What is Colostrum?
Colostrum is a nutrient and immunoglobulin rich fluid that is produced by the ewe shortly before parturition. Besides nutrients and immunoglobulins, colostrum also contains a wide variety of components essential to ensure the survival of a new-born lamb.
Colostrum is critical to lamb survival, insufficient intake of colostrum is a major cause of neonatal fatalities.
A lamb requires between 180-290ml of colostrum per kilogram of body weight, this means each lamb requires over a litre (based on an average birthing weight of 5-6kg) of colostrum. Colostrum requires a lot of investment, energy-wise by the ewe so if she gives birth to multiple offspring, it can be very demanding to keep up with the amount of colostrum required by her lambs. For maximum efficacy, new born lambs must consume the required amount of colostrum within the first 18 hours of life, putting even more pressure on the ewe.
A study by McNeill et al. showed that ewes bearing twin-lambs failed to provide enough colostrum in 30% of cases, whilst ewes bearing only a single lamb failed to produce enough colostrum in 10% of cases.
Why Is Colostrum Important?
Colostrum is important for two main reasons:
- It provides the new born lamb with a rich energy source to allow them to maintain homeostasis and survive
- It provides the lamb with maternally derived antibodies that help fight off infections while the lamb builds its own, stable immune system
Maternally Derived Antibodies
The immune system of a new born lamb can take some time to develop, if the immune system is required to respond to a pathogen – it can take some time to produce the required antibodies to defend the new born.
Because of this, the mother supplies immunological assistance in the form of antibodies. In some species, antibodies can be transferred via the placenta – this is not the case for sheep or other ruminants. This means, all maternally derived antibodies must be obtained from the colostrum, again highlighting the importance than a new born lamb receives upwards of a litre of colostrum.
If a lamb does not receive enough colostrum, they may not be able to adequately respond to an immunological threat.
The maternally derived antibodies can provide protection for the new born for a number of weeks.
It is imperative that the lamb receives colostrum as soon as possible; this is because there is only a short window of opportunity (<24 hours following birth) where the intestines are able to absorb the immunoglobulins from the mother’s colostrum. After this period, the digestive enzymes of the stomach would destroy any ingested colostrum.
Dealing with Colostrum Deficiencies
There are no specific signs that a new born lamb may have not received enough colostrum. General fatigue, lethargy and muscle weakness could indicate a deficiency. Of greater concern is the fact that, without enough colostrum, the new born could succumb to a plethora of bacteria diseases.
Time is of the essence when it comes to dealing with colostrum deficiency because, as mentioned earlier, there is only a window of around 18 hours to react. After this time it will become difficult for the new born to take on enough antibodies from the mother’s colostrum to provide a healthy immune system.
There are a number of methods to dealing with deficiency:
If noticed early:
- The lamb can be given colostrum from another ewe (sometimes colostrum is stored in the freezer, ready to defrost in emergencies – this does reduce the efficacy of the colostrum however)
- The lamb could be given a high quality lamb colostrum supplement that mimics the mother’s colostrum – being both rich in energy and containing the required immunoglobulins.
If noticed late:
- Antibodies (obtained from the plasma of the mother) could be given intravenously
- Broad spectrum antibiotics could be administered for the first few weeks of the new born’s life, to help fight off infections
Adapted from Nowak R., Poindron P. (2006) From birth to colostrum: early steps leading to lamb survival. Reprod. Nutr. Dev. Vol. 46 pgs. 431 – 446
McNeill D, Murphy PM, Purvis IW. (1988) Lactogenesis and colostrum production in ewes. Proc Aust Soc Anim Prod, 17: 437.