The benefits of ewe colostrum

We are all aware of the importance of ewe colostrum as the first feed and antibodies has always been the ‘buzz’ word, however, successful colostrum feeding is a considerably bigger picture.

The total solids of colostrum are over double that of normal ewe’s milk giving it that thick, sticky consistency. The extra solids come from the additional antibody proteins in the form of immunoglobulins (IgGs) and a staggering 15% fat; giving ewe colostrum an energy density that is truly lifesaving.

As we know 70% of the lamb’s pre-birth growth occurs in the last six weeks of pregnancy, alongside this huge requirement of our ewe’s energy her placenta is sending a hormone signal to kick start colostrum production. Here we need to be providing her with enough energy to maintain a strong body condition score while meeting these additional demands. It is also important to have administered your clostridial vaccine ahead of this onset of colostrum production.

Read more: How to protect livestock from Clostridia disease

Colostrum production varies greatly in both quality and quantity for reasons beyond nutrition and body condition score, it can be affected by breed, genetics within a breed, the age of the ewe and the number of previous lambing can all play a part. At lambing, the average IgG content of a ewe’s milk is 50g/L. The IgG concentration then declines over 24-36 hours at a rate of 3.3g/L/hour.

Read more: How to body condition score ewes

Lambs receive no transfer of antibodies across the placenta, so they are totally reliant on colostrum for passive immunity and protection against disease. Lambs are born with a permeable gut membrane to allow for IgG uptake; this also leaves the gut open to pathogens. It is, therefore, vital that the lamb receives colostrum before encountering any contaminated surfaces. Absorption of IgGs through the gut is 20–30% efficient in the first two hours of life but this ability declines to 0% by 24 hours. A lamb requires 30g of IgG and the sooner it can suckle, the higher the colostrum quality and ability to absorb it will be.

New-born lambs are at risk of hypothermia, their large surface area to body weight ratio makes them susceptible to heat loss. They lose heat at a much higher rate when wet, than when dry. Lambs are born with a finite amount of brown fat; this provides energy to bridge the gap between being born and finding their first feed. The high fat of the ewe’s colostrum makes it exceptionally energy-dense, sufficient uptakes provide enough energy for the lamb to regulate its body temperature. Clostridial fat also acts as a laxative to clear the lamb’s digestive tract.

Therefore, it is important the lamb receives the ewe’s colostrum as quickly and cleanly as possible. If harvesting a ewe’s colostrum, do so as soon after lambing as possible. Remember, the colostrum feeding window extends beyond that first feed to cover every feed within the first 24 hours. Almost 50% of all lamb losses occur within the first 48 hours, successful colostrum feeding could reduce that number considerably. If losses are occurring where colostrum has been fed, colostrum quality should be assessed using a refractometer. 

For more information or advice, contact a member of the Calf & Youngstock team.