monensin and Pulmonary-Edema

The effect of feeding monensin, with or without dry hay plus wilted forage, on ruminal formation of 3-methylindole (3MI) was investigated in pastured cattle. Eighty-two cows were allotted to 3 groups. Cows of group-1 served as controls and were given a daily energy supplement (1 kg/head) without monensin for 1 day before and for 7 days after being allowed access to lush pasture. Cows of groups 2 and 3 were given the same daily energy supplement, which also contained monensin (200 mg/kg of supplement). Cows of group 3 also were fed dry hay for 5 days before the start of the study and continued to be given supplemental hay for 4 days after being allowed access to lush pasture containing a layer of wilted forage. Ruminal 3MI and indole concentrations increased on day 1 after all groups were allowed access to lush pasture. By day 7, 3MI concentration in all cows had decreased to pregrazing concentration. Indole concentration did not reach pregrazing concentration until day 10 for cows of groups 1 and 2. Group-3 cows had pregrazing indole concentration on day 7. Ruminal indole concentration did not differ (P greater than 0.05) between groups 1 and 2. Ruminal indole concentration was lower (P less than 0.01) in group-3 cows on all sample collection days, except day 10, compared with that in the other groups. Monensin reduced (P less than 0.01) 3MI formation on days 1 and 7 in group-2 cows, compared with group-1 cows. Group-3 cows had lower 3MI concentration than did group-1 cows (P less than 0.01) on days -1, 1, 4, and 7.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Acute Disease; Animal Feed; Animals; Cattle; Cattle Diseases; Digestion; Fatty Acids, Volatile; Female; Hydrogen-Ion Concentration; Indoles; Monensin; Poaceae; Pulmonary Edema; Pulmonary Emphysema; Random Allocation; Rumen; Skatole

A series of in vitro and in vivo trials was conducted to determine if continuous monensin feeding for up to 56 d would reduce ruminal conversion of L-tryptophan (TRP) to 3-methylindole (3MI). Fourteen mature beef cows were adapted to a maintenance diet for 3 wk. In trial I, the sampling time to optimize 3MI production was determined. Trials II through IV were to determine the duration of efficacy of monensin on reducing 3MI concentrations in vitro and in vivo. During trials II, III and IV one-half of the cows were fed 200 mg monensin X head-1 X d-1 for 21, 36 and 55 d, respectively, while the remaining cows served as controls. All cows were fed the control diet for 21 d between each trial. Volatile fatty acid (VFA) concentrations and in vitro conversion of TRP to 3MI were determined in ruminal fluid samples collected during trials I through IV. On d 28 of trial IV, all cows were given an oral dose of .35 g TRP/kg of body weight to induce acute bovine pulmonary edema and emphysema (ABPE). Ruminal concentrations of 3MI and indole were measured at intervals for 96 h. Results of trial I demonstrated that ruminal fluid collected 15 h postfeeding produced the highest in vitro conversion of TRP to 3MI. Therefore, ruminal fluid samples were collected at that time in trials II, III and IV. In vitro conversion of TRP to 3MI was lower (P less than .01) in samples from monensin-treated cows (12.1%) compared with controls (25.6%). Monensin reduced 3MI production for 55 d, the longest time tested in these experiments.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Cattle; Cattle Diseases; Depression, Chemical; Fatty Acids, Volatile; Female; Food Additives; Furans; In Vitro Techniques; Indoles; Monensin; Pulmonary Edema; Pulmonary Emphysema; Rumen; Skatole; Tryptophan

Topics: Ammonia; Animals; Cattle; Cattle Diseases; Fatty Acids, Volatile; Female; Fermentation; Furans; Gastric Juice; Hydrogen-Ion Concentration; Indoles; Monensin; Poaceae; Pulmonary Edema; Pulmonary Emphysema; Rumen; Skatole