There are six steps to follow for improving the estrous detection rate in a particular herd.
These steps take into account the unique aspects of each herd’s management and the facilities for housing and exercise of cattle. The goal of these steps is to make the best possible use of the dairy producer’s time while watching cattle for estrus.
These steps may take 4 to 5 months to accomplish. It’s extremely important to follow the steps in order. Step 6 will not be as effective if the other 5 steps are not followed.
1. Draw a map of the barnyard. Include any exercise lot or pasture where the cows can go on a daily basis. Include major landmarks like feedbunks, silos, or trees as reference points. Put the map on the wall next to the records used to record breedings.
2. Place an X on the map at the location where a cow was mounted. Record only one X per cow per estrous cycle. Use the location of the first mount that is observed. Record the time of day (including a.m. or p.m.) next to the X on the map. Conclusions cannot be drawn from just a few mounts. A guideline to use is to record as many X’s as one half the total number of cows.
3. Look at the completed map for “hot spots”, or areas where X’s are grouped or clustered. “Hot spots” sometimes occur where they are not expected. Examine the area of the “hot spot” for unique aspects such as good footing or a location near other animals. Knowledge of these aspects may be utilized in step 5.
4. Look at the map for “hot times”. These times may vary with the changes in time of day for sunrise/sunset between seasons. “Hot times” during the winter may not be so during the summer. Thus steps 1, 2, and 3 may need to be repeated for each season. Also, timing of “hot times” is influenced a great deal by the time of day when milking and feeding occur.
5. Adjust the management of the cattle so that full advantage may be taken of “hot times and spots”. One example might be a “hot spot” located in the dirt exercise lot with “hot times” just after a.m. and p.m. milkings. Management of the cattle can be changed so cows are prevented from entering the exercise lot while the remaining cows are being milked.
An extension of an electric fence would be adequate. After all cows are milked, the fence is opened to let cows go out into the exercise lot and the cows would be watched for 20 to 30 minutes. Often the first cows to go into the lot will be in estrus. Another example might be a “hot time” right before a.m. milking. Management can be changed to increase the time for estrous detection immediately before milking.
This change can be made with the confidence of knowing that this is the best time to watch for estrus in that particular herd.
6. Make use of appropriate estrous detection aids (Fact Sheet IRM-7). It is important that a veterinarian be consulted before estrous synchronization drugs are used.
Source Purdue Ag Extension