Relationship between Serum TNF Activity and Insulin Resistance in Dairy Cows Affected with Naturally Occurring Fatty Liver

To clarify the relationship between tumor necrosis factor (TNF) and insulin resistance in dairy cows affected with fatty liver, naturally occurring cases were investigated. The affected cows were classified into following three groups according to histopathologic findings of the liver: mild fat droplet deposition (group 1; n=11), severe fat droplet deposition (group 2; n=10), and cloudy swelling (group 3; n=8). Serum TNF activities in Group 2 (8.67 ± 2.16 U/ml) and Group 3 (11.65 ± 1.92 U/ml) were significantly higher than that in Group 1 (3.57 ± 0.81 U/ml) (p