Lambing Season

Lambing most commonly takes place during the Spring, peaking in March/April, although the lambing season does run from February to April and there are some farms that lamb in December and January. During the lambing period, pregnant ewes are monitored very closely day and night, so this can be one of the busiest times of the year for many farmers.

Ewe health before lambing is incredibly important – a ewe that has not had sufficient nutrients during the last few weeks of pregnancy will not produce adequate colostrum to support her lambs.

What is Colostrum and Why is it so Important?

Colostrum, or first milk as it is more commonly referred to, it is the milk that is produced by the ewe for her lambs’ first feed. It has a thicker, almost sticky consistency in comparison to other milk and generally appears a more yellowish colour. Colostrum contains important antibodies (immunoglobulins (IgG)) from the mother that will ‘protect’ the new born lamb against disease, giving it passive immunity which gradually decreases after about 3 weeks of age. Colostrum is also a rich energy and nutrient source and a source of warmth for the lamb (which can help prevent hypothermia) in its first few hours of life.

A lamb being born.

The concentration of immunoglobulins within the colostrum begins to rapidly decrease after the ewe has given birth and is fully depleted around 23 hours after birth of the lamb. The lamb also loses the ability to absorb the immunoglobulins 4/6 hours after being born, so it is vital that the lambs begin to suckle or receive colostrum as soon as possible after birth to give them the best chance of a strong and healthy start to life. It is important to note that lambs are born with no antibodies of their own, which makes them vulnerable to disease, hence why intake of colostrum early on is so important.

Some ewes, for varying different reasons, may not have enough colostrum to support the lambs she has had or her colostrum may be poor quality. In this event, alternative or ‘synthetic/artificial’ colostrum should be used as soon as possible.  A lamb that has received no colostrum of any sort has little chance of surviving without illness.

Storage & Sources

Three lambs in pasture.

Colostrum from another ewe on farm would be ideal as the ewe will have similar IgG for farm specific pathogens.  Ewe colostrum can be stored from ewes that have lost a lamb or have only had a single birth. It can be stored in the fridge for up to 6 weeks or frozen for several months. If using frozen colostrum, care needs to be taken when defrosting as temperatures in excess of 40˚C will destroy the antibodies.

Farms that also have dairy cattle will often pool cow colostrum for lambs, on the principle that cows from the same farm would also have similar IgG for farm specific pathogens. Obtaining guidance from a vet is advised in this case. Synthetic/artificial or substitute colostrum is widely available on the market and comes in several different forms, although nothing is as good as the colostrum produced by the mother, any form will give the lamb a fighting chance for survival.

As lambs are let out into spring pasture other issues may affect their health. Read more here.

Written by Heidi Turgis