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 Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Johnson, W. P. Articles by Shor, A. L. Search for Related Content PubMed Articles by Johnson, W. P. Articles by Shor, A. L.

The Effect of Chlortetracycline on the Incidence of Enterotoxemia and Weight Gains in Lambs Maintained under Commercial Feed-Lot Conditions

Research Division, American Cyanamid Company, Pearl River, New York

Abstract

Studies were conducted with 798 lambs to determine the effect of chlortetracycline fed under feed-lot conditions. Lambs were divided randomly into 8 equal lots assigned to 4 feeding groups. The basal ration was fed to Group I. Group II received basal plus chlortetracycline at a level of 25 mg. per pound of feed for 21 days, followed by 10 mg. per pound of feed continuously. Group III received basal plus chlortetracycline at a level of 10 mg. per pound of feed continuously. Group IV received basal plus 25 mg. chlortetracycline per pound of feed for 21 days. The feeding period for all groups was 48 days.

Significantly fewer carcasses of sheep in Group IV were graded "choicel" than in Groups I, II and III, the shift being generally to the "good" classification. Under the conditions of this trial, supplementation during the entire feeding period proved to be highly effective in the control of enterotoxemia since no deaths occurred in four pens fed in this manner. In contrast, death did occur in both control pens and in both pens which had received chlortetracycline for 21 days followed by no antibiotic. All deaths in this latter group occurred after the discontinuance of chlortetracycline supplementation. Average final weights and average daily gains for the group receiving 10 mg. of chlortetracycline per pound of feed continuously throughout the experiment were significantly higher than the controls or other treatment groups.

¹ The authors wish to express their appreciation to Mr. Jack Schmidt, Manager, Morris Feed Yards Division, Kansas City Stackyard Co., Kansas City, Mo., for his cooperation in the conduct of the trial, to Mr. Ronald T. Hill of the Statistical Laboratory for the statistical analyses, to Mr. Edward Gianforte for bacteriologic examinations, and to Mrs. D. Budd for assistance in preparation of the manuscript.