|Jung, Hans Joachim|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/19/1998
Publication Date: N/A
Technical Abstract: Hypotheses related to factors important in feeding value and digestion kinetics of ruminant feeds are often tested by creating feeds that differ in a minimum of characteristics. However, because of the diverse nature of most feeds and the correlations that exist among feed characteristics, it is difficult or impossible to create feeds that differ by a single characteristic. Our approach consists of genetic selection within a singl population for divergent levels of a single factor, using smooth bromegrass (Bromus inermis Leyss.) as a model species. We have created clones that range from 300 to 465 g/kg in neutral detergent fiber concentration, from 26 to 40% in particle size reduction index, from 158 to 178 g/kg in lignin concentration, or 3.1 to 3.7 g/kg in etherified ferulic acid concentration (all P<0.01 and at vegetative growth stages). We have also succeeded in breaking the natural positive correlation that exists between core lignin concentration and etherified ferulic acid concentration, allowing for a potential test of the independent effects of these two cell wall constituents on feeding value of smooth bromegrass hay. Some of the difficulties of this research include low heritability, genotype x environment interactions, and natural genotypic correlations between cell wall constituents.