Dormant pastures and native grass hays often are deficient in protein and other nutrients
needed to support optimum performance of beef cattle. These nutrients are
essential for maintaining viable populations of symbiotic rumen microorganisms that
digest the fiber in forages. When nutrient deficiencies occur, microbial populations in
the rumen decrease, thereby limiting digestion of low-quality forages. This study was
conducted to evaluate changes in rumen microbial populations and digestive activity
when cattle consuming low-protein native grass hay are given access to high-protein,
free-choice block supplements.