Acrylamide Production in Autoclaved Rodent Feed.

Sterilization of rodent feed by steam autoclaving is a common practice in many research institutions. Often we only consider the beneficial effects of this process-the reduction of microbial contamination-and forget that the high temperatures and pressures can have negative effects on diet quality. The purpose of our study was to assess both the physical and chemical changes to a standard rodent feed autoclaved at multiple sterilization temperatures and the effects of the treated diets on mice.

The estrogenic content of rodent diets, bedding, cages, and water bottles and its effect on bisphenol A studies.

The lowest observed adverse effect level for bisphenol A (BPA) in mice and rats is currently poorly defined due to inconsistent study designs and results in published studies. The objectives of the current study were to (1) compare the estrogenic content of rodent diets, bedding, cages, and water bottles to evaluate their impact on the estrogenic activity of BPA and (2) review the literature on BPA to determine the most frequently reported diets, beddings, cages, and water bottles used in animal studies. Our literature review indicated that low-dose BPA animal studies have inconsistent results and that factors contributing to this inconsistency are the uses of high-phytoestrogen diets and the different routes of exposure.

Variations in phytoestrogen content between different mill dates of the same diet produces significant differences in the time of vaginal opening in CD-1 mice and F344 rats but not in CD Sprague-Dawley rats.

Background: The optimum test diet and rodent species/strain for evaluating endocrine-disrupting compounds (EDCs) are critical.

Objectives: We conducted studies to evaluate rodent species sensitivity and the effects of diets varying in phytoestrogen content on the time of vaginal opening (VO) in CD-1 mice, Fischer 344 (F344) rats, and CD Sprague-Dawley (S-D) rats.

Methods: Mice were weaned on postnatal day (PND) 15 and rats on PND19 and randomly assigned to control or test diets.

Dietary factors affecting uterine weights of immature CD-1 mice used in uterotrophic bioassays.

A study was conducted to determine the effects of dietary factors in natural ingredient and purified diets on uterine weights of immature CD-1 mice used in uterotrophic bioassays. Factors evaluated included body weight gain, dietary phytoestrogen content, total metabolizable energy, and percent crude fiber. Fifteen to 147 mice per group, housed 5 per cage, were randomly assigned to each of the 20 test diets.