Histological and molecular signature of in utero hyperthermia on the mammary fat pad of newborn heifers Supplemental Material

This study explored how in utero hyperthermia affects the mammary gland fat pad at birth. Multiparous cows were dried off at 54 ± 5 d before expected calving and housed in a free-stall barn during a subtropical summer. The average temperature humidity index throughout the study was 79, with hourly average temperature humidity index ranging from 75-83. Under these conditions, heat-stressed cows (HS) had elevated respiration rates (77.4 breaths/min) and skin temperatures (36.0°C) from dry-off to calving. In contrast, a second group of cows received active heat abatement (cooling) through fans and water soakers, which reduced respiration rates to 53.5 breaths/min and skin temperatures to 34.1°C, values within thermoneutral physiological ranges. Female heifers born to these cows were classified as either in utero heat-stressed (iuHS; n = 8) or in utero cooled (iuCL; n = 8) during late gestation.
Heifers were euthanized and mammary gland tissue was collected at birth (4 ± 2 h after calving). Mammary gland fat pad was utilized for RNA sequencing. This respository contains the complete list of differentially expressed genes, overrepresented pathways, and upstream regulators from analysis.