Group Title: Animal husbandry mimeograph series - University of Florida Department of Animal Husbandry ; 57-1
Title: The effect of feeding erythromycin to growing-fattening pigs
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 Material Information
Title: The effect of feeding erythromycin to growing-fattening pigs
Series Title: Animal husbandry mimeograph series
Physical Description: 5 leaves : ; 28 cm.
Language: English
Creator: Wallace, H. D ( Harold Dean )
University of Florida -- Dept. of Animal Husbandry and Nutrition
Publisher: University of Florida, Dept. of Animal Husbandry and Nutrition
Place of Publication: Gainesville Fla
Publication Date: 1956
Subject: Antibiotics in animal nutrition -- Florida   ( lcsh )
Swine -- Feeding and feeds -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
Bibliography: Includes bibliographical references (leaf 5).
Statement of Responsibility: H.D. Wallace ... et al..
General Note: Caption title.
General Note: "August, 1956."
 Record Information
Bibliographic ID: UF00072859
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 76950366

Full Text

Animal Husbandry Mimeograph
Series No. 57-1 August, 1956


H. D. Wallace, L. Gillespie, G. E. Combs, Jr.
and C. E. Haines 2/

Numerous experiments have demonstrated that certain antibiotics improve the

growth and production efficiency of swine (I). Chlortetracycline, oxytetracycline

and penicillin have proven most effective for this purpose. The chemists' shelf

contains many additional antibiotics which may or may not prove useful when and if

tested. A fairly recently discovered antibiotic, erythromycin, seemed particularly

promising because of its usefulness in human therapy and wide antibacterial spectrum.

A study by Gerard et al. (2) resulted in a growth improvement and an apparent pro-

tein sparing effect when erythromycin was added to the ration of young pigs. An

extensive search of the literature revealed no other reports on the feeding of

erythromycin to swine.

The experiments herein discussed were undertaken to further explore the feasi-

bility of using erythromycin as an antibiotic supplement in swine rations.

Experimental Procedure

Experiment I. Twenty-five purebred Hampshire and twenty-five purebred Duroc

pigs averaging approximately 38 pounds initially were divided on the basis of breed-

and initial weight into five experimental groups of ten pigs each. Each experimen-

tal group was further divided into two pens of five pigs each. The pigs were con-

fined in concrete pens which were cleaned and washed daily. The method of feeding

was by self feeders and the pigs had access to fresh water at all times.

j/ Supported in part by a grant-in-aid from the Eli Lilly Co., Indianapolis, Ind.

2/ Wallace, Associate Animal Husbandman; Gillespie, Research Assist
Assistant Animal Husbandman; and C. E. Haines, Research Assista epar
of Animal Husbandry and Nutrition, University of Florida, Gain ~sile, Flori

The basal ration used in the experiment is shown in Table I. This basal

ration contained approximately 16 percent of crude protein. The pigs in Group I

were fed the basal ration. The pigs in Groups 2 through 5, respectively, received

the basal ration plus 2, 6, 10 and 20 mg. of erythromycin per pound of ration.

Ingredients Percent

Ground yellow corn 77.0
Soybean oilmeal 21.0
Ground limestone 1.0
Steamed bonemeal 0.5
Salt-trace mineral 0.53

1/ Also fortified with thiamine, riboflavin, niacin, pantothenic
acid, pyridoxine, choline chloride, folic acid and vitamin B12.

The experiment started on May 10, 1954 and was terminated after 54 days.

Experiment II. Thirty-two purebred Duroc and Hampshire pigs averaging approxi-

mately:45 pounds initially were divided on the basis of breed and initial weight

into four treatment groups. Each group was further divided into two pens of four

pigs each. Management of the pigs was similar to that used in Experiment I. The

basal mixture fed in Experiment I was also fed in this experiment. Group I pigs

were fed the basal ration. The pigs in groups 2 through 4, respectively, received

the basal ration plus 2, 10 and 20 mg. of erythromycin per pound of feed. The

experiment started on November 6, 1954 and was concluded when the animals reached

a slaughter weight of approximately 195 pounds.

Results and Discussion

Results of the two experiments are summarized in Table 2.

The difference in average daily gains between the various treatment groups

in both experiments was very small and not statistically significant. One of the


most interesting results in the study concerns daily feed consumption. Normally

an increase in feed consumption is observed when effective antibiotics are fed to

swine. In both experiments it can be seen that the addition of erythromycin at

all levels reduced daily feed intake. Recent studies at this Station (3) on the

palatability of antibiotics indicated that pigs have a definite dislike for

erythromycin. However, it is interesting to note that the addition of the anti-

biotic at all levels in both experiments improved feed efficiency. The low level

of 2 mg. per pound of feed was as effective in improving feeding efficiency as

the higher levels of the antibiotic.

Two experiments, involving eighty-two weanling pigs, have been conducted

to determine the effect of adding erythromycin at levels of 2, 6, 10 and 20 mg.

per pound of feed to the ration of weanling pigs fed in drylot.

Average daily gains were not significantly affected at any level of supple-

mentation. Daily feed consumption was reduced at all levels of erythromycin

supplementation in both experiments.

The amount of feed required to produce a pound of gain was decreased as the

result of adding erythromycin to the ration.

- 3 -


Experiment I Experiment II
Group No. 1 2 3 4 5 1 2 3 4

Mg. erythromycin added
per pound of feed .0 2 6 10 20 0 2 10 20

No. of pigs 10 10 10 10 10 8 7* 8 8

Av. initial wt. lb. 37.1 38.2 38.3 38.5 38.3 45.8 44.3 45.4 45.4

Av. final wt. lb. 105.9 107.5 108.4 108.3 107.0 192.9 197.3 196.8 195.0

Av. daily gain lb. 1.28 1.29 1.30 1.30 1.28 1.54 1.59 1.60 1.60

Av. daily feed consumption Ib. 3.91 3.72 3.85 3.76 3.71 5.87 5.44 5.49 5.58

Feed per lb. gain lb. 3.06 2.90 2.96 2.91 2.92 3.81 3.42 3.43 3.49

Av. No. days on test 54 54 54 54 54 95.4 96.0 94.5 93.6

*One pig removed early in experiment because of


Literature Cited
1. Braude, R., Wallace, H. D. and Cunha, T. J. The value of antibiotics in the
nutrition of swine: A Review. Antibiotics and Chemotherapy 3: 271-291, 1953.

2. Gerard, W. E., Read, 0. C., and Pensack, J. M.
several antibiotics on chick and swine growth.
Food Chemistry, 1: 784-788, 1953.

A comparative evaluation of
Journal of Agricultural and

3. Tomlin, Don C. The effect of certain antibiotics upon the palatability of
rations for swine. A thesis presented to the Graduate Council of the Univer-
sity of Florida in partial fulfillment of the Requirements for the degree of
Master of Science in Agriculture. August, 1956.

Animal Husbandry
200 copies
September 18, 1956


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