Bovine serum is a by-product of the meat industry. Bovine blood may be taken at the time of slaughter, from adult cattle, calves, very young calves or (when cows that are slaughtered are subsequently found to be pregnant) from bovine fetuses. It is also obtained from what are called “donor” animals which give blood more than once.
Blood is available from bovine fetuses only because a proportion of female animals that are slaughtered for meat for human consumption are found (often unexpectedly) to be pregnant.
Bovine serum is categorized according to the age of the animal from which the blood was collected as follows:
- Fetal bovine serum” comes from fetuses
- Newborn calf serum” comes from calves less than three weeks old
- Calf serum” comes from calves aged between three weeks and 12 months
- Adult bovine serum” comes from cattle older than 12 months