Perfecting Pregnancy Scanning on your Farm
The time to pregnancy test hinds is fast approaching and at Melior, we are firm believers that ultrasound scanning is the most reliable method for doing this. We thought we’d share some insights and tips in the hope we can help make the process more efficient and effective for you, our valued commercial clients.
Why do we pregnancy scan deer?
It’s all about allowing farmers to make informed decisions about hind culling, and a powerful tool in terms of cost-savings and production benefits. In general, hinds are culled primarily on reproductive productivity. By identifying “dry” hinds before the onset of winter, they can be drafted for slaughter early which in turn reduces wasted costs of feeding non-productive animals. Further to this, pregnancy scanning enables farmers to obtain valuable feedback around what has worked and what hasn’t’ with their feeding and management. The benefit of ultrasound scanning certainly outweighs the cost, and we are big advocates for taking advantage of this technology.
Top Tip: When you kill the dry hinds it’s a good idea to get a liver biopsy done on 5-10 of them to test status for trace elements. This tells the farmer a bit about what’s going on with those hinds at that time of year and what they should be supplementing hinds with at that time of year – e.g. if a low copper result prevails, a copper supplementation programme needs to be put in place for the spring.
The best time to pregnancy scan hinds, via internal scanning, is usually late May to late-June, when gestation is between 30 and 80 days. Visualisation of the foetus is difficult to achieve if attempted too early, so we advise scanning no earlier than 45 days after the stag is removed. In contrast to this, scanning too late gives rise to its own set of challenges. The foetus needs to be sitting high enough in the pelvis to be detected – it moves further down as pregnancy progresses. Suffice to say the window of opportunity is limited, so maintain good communication with your vets to ensure a successful scanning outcome. As mentioned further on, external/flank scanning can be performed later on in gestation if needed.
This refers to the practice of determining the estimated age of a foetus at the time of ultrasound scanning within the first trimester. During this time, a foetus develops uniformly in terms of growth and development so a skilled and experienced scanner can visualise this through scanning. We highly recommend foetal ageing at Melior, as this means hinds can be sorted according to expected fawning date and feed can be managed accordingly. From here, you can set stock them into different mobs and then start rotating the earlier conception date hinds sooner post fawning, without running the risk of leaving behind any late fawns.
Top Tip: Determining the conception dates within a mob can also tell you a lot about what’s happened with the hinds at the time at which they’ve gone to the stag, i.e. did they still have a fawn at foot? What feed were they on at the time? What were the weather conditions? It also gives you a comparison against the “norm” which may explain variances in weaning weights, e.g. if conception has gone later than usual do you need to assess your feeding plans? Any information like this is very helpful when it comes to tweaking breeding plans for the following year to maximise success.
Top Tip: When we talk about birth dates, which of course is dependent on conception dates, for deer it is also affected by nutrition during pregnancy. A hind can alter her gestation length (+/- two weeks) as required. If we keep feed too tight, they are likely to increase gestation length which then has flow on effects that could negatively impact your operation. To make sure a foetus reaches viable weight, protein percentage of feed source is key during pregnancy, especially later on in gestation – feeds need to be reaching a certain protein percentage otherwise it can cause longer gestation or foetal loss.
How is it done?
Hinds can be tested for pregnancy via rectal or flank scanning. Internal scanning with a rectal probe can identify the age of a foetus (+/- five days) but it must be done between day 30 and 80 of pregnancy to be accurate. Flank scanning isn’t as precise in regard to foetal aging but it is faster and can be used to diagnose pregnancy at any stage of gestation (much later in pregnancy).
We understand that for some farmers, internal scanning isn’t always logical or practical, for example hinds are only brought in from the hill once or twice a year and this doesn’t always fall within the 30-80 days of gestation. It’s important to do what works with your individual farm programme.
Melior’s Tips for Best Practice;
- For rectal scanning make sure you book early to ensure you don’t miss the 30-80 day window of gestation.
- When AI has been used, aim for scanning 40-50 days after insemination.
- During pregnancy scanning make sure you minimise the time off feed and stress hinds are exposed to by yarding them on the day of.
- With pregnant hinds, note estimated foetal age on their ear tags or load into EID tags.
- Any dry hinds that were early scanned should be re-checked 20-30 days later.
- Ensure sound nutrition especially in latter stages of pregnancy to avoid longer gestations.
- Increase pasture allowances for mobs as fawning date approaches.