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Effect of Penicillin in the Diet upon Experimental Ascaridia Galli Infections in Chickens1
Effect of Penicillin in the Diet upon Experimental Ascaridia Galli Infections in Chickens 1 A. C. T O D D AND W. M .
STONE
Department of Animal Pathology, Kentucky Agricultural Experiment Station, Lexington, Kentucky (Received for publication May 16, 1951)
P R E V I O U S report from this laboratory presented experimental evidence of the anthelmintic action of three antibiotic agents, penicillin, streptomycin, and neomycin, following continuous oral administration, against the large intestinal roundworm of chickens, Ascaridia galli. The report was based on three separate experiments. The action of penicillin appeared to be somewhat superior to the action of the other two antibiotics tested. In comparison with exposed birds fed only a basal, or control, ration, exposed birds fed a penicillin ration developed fewer and smaller worms following controlled exposures, and gained more weight in the test period, Todd (1951).
tained in an antibiotic, or to reduction of parasite numbers. The previous tests with penicillin, moreover, did not determine most effective levels of penicillin for anthelmintic action against A. galli nor the tolerance of the host for the antibiotic under conditions of oral administration. The fourth experiment of the series, reported here, is concerned with the anthelmintic action of penicillin, fed a t the rate of 15 and 30 mg./lb. of feed, against experimental A. galli infections in chickens. The procaine penicillin tested was obtained through the courtesy of Merck and Company.
In the above experiments the recovery of fewer worms at postmortem in specific groups of experimental birds was associated with greater weight gains. The presence of added Bi 2 in certain test rations, however, did not allow superior weight gains in a given group to be ascribed to reduction of parasite numbers alone. T h e superior weight gains could have been derived from growth-promoting activity of the B12 separately, or residual Bj2 contained in the antibiotics tested, to a second growth-promoting factor con-
Chicks used in this test were straightrun New Hampshires obtained from a commercial hatchery in Richmond, Kentucky. The day-old chicks were started in an electric battery brooder and transferred to growing batteries after they feathered. T h e y were vaccinated against Newcastle disease by intranasal instillation a t two days of age; they were wing-banded at one week of age. The feed was a commercial starting and growing ration which also served as the basal, or control, ration in the test.
1 The investigation reported in this paper is in connection with a project of the Kentucky Agricultural Experiment Station and is published by permission of the Director.
When the chicks were 12 days old they were separated into three groups by means of a table of random numbers and the three test rations were fed thereafter. The two penicillin rations were compounded b y
MATERIALS AND METHODS
202
Downloaded from http://ps.oxfordjournals.org/ at University of Georgia on June 9, 2015
A
ANTHELMINTIC ACTION OF PENICILLIN
adding crystalline procaine penicillin G to the basal ration at the rate of 15 or 30 mg./lb. feed. The chicks were each exposed to 5 0 + infective A. galli eggs, obtained from prepared cultures, at 14 days of age. The birds were weighed at weekly intervals, beginning a t exposure, until the end of the test.
RESULTS AND DISCUSSION Mean weight gains of the three test groups, together with numbers and lengths of worms recovered are shown in Table 1. Forty-nine birds fed the basal ration only averaged 315.5 gm. weight gain in the test period and, on average, 7.04 worms with an average length of 25.88 m m . were recovered at postmortem. Fifty birds on the ration containing 15 mg. penicillin per pound of feed had an average weight gain of 334 gm. and had 3.98 worms, 24.97 mm. long, on average. T h e 50 birds fed the 30 mg. penicillin ration averaged 325.4 gm. gain and had 4.56 worms, 25.19 m m . long, on average, at post-mortem. Numbers of worms present a t postmortem again demonstrated the anthelmintic action of penicillin. The birds fed 15 and 30 mg. penicillin/lb. feed had significantly fewer worms; the significance of the difference in worm numbers between the penicillin groups and birds fed the basal ration exceeded the 1 percent level in an analysis of variance. Fewer worms a t postmortem again was associated with greater weight gains of the hosts; birds fed 15 mg. penicillin averaged 18.5 gm. greater gain than birds fed the basal ration, while birds fed 30
TABLE 1.—Weight gains of lest chicks and numbers of worms recovered
Group and Diet
Number chicks
Mean gain in test period (emY
Mean number worms recovere d
Mean worm length (mm.)
I. Basal II. 15 mg. penicillin/lb. III. 30 mg. penicillin/lb.
49 50 50
315.5 334.0 325.4
7.04* 3.98* 4.56*
25.88 24.97 25.19
* Significant beyond 1 percent level.
mg. penicillin averaged 9.9 gm greater gain. Reduction of worm numbers was not greater in birds fed 30 mg. penicillin than in birds fed 15 mg. penicillin. T h e advantage of about half a worm less in birds fed 15 mg. penicillin was without statistical significance as was also the advantage of 8.6 gm. greater weight gain. The present test may indicate t h a t most effective anthelmintic action of penicillin will result a t levels between 15 and 30 m g . / l b . feed. The test m a y also indicate t h a t chickens will not grow satisfactorily when the intake of procaine penicillin is as great as 30 mg./lb. feed. SUMMARY The anthelmintic action of two levels of procaine penicillin in the diet of chicks given experimental exposures to the large intestinal roundworm, Ascaridia galli, was tested. Either level of administration of penicillin, 15 and 30 mg./lb. feed, resulted in reduction of numbers of the test parasites present at postmortem in comparison with numbers of test parasites recovered from exposed birds fed the basal ration only. T h e higher level of penicillin administration, 30 m g . / l b . feed, did not result in greater anthelmintic action t h a n was obtained with 15 m g . / l b . feed. REFERENCE Todd, A. C, 1951. Effect of antibiotic agents upon experimental Ascaridia galli infections in chickens. Poultry Sci. 30: 763-766.
Downloaded from http://ps.oxfordjournals.org/ at University of Georgia on June 9, 2015
The test was continued for three weeks after exposure to infection. At t h a t time the birds were weighed, and then killed and examined for specimens of A. galli. Worms present were collected, preserved, counted, and measured.
203
STONE
Department of Animal Pathology, Kentucky Agricultural Experiment Station, Lexington, Kentucky (Received for publication May 16, 1951)
P R E V I O U S report from this laboratory presented experimental evidence of the anthelmintic action of three antibiotic agents, penicillin, streptomycin, and neomycin, following continuous oral administration, against the large intestinal roundworm of chickens, Ascaridia galli. The report was based on three separate experiments. The action of penicillin appeared to be somewhat superior to the action of the other two antibiotics tested. In comparison with exposed birds fed only a basal, or control, ration, exposed birds fed a penicillin ration developed fewer and smaller worms following controlled exposures, and gained more weight in the test period, Todd (1951).
tained in an antibiotic, or to reduction of parasite numbers. The previous tests with penicillin, moreover, did not determine most effective levels of penicillin for anthelmintic action against A. galli nor the tolerance of the host for the antibiotic under conditions of oral administration. The fourth experiment of the series, reported here, is concerned with the anthelmintic action of penicillin, fed a t the rate of 15 and 30 mg./lb. of feed, against experimental A. galli infections in chickens. The procaine penicillin tested was obtained through the courtesy of Merck and Company.
In the above experiments the recovery of fewer worms at postmortem in specific groups of experimental birds was associated with greater weight gains. The presence of added Bi 2 in certain test rations, however, did not allow superior weight gains in a given group to be ascribed to reduction of parasite numbers alone. T h e superior weight gains could have been derived from growth-promoting activity of the B12 separately, or residual Bj2 contained in the antibiotics tested, to a second growth-promoting factor con-
Chicks used in this test were straightrun New Hampshires obtained from a commercial hatchery in Richmond, Kentucky. The day-old chicks were started in an electric battery brooder and transferred to growing batteries after they feathered. T h e y were vaccinated against Newcastle disease by intranasal instillation a t two days of age; they were wing-banded at one week of age. The feed was a commercial starting and growing ration which also served as the basal, or control, ration in the test.
1 The investigation reported in this paper is in connection with a project of the Kentucky Agricultural Experiment Station and is published by permission of the Director.
When the chicks were 12 days old they were separated into three groups by means of a table of random numbers and the three test rations were fed thereafter. The two penicillin rations were compounded b y
MATERIALS AND METHODS
202
Downloaded from http://ps.oxfordjournals.org/ at University of Georgia on June 9, 2015
A
ANTHELMINTIC ACTION OF PENICILLIN
adding crystalline procaine penicillin G to the basal ration at the rate of 15 or 30 mg./lb. feed. The chicks were each exposed to 5 0 + infective A. galli eggs, obtained from prepared cultures, at 14 days of age. The birds were weighed at weekly intervals, beginning a t exposure, until the end of the test.
RESULTS AND DISCUSSION Mean weight gains of the three test groups, together with numbers and lengths of worms recovered are shown in Table 1. Forty-nine birds fed the basal ration only averaged 315.5 gm. weight gain in the test period and, on average, 7.04 worms with an average length of 25.88 m m . were recovered at postmortem. Fifty birds on the ration containing 15 mg. penicillin per pound of feed had an average weight gain of 334 gm. and had 3.98 worms, 24.97 mm. long, on average. T h e 50 birds fed the 30 mg. penicillin ration averaged 325.4 gm. gain and had 4.56 worms, 25.19 m m . long, on average, at post-mortem. Numbers of worms present a t postmortem again demonstrated the anthelmintic action of penicillin. The birds fed 15 and 30 mg. penicillin/lb. feed had significantly fewer worms; the significance of the difference in worm numbers between the penicillin groups and birds fed the basal ration exceeded the 1 percent level in an analysis of variance. Fewer worms a t postmortem again was associated with greater weight gains of the hosts; birds fed 15 mg. penicillin averaged 18.5 gm. greater gain than birds fed the basal ration, while birds fed 30
TABLE 1.—Weight gains of lest chicks and numbers of worms recovered
Group and Diet
Number chicks
Mean gain in test period (emY
Mean number worms recovere d
Mean worm length (mm.)
I. Basal II. 15 mg. penicillin/lb. III. 30 mg. penicillin/lb.
49 50 50
315.5 334.0 325.4
7.04* 3.98* 4.56*
25.88 24.97 25.19
* Significant beyond 1 percent level.
mg. penicillin averaged 9.9 gm greater gain. Reduction of worm numbers was not greater in birds fed 30 mg. penicillin than in birds fed 15 mg. penicillin. T h e advantage of about half a worm less in birds fed 15 mg. penicillin was without statistical significance as was also the advantage of 8.6 gm. greater weight gain. The present test may indicate t h a t most effective anthelmintic action of penicillin will result a t levels between 15 and 30 m g . / l b . feed. The test m a y also indicate t h a t chickens will not grow satisfactorily when the intake of procaine penicillin is as great as 30 mg./lb. feed. SUMMARY The anthelmintic action of two levels of procaine penicillin in the diet of chicks given experimental exposures to the large intestinal roundworm, Ascaridia galli, was tested. Either level of administration of penicillin, 15 and 30 mg./lb. feed, resulted in reduction of numbers of the test parasites present at postmortem in comparison with numbers of test parasites recovered from exposed birds fed the basal ration only. T h e higher level of penicillin administration, 30 m g . / l b . feed, did not result in greater anthelmintic action t h a n was obtained with 15 m g . / l b . feed. REFERENCE Todd, A. C, 1951. Effect of antibiotic agents upon experimental Ascaridia galli infections in chickens. Poultry Sci. 30: 763-766.
Downloaded from http://ps.oxfordjournals.org/ at University of Georgia on June 9, 2015
The test was continued for three weeks after exposure to infection. At t h a t time the birds were weighed, and then killed and examined for specimens of A. galli. Worms present were collected, preserved, counted, and measured.
203