|MACKOWN, CHARLES - Retired ARS Employee|
|CARVER, BRETT - Oklahoma State University|
|EDWARDS, JEFFREY - Oklahoma State University|
Submitted to: Crop Science Newsletter
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/2011
Publication Date: N/A
Interpretive Summary: Abstract Only.
Technical Abstract: Pasture bloat can be a serious problem for ruminant livestock grazing winter wheat (Triticum aestivum L.). Decreased gains with nonlethal bloat episodes, yearly herd deaths up to 2%, and the cost and risk of active intervention reduce profi ts. Wheat has high digestibility, crude protein (CP), and soluble N fractions, traits associated with bloat-provoking forages. We characterized variation in CP and initial in vitro dry matter digestion (IVDMD) of wheat varieties and experimental lines to gain knowledge needed to develop genotypes that might decrease frequency and severity of bloat. Late fall forage from seven trials (34 different varieties) and late fall and late winter forage from 221 experimental breeding lines were analyzed. Signifi cant (p < 0.05) differences among varieties and breeding lines were found for CP and IVDMD; trait variation among breeding lines was often greater than among the check varieties Duster, Endurance, Jagger, and Overley. Differences in CP among breeding lines were as great as 47% and averaged 15% for the variety trials. After an 8 h incubation differences in the percent IVDMD among breeding lines were as great as 97% and averaged 24% for the variety trials. Correlations of CP with initial IVDMD traits were not significant or only weakly correlated (variety trials, r = 0.11, p = 0.01, and n = 484), thus development of wheat varieties with reduced CP and low initial rates of IVDMD will require simultaneous selection for both traits.