A few weeks ago, I started a series featuring biotechnology tools used in cattle herds across the country. David and Jennifer Heim are friends of mine and own a dairy farm in northeast Kansas. The Heims milk 85-100 Holstein cows and raise their heifer calves as replacements. They also raise corn, soybeans, hay, and other forages, mostly for feed. Jennifer greatly enjoys spending time with her breeding and genetics program and does an awesome job blogging about the events and decisions made on the farm. When she wrote this blog post describing their use of Artificial Insemination in the herd, I was pretty excited that she is allowing me to share it with you.
Breeding is important, but it really doesn’t matter what you breed a cow to if she doesn’t get pregnant. Last spring, we started using blood tests to confirm pregnancies. Since then we’ve tweaked our protocol to best suit our herd’s needs. Our milk hauler picks up our blood samples, and I am usually home on Sundays to draw blood, so every other Sunday, when our milk will be picked up on a Monday morning, I take blood samples from cows and heifers that were bred between 8 and 10 weeks prior who have not shown a heat since. The test can indicate pregnancy at 28 days, but we were observing a lot of heats just shortly after testing, and about a month after testing, when we were testing earlier. We’ve been on the every-other week at 8 weeks bred schedule for 3 or 4 months now, and have had very few come back in heat after being confirmed pregnant.
Several weeks ago we wrapped up pregnancy confirmations on all our cows and heifers that were bred in 2012. We tallied everything up, and here’s what we learned:
What are your conception rates with artificial insemination?
We started out the year with great conception – about 60%. Then we had two unexplained terrible months in March and April. Summer brought normal lulls due to heat, but was still better than March or April. After the heat subsided and the herd adjusted, we finished the year with solid conception and a lot of pregnancies, including several cows who were on their final attempts. Next fall may be busier than this one was.
Artificial Insemination (AI) is the most valuable management practice to the cattle producer. The procedure makes efficient use of the generous supply of sperm available from an individual male in a manner that greatly increases genetic progress as well as improving reproductive efficiency in many situations.
Artificial Insemination: The deposition of sperm cells within the female reproductive tract by mechanical or instrumental means for the purpose ofbreeding. Biotechnology: biological processes developed in the laboratory and made available in the commercial markets.
AI was the first biotechnology applied to improve reproduction and genetics of farm animals. Reproductive efficiency using AI is at least as good as using natural mating when no diseases are present and good management practices are employed. When certain diseases enter the picture, especially venereal diseases, AI becomes an important factor in their control.
Advantages and Disadvantages of Artificial Insemination
Advantages of AI far outweigh the disadvantages:
Genetic improvement through more accurate evaluation of transmitting ability of males, continued after the death of the male
Use of semen from genetically elite sires increases the accuracy and intensity of selection
More economical than natural service when genetic merit is considered
Safer by the elimination of dangerous bulls on the farm, especially for the dairy breeds
Disadvantages of AI include the amount of time livestock managers must spend checking females for estrus. Some special facilities for corralling and insemination are required. Trained personnel are required to perform the technique.
Process of Artificial Insemination
First the semen is collected from males through artificial insemination methods
Technicians make certain the semen contains sperm of sufficient quality and quantity to survive freezing and thawing with enough viable sperm to complete conception
Semen is examined in the laboratory for foreign material and quality. Quality is determined by the number of sperm per millimeter of semen, how active sperm are (motility) and the shape of the sperm
Semen is preserved by storing it in tanks of liquid nitrogen at a temperature of -320 degrees F or below
At the time of insemination the semen containing the sperm is thawed, the technician then injects the semen into the female reproductive tract. This requires a degree of skill.
Artificial Insemination in Different Species
Merck Veterinary Manual gives a good overview of AI and reproductive technologies in many species:
This is an introduction to artificial insemination (AI) in livestock. If you have more specific questions, please leave a comment below or submit a question in the Ask a Farmer tab. Submissions will be used to answer questions in my series on biotechnology.
Most folks get to share “Peanut” photos of their kids, so I figure it’s only fair I get to share one from our cows
During the month of April, my schedule is jam packed and I’m finding myself on the road nearly every day. It’s breeding season for our cattle in Tennessee and it’s the best learning experience a guy could ask for! I’m ultrasounding for the presence of ovarian structures (signs of estrous activity), synchronizing estrous cycles, using artificial insemination to breed cows, collecting embryos from 15 donor cows, and doing fresh embryo transfer to 75 recipient cows. Then, in another month, I’ll be doing more ultrasound work to determine pregnancy rates. With over 700 cows and heifers to work with, my arms will definitely be sore.
Here’s your chance to learn more, pick my brain, and aid in my study skills.
What questions do you have about biotechnology as it relates to cattle reproduction?
Submit your questions in the comments below or submit a private message through the Ask a Farmer tab. Once my schedule relaxes a bit toward the end of the month, I will do some Q&A posts to share my experiences.
To get you started and give you an idea of what I’m talking about, any of the activities listed above are fair game, and these links should give you some good background reading material.
This month I checked another state off the list as I traveled to Columbus, Ohio for a work trip. We were there for a “Think Tank” meeting with some of the best reproductive physiologists in the academic world of cattle in the U.S. Along with this meeting we had the opportunity to tour the Select Sires Bull facilities near Plain City.
The bulls with a company like Select Sires go through a strenuous testing period starting at a very young age. The first cut for bulls happens at birth based on genetic lines. Do the bull’s genetics fit the direction of the desired traits in breeding herds? From a pool of 100 bulls, only a few may make the final cut for high-volume semen collection. At around 1 year of age bulls are collected for a young sire test. Several cows will be bred to the bulls and their offspring will be used to estimate the genetic value of the bulls. The bulls that graduate in the full program may then be used to collect semen for larger marketing.
At this point bulls may be 4-5 years of age, so time span is obviously a huge obstacle when predicting what genetics will be in demand by breeding herds years down the road. Bull semen companies like Select Sires are beginning to utilize genomic testing to narrow their bull selection pool, selecting bulls with higher genetic value at a younger age. The use of genetic testing is expanding in the industry and increases our ability to make quicker genetic progress.
Semen Collection and Processing
The semen collection process is relatively simple and has been narrowed down to a science by these companies. Bulls are collected with an artificial vagina 2-4 times per week and as many as eight. An average ejaculate may contain 1 billion sperm which are then diluted with an extender (made from a base of whole milk or egg yolk) and stored in 1/2cc straws for freezing. An average Holstein bull can produce 80,000 to 110,000 straws of semen annually. Each year, Select Sires produces 1,962 gallons of processed semen.
Prior to freezing the semen collection is checked for abnormalities of motility (forward movement) and morphology (normal shape, size, formation). A healthy sperm travels 12 feet per hour. In relative size that’s equivalent to a car traveling 37-41 mph.
The semen straws are then stored frozen in liquid nitrogen (-320*F) where metabolic activity of sperm comes to a halt. Select Sires uses over 500,000 gallons of liquid nitrogen annually and can process up to 75,000 straws per day.
I also had the opportunity to tour their facilities where sperm are sorted to produce sexed semen. Sperm carrying X- or Y- chromosomes have a different amount of genetic material and can be sorted to produce male or female semen samples. This is most commonly used in dairy herds looking to produce more heifer calves. The fertility of sexed semen is lower and the cost is higher, so use of sexed semen is not as frequent as non-sorted.
Companies like Select Sires, Genex, ABS, and numerous others contribute a great deal of information and technology to the cattle industry. Their money contributed to academic research allows us to investigate better management of reproduction in cattle, improving efficiency and genetic progress within herds across the country.
It’s all a pretty cool segment of cattle production, but this comes from a confessed cattle agnerd, so what do I know? Now if I can just get my cows to text me when they’re in heat…
Do you have any questions about semen collection of bulls or use of artificial insemination in cattle?
(Thanks to Select Sires for the numbers and information on semen collection)