QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Spears, J. W. Search for Related Content PubMed PubMed Citation Articles by Spears, J. W.

Ionophores and Nutrient Digestion and Absorption in Ruminants^1,2,3,

Department of Animal Science and Interdepartmental Nutrition Program, North Carolina State University, Raleigh, NC 27695-7621

This paper reviews the effects of feeding ionophores on nutrient digestion and absorption. In cattle, monensin and lasalocid increase apparent digestible energy by an average of 2.0 percentage units. In sheep, responses in digestible energy to ionophore feeding have been more variable, and neither monensin nor lasalocid have, on average, affected digestible energy. The effect of ionophores on fiber digestibility appears to depend on diet composition and source of fiber because both increases and decreases in fiber digestibility have been associated with ionophore feeding. Lasalocid and monensin reduce the percentage of starch digested in the rumen and increase the quantity of starch digested in the intestine. However, total gastrointestinal tract digestion of starch has generally not been affected by ionophores. Apparent nitrogen digestibility has been increased by ionophore feeding in a number of animal species. Apparent absorption of magnesium, phosphorus, zinc and selenium has been increased by ionophore supplementation. Absorption of calcium, potassium and sodium has been inconsistently affected by ionophores. Possible mechanisms whereby ionophores may affect nutrient digestion and absorption are discussed.

KEY WORDS: • ionophores • monensin • lasalocid • lysocellin • salinomycin • ruminants

¹ Presented as part of the 30th Annual Ruminant Nutrition Conference: Influence of Gut Metabolism on Nutrient Supply, given at the 73rd Annual Meeting of the Federation of American Societies for Experimental Biology, New Orleans, LA, March 19, 1989, and supported by grants from American Cyanamid Company; Cargill, Nutrena Feed Division; Carol S. Akey, Inc.; Monsanto; Pioneer HiBred International, Inc.; Pitman-Moore, Inc.; and SmithKline Beckman Animal Health Products.

² Paper no. 12,437 of the Journal Series of the North Carolina Agricultural Research Services, Raleigh, NC 27695-7643. Use of trade names in this publication does not imply endorsement by the North Carolina Agricultural Research Service or criticism of similar products not mentioned.

³ Guest editor for this symposium was K. E. Webb, Jr., Department of Animal Science, Virginia Polytechnic Institute and State University, Blacksburg, VA.

Manuscript received 25 July 1989. Revision accepted 5 March 1990.

This article has been cited by other articles:

				A. M. Gehman, P. J. Kononoff, C. R. Mullins, and B. N. Janicek Evaluation of Nitrogen Utilization and the Effects of Monensin in Dairy Cows Fed Brown Midrib Corn Silage J Dairy Sci, January 1, 2008; 91(1): 288 - 300. [Abstract] [Full Text] [PDF]

				R. Martineau, C. Benchaar, H. V. Petit, H. Lapierre, D. R. Ouellet, D. Pellerin, and R. Berthiaume Effects of Lasalocid or Monensin Supplementation on Digestion, Ruminal Fermentation, Blood Metabolites, and Milk Production of Lactating Dairy Cows J Dairy Sci, December 1, 2007; 90(12): 5714 - 5725. [Abstract] [Full Text] [PDF]

				J. L. Klotz and R. N. Heitmann Effects of weaning and ionophore supplementation on selected blood metabolites and growth in dairy calves. J Dairy Sci, September 1, 2006; 89(9): 3587 - 3598. [Abstract] [Full Text] [PDF]