The U.S. has seen a rapid decline in beef cattle numbers over the past four years. This decrease has largely been driven by drought conditions in states with high concentrations of cattle and associated high input costs. As a result, the current U.S. beef herd is one of the smallest on record.
Looking forward to the coming year, uncertainty related to the water situation continues in many of the afflicted areas. Precipitation has been above average in some locations, and those places are getting some drought relief. But other areas continue to see decreased precipitation, and drought effects remain a significant concern.
The resulting cattle liquidation has impacted many beef producers who have spent generations building a cow herd adapted to their production system. The loss of these animals will cause production issues for these operations for quite some time and limit the potential to recover quickly from drought impacts.
Technologies
Assisted reproductive technologies (ARTs) are tools that can help lessen the impact the loss of these cattle can have on an operation. And these tools can help accelerate the rate of rebuilding of the U.S. beef herd.
In the past, these technologies have generally been reserved for use in purebred operations to increase the rate of genetic gains within the herd. This strategy has been adopted in this manner because of the cost. However, technological advances have reduced the cost associated with ART implementation and use, making it more attractive across the industry.
ART techniques involve the collection of embryos or oocytes from a donor animal. In the case of multiple ovulation embryo transfer (MOET), a donor animal is administered follicle-stimulating hormone (FSH) during a four- to five-day period. At estrus, the donor is inseminated – and seven days later, the uterus is flushed to recover the resulting embryos.
In the case of ovum pickup (OPU-IVF), the donor animal may or may not receive FSH. The oocytes are removed from the ovary of a donor animal using an ultrasound-guided needle. Resulting oocytes are then graded, matured, fertilized and allowed to develop in vitro for seven days.
Alternatively, a second method of oocyte collection involves the harvesting of a donor animal’s ovaries. The ovaries are harvested from an animal that has died, been slaughtered or, in some cases, ovariectomized. Using this method, ovaries are removed from the animal and taken to a lab where the oocytes are aspirated from the ovary using a needle or other techniques. The resulting oocytes are processed in the same manner as OPU-IVF.
No matter which process is used, the resulting embryos are graded for quality and either immediately transferred into recipients or cryo-preserved for later use.
Advantages and disadvantages
When comparing the number of embryos that can be produced by MOET, OPU-IVF has a distinct advantage. The number of embryos recovered can be two to three times greater than in a traditional MOET program over the same amount of time.
This process is accomplished by repeated OPU-IVF sessions over time. In addition, OPU-IVF can be performed during early pregnancy without aborting the growing fetus. This can lead to the production of as many as 70 calves per donor per year. Additionally, IVF can be used to retain genetics from cattle that are leaving the herd.
Create a bank of genetics
Looking at the current situation, many operations have decreased cow numbers to create consolidated herds made up of their highest-genetic-value animals. The implementation of one or more of these ARTs would allow for a building of a bank of genetics. This bank of genetics can then be used when conditions allow beef producers to rapidly rebuild their herds with high-genetic-merit animals. Lower-quality animals, either purchased or from the herd, can then be used as recipients.
Purchase banked genetics
Another option is to purchase IVF or traditionally flushed embryos from organizations that produce embryos for sale. Many of these organizations produce them at a price point that allows for the mass use of desired genetics. In some instances, these embryos are made using sexed semen, resulting in a replacement female.
