Alterations in body mass and inflammometabolic indices in Holstein cows fed different levels of energy and receiving 2,4-thiazolidinedione

Overfeeding energy during the dry period increases the incidence of metabolic disease postpartum. Dry matter intake (DMI), body condition score (BCS) and blood inflammometabolic markers can serve as reliable indicator of health, inflammation and liver function. We evaluated DMI, BCS, metabolism, inflammation, and liver function in response to level of dietary energy and 2,4-thiazolidinedione (TZD) administration. Fourteen dry non-pregnant Holstein cows were assigned to treatments in a randomized block design. All cows were fed a control diet (CON; NEL = 1.32 Mcal/kg) to meet 100% of NRC requirements for 3 wk, after which half of the cows were assigned to a moderate-energy diet (OVE; NEL = 1.54 Mcal/kg) and half of the cows continued on CON for 6 wk. The OVE diet was fed ad libitum and resulted in cows consuming ~180% of NRC. CON cows were fed to consume only to 100% of NRC. All cows received 4 mg TZD/kg of BW daily starting 2 wk after the initiation of treatments and for 2 additional wk. The last 2 wk of the study served as the washout period. BW and BCS were recorded twice a week, while DMI was recorded daily during the entire study. Blood was harvested frequently during wk −1 to 6 for measurement of metabolites and hormones. Data were analyzed using PROC MIXED of SAS. In OVE compared with CON, the BW, DMI and DMI as a percentage of BW increased over time (P < 0.001), while BCS remained unchanged. The concentration of glucose, hydroxybutyrate (BHBA), cholesterol and aspartate aminotransferase-oxaloacetic transaminase (AST-GOT) increased (P ≤ 0.04) in OVE, but paraoxonase (PON) decreased (P ≤ 0.03) over time compared with CON. Overall concentration of NEFA and haptoglobin was lower (P < 0.05) in OVE than CON. An improvement of energy balance status in OVE cows was observed without a negative effect of TZD on DMI. The changes in AST-GOT and PON might reflect the effects of OVE on hepatic function. Excess dietary energy did not enhance inflammation and oxidative stress. In contrast with previous studies, TZD did not improve insulin sensitivity beyond what was observed with OVE alone.