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As concern over the possible overuse of antibacterials increases, attention has focused on reduction of antibiotic usage and on nonantibiotic alternatives. A nonantibiotic intramammary teat sealant, Teat Seal (Cross Vetpharm Group Ltd., Tallaght, Dublin, Ireland), has been available in Ireland, in combination with an intramammary tube of cloxacillin. Teat Seal has been reformulated for use in cows with low cell counts as an alternative to antibiotic dry cow therapy at the end of lactation. The product is now marketed as Orbeseal (Pfizer Animal Health). A comparison between this teat sealant and no treatment was made on new intramammary infections and clinical mastitis, on all cows within four herds, and on low cell count cows in three herds. No cases of clinical mastitis in the dry period were observed in cows treated with Teat Seal (n = 197), whereas a significant number (6 cows) were observed in the untreated cows (n = 204). In all herds, significantly more new infections at calving were found in the untreated group (62 cows in the untreated group compared with 21 cows in the Teat Seal group). In those quarters where infections were first detected at calving, the incidence of clinical mastitis was significantly greater in the untreated group. Quarters in both treatment groups that were infected at drying off with Corynebacterium spp. or coagulase-negative staphylococci were not protected against new infections and had an increased risk of new infection by Streptococcus uberis. The results will inform those restricting their use of antibiotic dry cow therapy in alternative management strategies and the additional risk of new intramammary infection.

OBJECTIVE -Markers of oxidative stress and plasma alanine transferase (ALT) levels are increased and circulating antioxidant concentrations are reduced in individuals with insulin resistance. Vitamin E improves glycemic control in people with diabetes. We tested the hypothesis that vitamin E would decrease markers of oxidative stress and plasma ALT levels and improve insulin sensitivity in overweight individuals. RESEARCH DESIGN AND METHODS -Eighty overweight individuals (BMI Ͼ27 kg/m2 ) were randomly allocated to receive either 800 IU vitamin E per day or a matching placebo for 3 months. The dose of vitamin E was increased to 1,200 IU per day for a further 3 months.RESULTS -Plasma peroxides decreased by 27% at 3 months and by 29% at 6 months in the group that received vitamin E and were positively correlated with plasma vitamin E concentrations at the 6-month time point. At 3 months, fasting plasma glucose and insulin concentrations were significantly reduced and homeostasis model assessment increased. These changes were not apparent at 6 months. Plasma ALT concentrations declined significantly throughout the study period.CONCLUSIONS -In conclusion, these findings indicate that vitamin E improves oxidative stress and hepatocellular function. Although insulin resistance also improves, this effect appears transient. Diabetes Care 27:2166 -2171, 2004T he prevalence of diabetes is increasing dramatically in the western world (1). This increase parallels that of obesity, with insulin resistance explaining the link between these two entities (2). Although the precise mechanism responsible for insulin resistance remains unclear, it would appear that a number of adipocyte-derived factors impair insulin activity and that the secretion of these factors is altered in the obese individual (3). Diabetes results when, in addition to insulin resistance, ␤-cell dysfunction occurs, leading to relative insulin deficiency. Interventions shown to be effective at preventing the progression to diabetes include lifestyle modification (4,5) and certain pharmacologic agents (4,6).One of the adipocyte-derived factors implicated in the pathogenesis of insulin resistance is the free fatty acid (FFA) (7). Although the rate of release of FFAs from individual adipocytes may not be raised in obesity, the increased amount of adipose tissue overall leads to an increase in the flux of FFAs to the liver and skeletal muscle, the two tissues most intimately involved in glucose handling (8). Once FFAs enter target tissues, they are either stored as triglycerides or are utilized as a substrate for oxidation by the cell's mitochondria. As a result of the normal process of oxidation, reactive oxygen species (ROS) are produced (9). These ROS are potentially harmful to cellular functions. To prevent these harmful effects, the cell has developed a complex antioxidant system to dispose of ROS. However, antioxidant concentrations are reduced in obese individuals, and the resulting imbalance between the production of ROS and antioxidant defenses results in o...

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