Make nutrition a priority to reduce lamb losses

Focusing on the diet of ewes in the crucial six weeks before lambing will have a significant impact on reducing lamb mortalities.

Lamb losses between scanning and sale average between 15%-20%, but a high number of these occur around lambing and can be avoided.

ADAS livestock consultant Kate Phillips calculates that when a farmer with a flock of 100 sheep scanned at 170% loses 20% of lambs, the loss, based on current market values, is £2380 in lamb value alone. When losses are reduced to 15% this is worth an extra £600.

Vets and sheep consultants agree the nutritional status of ewes pre-lambing plays a considerable part in the survival rates of newborn lambs.

In fact, vet Iain Richards, Westmorland Vet Group, says the one single aspect that improves a lamb’s chances of survival is the nutrition of the ewe in the six weeks before lambing

“This is not only when the lamb is growing the most, but also when the ewe’s mammary gland develops along with the colostrum and all its antibodies,” he says.

It is during this period that the lamb lays down fat around its kidneys to provide a source of energy in the first six hours of life. “When there are insufficient levels of this brown fat, the lamb has no energy source to feed on to maintain its body temperature in the first critical hours of life.”

Mammary development depends on sufficient protein supply in the final six weeks and no amount of supplementary feeding after lambing will make up for an under-developed udder.

Good quality colostrum is crucial during the first six hours because a lamb’s own antibodies take time to develop, making it susceptible to illnesses such as joint ill and watery mouth.

“When colostrum quality and quantity is good, milk yield is likely to be high and the lamb will have an excellent chance of survival,” says Mr Richards.

One of the most simple, but effective systems he has seen for ensuring lambs that can’t suckle get colostrum, without the risk of infection, was using plastic stomach tubes stored in a baby bottle steriliser. Ten tubes were stored in the steriliser and the farmer could select a clean one on demand.

>Care must be taken to prevent the tube going down too far or colostrum will flow into the undeveloped rumen where it will be ineffective. To avoid this, the tube should rest on the oesophagus.

The chances of lambs developing hypothermia are greater in severe winters, warns Mr Richards. “Glucose remains one of the best available treatments for this. We don’t have many miracle cures left, but glucose is one of them. It can be bought in a ready-made solution and mixed with boiled water.”

Hypothermic lambs should always be given glucose before they are warmed up, he warns.

Housing stocking density is another area that plays an important part in lamb survival rates. Kate Phillips says the spread of disease is much greater in tightly packed buildings and where ewes are kept in large groups.

When a ewe aborts in these conditions there is a significant chance another ewe will pick up the infection and abort, or will do so in future years. Foot rot can also occur and the condition will worsen in overcrowded sheds because of a build up of warm, moist bedding.

Ideally, individual pens should be cleaned after each ewe, says Ms Phillips. Attention to detail should also be paid to lamb hygiene. Navels should be dipped with iodine, although this is not always possible for outdoor lambing flocks and can be counter-productive because the interference can disturb the bond between the ewe and lamb.

When losses do occur, an accurate record detailing what happened will help identify the causes and prevent future losses, she suggests.