Advantages of A.I.
· The bull can have more offspring.
· Better genetics because they are known and the offspring is tested (progeny) and measured.
· Availability. The bulls not available to everyone. It’s much cheaper to buy his semen than to buy the bull.
· Small producers can have just as good genetics as the big producers.
· Shorter breeding season. The cows can be given a hormone to bring them into heat in a few days of each other and then they can all get A.I.ed.
· Bigger calves because they are about 10 days older than natural services.
· Shorter calving season because of a condensed breeding season. Tends to have fewer deaths and the owner can stay on top of calving for a couple weeks instead of spreading it out over months.
· Calving ease for the heifers because of sire selection.
· Safety issues for people and cows. Dairy bulls tend to get dangerous and aggressive the older they get. They also can damage cows when they are bred on cement etc.
· Makes for better record keeping and management. You’ll know when to breed, when to dry up, when they’re calving etc.
· More coverage: collect semen from a good bull and preserve his genetics and cover more cows
· Venereal diseases (reproduction diseases) eliminated. Bulls will be hidden carriers and every cow he injects will be infected. She’ll get pregnant but lose her pregnancy the 1st trimester and then breed back late. The bull and the semen will be tested before it is collected and sold.
· Crossbreeding is easier.
· Calf crop is more uniform and born closer together.
· In 60% of dairies they found it cheaper to A.I. Costs of a bull can be bull, feed, pen, damages, vet bills, etc.
· Conception rates are about the same: natural services or A.I.
Disadvantages of A.I.
· Bulls getting their semen sold that have a bad genetic trait; it will spread much faster using A.I.
· Time: human labor is greater, there’s handling of the cows involved, time and skill at pulling heat, and costs.
· You either have to have the skill to do it or hire it done.
· Facilities: corrals, shoots, etc.
· Availability of the cows when in heat: on summer pasture/ in the mountains/ no easy access/ no corrals to get them into.
70% of Dairy cows are bred A.I.
10% of Beef cows are bred A.I. Most of these are heifers because then you can select sires for calving ease.
Better Genetics from A.I.
Pounds of milk per year in Dairy Cows:
4600 lbs.- 30 years later= 9700
9700 lbs.- 30 years later= 18,000
18,000 lbs.- 10 years later= 20,000
20,000 lbs- now= 30,000
Heat Detection
· “Accurate heat detection= higher rate of pregnancy”
· Heat shows that the ovaries are about to release an egg
Signs of heat:
· Standing heat lasts 18 hours
· Most reliable sign is when she’ll stand to be ridden
· More alert
· Swollen and red vulva
· Going off feed
· Frequent urination
· Beller more
· Won’t let their milk down
· Walk a lot- nervous
· Mucous coming out of the vulva
· Bloody mucous means she was just in heat (2-4 days earlier) and you missed it
Cows will get in Sexually Active Groups (S.A.G.) and ride each other.
Best to check cows for heat- early in the morning and late in the evening, 12 hours apart, at least 2x a day, for at least 30 minutes is the recommended time.
Study Statistics: Cows that show heat at various times of the day
6 a.m. - Noon= 22%
Noon- 6 p.m. = 10%
6 p.m. - Midnight= 25%
Midnight- 6 a.m. = 43%
First calf heifers right after they calve are the hardest to get re-bred because they are still trying to finish growing and maturing and then produce milk. Get them in good body condition before they calve and try and keep them there to get them re-bred.
Aids in Heat Detection
· Patches: Estrotect (silver, friction rubs it off), Kamar, Bovine Beacon
· Gomer/ Spotter bulls: bulls that have been castrated can be used for heat detection.
· Chalk on the head of the tail- watch carefully because it rubs off so easy and the cows will lick it off as well.
· Heat Watch: is a computerized system with a pad on the cow so that it signals the computer and keeps track every time the cow is mounted and ridden. Then you know who is in heat. This system is very expensive and high tech.
· Chin Ball Marker: with an ink wall is attached to a spotter bull so that every time he mounts a cow it leaves ink marks on her back.
· Pedometer: is only used on dairies. The cows have a pedometer attached to their leg and it counts their steps. (If they are in heat they tend to walk more). When they enter the milking barn to get milked, their pedometer is read and if they have taken more steps than is normal, the computer sorts them into a pen after they are milked. Then the A.I. crew comes by later to check those cows for heat and breed them if they are ready.
Semen Collection
· Collect semen in an artificial vagina (A.V.). The temperature of the water should be around 115 degrees.
· Check the volume.
· Check the motility- the action and movement of the sperm.
· Morphology- the shape and health of the sperm- needs to be at least 70% good.
· Concentration- the count of sperm
· Calculate Extender
· Extender- milk protein, egg yolk citrate, glucose, antibiotics, pH balance, Glycerol (protects the sperm from the freezing process). Some put caffeine in the extender to “up” the motility rate and action of the sperm.
· Slowly cool down
· Package it in straws
· Freeze it in liquid nitrogen which is -320 degrees Fahrenheit
Half of the sperm will survive the freezing.
They can make 100’s of straws from one semen collection.
They can collect semen 2x a day 2-3x per week.
They test the bulls regularly to keep them disease free. They also try and keep everything clean and disinfected. They even put antibiotics in the semen for any bacteria.
CSS ( certified semen services) means they tested and followed all the regulations.
Semen Storage
· Direct sunlight damages the sperm. Keep and thaw out of the sun.
Semen Tank
· Cost for a new tank is between $700-$900
· A semen tank is a tank inside of a tank. (Double wall tank). In the space between the walls of the tanks, they have created a vacuum and filled it with insulation. The inner tank is filled with liquid nitrogen and the semen straws. Liquid nitrogen is not flammable, fairly cheap, doesn’t react easily, and is a -320 degrees Fahrenheit. But if it’s kept in a tight area it will explode big. Nitrogen is constantly letting off gas and when that’s held in it blows up. Nitrogen is heavier than air so when it gets poured it settles to the ground. But there are gases that rise that can’t be seen. Those gases can suffocate and kill you if you’re in a confined area with them. The lid and stopper on the tank are designed to fit loose so that these gases can escape and not blow the tank up.
· If you puncture the outside of the tank it will ruin the vacuum and fill up with air causing the tank to frost over and the nitrogen to leak out quickly.
What’s on the Straw
· Stud code #: Hoffman- 99; Genex- 1; Accelerated- 14; Select Sires- 7; ABS- 29
· Breed- AN= Angus
· Sire I.D.- 2991
· Sire Registered Name- TC Aberdeen 062
· Registration # (6-8 digits)- 06781239
· Date it was frozen is common on a straw- 4-20-99
Anatomy
· Vulva
· Vagina
· Cervix- the door between the vagina and the uterus.
· Uterine Body
· Uterine Horns
· Oviducts (fallopian tubes)- fertilization takes place here.
· Ovaries
· Corpus Ludeum (C.L.) – After ovulation, Luteal cells grow in the void on the ovary where the follicle was. In the next 5-6 days these cells grow to form the C.L. The C.L. produces the hormone progesterone and it prepares the uterus for pregnancy. It also causes a thick mucus plug to form in the cervix to keep viruses or bacteria from entering the uterus.
· Follicle
·
The Cycle
· Cows cycle every 21days on average (18-24).
· They are in heat for 6-18 hours on average. Some only for 6 hours and some for 24-30.
· An egg ovulates about 25-30 hours after the start of heat.
· A.M. P.M. rule for breeding cows- detect a cow in heat in the morning and then breed her at night or vice versa. There’s also the once a day rule: detect heat either morning or night and then breed 24 hours later (the next morning or night).
· It’s best to inseminate the cow with semen just before she ovulates if possible. That way the sperm will be all ready to penetrate the egg as soon as it drops.
· Egg goes bad about 10 hours after ovulated.
· Sperm life is variable but around 14-30 hours (fresh sperm lasts longer).
· Two to three follicle waves in a cycle. The dominant follicle is the one that ovulates and releases the egg. A shot of Ludalice will kill the C.L. and bring a cow into heat within 3 days depending on where she was at on her follicle wave.
· The day of heat is day 0. A day later she ovulates.
· Estrogen is high and is put out to show signs of heat.
· Progesterone is low during heat
· Virgin Heifers- Age, Weight, and Breed determine when they start cycling.
Hormones
· Progesterone (P4) – is high during the Luteal Phase and low during the Follicular Phase.
· Estrogen (E2) - is high during the Follicular Phase and low during the Luteal Phase.
· Prostaglandin (PGF) - destroys the C.L. so she can come back in heat.
· FSH- follicle stimulating hormone- causes follicles to grow on the ovaries.
· LH- Luteinizing hormone- causes estrogen production in large follicles.
· Sperm lasts approximately 24 hours.
How to A.I.
· Thawing semen- Put in warm water 93- 98 degrees. Leave in water no less than 40 seconds and no more than 15 minutes. Remove straw and quickly dry off before inserting in the insemination gun. (or warm it up in your hand or pocket).
· Insert the insemination gun in through the vulva at an upward angle until you hit the top of the vaginal wall. If you don’t do it at an angle and you accidentally stick it in the urethra, the cow will dance around and act like she’s in pain.
· With your gloved left arm in the rectum of the cow locate the cervix. With your right hand guiding the gun through the vagina and into the cervix. There are blind pockets on each side of the cervix. Make sure you go through the cervix. Don’t move the gun to go through the cervix but try and manipulate and guide the cervix over the gun. Continue through into the uterine body about ¼”-½’’ past the end of the cervix. Insert the semen into the uterine body. Don’t go too far or all the semen will end up in one horn which would be fine but we don’t know which side is releasing the egg.
· Horn breeding- Put half the semen in one horn and the other half in the other horn.
· With Virgin heifers, ½ of a straw of semen is generally just as successful as using a full straw to get them pregnant. So if it’s an expensive bull you’re A.I.ing these heifers with, it would cost half as much too only use half the straw. But don’t use half of a straw and then save the rest. You’ll have to have two heifers in heat ready to get bred right then.
A.I. Success Formula
AxBxCxD= % of cows pregnant
A= % of cows seen in heat and bred
B= % of cows that are fertile
C= % of the fertility of the semen
D= inseminators efficiency and technique
EX- 90x90x90x90= 60%
Average Rates of Conception:
· Beef Cows- 60-70% conception rate (If you get lower than this check your technique and her nutrition). Beef producers will breed a cow twice and if she doesn’t get pregnant they cull her.
· Dairy Cows- 30-40% conception rate. Dairy heifers actually conceive high like beef heifers than drop when they start milking heavy and get thin. Every decade since the 80’s the conception rate has dropped 10%. Probably because genetics have focused on milk production instead of conception rates. Dairy farmers will breed and rebreed (8-12 services) a cow that milks heavy to keep her milking. There’s no selection pressure. Holsteins are the worst. Jerseys are not that bad. They are closer to beef cows with their conception rates.
Estrus Synchronization:
· Benefits to E.S.
· Cows have a longer rest before getting rebred
· Calving season is shorter
· Calves are older and bigger
· Fewer calves lost
· Calves are more uniform in size
Shots:
· GnRh- Cystrorelin, Factrel, Fertagyl. Ovacyst--- releases FSH and LH and cause ovulation of the biggest follicle or it starts a new wave of follicles
· PGF- Lutalyse, Prostamate, Estrumate---- Kills C.L. and lowers P4
· CIDR- Progesterone—keeps out of heat, placed in the vagina, $10
· MGA- Progesterone like—keeps in heat 8 cents per day, placed in their feed
· Many of these are used together…..
