Two studies presented at the 2011 national scientific meetings of the American Dairy Science Association investigated bacterial contamination levels in fresh colostrum. Calf researcher Jim Quigley reviews both in a recent issue of his “Calf Notes” online calf management library.  Quigley reports:

In a nationwide study conducted by researchers at Iowa State University, samples of first-milking colostrum were collected from 67 different farms in 12 states. Total bacteria plate count was assessed in 892 colostrum samples, revealing:

  • Average plate count was 550,000 cfu/mL, well above the industry standard of 100,000 cfu/mL
  • 148 of the 892 samples contained more than 1,000,000 cfu/mL
  • Colostrum was transferred from one container to another an average of 2.5 times, with 9 percent of samples transferred up to four times before feeding
  • Average elapsed time from collection to feeding was 48 minutes, with more than half of samples being fed or stored over an hour after collection

Fresno State University researchers collected and analyzed 546 first-milking colostrum samples from seven dairies in California’s Central Valley over a 12-month period in 2009 and 2010. Three of the dairies added colostrum supplements, in which cases samples were gathered both before and after supplementation. Their results showed:

  • A total of 18 percent of unsupplemented colostrum samples contained bacterial levels higher than 100,000 cfu/mL
  • Supplemented colostrum was contaminated (>100,000 cfu/mL) in 57 percent of cases.  It was not clear whether contaminated equipment, or the supplement itself, was the source of additional bacteria
  • Four dairies consistently produced colostrum below the contamination threshold of 100,000 cfu/mL
  • The low-bacteria dairies had well-designed protocols for collecting, handling and storing colostrum, which were followed closely

Quigley concludes that most dairy enterprises could make improvements in colostrum handling, including detailed protocols for collection, feeding and storage. Read more of his observations and advice in Calf Note #163, “Bacteria in colostrum – how are we doing?”