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 Catron, D. V. Articles by Ashton, G. C. Search for Related Content PubMed Articles by Catron, D. V. Articles by Ashton, G. C.

Re-Evaluation of Protein Requirements of Growing-Fattening Swine as Influenced by Feeding an Antibiotic^{1, 2,}

Iowa Agricultural Experiment Station

Abstract

GENERAL observations of farm practice have shown that many hog producers have obtained satisfactory growth in swine when feeding rations containing lower levels of protein than those commonly recommended. The research leading to these recommendations was conducted almost a decade ago. In light of recent advances in animal nutrition it seemed advisable to re-evaluate the protein requirements of swine.

Keith and Miller (1939, 1941) fed rations varying in protein content from 12 to 27 percent and found that maximum and most economical gains from weaning to 75 pounds were made by those pigs fed the highest percent of protein. Twenty-two percent was recommended from weaning to 70 pounds, 17 to 20 percent from 75 to 125 pounds and 15 percent from 125 to 200 pounds. A series of studies by Carroll and Burroughs (1939) substantiated these conclusions. Mitchell (1939), using the same rations as Carroll and Burroughs, but employing the N-retention technique of measuring efficiency, stated that 40- to 50-pound pigs required more than 26 percent protein, 100-pound pigs in excess of 17 percent, 150-pound pigs 17 percent and 150- to 200- pound pigs 15 percent protein for maximum growth.

¹ Journal Paper No. J-2053 of the Iowa Agricultural Experiment Station, Animal Husbandry Department, Ames, Iowa. Project 930.

² The vitamins and antibiotics were supplied by Merck and Co., Inc., Rahway, New Jersey; Lederle Laboratories, Pearl River, New York and Standard Brands, Inc., New York, New York.

³ Acknowledgment is 31 made to Don Quinn, Animal Nutrition farm foreman and his associates for their assistance.