Until recently, assisted reproductive technologies such as multiple ovulation embryo transfer and in vitro fertilization (IVF) have seen limited use in the commercial dairy sector.
Traditionally, these technologies were reserved for use in registered cattle to increase the number of offspring from a genetically superior animal.
IVF was often reserved for cows that did not respond well to traditional embryo flushing methods. The use of these technologies on a large commercial scale was hindered by higher costs and lower reproductive rates than other reproductive management tools.
Additionally, embryos produced using IVF had reduced fertility after being cryo-preserved. Recent advancements in the IVF technologies have overcome these barriers, making IVF more economically feasible for implementation on a dairy.
The advancements in IVF have coincided with other advancements made by researchers in the accuracy and information available using genomic testing. Genomics is the study of cellular DNA markers associated with performance or phenotypic trait expressions of an animal.
Today, producers are using genetic markers to predict phenotypic genetic merit of animals for economically important traits. A number of laboratories provide the service of processing samples for producers and returning an interpretation of results. Genomic testing helps identify animals that possess high or low genetic value. Using this information, animals can be sorted and breeding decisions made.
Accelerating genetic advancement
The use of genomics allowed for the movement of IVF use primarily by registered herds to being used by large commercial herds. The combination of genomic testing with the use of IVF allows a herd to accelerate the rate of genetic advancement. One of the most reliable ways to increase herd performance and make lasting changes in production efficiencies is to accelerate genetic advancement.
Researchers have shown that the use of assisted reproductive technologies can result in increased selection intensity and reduced generation intervals, resulting in increased genetic gains.
By combining these technologies, a producer can identify genetically superior young heifers and impregnate them using sexed semen to generate elite replacement females for the herd. Techniques such as IVF and multiple ovulation embryo transfer can be used to increase the number of high-genetic-value embryos. Resulting embryos can then be transferred to the lower-genetic-valued recipients in the herd to maximize the number of offspring born each year.
This combination also puts further pressure on selection intensity, thus creating even shorter generation intervals. Genetic testing has facilitated the use of bulls at a younger age and identification of high-genetic-valued females earlier.
One of the main bottlenecks in the use of assisted reproductive technologies is the limited number of recipient animals available. One possible source is uses of some of the lower-genetic-valued animals in the herd. These animals can be implanted with a higher-genetic-valued embryo or a greater-economic-valued embryo.
Changing breeds
With the changing economic conditions in the dairy industry, some farmers have a desire to change the breed of cattle on their dairy. The use of IVF allows a producer to transplant embryos of the desired breed into the animals currently in the herd.
SCENARIO 1
A producer is changing where the dairy ships their milk and is paid higher premiums for components. To take advantage of this, the operation wants to convert part or all of the herd from Holstein to Jersey. In order to accomplish this change, they can sell the Holsteins and buy Jerseys, they can breed their Holsteins to Jersey sires and slowly breed up the herd to be eventually Jersey, or they can purchase Jersey embryos and use Holsteins as recipients.
Crossbreeding
Over the last decade, some producers have included crossbreeding in their breeding program. IVF allows for this combination and can be used as a tool to facilitate crossbreeding. A producer is able to create embryos from the desired breed combinations and transplant these embryos into any of the animals currently in the herd.
SCENARIO 2
A dairy has a herd of predominately F1-cross animals. They have experimented with various other crosses and have found they prefer the F1 cross. They are looking for a way to maintain their herd as all F1 crosses. Currently, they cannot supply enough replacements to meet their needs. IVF can provide a solution by creating F1-cross embryos that then can be put into their cross animals.
Salvage genetics
Every operation has animals of high genetic value that prematurely are culled from the herd for some reason. Until recently, most of the genetic potential of these animals was lost when the animal was sent to market or died. Use of in vitro techniques allows for the genetic potential to be captured and used.
Ovaries of these animals can be collected at slaughter or death, then transported to a lab where the oocytes are harvested. The viable oocytes are then matured, fertilized and grown. Resultant embryos can then be cryo-preserved for later use or transferred fresh.
Technologies such as IVF can be used to increase efficiencies of production in almost any dairy operation. The tool is very flexible and can be applied in many different ways to meet the needs and goals of an operation. In addition, when coupled with other technologies such as genomics and sexed semen, they allow for greater genetic advancement in the herd than was previously possible.
As with any technology decision, a cost-benefit analysis should be performed before investing in these technologies to determine if it is right for a given operation. PD
PHOTO: For a herd looking to maintain first-generation (F1) crossbred cows, IVF can be used to create F1 embryos for implantation into F1 recipients. Photo by Jeremy Howard.
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Jeremy Howard
- Simplot Corporate
- Animal Sciences
- Email Jeremy Howard
