By Kirsten Williams, beef and sheep consultant SRUC

The extended period of snowfall and plummeting temperatures couldn’t have come at a worse time for heavily in-lamb sheep and their stockmen. 
At this stage in pregnancy, ewes are under huge pressure, being heavily pregnant, growing lamb(s), forming mammary tissue, etc. As the abundance of snow melts, wet fields and flooding will be the next issue for sheep.
Nutrition is key in late pregnancy, even more so when the ground is covered in snow. The ewe’s energy requirements rise by an astonishing 60% between seven weeks and one week pre lambing (70kg ewe with twins). Plus a little extra for cold weather (0.11MJ for each 10kg). As well as nutrition being key, ensuring stress is kept to a minimum is vital.
Ewes must be supplemented sufficiently by offering ad-lib forage, eg hay/silage, this should be of high quality to ensure high intake levels. 
In addition, lifted brassicas such as Swedes, fodder beet, etc, can be offered to ewes to further supplement them. High quality concentrate should be offered to them but ensure there is adequate trough space (50cm/ewe) to reduce stress and competition, or use a snacker. 
If feeding high rates of concentrates, remember to gradually build up the ration and then split over two feeds per day, with no one feed being more than 0.5kg/head. 
High energy blocks/buckets are a great way to offer additional energy to ewes. Offer these to hill lambs this winter, in order to train them to eat blocks/buckets for the future. A guideline of one block/bucket per 30 ewes is recommended.  
Housing ewes in late pregnancy can be stressful. Ensure housing is the only management change within the day, eg don’t mix groups, vaccinate, change feeding, etc. to minimise stress and the risk of twin-lamb disease.
For those lambing indoors, there will no doubt be a backlog of pens. Ensure there are plenty of release pens and remember the importance of hygiene. 
A simple dusting of disinfectant powder and fresh straw between occupants of a pen greatly improves hygiene conditions for the new-born lamb.
It is inevitably going to be a late spring, with grass growth being slow. Ensure you plan for this by having adequate forage supplies for an extra month by means of conserved forage or lifted brassicas. 
If ewes do not have access to good quality forage, they will not supply adequate milk for their lambs (peak milk yield is 3-4 weeks post lambing), resulting in poor weaning weights and a possible increase in lamb losses. Managing ewe condition will be vitally important this year following the hard winter that they have endured.

Hypothermia

Hypothermia is a common cause of lamb death, so if there are concerns, take a lamb’s temperature. The normal temperature, is 39°C.  
If the lamb is between 37°C and 39°C and able to swallow, then it should be fed warm colostrum by stomach tube and returned to its mother in a warm, bedded pen with no draughts.  
If the lamb is below 37°C and able to swallow, then it should be warmed, using a heat box to 37°C, before being fed and returned to its mother.  
If the lamb is below 37°C and is more than five to six hours old, it is likely to be unable to swallow. In this scenario, an injection of warmed glucose can be given straight into the abdomen of the lamb, this is called intraperitoneal glucose. 
This should be injected using a sterilised needle, an inch below the navel and ½-inch to the side of the navel, with the needles pointed towards the lamb’s tail head (10ml/kg body weight). It is a good idea to ask your vet for a refresher of this process. 
If the lamb was under five to six hours old it would have brown fat ‘adipose’ to provide energy, once the lamb is more than five to six hours old these reserves will have gone and the lamb would burn muscle and produce ketones which can have a detrimental effect. 
Following this treatment the lamb should be placed in a warming box and checked every 20-30 minutes.
Ideally, colostrum should be from a ewe in the flock. Lambs should receive 50ml/kg of liveweight of colostrum in the first few hours of birth and by the time it is 24 hours old, should have received 200ml/kg. 
Beware, if heating or thawing frozen supplies, that you do not denature the protein-based immunoglobulins with extreme heat. As a guide, if the water is too hot for your hand then it is too hot for colostrum. It should be heated to 39°C. 
If feeding ewes’ milk through a tube or teat you may need to mix it with warm water to ensure it flows through the duct. Cow colostrum is often used, but it is not as concentrated as ewe colostrum, the quantity should be increased by about 30%. 
Remember, Johnes can be transmitted through milk, so ensure the colostrum is sourced from a Johnes-free herd.