Abstract
The extent of cellulose digestion by washed suspensions of rumen microorganisms was used as the index in evaluating the stimulatory or inhibitory effects of individually added B, Ba, Br, Cd, Cr, Co, Cu, F, Fe, I, Mn, Mo, Ni, Rb, Se, Sr, V or Zn upon rumen microbial activity (table 5). The elements and concentrations (in ppm) found to be stimulatory to cellulose digestion included: (P<.05) Co, 3; I, 20; Fe, 3–5; Mn, 5–30; Mo, 10-100; Rb, 20; Zn, 5-7; (P<.10) Cd, 5; (P<.20) Cr, 2 and Sr, 10–15. Depression of cellulose digestion (P<.05) occurred at the following levels (in ppm): Ba, 30; B, 300; Cd, 10; Cr, 7; Co, 7; Cu, 1; F, 0.5; Fe, 100; Mn, 100; Ni, 0.5; Se, 7; Sr, 200; V, 5 and Zn, 20. Bromine concentrations of 1 to 1,000 ppm had no effect on cellulose digestion. Levels up to 1,000 ppm 1, 500 ppm Mo and 1,000 ppm Rb had no significant detrimental effect upon cellulose digestion by washed suspensions of rumen microbes. Copyright © 1970. American Society of Animal Science . Copyright 1970 by American Society of Animal Science