An HPLC to Strengthen Analytical Opportunities in Bovine Mastitis
The risk of mastitis is greatest during the transition period. The cost of mastitis is greater than $1.7 billion each year and represents a significant loss for the dairy industry. During the last 25 years, there has been improvement in mastitis prevention and control as well as a greater understanding of the effects of dietary nutrients on immune function. However, research on nutritional factors affecting immune function in particular, bovine retinoid metabolites and RBP, the carrier protein for retinol, are limited for dairy cows and in response to intra-mammary infection. Our laboratories have been investigating the metabolic challenges during the transition period in dairy cows and their effects on specific immune measures and, in particular, on mastitis. This proposed project will create new knowledge of the effects of the retinoids and
RBP status on immune system enhancement in dairy cows. Mastitis affects the composition of fluid milk and the extent to which composition is altered depends on the causative agent and host inflammatory response to the infection. In response to an infection, major changes occur in the mammary gland. One of the perceived minor changes that occurs is in the lipid composition of milk. Increased concentrations of free fatty acids in milk are common during mastitis in cows. Increases of 50 to 100% in free fatty acid content of milk from cows with mastitis have been detected. The increase in free fatty acids during infection of the mammary gland is not constant among all fatty acids. Preference for fatty acids C4:0, C6:0 and C8:0 is at the sn-3 position, while C12:0, C14:0, and C16:0 are located at the sn-2 position. These "released" fatty acids in milk may act as antimicrobials reducing the
growth of the pathogen.