There are a few of important dates in the sheep farmer’s calendar, scanning day being one. After meticulously studying the different raddle-marked backsides from tupping now is the time to really see if the rams have earnt their keep.
Scanning provides measurable values that can be compared to previous years figures for the individual flock or bench marked with similar production systems and national performance targets, all of which are focused on ensuring productivity of the business as a whole.
We’ll look at a few KPI’s from scanning and how these can impact your flock:
- Scanning % – this figure looks at the percentage of lambs scanned based on the number of ewes scanned or the number of ewes put to the tup. The latter is used for benchmarking as it gives a broader view of your tipping success; however, it will be lower than if you only include the ewes which you scan
- Barren % – again this figure can be calculated from ewes scanned or ewes put to tup. Generally, acceptable figures are 2% of ewes put to tup for ewes, 20% for ewe lambs. Often barren ewes are culled due to lack of productivity however, these sheep are good indicators if there is potentially an infectious reason for reduced fertility on a flock wide level. Most notably enzootic abortion (EAE) and toxoplasmosis, exposure to these can be tested for and both can be vaccinated against to help control the disease within flocks. If present in un-vaccinated flocks abortion rates, weak lambs and mummified lambs may occur at lambing time.
- Age of lambs – this may give an indicator of how long lambing is going to be and when the busy times are. Thus, allowing you to source additional labour and resources for the busy times.
- Dead lambs – again this can indicate the presence of infectious disease but could be the result of management practices from tupping to scanning. Limiting any non-essential handling or moving of sheep in the 3 weeks post-tupping allows the embryos to develop and the pregnancy to establish correctly.
It is worth making note of and having a plan in place for isolating any ewes that abort, have dead or mummified lambs at lambing time. Isolating them from the rest of the flock reduces the risk of disease spread. Speak to your vet to discuss the case to help reduce further losses in the flock.
- Litter size – allows consideration of nutritional needs of the ewe, and the supplementary feeding that is required. Those with multiple lambs will have a higher energy demand and less rumen space during late gestation so will need managing separately to reduce the incidence of pre-lambing diseases like twin lamb and low calcium. Ensuring adequate feed intake is vital for ewe health and udder development as well as lamb growth.
- Ewe age and condition – dividing ewes, shearlings and ewe lambs is helpful as shearlings and ewe lambs will still be growing themselves so their nutrient need will be different. Ewes that are over or under condition also need different management to prevent pre-lambing diseases. If there are high numbers of thin ewes at scanning speak to your vet as there is likely an underlying cause;e.g. worms, fluke, feed availability, lameness, trace-element status.
Recording scanning figures allow year-on-year comparisons and a tangible impact of changes in management strategies. To get the most out of your figures share them with your vet to help you interpret any problems or concerns you may have. We can also keep a record of them in your flock health plan, ensuring the data is as accurate as possible to get the most out of the annual review.
Next steps are ensuring as many lambs as possible survive. This will allow the lambing percentage to be calculate where: