By Dr Claire Morgan-Davies, Poppy Frater and Cathy Dwyer, SRUC

Most lamb mortality occurs on the day of birth, and up to 75% of deaths happen within the first week of life.

Many causes of lamb death can be traced back to insufficient colostrum. Colostrum helps maintain body temperature, provides immunoglobulins to fight off disease and stimulates gut development.

Therefore, it was no surprise that colostrum management techniques ranked highly during our SheepNet workshops in Spain and Romania, last year.

On day of birth, the lamb should consume more than 200ml of colostrum per kg of birthweight, with at least 50ml/kg of birth weight within two hours of lambing.

The best colostrum is from the mother. As such, ewe nutrition and promotion of the ewe-lamb bond has been covered in several factsheets in the SheepNet knowledge reservoir – ensure adequate quality colostrum is available and the ewe and lamb’s behaviour leads to the lamb sucking quickly.

The next-best option is a supply of colostrum from another ewe in the flock. The opportunity to use another ewe’s colostrum may arise at birth, for example: there may be a good single mother lambed at the same time as a set of triplets, but having a store will be invaluable at other times.

Ewes in good condition, suitably fed and vaccinated are the best candidates for colostrum collection. The colostrum can be refrigerated for up to two days, or frozen at -18oC for up to two years. When defrosted, the temperature should not exceed 60oC to avoid protein breakdown.

Storage ideas:

During the SheepNet workshops, the Scottish farmers suggested using freezer bags designed for expressed baby milk, as these often have a ml gauge on the front to store the exact amount of colostrum needed.

They also suggested using baby bottles. Likewise, the French farmers proposed to freeze the colostrum in ice cube freezer bags, and the Spanish used single-use plastic bottles. Defrosting small doses in plastic is fast (in hot water) and convenient.

Colostrum quality

Before storing the colostrum, it is useful to check the quality. The French SheepNet partners proposed a series of inexpensive tools to evaluate the IgG concentration in colostrum.

They proposed either using a Brix refractormeter (a tool often used in the wine or fruit processing industry to check sugar content), or a colostrometer. Ideally, the evaluation should be done within four hours from lambing.

Idele and INRA (the French partners in the SheepNet group) developed a protocol for use of these tools, and proposed decision thresholds to grade the colostrum quality: less than 50g/l of IgG, poor quality, between 50g and 100g/l, good quality, less than 100g/l of IgG, excellent quality.

It is recommended to only freeze colostrum of good to excellent quality, to improve the transfer of immunity in lambs.

n More information is available at http://www.sheepnet.network/node/292