Abuelo, Angel, et al. Journal of veterinary internal medicine 30.3 (2016): 892-898.
DL-alpha-Tocopheryl acetate is a potent lipid-soluble, chain-breaking antioxidant; this randomized placebo-controlled trial tested whether parenteral antioxidant supplementation before calving improves postpartum glucose tolerance in dairy cattle.
Experimental Protocol: Ten late-pregnant Holstein cows entering their 2nd to 5th lactation were used. At 15 +/- 2 days before expected calving, the treatment group received an injection of DL-alpha-tocopheryl acetate at a dosage of 6 mg/kg body weight (equivalent to 6 IU/kg body weight of vitamin E) plus 0.06 mg/kg body weight of sodium selenite, while the control group received isotonic saline. During the first week after calving, both groups underwent intravenous glucose tolerance testing with 0.25 g glucose/kg body weight, and commercial assays quantified blood glucose, insulin, nonesterified fatty acids (NEFA), beta-hydroxybutyrate and redox status markers; data were analyzed using the Mann-Whitney U-test (a = 0.05).
Performance Evaluation: Supplemented cows showed a lower risk for oxidative stress, reflected by a lower oxidative stress index (P = .036), and different areas under the curve for glucose (P < .01), insulin (P = .043) and NEFA (P = .041), along with more rapid elimination rates and shorter half-lives of these metabolites, thereby indicating greater insulin sensitivity after calving.
Rey, A. I., et al. Journal of Animal and Feed Sciences 26.3 (2017): 226-235.