Chemical Additives in Rumen Fermentations: In Vitro Effects of Various Drugs on Rumen Volatile Fatty Acids and Protozoa

O’Connor, John; Myers, Gordon S.; Maplesden, D. C.; Noot, G. W. Vander

doi:10.2527/jas1970.305812x

Cited by 12 publications

(5 citation statements)

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“…O'Connor et al [90] observed that chlortetracycline, oxytetracycline, and dimetridazole reduced protozoal activity, which possibly alters the ruminal microflora population by reducing predation of bacteria by protozoa. O'Connor et al [90] also examined changes to VFA in the presence of antibiotics and steroids. In general, antibiotics decreased total VFA production and increased the acetate-to-propionate ratio.…”

Section: Microbial Fermentation In the Rumenmentioning

confidence: 99%

“…Antibiotics can alter ruminal microbial population [88] and fermentation [89]. O'Connor et al [90] observed that chlortetracycline, oxytetracycline, and dimetridazole reduced protozoal activity, which possibly alters the ruminal microflora population by reducing predation of bacteria by protozoa. O'Connor et al [90] also examined changes to VFA in the presence of antibiotics and steroids.…”

Section: Microbial Fermentation In the Rumenmentioning

confidence: 99%

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Effects of ractopamine hydrochloride are not confined to mammalian tissue: Evidence for direct effects of ractopamine hydrochloride supplementation on fermentation by ruminal microorganisms1

Walker

Drouillard

2010

Journal of Animal Science

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Beta-adrenergic agonists, which are synthetic catecholamines, increase rate of gain, improve feed efficiency, and decrease carcass fat when fed to cattle before slaughter. However, little attention has been given to the potential effects of beta-adrenergic agonists on the rumen ecosystem. Natural catecholamines, such as norepinephrine, epinephrine, and dopamine, have been observed to stimulate bacterial growth. The objectives of this research were to determine if ractopamine hydrochloride (RAC) a synthetic catecholamine has direct effects on growth and fermentation products of ruminal bacteria, and to determine the effects of protein source on ruminal fermentation and proteolysis when cattle are fed RAC. The effects of varying concentrations of RAC on ruminal fermentation were evaluated in vitro. Ractopamine hydrochloride had a quadratic effect on in vitro gas production (P < 0.05). Total VFA production was not changed with RAC (P > 0.50). Different concentrations of RAC were evaluated in vitro with different nitrogen sources to determine effects of nitrogen degradability on response to RAC. There was an interaction between RAC and nitrogen substrate (P < 0.01), with more degradable forms of nitrogen eliciting greater changes in in vitro dry matter disappearance (IVDMD) with RAC supplementation. Significant main effects also were detected for RAC, substrate, and hour (P < 0.001). In vitro analysis of proteolysis revealed that RAC lowered ammonia and amino acid concentrations (P < 0.001). In vivo ruminal ammonia concentrations also were lower when RAC was fed in combination with dry-rolled corn, but not when fed in conjunction with steam-flaked corn (grain processing × RAC, P < 0.01). Addition of RAC, steam-flaked corn, and distiller's grains (DG) all resulted in lower ruminal ammonia concentrations (P < 0.01). Amino acid concentrations were decreased when RAC was added to diets with DG but were unchanged in diets without added DG (DG × RAC, P < 0.05). Results from these studies suggest that RAC affects fermentation by ruminal microflora. However, there were no differences in growth or fermentative end products of pure bacterial cultures with the addition of RAC (P > 0.10). Overall beta-adrenergic agonists alter ruminal fermentation, which could have important implications for diet formulation. EFFECTS OF RACTOPAMINE HYDROCHLORIDE ARE NOT CONFINED TO AbstractBeta-adrenergic agonists, which are synthetic catecholamines, increase rate of gain, improve feed efficiency, and decrease carcass fat, when fed to cattle before slaughter. However, little attention has been given to the potential effects of beta-adrenergic agonists on the rumen ecosystem. Natural catecholamines, such as norepinephrine, epinephrine, and dopamine, have been observed to stimulate bacterial growth. The objectives of this research were to determine if ractopamine hydrochloride (RAC) a synthetic catecholamine has direct effects on growth and fermentation products of ruminal bacteria, and to determine the effects of protein source on rumin...

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Section: Microbial Fermentation In the Rumenmentioning

confidence: 99%

Section: Microbial Fermentation In the Rumenmentioning

confidence: 99%

Effects of ractopamine hydrochloride are not confined to mammalian tissue: Evidence for direct effects of ractopamine hydrochloride supplementation on fermentation by ruminal microorganisms1

Walker

Drouillard

2010

Journal of Animal Science

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“…Antibiotics can alter ruminal microbial population [90] and fermentation [91]. O'Connor et al, [92] observed that chlortetracycline, oxytetracycline, and dimetridazole reduced protozoal activity, which possibly alters the ruminal microflora population by reducing predation of bacteria by protozoa. O'Connor et al, [92] also examined changes to VFA in the presence of antibiotics and steroids.…”

Section: Microbial Fermentation In the Rumenmentioning

confidence: 99%

“…O'Connor et al, [92] observed that chlortetracycline, oxytetracycline, and dimetridazole reduced protozoal activity, which possibly alters the ruminal microflora population by reducing predation of bacteria by protozoa. O'Connor et al, [92] also examined changes to VFA in the presence of antibiotics and steroids. In general, antibiotics decreased total VFA production and increased the acetate-to-propionate ratio.…”

Section: Microbial Fermentation In the Rumenmentioning

confidence: 99%

Effects of Catecholamines on Gut Microflora and Potential for Beta- Adrenergic Agonists to Impact Ruminal Fermentation

Walker¹,

Drouillard

2012

TOASJ

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Catecholamines are produced by chromaffin cells of the adrenal medulla and adrenergic and dopaminergic neurons from tyrosine. Catecholamines regulate many vital physiological and metabolic responses because of the location of receptors. The impact of catecholamines is not limited to mammals; direct effects of natural catecholamines on bacteria have been researched extensively to understand the potential impact of these compounds on bacterial infections in humans. Catecholamines have increased the growth of bacteria, virulence-associated factors, and adhesins and increased biofilm formation. Beta-adrenergic agonists are similar in structure and pharmacological properties to natural catecholamines. Beta-adrenergic agonists enhance performance of finishing cattle during the final days prior to harvest. Responses to beta-adrenergic agonists include increased average daily gain, improved feed efficiency, and increased carcass lean. These responses have been observed as a direct effect to the animal; however, a review of the literature suggests that the response to beta-adrenergic agonists also could be mediated by a direct or indirect effect on ruminal microorganisms. Ractopamine hydrochloride increased fermentation in vitro, particularly with increased amounts of degradable intake protein. Inclusion of ractopamine hydrochloride in vivo decreased ruminal concentrations of ammonia and amino acid. The rumen is host to a large population of diverse microorganisms, and a direct impact of a synthetic catecholamine on the microbial population could potentially alter fermentation and the ruminant performance. Reviewing literature on catecholamines and their direct impact on microorganisms could lead to improved decisions regarding dietary supplementation of beta-adrenergic agonists, threreby increasing the growth performance response in ruminants.

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“…In the search for biologically active agents in general, and antiprotozoal agents in particular, in vitro tests are invaluable as they allow large numbers of compounds to be tested quickly and require only small quantities of each compound (Baines et al 1969). Previous reports of in vitro tests for agents toxic to rumen protozoa relied on visual assessment of protozoal viability after exposure to the compound (Willard & Kodras 1967;O'Connor et al 1971). Such an approach serves well as a primary screen for identification of activity.…”

Section: Received 18 February; Revision 14 June 1982mentioning

confidence: 99%

An in vitro assay for compounds toxic to rumen protozoa

Campbell

Cumming

Graham

et al. 1982

New Zealand Journal of Agricultural Research

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The viability of protozoa in whole rumen fluid was assessed by measuring the incorporation of Me-14 C-choline in vitro. The use of the technique as an assay for testing antiprotozoal agents was evaluated with a variety of surfactant detergents which have previously been shown to have anti protozoal activity in vivo. A good correlation was obtained between the potency of these compounds in vitro and in vivo.

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Chemical Additives in Rumen Fermentations: In Vitro Effects of Various Drugs on Rumen Volatile Fatty Acids and Protozoa

Cited by 12 publications

References 11 publications

Effects of ractopamine hydrochloride are not confined to mammalian tissue: Evidence for direct effects of ractopamine hydrochloride supplementation on fermentation by ruminal microorganisms1

Effects of ractopamine hydrochloride are not confined to mammalian tissue: Evidence for direct effects of ractopamine hydrochloride supplementation on fermentation by ruminal microorganisms1

Effects of Catecholamines on Gut Microflora and Potential for Beta- Adrenergic Agonists to Impact Ruminal Fermentation

An in vitro assay for compounds toxic to rumen protozoa

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