When your bulk tank volume takes a plunge through the last bout of heat, do you ever wonder exactly WHY? What is it in the udder that changes to cause the decline? Why do we also commonly see elevated SCC in our tanks too? To best understand the why, the Virgina Tech dairy team collected tissue samples from the mammary gland of cows in controlled environmental chambers. This month we invite Dr. Ben Corl to explain the cellular changes observed in the alveoli, epithelial and even immune cells of the mammary gland of cows undergoing a controlled heat stress challenge.   Additionally, he’ll describe the changes in gene expression in those same tissue samples that controls protein production and mammary health. This continuation of our heat stress series features two papers titled: (1) Cyclical heat stress during lactation influences the microstructure of the bovine mammary gland(2) 2022: Heat stress increases mammary epithelial cells and reduces viable immune cells in milk of dairy cows Topics of discussion 1:28       Introduction of Dr. Ben Corl2:36       Describe the experimental design 3:58        Pair Feeding – Intake experimental design7:14        Could the cows cool during the evening ? 8:47        Microscopic changes to the mammary 10:31     Cellular turnover in the alveoli  13:20     Increased losses of epithelial cells, a portion of the somatic cell population 16:39     Decline in viable Immune cell population in the mammary 19:38     Body temperature before and after milking 20:16     Number of alveoli24:07     Gene & protein expression changes 24:56     Gene expression pathway for cellular health in the mammary26:25     What do you want Boots on the ground dairyman to know Background Information:Temperature Humidity Index (THI) #2xAg2030; #journalofdairyscience; #openaccess; #MODAIRY; #heatstress; #alveoli; #milk; #mammarydevelopment; #mammary; #dairysciencedigest; #ReaganBluel;