Two terms to know. Semen and sperm. Semen refers to the entire ejaculate, which contains both sperm and prostatic fluid. Prostatic fluid is made from the prostate gland and this fluid is how sperm is transported. Sperm refers only to the DNA carrying "swimmers" they will swim up stream to the egg to penetrate the egg.
A toy size dog will ejaculate around 300-400 million sperm per ejaculate to fertilize 2-6 eggs of a toy size bitch. Your stud can ejaculate 300-400 million sperm every day for 5 days without a noticeable loss of semen quality or libido. Studies have shown that if a dog is collected daily for 10 to 12 weeks there will a loss of libido. Sperm quality and quantity will begin to decline after 5 to 7 days of daily collections. But even one hour after an ejaculation, the stud will still produce 70 to 80% of the sperm in the first ejaculation. That's still quite a significant number of sperms. Know that the stud is only responsible for the gender of the puppies and not the size of the litter.
Why 400 million sperm to fertize 4 eggs? While sperm are inded determined and driven, they are also easily distracted by objects other than an egg. Just about everything will kill sperm from temperature increase in the testes of a couple degrees over normal bady temperature lasting 2- minutes. This increase of temperature will not kill the manufacture plants in the teses but will kill the sperm that is already there. Sperm will regenerate but it takes up to 6 weeks or so for sperm producing abilities to be at full capacity. Repeating the insult to the testicles over time can cause permanent sterility. Some dogs that have been taken into sterility from blow drying getting ready for a spot in the show ring.
Other cause of increase of temperature.
Fever caused by an illness or infection. Usually the body has protective ways by attempts to save the sperm. The dog will drop
the testicles as far from the heat source as possible. This happens on a hot day. As the body heats up the testicles will lower and lower in an attempt to remove themselves from the body and cool themself.
A good hot bath will cause a body temperature to increase. Show dogs that have a long week end with a couple of good hot baths and long blow drying the rear end may cause your boy to miss when you breed him that week. What to do. Keep water tepid and use your hand to hold the testicles while directing the blow dryer away from the testicles for grooming.
Other killers of sperm.
Water will kill sperm. If there is water inside the syringe used for insemination or inside the bag that collects the sperm will upset the saline/water content of the sperm. Water will be pullled into the sperm cells and the cells will explode. Even using water on the vulva of a bitch prior to breeding will kill some of the sperm.
What to do. Just don't use water before breeding. Use a normal saline solution to clean and rinse your insemination equipment and avoid use of water on the vulva or penis at time of breeding. Lubricants such as K-Y Jelly will kill sperm. It's water based.
Latex will kill sperm. Any touching from a latex glove will casue the death of sperm. Never use an soft latex catheter to do artificial insemination. This will casue the death of thousand of sperm. Make sure you only use equipment that is latex free. Read labels making sure your equipment is latex free. One of the best storage/collection is the Playtex baby bottle inserts. They are clean and very inexpensive. Sperm are very determined in it's efforts to swin up stream to find a large smooth round object(egg). The problem is the sperm will try to penetrate just about any large round object on the way to the eggs. If you place a drop of sperm on a slide you will see them try to penetrate an air bubble.
How do millions of sperm get distracted on the way up stream?
They spend their lifespan trying to penetrate a random red blood cell or a nicely rounded piece of smooth cellular debris.
Some just take a wroung turn and end up in a small fold of vaginal tissue.
It all starts
A puppy will begin to manufacture sperm between 7 months and 1 years old. By the time his is 6 or 7 years old his sperm quality and quantity will decrease somewhat but still can produc puppies until at least the age of 10 years old sometimes even older. His prime time is between 18 months and 6 years old. Very young and very old dogs have poor sperm quality.
The amout of semen ejaculated during a single ejaculation varies between 1 and 75 ccs. Remember semen is the entire ejaculate and contains prosta fluid. The amount of semen is size related so a toy size dog will produce much less than larger breeds. The amount of sperm ejaculated ranges between 1 and 6 ccs. Here' rough breakdown of sperm production in milliliters/cubic centimeters. This is sperm only, not prostatic fluid. Some may produce more and some less.
Body weight and sperm quantity 10-34lbs 2.5 cc 35-40lbs 4.0cc 50-60lbs 5.0cc 60-84lbs 6.0cc
The number of sperm for those sizes is somewhere between 300-400 million on the small dog end to 1.5 billion on the large dog size. There are 3 fractions in every ejaculation. The first fraction is prostatic fluid. It's clear and very small amount, just a few drops. This ejaculaduring the really hard thrusting stages. The second fraction is the sperm and is ejaculated near the end of the thrusting stage and the beginning stage of the tie. These first two fractions do not appear to have any sort of force behind them. They just drip out. The third fractioe prostatic fluid and is ejacjlated during the remainder of the tie. This fraction is ejected during a rhythmic pulsation of the penile tissue the part behind the bulb. For natural breeding you will get and use all three fractions. For collection to do artificial insemination you will not need nor want the third fraction. Once the thrusting has stop allow 3-4 pulsations and then stop the collection.