Bovine serum: reducing the variables through the use of donor herds.

Biological materials are variable by their very nature. Serum in particular is a complex mix of substances and may contain adventitious agents. Serum for pharmaceutical use is controlled on a batch to batch basis given that each batch may have differing properties. Control points for slaughterhouse obtained bovine and foetal bovine serum exist with the disease status and disease surveillance of the country of origin, veterinary inspection for clinical disease, collection methods and post collection quality control. With these control points many batches of commercially available serum are contaminated with viruses such as BVD. The use of donor serum provides a mechanism to extend Good Manufacturing Practice principles back to the farm environment giving the manufacturer the ability to increase control on production parameters in the donor animal such as disease and specific antibody status, genetic type and history, age, diet, treatments and origin of feed. As well as providing a secure supply of serum for manufacture, donor herds provide added traceability and give the opportunity for in vivo manipulation of the serum and specialised selection of the animals for specific applications with more consistent reproducibility of performance. The BSE crisis of the last 10 years has highlighted the added control that donor serum producers can exert: Many producers of donor serum applied ruminant feed bans on their animals ahead of nation-wide bans in their own countries. SPF donor herds can be set up in several ways and the purchaser should make themselves familiar with the methods used. SPF herds with accompanying seronegative status allow quality control testing of product free from the interference of specific antibodies. Such specific antibody freedom may also allow better growth of viruses for vaccine manufacture.