Agreement Between Pregnancy Detection Tests

Alertys and provide adequate shed space during inclement weather. There are also health benefits that can be realized when calf ages do not vary greatly within calving groups. Calves born late are more likely to become exposed to the scour-causing organisms that have been building up from the beginning of the calving season.

When we consider combining pregnancy determination with other reproductive technologies, it allows us to determine how these technologies are performing. With artificial insemination (AI), it can be difficult to determine an AI pregnancy from a natural service pregnancy when pregnancy determination is done following the end of the breeding season. By waiting at least 10 days after the end of the AI program to turn bulls out with the cows, a blood sample could be collected at day 30 to determine which animals conceived to AI.11 These results can be made available to a veterinarian for confirmation at the final pregnancy diagnosis following the end of the breeding season. In addition, they can be used to verify if any embryonic loss occurred between the first and final pregnancy diagnosis. Determining pregnancy status early in the breeding season can be combined with synchronization to resynchronize animals. By initiating a synchronization protocol on day 21, after an initial AI, pregnancy status can be determined on day 28 (before a Prostaglandin f2α injection is given) and two rounds of fixed-time AI can be performed. This method increased the percentage of the herd that conceived to AI by 15%.4

In Conclusion

There are now several options available for pregnancy determination in cattle, the newest of which are chemical pregnancy tests. Chemical tests allow for pregnancy diagnosis when a skilled clinician is not available and can now be performed chute-side. Whichever method of pregnancy determination is used, the knowledge gained by knowing which cows are pregnant at the end of the breeding season and, if possible, when they conceived during the breeding season allows for increased management of your herd through culling of non-pregnant animals, grouping by calving date, and increasing the efficiency of your operation.

Sources

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