By Kath Aplin

Last updated 21:49, Tuesday, 12 February 2008

Cold is one of the biggest killers of young lambs – accounting for about 40 per cent of all lamb deaths in the UK.

If the weather takes a turn for the worse during lambing, particularly in early lambing flocks, shepherds may be faced with many weak lambs whose temperatures have fallen below the normal range of 39-40°C.

It is useful to have a protocol for dealing with chilled lambs.

When any lamb is suspected of being chilled it should be caught, examined and dried with a towel if wet. Subsequent decisions then depend on three things:

n The lamb’s age

n Its ability to swallow

n Its rectal temperature, taken with a thermometer.

Lambs with body temperatures in the range of 37-39°C (mild hypothermia) will be weak and slow, but just able to suck from the ewe.

Whatever their age they are generally capable of raising their body temperature to the normal level if they are dried and given a feed.

These lambs should be fed via a stomach tube or bottle and then returned to their mothers in a sheltered spot where they can be easily examined later.

If a lamb does not appear fully revived it should be kept indoors with the ewe for closer attention and possibly additional feeds.

Lambs with temperatures of less than 37°C (severe hypothermia) are generally arch-backed, depressed, empty-looking and unable to suck. Their treatment depends on their age.

A lamb that is less than five hours old should be placed in a warming box and checked regularly until its temperature has increased to 37 or 38°C.

It should then be given a colostrum feed by stomach tube and returned to its mother in a dry, well-bedded, indoor pen.

Lambs more than five hours old will have used up the energy supplies they were born with and will generally have low blood sugar in addition to being chilled.

If they do not receive energy before being warmed, warming may actually produce a fatal hypoglycaemic fit.

If such a lamb can hold its head up it is likely to retain the swallow reflex and can be safely fed by stomach tube.

If collapsed and unable to lift its head, the lamb must be given an injection of glucose solution into the abdomen.

These lambs can then be safely warmed back up to 37°C before being given a feed by stomach tube and returned to the ewe in an indoor pen.

The glucose injection technique works well and can save many lambs.

If you are not familiar with this method, ask your vet to show you how it’s done.

Warming boxes can save lives, but when used throughout a lambing period for sick lambs, bugs can build up resulting in the warming box being a source of disease. It’s important to clean and disinfect the box between lambs. A box provides more even, draught-free warming than a heat lamp.

Providing extra shelter outdoors can enable lambs to be kept outside without getting chilled in weather conditions that might otherwise warrant bringing them in.

A variety of different methods have been used – one practical solution is to use old tyres cut in half. These offer good shelter to ewes and young lambs and they have the advantage that they can be easily moved to prevent poaching and turned to provide shelter from the prevailing wind.

The bigger the tyre, the better the shelter.