How do we preserve colostrum for our calves?

By Katie Denholm, Herd Health Veterinarian

Historically we have used a wide range of chemical and probiotic preservatives to preserve colostrum in New Zealand; these include Formalin, Hydrochloric acid and Formic acid. However, the issue with these old compounds is that many of them are not approved for use in the food producing industry and some of them are classed carcinogens.

Last season our Cognosco research team completed a study into refrigeration, probiotic yoghurt and a chemical called Potassium sorbate to preserve colostrum. Off the back of this research, there is a new school of thought on colostrum preservation in New Zealand; that is the use of Potassium sorbate. This is a method that has been employed for a number of seasons in the Australian dairy sector to great effect. The chemical has also been approved for use in the food-producing industry for making wine and cheese, and is totally safe for human consumption unlike the acid and formaldehyde-based products which have been used in the past. Better still, Potassium sorbate is inexpensive and works extremely effectively to preserve colostrum even at room temperature. Since very few farmers have refrigeration facilities for colostrum storage this means that a bit of potassium sorbate added to the drum can go a long way towards ensuring colostrum stays fresh and doesn’t spoil as readily.
Mixing instructions for Potassium sorbate.

Potassium sorbate comes in a granulated form and needs to be mixed up as a 50% solution; for example 2.5kg to 5 litres of tap water.
Add this 50% solution at a rate of 1% to your colostrum vat; so if you have 500 litres in your drum, you will need 5 litres of Potassium sorbate. Treat each additional volume of colostrum with 1% Potassium sorbate before you add it to your vat. Do not use any Potassium sorbate that has been mixed up for more than a week.

Easiyo yoghurt doesn’t work:
The latest research from our laboratory showed that Easiyo probiotic yoghurt is not effective at preserving antibody levels in colostrum and preventing bacterial proliferation. The concept of promoting ‘good bugs’ in the colostrum to counteract the ‘bad bugs’ by adding yoghurt has simply been shown to be ineffective; although the practice of adding yoghurt to the colostrum vat has been fashionable for a number of years.

Using temperature to preserve colostrum - refrigeration and freezing:
Refrigeration and freezing of colostrum to preserve it remains a good option, although facilities may be in short supply. Repeated freezing and thawing of colostrum may lead to denaturing of the large antibody molecules we are so interested in preserving, so it is best to freeze and reheat once only, preferably in a large bucket of boiling water.

Date Added: Monday, 25th July 2016