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Considerations for successful reproductive management/part two

Michael W. Overton and Bradley D. Heins Published on 31 January 2013

Editor’s note: This is the final article of a two-part series about how to investigate and, if necessary, change a herd’s reproductive performance. Click here to view the first article.

A variety of approaches and details on how to monitor and evaluate reproductive records have been described elsewhere.

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Today’s computer records programs have the ability to create many different graphs and figures.

Unfortunately, many people settle for the pre-formed graphs or canned reports and try to determine what these reports are telling them. However, the population at risk is often not defined, the time at risk is not specified, or the metric reported does not necessarily reveal the true condition of the system.

A better approach is to use a few general reports or graphs that describe a few important outcomes of interest as screening tools.

Then, ask more specific, appropriate questions, preferably related to the processes rather than simply the outcome, and find the data that answers the questions posed.

With this approach, the operator must first think of the question (i.e., the problem) and look to find answers using specific ranges in time.

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Selecting the appropriate items to record for monitoring is important; do not ask employees to collect mountains of data simply for the sake of collecting data, unless there is a plan to use it.

Once it is collected, use the information to provide feedback, both positive and negative, to employees. Otherwise, with a lack of feedback, data collection deteriorates, the quality of both the records and the work declines, and the data becomes useless for monitoring.

When evaluating reproduction, there are a few key questions that should serve as the basis for investigation, with additional questions developed as the investigation continues, depending on the initial outcomes.

One potential approach towards investigating potential issues as they relate to compliance and reproductive management of TAI protocols will be detailed.

For the purposes of this article, the DairyComp 305 records from several large dairy herds, milking between 1,500 and 3,000 cows each, will be utilized to illustrate specific examples. Each of these herds utilizes TAI to varying degrees and is located within the U.S.

When investigating reproductive performance, one of the first areas to examine is the days-to-first-insemination graph to assess the voluntary waiting period, to try and understand their approach to first service and to assess the consistency with which cows have been presented for first service.

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Herd A: Days to first insemination graph
In Figure 1, the first-insemination history for the past year for Herd A, a 1,900-cow Holstein dairy, is shown.

Each red square represents a cow and the y-axis is the DIM at first insemination and the X-axis reflects the current DIM for cows in the herd.

The red squares at lower left are cows that have not yet been inseminated.

Based upon this figure, Herd A is utilizing some form of TAI (Double-Ovsynch) with a very high level of compliance, since very few cows are inseminated outside of the one-week range starting at the voluntary waiting period of 70 DIM for first service.

The table below Figure 1 is the historical reproductive performance for this herd for the first five 21-day cycles following the voluntary waiting period for one year, and it shows the net impact of this high level of compliance and a high first-service conception rate (CR).

This herd is a Southeastern dairy that has adopted the use of RFID and takes great advantage of this tool with an annual pregnancy rate (PR) of 26 percent.

The advantage of this system is that there are no misread numbers, no missing cows (assuming all tagged animals are scanned) and a faster ability to locate animals for injections, vaccinations, examination, etc.

Based upon the computerized records, 97 percent of all cows on Herd A are inseminated for the first time between 70 and 76 DIM with 99 percent serviced between 70 and 90 DIM, thanks in large part to the excellent compliance afforded by the RFID system.

For comparison, consider Herd B, a Southwestern dairy that utilizes a commercial reproductive management team that relies heavily on ultrasound to make individual cow-based breeding decisions.

The herd is set up on a Presynch-Ovsynch program, but individual decisions are made for each cow based upon findings at each weekly ultrasound.

Instead of achieving 95 percent insemination efficiency or more within the first week of the voluntary waiting period, as is expected with a weekly TAI program, this herd breeds 43 percent within the first week.


This program was implemented in an attempt to maximize CR but suffers from compliance challenges and delays in actually delivering inseminations.

Herd B: Days to first insemination graph

Figure 2 shows the first-insemination history for Herd B.

This herd has 10 different recorded breeding codes for first service, and despite all of the weekly ultrasound examinations and individualized decisions for guiding the inseminations, the first-service CR is only 32 percent.

The table below Figure 2 reports the annual PR results for the first few 21-day cycles of breeding.

Based upon the annual PR of 13 percent and the poor overall results within the first few cycles, it is quite clear that Herd B struggles to get cows inseminated in a timely and efficient manner.

By delaying some inseminations, only 82 percent of cows are inseminated in the first 21-day cycle.

This herd’s reproductive performance suffers from its very complex breeding system and might benefit from simply placing cows onto a more regulated Presynch-Ovsynch or Double-Ovsynch program for first service instead of delaying completion of the TAI program based on ultrasound findings of the ovaries.

Another key figure that may be useful in terms of assessing overall herd compliance issues is the consistency with which the herd’s management team presents cows for pregnancy evaluation. In DairyComp 305, this graph is created using the following command: “GRAPH PREG BY DSLH\W1.”

Herd A: Days from breeding to first and second pregnancy graph

Figure 3 on page 55 shows the days since last insemination for the first pregnancy determination (35 to 41 days since last insemination) and for the verify exam (71 to 77 days since last insemination) for Herd A.

The Y-axis is a count of events and the X-axis is the days between insemination and pregnancy determination for either the first pregnancy determination or the pregnancy verification (second pregnancy examination for pregnant cows).

Not pictured here is the final pregnancy examination that occurs between 211 and 217 days of conception.

Notice the scarcity of data points after each set of pregnancy examinations.

This herd conducts pregnancy evaluations once a week, and the few points that appear out of the schedule are most likely cows that were flagged for rechecks due to issues detected by palpation per rectum. The highest columns correspond to cows inseminated via TAI.

Herd C: Days from breeding to first and second pregnancy graph
For comparison, consider Herd C’s graph shown in Figure 4 using a slightly different command string and compared to a different dairy, Herd C, which is a 3,000-cow Western dairy.

Again, the X-axis represents the number of days since insemination for the pregnancy examination and the Y-axis is a count of cows.

Herds A and C both utilize only A.I. for first service and both herds utilize a veterinarian for pregnancy determination on a weekly schedule.

The major difference between the two herds is that Herd A uses RFID to find all cows on the list and will seek out cows that are missing, while Herd C uses a paper list and has the philosophy of “well, we’ll get her next time” if she is not found during the herd check.

Table 1
To better compare the two herds, consider Table 1, which contains a breakdown of the days since conception at pregnancy evaluation for each herd.

Herd C has approximately 10 times greater odds of having cows experience a delayed pregnancy evaluation as compared to Herd A.

If all cows were pregnant at examination, there would be no issue – but when cows are skipped and later found to be non-pregnant, the herd has experienced an economic loss via a lost opportunity to intervene with a strategy to deliver the next insemination.

Also, an attitude such as the one shown by Herd C is likely to carry over into the administration of injections for TAI protocols, delivery of vaccinations, movement of cows, etc.

Depending on where the cow is in her injection schedule, a single missed injection could be the difference between a pregnancy and another 40 or more days open, as well as the wasted injections.

The average conception risk and service-specific conception risk for Herd A
Another area that should be examined when investigating reproductive performance, and TAI specifically, are the results of the inseminations, including the CR by breeding code and whether or not the results match the intent of the reproductive program. (See Table 2)

For example, Herd A’s goal is to breed all cows for the first time using the Double-Ovsynch protocol.

After first service, cows are examined daily for estrus and bred accordingly. If not observed in estrus within 28 to 34 days, cows receive a GnRH injection as part of the resynchronization protocol.

Pregnancy examination occurs at 35 to 41 days since previous service and non-pregnant cows then receive a prostaglandin injection and complete the Ovsynch protocol, with the next service occurring at 45 to 51 days since the previous service.

In this herd, 100 percent of the first inseminations are via Double-Ovsynch and 55 percent of the second services are via estrus detection, with the remainder occurring via Ovsynch.

Based upon the authors’ clinical experiences, the CR for each of these services is above average for herds in the Southeast. One concern that some may express is that only 55 percent of the second services were performed via estrus detection.

However, considering the resynchronization approach used in this herd, cows have only one opportunity to recycle with a normal return to estrus prior to starting the Ovsynch program for the second service.

In addition, there is a conscious decision to not inseminate cows that display marginal signs of estrus and instead allow them to pass through to the Ovsynch program. As a result, both of the second-service approaches yield very acceptable levels of CR and yet are performed in a timely manner.

Space does not allow the full explanation of how to completely evaluate CR, but in addition to examining it by service number, breeding code and interval length since previous service, CR should be evaluated by parity, technician, day of the week, month and by combinations of these factors.

However, with each additional strata, the sample size gets smaller and our ability to accurately interpret binomial outcomes such as CR decreases.

Summary
One of the tools successful managers have used to improve reproductive performance in their dairy herds has been TAI. A wide variety of protocols exists, but each one is designed to synchronize ovulation in order to afford an acceptable CR via appointment breeding.

One of the clear differences between herds that have been successful with TAI and those that have failed has been the attention paid to compliance to the protocol.

When utilizing TAI, careful selection of the appropriate protocol, followed by consistent implementation and routine monitoring of both the processes and the ultimate outcomes, are all key components for success.  PD

References omitted due to space but are available upon request. Click here to email an editor.

—Excerpts from Society For Theriogenology Conference

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