Early pregnancy detection in replacement heifers or cows is a tool producers can use to increase profit. Traditionally, cows and replacement heifers are pregnancy tested in the fall of the year and then non-pregnant cows and cull cows are marketed at that time. With several options available, having a plan for testing can impact not only herd management, but your bottom line.
Blood test methods can detect pregnancy in cows as early as 28-30 days and do not require the same level of specialized experience as palpation or ultrasound. For these tests to be accurate in cows that have already calved, they generally need to be at least 75 days postpartum so pregnancy-associated proteins from the previous pregnancy have cleared. Cost is typically relatively low, although shipping and laboratory fees need to be considered. Depending on the test used, results may be available chute-side or may require sending samples to a laboratory. Blood tests cannot determine the age or sex of the calf.
Ultrasound can similarly detect pregnancy as early as 30 days and has the benefit of providing an estimate of fetal age and viability, along with immediate results. Fetal sex can also potentially be determined, typically later in pregnancy around 60-90 days. Ultrasound does require an experienced technician, and cost will vary depending on herd size, travel, and who performs the testing.
The final option, palpation, requires a bit later window of around 35-50 days before pregnancy can be detected. Experience of the person palpating can make a significant difference on how early in this range pregnancy can be detected. While the sex of the calf cannot be determined, an estimate of fetal age can be provided and results are immediate. Again, an experienced technician is required.
There are several advantages and disadvantages to each of the three methods of pregnancy testing. In some instances, using a combination of these methods within a herd may be a valuable tool to accomplish management and marketing goals.
Producers should also realize that early pregnancy is a period when pregnancy loss can occur naturally, and handling stress, timing, and technician experience may influence that risk. Research evaluating heifers pregnancy checked between about 42 and 74 days has reported losses in the 1-3.5% range, with greater losses associated with earlier diagnosis and less experienced technicians.
For cow herds calving January through April, cows can be pregnancy tested in late summer or early fall and non-pregnant cows marketed at that time. There are a few things that help make this a strategy to consider.
The first is that cull cow prices have historically been stronger during the summer and early fall before increasing numbers of cull cows come to market later in the fall.
The second is that cows nursing a calf may lose weight as we move toward weaning if forage quality has matured and declined while nutrient demand from lactation remains high.
Selling non-pregnant cows earlier, when they may weigh more and before the seasonal increase in cull cow numbers, provides an opportunity for producers to capture more value rather than leaving calves on the cows and waiting to pregnancy test at weaning.
Early weaning calves will require additional high-quality feed and management. However, calves at this age are efficient at converting a high-quality diet to gain. Whether early weaning pays will depend on feed costs, calf performance, forage savings, and cow value, so producers should pencil out the economics for their operation.
For producers whose first-calf heifers calve in the January through May time frame, utilizing early pregnancy diagnosis on these heifers as yearlings provides the opportunity to timely market non-pregnant heifers. These non-pregnant heifers can be marketed as soon as they are identified, or a producer may choose to continue putting weight on them and market later if conditions warrant. An approved growth implant may also be an option for non-pregnant heifers intended for slaughter, provided label directions and any marketing program requirements are followed and ownership will be retained long enough to see the benefit.
For producers, leaving bulls with the cows for a longer breeding season provides the opportunity to potentially get a higher percentage of cows pregnant. Cows that will calve later than desired can then be sold to someone whose calving season fits that time frame. This can be a way to capture additional value from later-calving cows that would otherwise be sold as non-pregnant females in a shorter breeding season, provided feed resources allow this.
Non-pregnant heifers and cows, as well as cull or bred cows, can provide a significant portion of the gross income to a cow-calf operation on an annual basis. Taking advantage of opportunities to effectively add value to and market these cows through timely pregnancy diagnosis, along with an understanding of market seasonality, can allow producers to capture more profit from this segment of the cow-calf operation.
Ben Beckman is a livestock systems Extension Educator based out of the Cedar County Extension office in Hartington, serving northeast Nebraska. You can reach him by phone: (402) 254-6821 or email: ben.beckman@unl.edu.
