When I read this, my mind immediately went to this answer," both mine were positive, and I have two daughter,"
Then I remember we are talking goats not people.
I appologise for my weird sense of humor. But I just could not help myself. :bonkembarrassed)
With a 50% chance of being correct, there would be some folks it "worked for" and others it didn't. I tried it on 10 bred does. (Hand bred). 2 positives, 8 neg. the 2 positives didn't kid, the others did!
(This was a few years ago when I first read about the p test).
So, I say it is a toss of the coin. Blood test and/or ultrasound is more reliable, in my mind!
I haven't seen any comments about Pregnancy Testing with a Milk Sample yet...thought I'd toss this one in for a laugh. : )
Last year, after the kids were weaned and gone to new homes, I sent a milk sample in to get tested. With a milk sample, they tested for Protein - Butterfat - Somatic Cell and...Pregnancy. I did the pregnancy test just for kicks mostly. Of the two does that I would've been most concerned about being pregnant (by her own buckling)...she tested "OPEN" and my other doe (who I was not worried about at all) tested "PREG/RECHECK". Both does were OPEN/UNBRED in reality.
I can safely say through my experience that a Pregnancy Test with a Milk Sample may not be very reliable. I will be blood testing (if in doubt) going forward.
I used these tests for 3 years. The first year, I tried to quantify the color changes (I'm a scientist). The results were all over the place. I tested one doe I wasn't sure about and she was negative and then kidded the next week. It is a great idea, but the resolution on the test is not adequate. I would like a urine pregnancy test as an alternative to ultrasound - I looked into a personal ultrasound intrument for me because of the cost. Would like a more definitive method of confirming pregnancy.
Blood test is easy and not that expensive. Depending on who is reading the ultrasound and how far along the doe is in pregnancy, there can be mistakes made there as well. I do like the at least 30 days post breeding with a blood draw. You can do these and send in yourself.