How do I use P4Gold?

Easy to follow instructions are included in the P4Gold test kit, along with all the equipment you need. Simply take a mixed fresh sample of milk and use the pipette to add the right amount to a test tube. Add the reagent included, mix and then add the test. Leave the test strip in the milk for exactly 20 minutes, then remove and see the result. The test will show you the progesterone level in your cow’s milk.

How much milk do I need?

Add 5 drops of milk using a clean pipette provided.

What temperature does the milk need to be?

The milk needs to be at approximate ambient temperature. If the milk has been refrigerated, you should wait for it to warm up before performing the test.

How long does the test take?

The test takes exactly 20 minutes from when you place the test strip into the milk sample.

Why is the test not working?

If the test has not been stored correctly, or has become wet or dirty, it may not work correctly. In this case, take a new test and sample, and re-do the test.

How quickly do the lines appear on the test?

The lines may start to appear before the full 20 minutes are up, but make sure to give the test the correct amount of time to develop fully. Reading before the 20 minutes is up may lead to an inaccurate result.

How would I use it regularly as part of daily farm life?

  • Identify if your cow is in heat, to ensure correct timing of Artificial Insemination
  • Detect return to cycling after calving by testing once a week for three weeks from 21 days after calving. You should see at least one low result. The next heat can then be calculated by counting 21 days from the low result.
  • Determine if a cow has returned to cycling after AI. When tested 21-24 days after the AI, if the cow has a low progesterone level, you can safely assume that the cow has returned to cycling and is not pregnant. It is then safe to AI again.

Can I reuse the test?

No, the tests are single use only.

Can I use old or frozen milk samples?

The best results will be gained from fresh milk samples. If it is impossible to do the test immediately after gathering the sample, it can be refrigerated for up to 24 hours. Make sure the milk is mixed well before taking the subsample for the test. Samples that are older than 24 hours or those that have been left out or frozen will not be useable.

Can I use a blood sample?

No, the test is designed to run on milk samples so it is as non-invasive as possible.

Can I use it for other animals?

At the moment, the test is only designed for use on cattle and has not been validated for use on any other animal.

Can I use it alongside other heat detection methods?

Absolutely! P4Gold is very effective at detecting heat in cows, but visual appraisal and other heat detection methods are valuable as well. Visual signs can be a good indicator of when to test your cow. P4Gold can detect whether bulling or standing behaviours are true indicators of heat, or are just false behaviours.

Does the quality of the milk affect the test results?

It is important that the milk sample used is as fresh as possible and should be well mixed before testing. If the milk sample starts to curdle the test will not work effectively. Similarly, we do not recommend use with milk from quarters with mastitis or blood present in the milk.

Why have no lines appeared on my test?

The control line (the uppermost line) should always appear, irrespective of the progesterone level in the milk. If you do not see at least one line appear after 20 minutes, the test has failed. This could be down to a number of reasons but you should run a new test and potentially use a new sample of milk as this could be a cause.

Why should I use P4Gold?

Research shows that up to 30% of cows do not show behavioural indicators of heat, including standing heat and other bulling behaviour (Esslemont and Bryant 1976). Even in cows which do exhibit these behaviours, they are not necessarily a true indicator of heat. Progesterone testing is 99% accurate in determining if a cow is in heat (McLeod and Williams 1991). P4Gold allows you to identify if a cow is in heat with a high degree of certainty, in only ten minutes.

P4Gold is non-invasive, fast, easy and accurate. It can help improve AI percentages, give insight into poor fertility, help your vet to diagnose fertility problems, and work alongside other heat detection methods to remove false positives.

How will P4Gold save me money?

P4Gold will save you money on wasted straws, AI technician fees and unnecessary culling. It will help you improve your herd productivity by increasing your reproductive performance. Without progesterone testing, 5-26% of cows sent to AI are not in oestrus (Hoffmann et al. 1976; Claus et al. 1983) meaning wasted costs and longer calving intervals.

Missed heats and long breeding seasons can incur high costs and reduce resource efficiency (Beukes et al. 2010). With accurate and consistent identification of heat, cows can be sent to AI at the correct time. Optimal reproductive management underpins economic success and P4Gold will help you to get the best out of your herd.

How do I tell if my cow is in heat?

Two bold lines will appear on the test strip, with the lower test line darker than the upper control line which means that your cow has low progesterone levels and is likely in heat. She can then be sent for AI or service as soon as possible.

Do I need to test on a specific day?

The day you test on will be determined by what you are using P4Gold for. If you want to check that a cow is genuinely in heat then, you can test when she is showing signs of heat, or when you suspect she is in heat according to her cycle or other heat detection devices.

If you want to check whether a cow has returned to heat after AI then you should test between 21 – 24 days post-AI, and then at 42-48 days again if necessary. These days are important as progesterone rises in between heats in a non-pregnant cow but remains high in a cow that is pregnant, so your result could either indicate she has returned to cycling (Low or Medium result) or she is pregnant (High result).

If you wish to detect the timing of heat, then test once weekly for three weeks. You should get one Low or Medium result, indicating heat just before or after this day. You can do further tests daily to determine exactly which day your cow goes into heat.

If testing immediately after calving then begin testing three weeks (21 days) after parturition.

My cow is bulling, but the test shows medium or high progesterone.

The bulling is false. Test again the next day if the result was medium and test again in a week if high progesterone was indicated (only one strong line).

Oestrogen waves can occur during pregnancy and cause signs of bulling. Checking the progesterone level can reassure you that the cow has high progesterone due to pregnancy or not being in heat, and should not be re-inseminated. Insemination of a cow that is pregnant risks aborting the pregnancy. There is an increased risk of causing infection if a cow is inseminated when not in oestrus.

How do I tell if my cow has returned to cycling after calving?

Testing once a week for three weeks from 21 days after calving will help to determine if the cow has started cycling again. If you get two High P4 and one Low or Medium P4 then she is cycling.

How often should I test my cows to detect heat?

The test should be used three times weekly from 21 days after calving to detect the start of heat.

Is my cow pregnant?

If you run the test 21-24 days after service and the test shows high progesterone, then it is possible that she is pregnant.  A low progesterone level means the cow is not pregnant and can be served again. If the test is not done on day 21-24, then a high progesterone level may not be an indicator of pregnancy and might just be a normal part of her cycle.

The test can be repeated at 42 days after AI to make sure the cow remains in calf. If she is still pregnant, the test will show a high progesterone level.

If a cow has poor condition or nutrition, she may have relatively a low level of progesterone and still be pregnant. In this case, we recommend confirmation by ultrasound or PAG testing.

Does P4Gold show how many days into gestation a cow is?

No, the test will only show the progesterone level of the cow. As a result, it cannot determine how far along the pregnancy may be.

If I don’t know the date of service, can I tell if my cow is pregnant?

You can but this will require more thorough testing. The typical cycle is 21 days, for which most part the cow has high levels of progesterone. A pregnant cow has continuous levels of high progesterone, so any Low or Medium result would indicate that the cow is not pregnant. You could test every 2 days and keep a record of your results. If you get a Low or Medium result at any point, she is not pregnant and is cycling. If your cow has fertility issues or has poor health, she may not be producing normal amounts of progesterone and therefore appear to have lower levels throughout her cycle.  An easier way to differentiate pregnant cows from cycling cows without a service history, would be a pregnancy test (PAG or ultrasound).

Does this mean I don’t need a vet/PD scanner?

No, this serves as an early detection of non-pregnancy so this test allows cows that are confirmed empty to be served again. Even if the cow is pregnant at 21 days, many pregnancies are lost in the first 5 weeks, so later checks can be used to confirm that the pregnancy is sustained.

How quickly can P4Gold detect calf loss?

A cow’s progesterone level will drop very rapidly after calf loss, so the test can confirm this if there is a suspected problem. However if the progesterone levels are still high, it does not necessarily mean the pregnancy has not been lost. For best results, test in 3 week/21 day points after conception, ensuring the progesterone remains high. Here if you see a Low or Medium result, it is likely the calf has been lost.

How does it compare to PAG testing?

Using P4Gold, an accurate non-pregnancy diagnosis can be obtained if the cow is tested 21-24 after AI. The test can indicate whether a cow might be pregnant, if the progesterone level is high, but there are other causes of this and so further PD is required to confirm. P4 testing is quicker and cheaper than PAG testing and does not need to be sent off to a lab for analysis. PAG testing allows accurate pregnancy information to be gathered after a successful AI without needing to be run on specific days, but can only be used reliably from 70 days after AI. If non-pregnancy has been confirmed at 21 days though P4 testing, the cow can be returned to AI much sooner than if only relying on PAG, reducing the number of days open and increasing the profitability.

How does it compare to other PD methods?

P4 testing is best used as a non-pregnancy test and in conjunction with other PD methods. If a cow has high P4 at 21 – 24 days after AI, then it is probable that she is pregnant. Other PD methods should then be applied to confirm this.

Can I diagnose fertility problems?

It can be a first step in identifying cows that appear not to be cycling (lack of bulling behaviour) but are actually in silent heat. If a cow appears not to be cycling, test weekly for three weeks. Three of the same results over a three week period, could mean she is cystic or anovular. If this happens, it is best to consult your vet.

Have your questions been answered?

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