Heat detection through activity monitoring has changed the game for thousands of dairy producers. Instead of walking pens and watching for heats, breeders can rely on a daily list of cows ready to be bred. Now, researchers are exploring advanced methods that combine activity monitoring technology with fertility programs to take reproductive outcomes to an even higher level. One approach is called targeted reproductive management (TRM), and here's what it could mean for your herd.
TRM leverages the valuable data that monitoring technology provides to intervene early or identify cows not likely to show typical signs of estrus. It also showcases the value of using activity monitoring throughout lactation and traditional synchronization protocols for an even more successful outcome than either practice alone.
Some cows do not show heat in the way we’d expect. Research has confirmed that even using monitoring technologies or more traditional heat detection methods, you are likely to only identify about 70% of cows in heat.
But what about the other 30% of nonconformists – cows that don’t show typical heats or may not be cycling due to underlying issues?
Monitoring technologies can help address the 30% by providing input on when and how to use estrus synchronization programs. That’s where TRM comes into play.
A plan for the nonconformists
Researchers at the University of Florida used activity monitoring to identify heats in the first 41 days postpartum for cows with two or more lactations and in the first 55 days postpartum for first-lactation cows. They then compared pregnancy rates based on two different breeding protocols – one a typical Double Ovsynch program and the other using TRM.
Figure 1 describes the protocols used in the research. Cows were divided into the following treatment groups based on data gathered during the early postpartum period:
- Enrolled directly into a standard Double Ovsynch program
- Enrolled in a TRM group
In the TRM group, cows that showed at least one high-intensity estrus were bred based on activity over the course of 42 days. If an estrus was not detected, they were assigned to a Double Ovsynch protocol. Those that did not show estrus or had low estrus intensity during the post-calving period were enrolled in a Double Ovsynch protocol.
Results from the University of Florida study that evaluated the TRM approach showed the average days in milk at first service was about equal for cows that went straight to a Double Ovsynch protocol compared to those in the TRM group.
However, there were some differences when evaluating pregnancy success. Second-and-greater-lactation cows on the TRM protocol had significantly more pregnancies at 30 days and at 65 days post-insemination. It is important to understand this dynamic since older, higher-producing cows are significant profit contributors to dairy operations. However, these cows may also be at higher risk of health challenges. Interestingly, first-lactation cows had a higher pregnancy rate when they went straight into a Double Ovsynch protocol.
Early intervention
Another way that monitoring technology is advancing reproduction is through early intervention. Data gathered can help catch health challenges before they become clinical and affect cow fertility. If cows are fitted with automated monitoring systems consistently throughout lactation and the dry period, this can be a very successful way of addressing health challenges before they impact reproduction.
Another University of Florida study evaluated 5,719 lactating dairy cows daily during the initial postpartum period and then tracked reproductive success. It solidifies the association between early lactation health challenges and impaired reproductive performance.
In this study, 80% of cows that experienced one health challenge returned to estrus but only 43% were confirmed pregnant. Just 34% of cows that experienced more than one health challenge became pregnant, and nearly 16% of them lost the pregnancy.
Besides activity, tracking rumination has become another valuable data point from monitoring technology. Rumination data combined with cow activity is analyzed by monitoring technology algorithms, identifying cows that need a closer look, especially in the first couple of months post-calving.
When rumination and activity flag a potential issue, proactive support interventions should be a priority. Hopefully, this intervention can help cows maintain a healthy status or recover faster than without intervention. This approach can help decrease the proportion of cows in the unfortunate 30% mentioned earlier.
When early intervention is unsuccessful, health challenges such as metabolic disorders or metritis in these first 60 days post-calving are a priority concern. A case of ketosis or displaced abomasum (DA) not only reduces milk production and increases veterinary costs and culling risk, but it also reduces the likelihood of successful breeding.
Cows that experience these health challenges early in lactation are less likely to return to a normal estrus cycle, become pregnant or stay pregnant. Our goal should always be to keep cows as productive members of the milking herd, which requires successful reproduction.
A Cornell University study confirmed that monitoring technology, including rumination, can successfully identify early indicators of health disorders. Once addressed, monitoring technology can also help managers watch for a return to normal rumination and, ultimately, recovery.
The industry continues to learn more about using estrus synchronization and monitoring technology to optimize cow fertility. Talk to your veterinarian about the best protocols for your farm to help you intervene earlier and determine the best path to a successful preg check.
References omitted but are available upon request by sending an email to the editor.
