Winter wheat (Triticum aestivum L.) is the predominate cool-season forage grown in the southern Great Plains and is considered excellent forage capable of producing gains > 1.4 kg/day in stocker cattle (Bos taurus L.). High digestibility, soluble proteins, and intake of lush growing wheat contribute to pasture bloat, leading to substantial economic loss. In the 1999-2000 grazing season 41% of OK producers reported pasture bloat with 40% of animal deaths attributed to bloat causing a $5 million loss. Forage tannins can reduce the incidence and severity of bloat, promote better use of forage protein, and provide a passive means to manage pasture bloat. The objective of our research was to measure tannin content and variability in wheat cultivars and experimental lines to determine the feasibility of using traditional breeding methods to give producers a passive choice to reduce the incidence of bloat. Fall forage samples were collected from 218 diverse experimentals and four check cultivars distributed among 12 blocks in an augmented randomized complete block design. There were significant (P ≥ 0.05) forage yield differences among the experimentals (range, 188-1140 kg/ha; mean, 556 kg/ha not different from checks). Differences among the experimentals in methanol-water extractable phenolic acids (tannic acid equivalents) were significant (range, 14.8-32.8 mg/g dry wt.; mean, 23.4 mg/g dry wt.), but condensed tannin (quebracho equivalents) differences were not significant (range 1.46-4.82 mg/g dry wt.; 2.67 mg/g dry wt.). While we observed marked differences in tannic substances among the experimentals, even the greatest amounts detected are unlikely sufficient to render the forage bloat-safe. Perhaps those experimental lines with the most abundant tannin levels could be used in a traditional breeding program to increase the level of tannins in wheat forage, but to make substantial changes in amounts of condensed tannins will require additional screening or a molecular engineering approach.