DSD 7.4 | Impact of infection on mammary development in pregnant heifers

The trajectory of the success for a dairy cow begins with mammary development, long before lactation begins.  Dr. Benjamin Enger, Associate Professor for The Ohio State University in Wooster, has worked with his team for years to best understand how infection can change the development and if the timing of infection impacts that response.

He was specifically interested in Staphylococcus aureus (SA), a common contagious pathogen in dairy farms. To study this, 21 bred heifers at three stages (6.5, 7.5 and 8.5 months) of pregnancy were inoculated, and tissue samples were collected 21 days later to determine the damage done.

In this edition, there is much discussion about the physiology of mammary gland development and how different stages of pregnancy impacts progress towards lactation. Understanding the development of the mammary, will likely illuminate the importance of seemingly meniscal management steps. Analyzing your farm’s data could hold the key to eliminating what might be the source of this devastating pathogen.

Listen in today to learn more!

Topics of discussion

1:40      Introduction of Dr. Ben Enger  
3:08      Project set up
3:47      Knowledge gained in projects leading up to this hypothesis
6:53      What is mammary epithelial cells (MEC) and stromal cells
10:18    How did Staph Aureus (SA) impact amount of MEC and stromal cells in infected quarters
13:21     Cellular changes in heifers 6.5 vs 8.5 months pregnant
17:00     Cellular differences between the edge tissue vs the center (pic p4)
18:40    Duration of impact as the result of SA infection in pregnant heifers  
20:54     How does SA get into calves prior to freshening?
22:53    Did you observe immunotolerance in the pregnant heifers?
25:53    What do you want ‘boots on the ground’ dairymen to know about your project 
27:26    Experimental increase of milk using blanket therapy to heifers precalving
28:17    Examine first test SCC in first calf heifers
27:20     What do you want ‘boots on the ground’ dairymen to know about your project 
              

Featured Articles:

Impact of Staphylococcus aureus intramammary infection on cellular proliferation and apoptosis on developing mammary glands of pregnant dairy heifers

Supporting article:
Impact of intramammary infections on mammary gland development in pregnant dairy heifers during late gestation

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