16S rRNA gene sequencing of rumen epithelial and content samples from dorsal sac of a Holstein-Friesian Dairy cow during heat stress

Rumen epithelium and content samples were taken from twenty rumen-fistulated, lactating Holstein-Friesian dairy cows of differing parity. The twenty cows were divided into two replicates of ten, and these which were further divided into five treatment and five control cows. Replicate 1 cows were all first parity, ranging in body weight from 1140-1385 lbs, and between 62-122 days in milk, and were producing 62-87 lbs of milk per day. Replicate 2 cows were from parities 1-3, ranging in body weight from 1170-1405 lbs and, between 31-85 days in milk, and were producing 90-123 lbs of milk per day. Cows within the treatment group received 2 g Sucram a day, manually mixed into the feed as per feeding protocols provided by Pancosma. Each replicate was subject to a 7-day adaptation period where no heat stress was applied, and each experimental group was provided their respective diets. The adaptation period was followed by a 14-day heat stress period, where animals were subjected to THI >80 during the hours of 0800-1800.