Hypothermia in lambs

While snowfall is expected to be short-lived, wintry showers will remain over the weekend and possibly into next week leaving chill or hypothermia a high risk in young lambs. There are two degrees of severity. Mild hypothermia occurs when a lamb’s body temperature is between 37oC and 39oC and is generally brought about by lambs born into a cold environment or consuming insufficient colostrum to generate heat. It can be usually rectified by warming the lamb and ensuring it receives colostrum/milk.

The more serious condition is where a lamb’s temperature drops below 37oC. Treatment here will depend on the severity of hypothermia and age of the lamb. For newborn lambs that are still able to suckle, drying, warming and stomach tubing with colostrum should suffice. However, if the lamb is very weak and unable to suckle, irrespective of age, then colostrum or milk should not be given as there will be a higher risk of milk getting into the lamb’s lungs.

The optimum treatment route here is getting a rapid source of energy into the lamb, which is best achieved by administering a glucose injection into the lamb’s abdominal cavity (stomach). Veterinary advice is to administer 10ml of a 20% glucose injection per kg bodyweight (50ml for a 5kg lamb). The solution should be warmed to body temperature and if diluting, add recently boiled water that has been allowed to cool or sterile water. The injection site is one inch out and one inch down on the right hand side of the lamb’s navel with the solution administered into the abdominal cavity (inside the skin) and not the gut of the animal. This can be achieved by inserting the needle downwards at a 45-degree angle. The lamb should only be warmed once the injection has been administered, avoiding overheating. This should bring the lamb back to a state of being able to suckle or stomach tubed. Remember, a ewe’s colostrum is the optimum source with the advice to use alternative colostrum sources, where possible, as a top-up supply.

Supplementing animals

The current weather is also putting a lot more pressure on housing in flocks currently lambing. Maintaining high levels of hygiene (sufficient straw and applying lime to high risk areas will help) is vital in preventing disease from gaining a foothold while feeding levels will need to be increased in early lactation where ewes and lambs cannot get out to grass.

Twin-suckling ewes in good body condition and offered ad-lib access to average- to moderate-quality silage of 68 to 70 DMD (or top-quality hay) will require concentrate supplementation in the region of 1.2kg to 1.5kg concentrates daily, rising to 1.5kg to 1.7kg where ewes are in poor body condition. Single-suckling ewes on the same forage will require 0.5kg to 0.7kg concentrate, rising to 1kg for thin ewes. A similar feeding rate will apply for ewes and lambs outdoors with no access to grass.

The demand for protein remains high in early lactation and as such it is important to persist in feeding concentrates with a protein content of 18% to 20% (will be influenced by forage). Introduce meals slowly and split feeding levels to prevent acidosis. Offering free access to water is vital, something that should also be kept in mind where lambs are being finished on a high-concentrate diet.