Any stress during early pregnancy can affect embryo implantation. This is where the impact of bad weather can be seen and can result in a lower scanning percentage. Unfortunately, weather is becoming more unpredictable, but there are still measures we can take to limit the risks during their most sensitive pregnancy period.
The high-risk period is from mating until 45 days after tup introduction. Beyond this stage, the ewe and her embryos are relatively resilient. Firstly, management should aim to reduce any stressful activities during this time. Avoid dietary changes, mixing ewe groups and handling. However, if bad weather hits, some of these measures might have to be compromised.
Here is what you can do:
- React to a high snowfall forecast promptly. Where heavy snow is highly likely, see if you can bring them closer to home, into the best sheltered fields, best drained fields and/or those with best access for feeding.
- Consider snacker- or trough-feeding ahead of the snow. Particularly those who plan to feed concentrates when snow cover prohibits grazing; this helps transition to the higher starch diet. Start on no more than 200g/head/day and work up in 50g increments to target amount. The full amount will depend on their weight, feed quality and forage access but 250g of 12.5 ME concentrate will meet a third of energy requirements for 70kg ewes providing they have some access to forage. This also helps maintain their condition as their intakes will reduce during a storm.
- Have forage in reserve to sustain the flock in case of three weeks of heavy snow cover. For example, 100 ewes will require around 17 bales of average silage (700kg bales) or 14 bales of hay (250 kg) to meet their full requirements for three weeks.
- Following the high-risk period, be sure to go through them and assess condition, those that are leaner than target should be managed to regain condition as this will benefit the scan result and increase likelihood of her giving birth to a viable lamb. Return to usual vaccination and drenching programme.
It is always worth preparing a plan to reduce the stress of decision-making and avoid knee jerk decisions that may be detrimental to the flock. There are no perfect solutions and I hope the winter weather becomes kinder to us again, but forethought is never a waste of time when it comes to extreme weather planning.
Poppy Frater, firstname.lastname@example.org
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