with the owner of the sire should chilled or frozen semen shipment be chosen. My spreadsheet/chart will identify the optimum number of days after her extropolated progesterone level of 5.0 occurred and the best time to breed based on the type of breeding chosen.
To use the spreadsheet/chart you will need Microsoft excel normally available on all computers. It is simple to use. You fill in the dates and data to determine when the progesterone level crosses the 5.0 line.
Using this information should provide the greatest opportunity for pregnancy and maximum litter size (based on the age of the female, e.g. younger females usually have larger litter than much older females.) To support the predictability of the spreadsheet/chart, it was even used successfully to produce a litter of 9 puppies by a 7 year old female using frozen semen from a great champion sire that had been frozen for 20 years!
If interested, you can receive the spreadsheet/chart and my recommendation for timing of breeding based on the type of breeding for only $30 dollars. You can pay by PayPal (send as a friend) to receive this valuable information tool. The PayPal icon is at the bottom of my "Home" page. Please send me an email at firstname.lastname@example.org in order that I can send you this valuable information to assist/improve your breeding. Start using this information now for the one time fee and enjoy continued successful breeding. I will be available for any assistance.