Use of potassium depletion to assess adaptation of ruminal bacteria to ionophores

Lana, R.P.; Russell, James B.

doi:10.1128/aem.62.12.4499-4503.1996

Cited by 31 publications

(18 citation statements)

References 25 publications

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“…Previous work with mixed ruminal bacteria indicated that energized cells could counteract monensin-dependent potassium e¥ux, but monensin caused a decrease in the steady state concentration of intracellular potassium [12]. The relationship between monensin concentration and steady state potassium was a saturation function.…”

Section: Discussionmentioning

confidence: 87%

The binding and degradation of nisin by mixed ruminal bacteria

Lee¹

2002

FEMS Microbiology Ecology

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We found that nisin catalyzed potassium efflux from glycolyzing Streptococcus bovis JB1 cell suspensions and that the steady state concentration of residual potassium was dependent upon the amount of nisin added. The relationship between nisin concentration and potassium depletion was a saturation function that had considerable cooperativity. By pre-incubating mixed ruminal bacteria with nisin and removing them prior to S. bovis JB1 addition, it was possible to estimate the ability of mixed ruminal bacteria to bind or degrade nisin. Low concentrations of mixed ruminal bacteria did not bind or degrade all of the nisin in 6 h, but little nisin remained if the mixed ruminal bacteria were present at more than 50 microg protein ml(-1). Because cell-free ruminal fluid (10% v/v) inactivated the nisin in less than 2 h, and this inactivation could be counteracted by autoclaving, ultra-filtration or proteinase inhibitor, it appeared that there was an enzymatic degradation of nisin. Mixed ruminal bacteria degraded nisin rapidly, but this degradation did not prevent potassium depletion from mixed ruminal bacteria. These latter results indicated that nisin binding was faster than nisin degradation. The idea that nisin binding could protect nisin from degradation was supported by the observation that intact nisin could be extracted from mixed ruminal bacteria. These observations support the hypothesis that bacteriocins can be used to modify ruminal fermentation, but further work will be needed to see if these peptides can be produced economically.

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Section: Discussionmentioning

confidence: 87%

The binding and degradation of nisin by mixed ruminal bacteria

Lee¹

2002

FEMS Microbiology Ecology

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“…Four-week periods were used in the Latin square with ruminally cannulated cows because16-wk was the total length of the production trial and because there was evidence in the literature that adaptation to mo-nensin is rapid. The potassium depletion effect of monensin on mixed ruminal bacteria occurred within less than 15 min in vitro and within 4 d in vivo (Lana and Russell, 1996). Yang and Russell (1993) reported that decreased ruminal NH 3 occurred within 3 to 5 d of adding monensin to the diet.…”

Section: Ruminal Metabolism Trialmentioning

confidence: 99%

Effect of Low Level Monensin Supplementation on the Production of Dairy Cows Fed Alfalfa Silage

Broderick

2004

Journal of Dairy Science

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Effectiveness of low level monensin supplementation on N utilization in lactating dairy cows fed alfalfa silage was assessed using 48 multiparous Holsteins. Cows were fed a covariate diet [% of dry matter (DM): 56% alfalfa silage, 39% ground high moisture corn, 3% soybean meal, 1% ground corn, 1% vitamin-mineral supplements] for 2 wk, then grouped by days in milk into blocks of 4. Cows were randomly assigned within blocks to 1 of 4 diets that were fed for 10 wk: 1) control (covariate diet), 2) control plus 3% fish meal (replacing DM from high moisture corn), 3) monensin (10 mg/kg DM), and 4) monensin plus 3% fish meal. Diets 1 and 3 averaged 16.7% crude protein (25% from free AA in alfalfa silage); diets 2 and 4 averaged 18.5% crude protein. Monensin intake averaged 16 mg/d on diets 1 and 2 (due to contamination) and 248 mg/d on diets 3 and 4. There was no effect of fish meal or monensin on DM intake. However, weight gain and yield of milk, protein, and SNF increased with fish meal feeding, indicating metabolizable protein limited production. Feeding monensin increased blood glucose but reduced yield of 3.5% fat-corrected milk, milk fat content and yield, and milk protein content and yield. Apparent N efficiency was greatest on monensin (diet 3) but lowest on monensin plus fish meal (diet 4). Fish meal reduced blood glucose concentration and apparent N efficiency, and increased concentrations of milk and blood urea. Monensin increased ruminal propionate concentration and decreased concentration of acetate and butyrate and acetate:propionate in ruminally cannulated cows fed the experimental diets. However, these changes were small, suggesting that too little monensin was fed. Fish meal reduced ruminal total amino acid (AA) but monensin did not alter ruminal NH(3) or total AA. Both fish meal and monensin increased NH(3) formation from casein AA using ruminal inoculum from the cannulated cows. There was no evidence from this trial that feeding 250 mg of monensin per day to lactating cows improved N utilization by reducing ruminal catabolism of the large amounts of free AA in alfalfa silage.

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“…The transfer of genes encoding resistance was thought to be less likely because of the long-term (20 yr or more) effective use of monensin in the beef cattle industry. The suggestion has been made (Lana and Russell, 1996) that ionophore resistance is a fundamental aspect of growth and not the result of microbial mutation. These authors measured the concentrations of monensin required to cause halfmaximal K + depletion ( ) in ruminal bacteria and K d + observed that approximately half the population of unadapted, mixed ruminal bacteria are resistant to high levels of monensin.…”

Section: Effects Of Monensin On Ruminal Volatile Fatty Acidsmentioning

confidence: 99%

Methane output and lactation response in Holstein cattle with monensin or unsaturated fat added to the diet.

Sauer

Fellner

Kinsman

et al. 1998

Journal of Animal Science

171

125

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We measured effects of continuous vs twice-daily feeding, the addition of unsaturated fat to the diet, and monensin on milk production, milk composition, feed intake, and CO2-methane production in four experiments in a herd of 88 to 109 milking Holsteins. Methane and CO2 production increased with twice-daily feeding, but the CO2:CH4 ratio remained unchanged. Soybean oil did not affect the milkfat percentages, but fatty acid composition was changed. All saturated fatty acids up to and including 16:0 decreased (P < .01), whereas 18:0 and trans 18:1 increased (P < .001). The 18:2 conjugated dienes also increased (P < .01) when the cows were fed soybean oil. Monensin addition to the diet at 24 ppm decreased methane production (P < .01); the CO2:CH4 ratios reached 15, milk production increased (P < .01), and milkfat percentage and total milkfat output decreased (P < .01), as did feed consumption, compared with cows fed diets without monensin (P < .05). Milk fatty acid composition showed evidence of depressed ruminal biohydrogenation: saturated fatty acids (P < .05) decreased and 18:1 increased (P < .001); most of the increase was seen in the trans 18:1 isomer. As with soybean oil feeding, addition of monensin also increased (P < .05) the concentration of conjugated dienes. The monensin feeding trial was repeated 161 d later with 88 cows, of which 67 received monensin in the diet in the first trial and 21 cows were newly freshened and had never received monensin. Methane production again decreased (P < .05), but this time the CO2:CH4 ratio did not change and all other monensin-related effects were absent. The ruminal microflora in the cows that had previously received monensin seemed to have undergone some adaptive changes and no longer responded as before.

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Use of potassium depletion to assess adaptation of ruminal bacteria to ionophores

Cited by 31 publications

References 25 publications

The binding and degradation of nisin by mixed ruminal bacteria

The binding and degradation of nisin by mixed ruminal bacteria

Effect of Low Level Monensin Supplementation on the Production of Dairy Cows Fed Alfalfa Silage

Methane output and lactation response in Holstein cattle with monensin or unsaturated fat added to the diet.

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