| | For specific flock health advice always contact your veterinarian.
Additional information is provided in the "Sheep & Goat Management in Alberta - Health Module" on the Alberta Lamb Producers website.
Hypothermia is low body temperature caused by exposure and starvation and is the most common cause of death in newborn lambs. Lamb death losses in the first 48 hours after birth result in significant economic losses. Whether extensive, pasture lambing flocks or larger, intensively managed confinement flocks neonatal lamb death losses must be minimized for flock profitability.
Hypothermia is the result of a combination of exposure and starvation. Exposure is where the lamb cannot produce heat as quickly as it loses it. Exposure can be due to poor mothering where the lamb isn't licked off, is one of a litter of lambs, or is abandoned. Exposure can also be due to environmental conditions where lambs become chilled and then run short of blood glucose or energy needed to survive. Lambs with inadequate energy have used up the brown fat reserves they were born with and have not nursed enough colostrum. Hypothermia can lead to, or contribute to, the lamb’s inability to nurse. Lambs must consume enough colostrum to provide energy to maintain body temperature and blood glucose levels. Factors contributing to hypothermia can include: exposure to inclement weather; poor mothering, inadequate colostrum, and low birth weights caused by poor ewe nutrition during pregnancy; weak lambs due to nutrition, disease, multiple lambs in a litter or delivery problems. Management of ewe nutrition, flock health as well as adequate facilities and supervision at lambing all factor into reducing hypothermia and neonatal lamb deaths.
Lambs found dead are often assumed to have been abandoned, laid on by the ewe in the lambing pen or any other of assorted causes. Identifying the cause of all lamb deaths is key to finding solutions. When hypothermic lambs are found alive they are weak or even comatose. The lamb's mouth and extremities will be cold, the belly sunken and empty, and the body temperature below normal. Monitoring lamb body temperature should be standard management in the lambing barn
A thermometer is a key management tool. The normal temperature for a lamb is 39C to 40C (102F to104F). Moderate hypothermia will show as 37C to 39C (99F to 102F). Severe hypothermia is where the lamb's body temperature is less than 37C (99F). The treatment you choose depends on the age of the lamb and the severity of the hypothermia as determined by the lamb's body temperature. Any lamb that gives the slightest cause for concern should immediately have its temperature taken and if still wet be thoroughly towel dried. A warming box with a warm air fan is incredibly valuable in a busy lambing barn. The 'hot box' provides external heat and reduces the risk of over-heating the lamb when using heat bulbs. It also reduces the risk of heat bulb caused barn fires. Any heat source in a barn should be carefully monitored and have shut off timers. Lambs in the warming box should have their temperature taken every half hour and provided with colostrum via a stomach tube.
Lambs over five hours old are unlikely to have much, if any of their brown fat reserves left. It's important to not warm these lambs without providing energy - glucose or colostrum - first. Ask your veterinarian for a demonstration on injecting glucose solutions and on correctly using a stomach tube if you haven't done it before. After the lamb has had a glucose injection it can be warmed and then given colostrum. For feeding colostrum to chilled lambs a stomach tube is essential. Hypothermic lambs usually won't suck and can inhale colostrum with dire results. To feed lambs with a stomach tube: do not tube very weak or unconscious lambs; feed colostrum warmed in water, overheating damages antibodies; feed four to five times in the first 24 hours. To stomach tube gently insert the tube into the left side of the mouth. Don't force it. If the lamb shows signs of distress remove and try again. Attach the syringe to the tube and slowly depress the plunger. Repeat until colostrum is gone. Be sure to keep the tube and syringe scrupulously clean. Stomach tubing lambs is one of those essential shepherding skills.
Preventing problems is always better, cheaper and less stressful than trying to fix them. Minimizing hypothermia and starvation death losses begins with a good feeding program for pregnant ewes. Managing ewe nutrition will assure good birth weights in newborn lambs (over eight pounds for twin lambs). Very small lambs have higher death rates. Good ewe nutrition also means the ewes are willing to do a better job of mothering their lambs and will have adequate colostrum for them. Additionally a well-fed ewe is prepared to produce enough milk to raise and wean uniformly well-grown lambs. Selecting ewes who are good mothers and wean well-grown lambs is critical for lamb survival and flock profitability. In addition to providing good feed, providing adequate shelter for lambing ewes and newborn lambs also helps reduce deaths. Close supervision of lambing ewes helps detect problems that can contribute to lamb deaths. Again, it is important to know exactly why baby lambs die. Postmortems provide accurate and critical information. Discuss flock health, ewe nutrition, and lamb deaths with your veterinarian so you make the right management choices.
External information on Hypothermia in Lambs |
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