HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) 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 Google Scholar Google Scholar Articles by Clark, J. H. Articles by McCoy, G. C. Search for Related Content PubMed PubMed Citation Articles by Clark, J. H. Articles by McCoy, G. C.

Effects of Calcium Carbonate on Ruminal Fermentation, Nutrient Digestibility, and Cow Performance¹

Department of Animal Science, University of Illinois, Urbana 61801

ABSTRACT

Sixteen Holstein cows were used in a 4 x 4 Latin square design (four replicates) to investigate the effect of feeding calcium carbonate on feed intake, ruminal fermentation, apparent total tract nutrient digestibility, milk yield, and milk composition. Supplementation of calcium carbonate to diets that contained 60% concentrate and 40% corn silage (DM basis) decreased DM intake and milk production and was not effective in altering ruminal fluid pH, ruminal fluid dilution rate or outflow, molar proportions of ruminal fluid VFA, or synthesis of milk fat and milk protein by dairy cows. Calcium carbonate supplementation to the diet tended to improve efficiency of feed utilization (4% FCM/DM intake). The exact site of action of calcium carbonate, if any, is not known. However, these data suggest that calcium carbonate exerts little or no buffering effect in the rumen when the pH is 6 or above regardless of its reactivity rate in strong acid or its mean particle size. This lack of effect is probably because of its low solubility in ruminal fluid at pH above 5.5.

¹ Suported in part by the University of Illinois Agricultural Experiment Station and Church and Dwight Company, Inc.