| Material Information
||Antibiotic combinations for young pigs
||Department of Animal Science mimeograph series
||4 p. : ; 28 cm.
||Combs, G. E ( George Ernest ), 1927-
Wallace, H. D ( Harold Dean )
University of Florida -- Agricultural Experiment Station
||Florida Agricultural Experiment Station
||Place of Publication:
||Swine -- Feeding and feeds -- Florida ( lcsh )
Antibiotics in animal nutrition -- Florida ( lcsh )
||government publication (state, provincial, terriorial, dependent) ( marcgt )
non-fiction ( marcgt )
||Statement of Responsibility:
||G.E. Combs and H.D Wallace.
| Record Information
||University of Florida
||All rights reserved by the source institution and holding location.
||oclc - 77225451
Department of Animal Science Florida Agricultural
Mimeograph Series No. 63-8 Experiment Station
August, 1962 Gainesville, Florida
ANTIBIOTIC COMBINATIONS FOR YOUNG PIGS
G. E. Combs and -1. D. Wallace I/
Previous investigations (Mimeo. Series 63-5) indicated that a combina-
tion of chlortetracycline, oxytetracycline, penicillin and streptomycin was
a more effective growth stimulant and permitted more efficient utilization
of feed than chlortetracycline alone or in combination with mycostatin.
Since the two tetracyclines and a combination of penicillin and streptomycin
have generally the same bacterial spectrum but different specificities, it
becomes of interest to determine which antibiotic or antibiotic combination
possesses the greatest growth promoting ability.
The following study was initiated to compare the effectiveness of
chlortetracycline, oxytetracycline and a combination of penicillin and
streptomycin alone and in combination with the tetracyclines when added to
Forty-eight pigs weaned at 2 weeks of age were allotted into 12 groups
of 4 pigs each. All groups were self-fed ad libitum in concrete floor pens;
water was provided in automatic waterers and the experiment was for a period
of 42 days.
The composition of the basal rations is presented in table I. Basal
ration I was fed for the first 28 days and basal ration 1I for the last 14
The experimental treatments were as follows:
Treatment I Basal ration
Treatment 2 Basal + 80 gm. chlortetracycline per ton
Treatment 3 Basal + 80 gm. oxytetracycline per ton
Treatment 4 Basal + 40 gm. penicillin and 40 gm. streptomycin per ton
Treatment 5 Basal + 40 gm. chlortetracycline + 20 gm. penicillin + 20
gm. streptomycin per ton
Treatment 6 Basal + 40 gm. oxytetracycline + 20 gm. penicillin + 20 gm.
streptomycin per ton
I/ Combs and Wallace, Associate Animal Nutritionist and Animal Nutritionist
respectively, Department of Animal Science. The assistance of W. E.
Collins and L. S. Taylor, Swine Herdsmen, is gratefully acknowledged.
This study was supported in part by funds and materials supplied by
American Cyanamid Co. and Chas. Pfizer and Co.
The results of this study are summarized in table 2. The pigs fed the
basal ration or the basal ration supplemented with either chlortetracycline
or oxytetracycline gained at a comparable rate. The gains of all groups fed
a combination of antibiotics were also similar. However, the average gain
of pigs fed the penicillin-streptomycin combination were significantly higher
than those pigs given the basal ration or the basal ration supplemented with
a single antibiotic. No statistically significant differences were observed
among treatments with either feed consumption or feed efficiency.
A partial explanation for these findings may be found in the antibiotic
feeding practices followed at the University Swine Unit. In general the
tetracyclines have been used for the past 12 years. This may have resulted
in the build-up of tetracycline-resistant bacteria. Consequently, a relatively
large response is obtained by using antibiotics with a slightly different
Pigs weaned at 2 weeks of age were used to study the efficiency of
several antibiotics in starter rations. Chlortetracycline, oxytetracycline
or a combination of penicillin and streptomycin were added singly or in
combination at the rate of 80 grams per ton of feed.
Average daily gains of pigs fed the penicillin-streptomycin combination
were significantly (P = .05) higher than pigs fed the basal ration or rations
containing either chlortetracycline or oxytetracycline. When either of the
two tetracyclines was used in combination with the penicillin-streptomycin
mixture, no increase in performance was observed.
In the instances where a particular antibiotic has been used extensively
over a period of years some benefit may be derived from using another anti-
biotic or antibiotic combination.
Table I. COMPOSITION OF BASAL RATIONS
Ingredient Basal 1 Basal t1
Gr. yellow corn 22.15 76.70
Sugar 22.25 ---
Dried skim milk 40.00
Soybean meal 9.00 15.00
Tankage --- 4.00
Lard 3.00 ---
Limestone --- .70
Bonemeal 1.00. 1.00
Salt .50 .50
Trace minerals .10 .10
Vitamin premix 1/ 2.00 2.00
I/ Contained the following:
Vitamin A (10,000 I.U./gm.)
Vitamin D (9,000 l.U./gm.)
Choline chloride (25%)
Folic acid (3%)
Vitamin B12 (9 mg./lb.)
Table 2. RESPONSE OF EARLY WEANED PIGS TO ANTIBIOTICS
Treatment No. I 2 3 4 5 6
Antibiotic Basal Chlortetra- Oxytetra- Penicillin Chlortetra- Oxytetra-
cycline cycline + cycline + cycline +
Streptomycin Penicillin + Penicillin +
No. of pigs 8 8 8 8 8 8
Av. initial weight, lb. 8.3 8.3 8.3 8.2 8.2 8.2
Av. final weight, lb. 39.2 40.6 38.7 45.7 43.2 42.9
Av. daily gain, lb. .74 .77 .72 .89 / .83 .82
Av. daily feed, lb. 1.52 1.56 1.54 1.75 1.57 1.66
Feed/lb. gain, Ib. 2.06 2.03 2.14 1.97 1.89 2.02
I/ Treatment 4 significantly (P = .05) larger than Treatments 1, 2 and 3.