Pregnancy testing alpacas

Written by Nic Cooper from Southern Alpacas Stud

So your alpaca has been mated and you hope that she is pregnant. You need to ensure that she is pregnant and that you maximise your chances in about 11.5 months time of getting a baby cria.

There are a number of reasons why alpacas do not conceive or slip their pregnancy in the early days after conception. Corrective action can be taken in these circumstances, but first you need to know that the slippage has happened.

Natural pregnancy test

Female running away

This is called the "spit-off" pregnancy test. It is easy to do, as long as you have a male alpaca present and gives you a good (but not foolproof) test of pregnancy.

Once a female alpaca is pregnant, she refuses the male, and continues to do so through the entire 11 and a half months of pregnancy. She runs away from the male, with her ears back, and prepares to spit at him to drive him off - hence the name "spit-off".

The theory is that mating kick-starts production of progesterone in the female. Once pregnancy is established, at about day 10 after mating, progesterone continues to be produced, which causes the female to reject the male fairly violently.

So if introducing the male to the female 14 days after mating produces a rejection symptom - there is a likely pregnancy. If fertilisation fails the female will be receptive to the male and will sit to be mated.

Usually another spit-off is done at about 28 days from mating, to catch early slippages or vagaries of differing progesterone cycle lengths.

Ultrasound pregnancy test

Abdominal scan

The results from an ultrasound scan pregnancy test depend largely upon the skill and experience of the operator and the quality of the machine used. However, the best can see pregnancies and foetal development 20 days post mating. A pregnant scan shows a dark area, which is the fluid-filled uterus, and the cria is seen as a brighter area inside this.

You can do scans yourself if you invest in the machinery, your vet can do them, and in some areas mobile sheep scanners can scan your alpacas for you.

Rectal scans are effective in picking early stages of pregnancy. Rectal is also used to investigate the state of the uterus and ovaries.

Exterior abdominal scans are effective from day 40 of pregnancy. We normally exterior scan females at 90 days of pregnancy because if we see a pregnancy then, it is likely to be retained for full-term.

Blood pregnancy test

Blood tests can be done to test for progesterone levels - which indicate pregnancy. These tests are more expensive and can give false readings.

It is important that the labs/vet tell you the actual progesterone level (a number) and not just "pregnant/not pregnant".

A word to the wise

With experience and with knowledge of the individual behaviour patterns of your alpacas, you can actually look at alpacas and tell whether they are pregnant or not. Hormonal change creates behavioural change. So a sweet friendly alpaca can become a grumpy one once she is pregnant, which is a mixed blessing.

There is of course a lot more to this in terms of why alpacas slip their pregnancy, what can cause inaccurate signals of pregnancy, and what to do when you get a slippage.

Note that between 15% - 18% of alpaca pregnancies do slip in the first 90 days so be vigilant. Testing for pregnancy at the appropriate times will save you waiting and watching your prize female for 12 or 13 months and wondering why she is not producing the eagerly awaited cria.

Author Profile

Nic Cooper is in his 20th year of farming and breeding alpacas, and is an experienced studmaster. Southern Alpacas has over 20 studs (see http://www.alpacasnz.co.nz/stud.htm ) which mobile mate throughout New Zealand, and some of their progeny are now being born in the UK and Europe. Supervising over 300 matings each year for many years along with spit off's and the consequences of, and reactions from those, has given Nic the ability to thoroughly understand both the normal mating process, and the abnormal.