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

This Article Full Text 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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Bevans, D. W. Articles by McAllister, T. A. Search for Related Content PubMed PubMed Citation Articles by Bevans, D. W. Articles by McAllister, T. A.

Effect of rapid or gradual grain adaptation on subacute acidosis and feed intake by feedlot cattle^1,2

D. W. Bevans^*,, K. A. Beauchemin^*, K. S. Schwartzkopf-Genswein^*, J. J. McKinnon and T. A. McAllister^*,3

^* Agriculture and Agri-Food Canada Research Centre, Lethbridge, Alberta, T1J 4B1 Canada; and and Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5A8 Canada

³ Correspondence: P.O. Box 3000 (phone: 403-327-2240; fax: 403-382-3156; e-mail: mcallister{at}agr.gc.ca).

The effects of grain adaptation protocol on subacute acidosis and feed intake by cattle were studied in a completely randomized experiment using 12 crossbred heifers (384 ± 25 kg BW). The dietary proportion of concentrate was increased from 40 to 90% (DM basis) either by rapid adaptation (65% concentrate diet fed for 3 d) or by gradual adaptation (five intermediate diets containing 48.3, 56.7, 65.0, 73.3, and 81.7% concentrate, fed for 3 d each). Feed intake and ruminal pH (by indwelling ruminal electrodes) were monitored over 20 d. Mean daily pH variables did not differ (P 0.10) between treatments on any of the 3 or 4 d that 65 or 90% concentrate was fed. Variances of a number of pH variables were greater (P < 0.05) for rapidly adapted heifers than for those on the gradual adaptation protocol during adaptation to 65 and 90% concentrate. Mean hourly pH did not differ over the first 24 h of adaptation to 65% concentrate, but variance of hourly pH tended (P < 0.10) to be greater for rapidly adapted than for gradually adapted heifers for eight of the first 24 h. On the first day of feeding 90% concentrate, ruminal pH tended (P = 0.07) to be less at 11 and 12 h after feeding with rapid adaptation than with gradual adaptation. Variance of hourly pH increased steadily in rapidly adapted heifers from 6 h after feeding onward. Ruminal VFA concentration and osmolality did not differ between treatments. Ruminal lactate concentration was <1 mM, except in two rapidly adapted heifers and one gradually adapted heifer after introduction to 90% concentrate. Adaptation method did not affect DMI or day-to-day variation in DMI. Detection of acidosis was associated with increased variance in ruminal pH variables. A range of individual responses to grain challenge was observed, but current management strategies for preventing acidosis in pens of cattle are based on responses of the most susceptible individuals. A better understanding of factors governing individual responses to acidotic challenge may allow for the development of more effective acidosis prevention practices.

Key Words: Acidosis • Concentrate • Grain Adaptation • Ruminal pH • Volatile Fatty Acids

This article has been cited by other articles:

				J. T. Vasconcelos and M. L. Galyean ASAS Centennial Paper: Contributions in the Journal of Animal Science to understanding cattle metabolic and digestive disorders J Anim Sci, July 1, 2008; 86(7): 1711 - 1721. [Abstract] [Full Text] [PDF]

				Q. Zebeli, J. Dijkstra, M. Tafaj, H. Steingass, B. N. Ametaj, and W. Drochner Modeling the Adequacy of Dietary Fiber in Dairy Cows Based on the Responses of Ruminal pH and Milk Fat Production to Composition of the Diet J Dairy Sci, May 1, 2008; 91(5): 2046 - 2066. [Abstract] [Full Text] [PDF]

				V. Robles, L. A. Gonzalez, A. Ferret, X. Manteca, and S. Calsamiglia Effects of feeding frequency on intake, ruminal fermentation, and feeding behavior in heifers fed high-concentrate diets J Anim Sci, October 1, 2007; 85(10): 2538 - 2547. [Abstract] [Full Text] [PDF]

				T. G. Nagaraja and E. C. Titgemeyer Ruminal Acidosis in Beef Cattle: The Current Microbiological and Nutritional Outlook J Dairy Sci, June 1, 2007; 90(13_suppl): E17 - E38. [Abstract] [Full Text] [PDF]

				G. B. Penner, K. A. Beauchemin, and T. Mutsvangwa Severity of Ruminal Acidosis in Primiparous Holstein Cows During the Periparturient Period J Dairy Sci, January 1, 2007; 90(1): 365 - 375. [Abstract] [Full Text] [PDF]

				W. Z. Yang and K. A. Beauchemin Physically effective fiber: method of determination and effects on chewing, ruminal acidosis, and digestion by dairy cows. J Dairy Sci, July 1, 2006; 89(7): 2618 - 2633. [Abstract] [Full Text] [PDF]

				G. B. Penner, K. A. Beauchemin, and T. Mutsvangwa An evaluation of the accuracy and precision of a stand-alone submersible continuous ruminal pH measurement system. J Dairy Sci, June 1, 2006; 89(6): 2132 - 2140. [Abstract] [Full Text] [PDF]

				M. S. Brown, C. H. Ponce, and R. Pulikanti Adaptation of beef cattle to high-concentrate diets: Performance and ruminal metabolism J Anim Sci, April 1, 2006; 84(13_suppl): E25 - E. [Abstract] [Full Text] [PDF]