Glucose and lipid metabolism are modified by short‐term alterations to milking frequency in grazing dairy cows

Short‐term changes to milking frequency (once daily, 1X; or thrice daily, 3X) alter metabolic balance in dairy cows. There are contradictory results regarding effects when cows are switched to normal milking (twice daily; 2X). Cows were allocated to 3 or 6 weeks of 1X or 3X milking post‐calving, switched to 2X milking for the rest of lactation, and compared with cows milked 2X for the whole lactation. Serial liver and adipose biopsies were collected in the first 9 weeks (n=12 cows/trt) and gene expression measured by RT‐qPCR. Data suggests that cows milked 1X had reduced gluconeogenesis and β‐oxidation in liver tissue but increased β‐oxidation and lipolysis in adipose tissue during treatment, compared with cows milked 2X. Cows milked 3X for 6 weeks exhibited reduced lipogenesis and lipolysis in adipose tissue during and post‐treatment. Results indicate that alterations to milking frequency affect carbohydrate and lipid metabolism during, and after treatment. These results increase understanding of the regulation underlying responses to altered milking frequency, and may have implications for farm management. This research was funded through DairyNZ Inc. and the Ministry of Science and Innovation, NZ