ENUMERATION OF AMMONIA PRODUCING RUMINAL BACTERIA FROM CATTLE FED EITHER GRAIN OR HAY

Authors: RYCHLICK, JENNIFER - CORNELL UNIVERSITY; Russell, James

Submitted to: American Society for Microbiology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/22/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Mixed ruminal bacteria from cattle fed grain-based diets produced less ammonia than bacteria from cattle fed only hay (20 versus 40 nmol NH3/mg protein/min). Carbohydrate-fermenting bacteria isolated from both groups of cattle had low specific activities of ammonia production (<20 nmol NH3/mg protein/min), and many produced no ammonia at all. Dilution series indicated that both groups of cattle contained bacteria that could grow solely on peptides and amino acids, but cattle fed grain-based diets had a higher number of amino acid-utilizing bacteria than hay-fed cattle. However, a sharp transition from growth to no growth was not observed, rather, these dilution series gradually "faded out". Three existing 16S rRNA probes were utilized to determine the numbers of hyper-ammonia producing bacteria (HAB) in cattle fed both diets. Results indicated that Clostridium sticklandii was present in the 108 and 109 dilutions of ruminal lfluid from cattle fed hay and grain, respectively. C. aminophilum was not detected in hay-fed cows but was found in grain-fed cattle (105 to 107). Peptostreptococcus anaerobius was not detected in grain-fed cattle but was found at 107 in hay-fed cattle. These data indicates that hay- and grain-based diets support different populations of hyper-ammonia producing bacteria.