AT THE practice, we are starting to see the emergence of lambs from a few early lambing flocks.

The decision for farmers to lamb early is often for one of two reasons.

Either they are running a pedigree flock and intend to sell the male lambs as breeding tups in the autumn. Being born earlier, lambs will have the chance to grow bigger than later-born lambs before the sales.

Alternatively, commercial sheep farmers may lamb early to have the lambs fat and ready for market by May.

This is often when lamb prices peak before they dip as the main lamb crop born in the spring starts to filter onto the market.

The obvious trade-off for exploiting this early market is much higher production costs associated with winter lambing.

For the majority of farmers who operate a more conventional spring lambing, January is the time for preparation.

Many have their sheep scanned in mid-January to see if the ewe is expecting a single lamb, twins or even triplets. It allows them to be grouped depending on the number of lambs they are expecting and fed accordingly.

Generally, flocks have scanned very well this year with several clients reporting they have scanned at well over 200pc, which means for every 100 ewes scanned over 200 lambs are expected.

Obviously people would never “count their chickens before they hatch”, but without a good scanning percentage at this stage, there is no potential to sell plenty of lambs.

At home in Askrigg, the sheep scanned at 172pc. This is very good for a hill flock and everyone is very pleased.

The flip side is that ewes that are expecting twins and triplets require much higher levels of feeding – with forage in very short supply and cereals at over £200 per tonne getting sufficient energy into them is likely to be expensive.

If a pregnant ewe is not fed sufficient high-quality feed to fulfil her energy requirement, she will begin to metabolise her own body reserves of fat, a by-product of which are ketones.

At low levels, ketones can be metabolised, but if the ewe is malnourished for an extended period, or to a severe extent, the levels of ketones in the blood build and eventually reach toxic levels.

This is known as ‘pregnancy toxaemia’ or ‘twin lamb disease’ and manifests as recumbent, lethargic ewes, unable to stand.

Even in less severe cases that do not progress to twin lamb disease, malnutrition in the final six weeks of gestation can be severely detrimental to lamb survival.

Lambs are born smaller and weaker with reduced brown fat reserves. Brown fat surrounds the internal organs of neonatal animals. It can be metabolised rapidly to provide nutrition and generate body heat if the lamb is cold or hungry in the first days of life.

Lambs with less brown fat are more susceptible to adverse conditions leading to higher overall lamb mortality.

In addition, it is within the final stages of pregnancy that the ewe’s udder develops.

Those that are malnourished will produce less milk postlambing and poorer colostrum.

This means the lamb receives fewer antibodies, making them more susceptible to infection and having a reduced food supply.

No amount of feeding postlambing makes up for shortfalls during gestation.

It is therefore crucial to ensure ewes are adequately nourished over the forthcoming weeks to ensure a large, healthy and profitable lamb crop for next autumn.

Sheep farmers face a difficult balancing act over coming weeks as they try to balance escalating costs while attempting to limit the impact on the quality and quantity of the lamb crop.

Lamb prices have been buoyant during 2009 and 2010 and there is plenty of optimism that this will continue into 2011.

Feeding pregnant ewes should always be viewed as an investment – the increased prices of both inputs and outputs makes the cost of getting the balance wrong much more serious.