You can use your own currently running mares in a breeding but they have to be at least 5 years old... however for an extra cost you can push the envelope and use a 4yr old mare to breed. You can also use a retired mare to breed... either your own (which is cheaper) or there are some mares that anyone can use for a slightly higher cost... these are so marked as stated on the retired horse's page. You can breed a 2yr old or a 3yr old. However, if you breed a 3yr old using a currently running 5yr old mare you will have to pay an extra fee because, once again you are pushing the envelope... it's the same idea as trying to breed a 2yr old using a 4yr old currently running mare. In the case of breeding a 3yr old, therefore, you must use a mare 6yrs or older to not incur a higher fee.
The benefit is... yes... it is cheaper to breed using your own mares.
For specifics check this out...
Breeding
To breed a new horse, you must have enough bps to pay for the breeding you desire. You can breed a horse using an existing horse’s pedigree, using a retired mare, or you may breed from scratch.
However you choose to breed a horse, you will have to pay the full cost of the sire of the new horse. The cost and the ID number of available sires can be found using the Horse Ticker. To use the horse ticker:
Click on Breeding
Click on Horse Ticker
Enter the name of the sire you are interested in
The computer will return a list of the first 10 horses matching the information you entered. The chart will show the horse’s ID number, complete name, and the current cost to use the sire, as well as the cost in 6, 12, and 24 hours. If breeding has not yet started for a particular sire, the chart will show
instead of an amount and the approximate number of hours until the sire is available. The mose expensive sires will start around 500 points and decrease through the week based on the number of runners by them which already exist in the game and their quality as a sire.
If you want to use a horse without waiting for it to begin breeding for the week, it will cost 1000 points.
The last column will indicate whether a sire is available for use as a credit breeding. A sire may be used for a credit breeding only once per week, regardless of position in the pedigree. If that horse has been used this week, you must wait until next week to use it for a breeding from credits.
Note: You may breed to an existing mare or a retired mare using credits, even if the horses in her pedigree have already been used for a credit breeding.
Breeding Using an Existing Horse
If you wish, you can use an existing horse’s pedigree to create a new horse. Horses bred in this way will take on some of the characteristics of the parent. A well bred horse that has performed well on the track is most likely to produce an offspring that will run well. A well bred horse that has not performed well is less likely to produce a successful runner.
Breeding
When you breed a horse, you will need to enter a name for it. The game does not allow multiple horses to have the same name, so you may want to check at Coker’s Utilities to see if the name you want to use has been taken. If the name you enter has already been taken, the computer will add a II or too or again, to the end of it. This can turn out some odd names, so it is always worthwhile to try to avoid duplicating names.
To breed this way,enter the ID number of the horse whose pedigree you wish to use in "ID of Horse to Eliminate" field and check the box "Use Eliminated Horse." Enter the number of the sire you wish to use and a name for the horse in both fields if you do not want to choose the gender of the offpsring. If you want to choose the gender, enter a name on only one line. Click "Submit form."
The next screen will show the names you have chosen and the name of the horse you are eliminating. Next to "Use Horse For Breeding" it should say Yes. It will also show the age of the horse to be bred, either 2 or 3.
Below that will be box showing the pedigree of the horse that you are creating. The first line will show the sire you chose, how much it will cost to use that sire, and the number of breedings still available for the sire this week. Below that will be the pedigree information from the horse you are eliminating. Note that there will be no cost or breedings available shown. This is because cost of the breeding is determined by the horse you are using, and this breeding will not count against the breedings available for these sires.
Cost
The costs for breeding to an existing horse are determined by the age, gender, and number of races the horse has run. The horse's pedigree has no affect on the cost to breed using an existing horse. An expensive pedigree will not cost more and an inexpensive pedigree will not cost less. The costs for breeding are:
Using a female: 50 bps (will change to the cost of the sire / 2, with a 25 point minimum and a 150 point maximum starting week 2328 - the week of December 4th, 2004)
Using a male: 125 bps (will change to 250 points starting week 2328 - the week of December 4th, 2004)
Breeding a 2 year old using a 5 year old existing horse with 6 or more starts: no extra charge
Breeding a 3 year old using a 6 year old existing horse with 6 or more starts: no extra charge
Pushing the envelope - Breeding a 2 year old using a 4 year old existing horse: 250 bps
Pushing the envelope - Breeding a 3 year old using a 5 year old existing horse: 250 bps
Using a horse with fewer than 6 starts: 100 bps
The cost of the sire of the new horse will be added to these charges. For example:
You want to breed a 2 year old sired by Thunder Gulch using the pedigree of an existing horse in your stable. The horse is a 6 year old mare with more than six starts. Thunder Gulch currently costs 225. Breeding this horse will cost you:
50 points (using a female) + Thunder Gulch’s cost of 225 = 275bps.
If the horse you wanted to use was a 4 year old male with only 4 starts, the cost would be:
125 (breeding with a male) + 250 (pushing the envelope) + 100 (fewer than 6 starts) + 225 = 700 bps
Note: If the horse you use for breeding is a mare 5 years old or more, she will not be eligible for breeding as a retired mare until the following year.
Breeding using a retired mare
Starting in week 1971, retired mares will be available for breeding. When breeding to a retired mare, you must always add a new horse to your stable; you cannot breed over an existing horse. You must have room in your stable for the new horse (have 9 horses or fewer) at the beginning and end of the week. You can only add one horse to your stable per week, this includes horses bred from scratch as well as horses bred using a retired mare.
What mares can be used for breeding?
the mares must be a female, retired male horses are not available for breeding
the mare must be 5 year olds or older
the mare cannot have been used for breeding this year
you must be listed as a Previous Active Owner
There are two exceptions to the Previous active owner rule:
If there are no Previous Active Owners, the horse can be bred by anyone for an additional 100 points
If it is the year 2004 or later and it is October through December, anyone can breed to a mare that has not been bred during the current year, regardless of whether or not they are listed as a Previous Active Owner, for an additional 250 points.
Breeding
To breed to a retired mare:
Go to the Breeding link
Go to the Retired Horses link
Use the form to find the horse you want to use as a mare
Click on the horse
Note: The historic grade of the mare is not directly factored into the ability of the of the offspring. The grade is a reflection of the mare’s on track performance and is useful as a searching tool but may not reflect the mare’s actual ability. If a mare is retired before being given the opportunity to run in a graded stakes, for example, she may have been a better racehorse than this grade indicates. It is the mare’s actual ability that is a factor in the ability of the offspring.
At this point you will see one of three things beneath the list of the previous active owners:
a button allowing you to breed to the mare,
a message that a breeding to the mare is pending, or
a message that your stable is not yet eligible to breed to the mare or that the mare has already been used for breeding
If you get a message that a breeding is pending, this means that someone has already used the mare for breeding this week. The mare will probably produce the offspring the following week and no more breedings will be allowed for the year.
If the message states that you are not eligible to breed to the mare or the mare has already been used for breeding, then the mare has either already produced a runner this year (which can be validated by checking under its Progeny section) or the stable you are logged into was not a previous active owner and it is not yet October (of 2004 or later).
If you are able to breed to the mare, clicking on the button will take you to a screen asking you to enter a name for the foal, both male and female, and the sire ID to breed to. There may also be one or two black boxes near the top of the screen telling you that breeding has not begun for the week or that breeding to the particular mare you have chosen has not begun for the week. The box will give you an estimated time that the breeding will begin.
Note: You cannot choose the sex of the horse by leaving a box blank.
When you breed a horse, you will need to enter a name for it. The game does not allow multiple horses to have the same name, so you may want to check at Coker’s Utilities to see if the name you want to use has been taken. If the name you enter has already been taken, the computer will add a II or too or again, to the end of it. This can turn out some odd names, so it is always worthwhile to try to avoid duplicating names.
After filling out the form, click the "enter" button. The following screen will give you information on whether or not the breeding you entered will be allowed to take place. If there is an error in the breeding, it will tell you what is wrong (for example: sire already used too many times, duplicat horse name, etc). If everything is good, you will be given the cost and a confirmation button.
Once you confirm the breeding, you will be given a final confirmation on if the breeding was able to take place. (There is a chance that someone else bred to the mare while you were waiting to confirm). If you are given the final confirmation, the mare will be changed to Pending status. As long as you have room to create a horse at the week’s end and enough points/credits to allow the breeding, you will be given the offspring of the horse on the following Sunday.
Note: Mares are available to Previous Active Owners on a first com, first serve basis. All the Previous Active Owners have an equal chance to use a mare.
Note: All breedings to retired mares produce 2 year old offspring. You cannot produce a 3 year old.
Cost
When breeding to a retired mare, the cost is the entire cost of the sire, plus half the cost of the mare’s sire, plus one-quarter of the cost of the mare’s dam’s sire. This half of what it would cost for the dam’s sire and dam’s dam’s sire if you were breeding a horse from scratch. For example:
You want to breed to a mare whose sire is Theatrical(IRE) and dam’s sire is Red Ransom. Theatrical(IRE) costs 320 and Red Ransom costs 280. The sire you have chosen is Galileo, who currently costs 275. The cost of the foal would be:
275 + 320/2 + 280/4 = 275 + 160 + 45 = 480
Breeding the same horse from scratch would cost 735 points.
Note: The minimum cost for breeding to a retired mare is 100 points.
Breeding from Scratch
If you breed a horse from scratch, you can eliminate a horse of any age or gender to create a new one at no extra cost. You must own the horse you choose to eliminate and it must not be in the auction. If you wish to breed a horse without eliminating one from your stable, you will have to pay an extra 50 bps.
To find out how much a sire costs, you can check the horse ticker. Enter all or part of the name of the horse you want to use as a sire, and the computer will list the first ten horses that match that name. The current cost of the horse is shown in the left column. The other columns show how much the horse will cost to use if you wait for a while before breeding. The number shown in the ticker is how much it will cost to use a horse as either sire or dam’s sire. The cost of using a sire as dam’s dam’s sire is half the amount shown on the ticker, rounded down. For example: you want to breed a horse with the lineage Real Quiet x Storm Cat x Seattle Slew. Real Quiet is currently 108, Storm Cat is 130, and Seattle Slew is 141. The cost to breed a horse with this lineage is:
108 + 130 + 141/2 = 108 + 130 + 70 = 308 bps
When breeding a horse, you will need to enter the number of the sires you are using. This is the number to the left of the horse’s name.
Note: If you retire a mare 5 years old or older by eliminating it from your stable without using it for breeding, it will be treated like any other retired mare. Previous owners could breed to that mare as early as the following week. If it is October-December or 2004 or later, any player can breed using the mare. If you want to breed to a mare that you are retiring, you should do so directly by breeding to an existing horse instead of trying to come back and breed later.
Bargain Breds
If the horse you create costs less than 100 points to breed, whether breeding from scratch or using an existing horse’s pedigree, it is a "bargain bred." The cost of breeding this horse will be halved, to a minimum of 25 points.
For example: You want to breed a horse with the lineage of Cash Attack x Night Club x Smooth Stuff. The total cost would be
12 bps (Cash Attack) + 29 bps (Night Club) + 22/2 bps (Smooth Stuff) = 12 + 29 + 11 = 52 /2 = 26 bps
If the cost was even lower, the breeding would be:
2 bps (Cash Attack) + 9 bps (Night Club) + 11/2 (Smooth Stuff) = 2 + 9 + 5 = 16/2 (bargain breeding) = 8 bps Because the minimum cost to breed a horse is 25 bps, the cost is then adjusted upward to 25 bps.
You may breed only one bargain bred per stable per week. Credits may not be used to create a bargain bred.
Breed Horse
When you breed a horse, you will need to enter a name for it. The game does not allow multiple horses to have the same name, so you may want to check at Coker’s Utilities to see if the name you want to use has been taken. If the name you enter has already been taken, the computer will add a II or too or again, to the end of it. This can turn out some odd names, so it is always worthwhile to try to avoid duplicating names.
If you want to choose the gender of your new horse (only a colt or only a filly), you may do so for an extra 500 bps. To do this, enter the name only on the line of the gender you want your new horse to be, the top line to ensure a colt, the bottom line to ensure a filly.
When you have selected the lineage you want, gotten the numbers of the sires, and chosen a name for the new horse, click on the "Breed Horse" link to bring up the breeding screen. Enter the name of the new horse and the ID number of the horse you are eliminating (if any). Select the age of the new horse (2 year old or 3 year old). If you want to use the pedigree of the horse you are eliminating, check the box to "Use Eliminated Horse," otherwise leave it blank. Then enter the ID numbers for the sire(s) you are using. (If you are using the pedigree of an existing horse, you will only need to enter the sire’s ID, and leave the dam’s sire and dam’s dam’s sire blank). Click on Submit Form.
The next screen will show the name of the horse that will be created, the horse you are eliminating, whether you are using that horse’s pedigree and the age of the horse to be created. Below that will be a box showing the sires you have chosen and their cost.
If all the information you entered makes sense, below that box will be the cost breakdown and the total amount the horse will cost. Sire costs update every 15 minutes, so the cost may be slightly different than what you calculated earlier. This screen will also tell you if you currently have enough bps to create the horse you decide.
You have 15 minutes to accept the breeding you have selected. If you do not act within 15 minutes, the choices will be nullified and you will need to re-enter the information. If you decide to continue and you have enough bps, the horse you chose to eliminate will be removed from your stable along with the bps for the selected breeding and your new horse will appear in your stable. This typically happens on Sunday.
Hope this helps...
Larry 
instead of an amount and the approximate number of hours until the sire is available. The mose expensive sires will start around 500 points and decrease through the week based on the number of runners by them which already exist in the game and their quality as a sire. 