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 Jensen, A. H. Articles by Catron, D. V. Search for Related Content PubMed Articles by Jensen, A. H. Articles by Catron, D. V.

Different Protein Levels with and without Antibiotics for Growing-Finishing Swine: Effect on Growth Rate and Feed Efficiency^{1, 2, 3}

Iowa Agricultural Experiment Station

Abstract

Protein levels of 10, 12, 14, 16, 18 and 20 percent, with and without 5 mg. of aureomycin or terramycin per lb. of ration, were fed in two experiments (numbers 536 and 554) to a total of 288 pigs. The fortified corn-soybean oil meal rations were fed in concrete drylot to pigs weighing from 31 to 36 lbs. to 200 lbs.

The level of protein in the ration significantly affected the rate of gain made by the pigs in both experiments as measured by the linear and quadratic components. In general, the average daily gains of the pigs reached a maximum between 16 and 18 percent protein without antibiotics and at 14 percent protein with antibiotics (effect not statistically significant) and then leveled off or declined. Feed efficiency was not significantly affected by the level of protein fed in the first experiment. However, in the second experiment, the protein level had a significant effect on feed requirements which paralleled the performance in daily gains.

In the first experiment, terramycin (but not aureomycin) significantly increased the rate of gain of the pigs during the 36- to 75-lb. period. However, this effect had disappeared by the time the pigs reached 200 lbs. Although the pigs fed aureomycin or terramycin required 21 and 18 lbs. less feed per 100 lbs. of gain respectively, these differences were not statistically significant.

In the second experiment, the feeding of aureomycin significantly increased the daily gains and feed efficiency of the pigs for the entire feeding period, but not for the 31- to 75-lb. period.

The effect of protein levels and antibiotic feeding on carcass measurements will be reported separately.

¹ Journal paper No. J-2556 of the Iowa Agricultural Experiment Station, Ames, Iowa. Animal Husbandry Department. Project 930.

² This work was partially supported by grants from Lederle Laboratories Division, Pearl River, New York, and Chas. Pfizer and Co., Brooklyn, New York. The vitamins and antibiotics were also supplied by them.

³ The terms aureomycin and terramycin are used to refer to chlortetracycline and oxytetra-cycline respectively throughout this manuscript.

⁴ Present address, Department of Animal Science, University of Illinois, Urbana, Illinois.

⁵ Present address, Animal Husbandry Department, Oklahoma A. and M. College, Stillwater, Oklahoma.

⁶ Present address, Lederle Laboratories, New York, New York.

⁷ Department of Statistics.

⁸ Department of Agricultural Economics.

⁹ Acknowledgment is made to Mr. Don Quinn, Swine Nutrition Research Farm, and his associates, and to Mr. Roger Woodworth, former graduate student in Agricultural Economics, for their assistance.