Effects of lasalocid or monensin on legume or grain (feedlot) bloat.

Journal of Animal Science (Impact Factor: 2.09). 07/1983; 56(6):1400-6.
Source: PubMed

ABSTRACT Doses of .66 to .99 mg monensin/kg body weight reduced legume bloat in cattle about 66% when compared with pretreatment bloat scores. Similar doses of lasalocid reduced legume bloat about 26%. A dose of 44 mg poloxalene/kg body weight (recommended dose for field use) reduced legume bloat 100%. Monensin or lasalocid combined with 25 or 50% of the recommended dose of poloxalene reduced bloat under that of the antibiotics alone, but did not achieve 100% reduction. The antibiotic thiopeptin provided no preventive effect on legume bloat. Lasalocid, monensin or an experimental polyether antibiotic (X-14,547 A) at a dose of 1.32 mg/kg body weight when tested on cattle bloated on high grain diets reduced bloat by 92, 64 and 25%, respectively. Lasalocid at .66 mg/kg effectively prevented bloat from developing when given to animals before the feeding of high grain diets; however, a 1.32-mg dose was required to control bloat in cattle that were already bloating before they were given lasalocid. A dose of 1.32 mg salinomycin was ineffective in controlling grain bloat.

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    ABSTRACT: Improvements in feedlot management practices and the use of various feed additives have reduced, but not eliminated, the occurrence of bloat in feedlot cattle. Feedlot bloat reduces the profitability of production by compromising animal performance and more directly by causing fatalities. In feedlots, bloat is associated with the ingestion of large amounts of rapidly fermented cereal grain and destabilization of the microbial populations of the rumen. An abundance of rapidly fermented carbohydrate allows acid-tolerant bacteria (e.g., Streptococcus bovis and Lactobacillus spp.) to proliferate and produce excessive quantities of fermentation acids. As a result, ruminal pH becomes exceedingly low, and this impairs rumen motility. Further, the excessive production of mucopolysaccharide or "slime" increases the viscosity of ruminal fluid and stabilizes the foam implicated in frothy feedlot bloat. Although protocols have been developed to treat feedlot bloat, the most profitable approach is to use management strategies to reduce its likelihood. Amount of roughage, grain processing techniques, selection of cereal grain (e.g., corn, barley, and wheat), dietary adaptation periods, and various additives (e.g., ionophores) can influence the occurrence of bloat in feedlot cattle. Successful management of these factors depends on a thorough understanding of the behavioral, dietary, and microbial events that precipitate bloat in feedlot cattle.
    Journal of Animal Science 02/1998; 76(1):299-308. · 2.09 Impact Factor
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    ABSTRACT: Ionophores (such as monensin, lasalocid, laidlomycin, salinomycin and narasin) are antimicrobial compounds that are commonly fed to ruminant animals to improve feed efficiency. These antimicrobials specifically target the ruminal bacterial population and alter the microbial ecology of the intestinal microbial consortium, resulting in increased carbon and nitrogen retention by the animal, increasing production efficiency. Ionophores transport ions across cell membranes of susceptible bacteria, dissipating ion gradients and uncoupling energy expenditures from growth, killing these bacteria. Not all bacteria are susceptible to ionophores, and several species have been shown to develop several mechanisms of ionophore resistance. The prophylactic use of antimicrobials as growth promotants in food animals has fallen under greater scrutiny due to fears of the spread of antibiotic resistance. Because of the complexity and high degree of specificity of ionophore resistance, it appears that ionophores do not contribute to the development of antibiotic resistance to important human drugs. Therefore it appears that ionophores will continue to play a significant role in improving the efficiency of animal production in the future.
    Current issues in intestinal microbiology 10/2003; 4(2):43-51.
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    ABSTRACT: Ionophores, are used commonly for improving the feed efficiency and weight gain in ruminant nutrition. Ionophores increase the proportion of propionic acid and decrease the proportions of acetate and butyrate by modifying ruminal fermentation in the rumen. The increase in rumen propionic acid decrease the amount of methane produced in the rumen. Ionophores alter the flow of cations across cell membranes.


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