Proper preparation is key to reducing lamb mortality

THE average lamb mortality from scanning until weaning or sale is between 15 and 20 per cent worldwide, but there is significant variation between flocks. Lamb mortality is highest on the day of birth, and nearly half of all deaths occur within the first week of life.

Lambs die for many different reasons including difficult birth process (Dystocia) causing hypoxia (lack of oxygen), infectious disease, congenital malformation, predation, starvation, and more.

Indoor lambing systems can protect from hypothermia and predation, but deaths from infectious causes may be more common. In outdoor systems confined mainly to late lamb production, lambs may be more likely to die from starvation, hypothermia and predation, but will be less exposed to the build-up of infectious agents.

Nutrition is key to producing healthy lambs, and this begins with the pregnant ewe. Ewes that are underfed in pregnancy will deliver lighter lambs, produce less colostrum, and milk is of a poorer quality than well-fed ewes. These smaller lambs are then more prone to infectious disease.

It is important to vaccinate ewes against clostridial diseases pre-lambing as this will provide protection for the newborn lambs through colostrum.

Sheep lambing for the first time are less efficient, give birth to smaller lambs, and might be slower to bond with lambs, which can increase the risk. Stress or disturbance at lambing can cause the birth process to be prolonged ,which increases the risk of lambs being hurt. Highly stocked sheep pens can cause disruption to lambing, increase the chances of mismothering, and decreases ewe and lamb suckling frequency.

Many of the causes of lamb mortality are preventable by tackling the main causes and risk factors present on the farm. Advanced preparation for lambing can improve flock productivity and is the key to a successful season. Start by preparing sheep housing, disinfect the pens either with jeyes fluid or lime, and then bed with straw. It is vital to have all supplies andequipment available on farm at lambing, as this will reduce lamb and ewe mortality and reduce farmer stress.

To assist lambing, wear disposable lambing gloves, have lubricant, lambing ropes, lambing aid and fostering crate available if needed. Once the lamb is born, disinfect the navel with iodine and ensure the lamb receives adequate colostrum in the first few hours of life. Measure temperature with a thermometer and place hypothermic lambs in a heat lamp/heat box. This greatly reduces the risk of mortality.

Once the farmer has good housing facilities, correct ewe nutrition, ewe vaccinations, all necessary lambing equipment and good animal husbandry skills, mortality will be greatly reduced in the first week after birth.

When the time is right, ewes and lambs will be moved from the shed to grass. So it is up to the farmer to identify fields for early nitrogen, close to the shed, if possible. Ideally, 35 per cent of the farm should have been closed off from grazing the previous October. This grass would be ideal for ewes and lambs to continue to thrive.

As the lambing season is full on, it might be a good idea to arrange for additional labour for larger flocks. This can be done by advertising in the local paper or by contacting an agricultural college for a student who might be interested in a short term work placement. Be organised and ready, delegate work properly, and develop good time-management skills to ensure a prolific flock does not suffer high mortality rates.