Things are getting HOT today, we are talking about reproduction! (Cue sexy music). Okay, cool your jets; it is not as wild as you might think. In fact, on many dairy farms, reproduction in cattle doesn’t even involve a live male (bull). A majority of today’s dairy farmers artificially inseminate their cattle with specially selected semen that they purchase from a stud, a.k.a. a company that collects and sells semen.
Artificial Insemination is great for a number of reasons:
- It eliminates the need to keep bulls, who tend to be mean and dangerous by nature, on the farm. I have heard and experienced horror stories involving bulls and am thankful that the stories I am familiar with did not have a fatal ending for any of my family members.
- It allows farmers to choose from a variety of bulls therefore, decreasing the chance of inbreeding.
- Farmers are able to control when the cow is bred and predict a due date.
- Farmers are able to produce higher quality animals by choosing bulls that are known for specific traits such as milk production, size, longevity, feet & legs, calving ease, etc. Seriously, the list could go on and on. The amount of information that is available when choosing who to breed your cow to is amazing!
Every dairy farm is different and focuses on particular traits when choosing “who will be the daddy”. On our farm, we choose bulls with traits that will produce a cow that milks well, is of proper size to be comfortable in our facilities and lives a long, healthy life. Once per month, our semen salesmen pays us a visit and talks bulls with my husband. There are always new bulls to choose from and we normally purchase semen from 12-14 different bulls.
The semen collected from the bulls is frozen and kept in a tank of liquid nitrogen until it is ready to be thawed and used. (How the semen is collected is a crazy story for another day, but if you just can’t wait, learn more here.)
Virgin heifers are bred for the first time around 13 to 14 months of age, depending on their size and health, and older cows are eligible to be bred around 70 days in milk (or days since they have given birth). Now, you can’t just be throwing semen at cattle hoping they will get pregnant, you have to be certain that the cow is in good health and watch for a “heat”. Cows come into heat every 21-24 days and provide a short window of time to be bred and become pregnant, this is called the estrous cycle.
Signs a cow in heat include:
– mounting other cows
-swelling and reddening of the vulva
-bellowing, restlessness and trailing
-head raising, lip curling
-decreased feed intake and milk production
Cows in heat can be quite humorous and fun to watch:
Not only are we able to detect cows in heat visually, but we can also use pedometers to identify a cow that is ready to be bred. All the cows on our farm wear a collar with a pedometer and it is part of an activity system. The pedometer monitors the cows’ activity and relays the information to our computer. When a cow has increased activity a signal is sent to the computer and we take a look at the cow; it is likely that she is in heat and ready to be bred. In order to keep our herd growing and to remain profitable it is important to breed the cows via artificial insemination in a timely fashion; the activity system helps us do this.
Sometimes, cows don’t show a good heat and can be tricky to get pregnant. When this happens we have our vet check her out and usually give the cow a series of reproductive hormone shots that make her come into heat and increase her chances of becoming pregnant. It is somewhat similar to fertility drugs in women. The reproductive hormones given to the cattle are hormones that the cow produces naturally and will have no effect on you or the dairy products you consume. Many dairy farmers choose to keep a bull or two around to breed the cattle that are difficult to impregnate; nothin’ gets the job done like the real deal.
Once we have detected a cow in heat, we unthaw the semen that has been specially selected for her and put on the long, plastic glove. We palpate the cervix through the rectum and things tend to get messy (hence the glove). After the cervix has been located, the straw of semen is inserted through the vagina and the semen is ejected. We give ole Bessie a friendly slap on the rear, send her on her way and hope that we have a confirmed pregnancy in 32 days.