Energy Balance and Mastitis Resistance in Dairy Cows - A Transcriptional Profiling Approach 

Funded by Section 1433 - Animal Health & Disease (ILLU-538-952, 2005-2006)

Objectives: The overall objective is to determine the molecular mechanisms underlying mastitis infections and alterations of mammary tissue function in dairy cows with different plane of nutrition.  We will use genomic analysis to compare gene expression profiles in mammary tissue with and without mastitis from cows in positive or negative energy balance to identify disease-specific genes that may play crucial roles in mastitis defense.  Our hypothesis is that negative energy balance reduces the clinical response to mastitis infection, in part through downregulation of the expression of genes associated with inflammatory responses, cytokine function, and/or response to stress in the mammary gland.  Thus, diet-induced negative energy balance leads to higher susceptibility to developing natural mastitis.

Specific objectives are 1) To determine global gene expression patterns in mammary tissue in response to energy balance and intra-mammary infection, and 2) To relate mammary gene expression profiles with other physiological measurements associated with immune and/or metabolic responses to energy balance and mastitis challenge.

Potential benefits:  Mastitis is the most costly disease in animal agriculture.  Dairy cows are most susceptible to mastitis around the time of calving, i.e. the periparturient period.  Around calving, cows experience a period of negative energy balance that may contribute to diminished immune function.  This infection model will allow us to examine the molecular and cellular basis of the host-pathogen interaction in the bovine mammary gland in response to energy balance status.  Determination of relationships between energy balance and host response to mastitis infection might lead to better recommendations for nutrition and management during the dry period to decrease susceptibility to mastitis around parturition.  Investigating the effects of plane of nutrition on mammary tissue response to a mastitis challenge represents an important benchmark for work in this area, and will be a major advancement in our knowledge of nutrition-gene interactions and disease.  The ultimate benefits of research in this area will be improved health and well being of dairy cows and increased profitability of dairy enterprises in Illinois and beyond.