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Prevention of Coccidiosis in Bobwhites by Medication
ENVIRONMENT AND HEALTH Prevention of Coccidiosis in Bobwhites by Medication M. D. RUFF, G. C. WILKINS, and M. B. CHUTE USDA, Agricultural Research Service, Animal Parasitology Institute, Protozoan Diseases Laboratory, Beltsville, Maryland 20705 (Received for publication November 6, 1986) ABSTRACT The efficacy of amprolium, monensin, and salinomycin in preventing coccidiosis in bobwhite quail was studied using a mixed inoculum of equal numbers of Eimeria dispersa and E. lettyae. A total dosage per quail of 106 sporulated oocysts was chosen because this dosage gave a good (77%) depression of weight gain from Day 18 to Day 24. Levels of .008% monensin or .0055% salinomycin were the most effective for prevention of coccidiosis as evaluated by body weight gains. These levels significantly reduced parasite numbers in the duodenum with monensin administration and in both the duodenum and ileum with salinomycin administration. Monensin reduced parasite numbers in the illeum significantly in one experiment and in a second. Amprolium was ineffective for prevention of coccidiosis, as evaluated by body weight gains. Amprolium was also ineffective in consistently reducing parasite numbers in the duodenum and ileum. Both monensin and salinomycin had a reasonable safety margin in quail. Levels of monensin of .016%, twice the proposed level, significantly reduced body weight at 14 days of age compared with unmedicated controls or quail given .008% monensin. By 28 days, however, this effect was no longer significant. Levels of salinomycin at the proposed level of .0055% significantly reduced body weight at 14 days of age compared with unmedicated controls. By 28 days, however, this effect was no longer significant in quail given .0055% or .00825% salinomycin, although in quail fed .011% salinomycin body weights remained significantly lower (16.5%) at that date. There were no detectable monensin residues in the liver of quail fed a ration containing .008% monensin for 8 wk. Detectable salinomycin residues in the skin and fat of quail fed a ration containing .0044% salinomycin for 8 wk were well under the tolerance level of .68 ppm. Accordingly, a zero withdrawal is recommended for both drugs. (Key words: bobwhite, quail, coccidia, monensin, salinomycin, amprolium, anticoccidial drugs) 1987 Poultry Science66:1437-1445 INTRODUCTION
MATERIALS AND METHODS
Coccidiosis causes frequent and often severe problems in commercially reared gamebirds. Relatively few drugs are approved by the US Food and Drug Administration (FDA) for use in gamebirds and none for the control of coccidiosis in bobwhite quail. In the past, the relatively low market potential for gamebird medication has not made it economical for pharmaceutical companies to request FDA approval for such uses. More recently, however, some financial relief has been obtained under the IR-4 program, a joint project of FDA and US Department of Agriculture that is administered at Cook College, Rutgers University, by Robert Kupelian. This program allows for the facilitated approval of medications after IR-4-sponsored experiments showing efficacy, safety, and acceptable residues in the target animal species. One medication, amprolium, has already been cleared for use in pheasants based on data collected for this program (Patton et al., 1984). Trials reported here tested the efficacy and safety of monensin, salinomycin, and amprolium for the prevention of coccidiosis in the bobwhite quail.
Quail. Straight run bobwhites (Colinus virginianus) were used in all studies. These quail were hatched at the Animal Parasitology Institute from eggs collected from breeding flocks at the institute. Quail were housed in battery brooders with wire floors. These brooders were cleaned and sterilized in a steam chamber between trails. Unmedicated, uninoculated quail were examined and weighed at weekly intervals to ensure general health and expected growth. All quail were given feed and water ad libitum. Quail were housed under constant lighting. Access to experimental buildings was limited to essential personnel and a record of all persons entering the building was kept. Quail were checked twice daily throughout the experimental period. Any mortality was recorded and dead quail were examined for cause of death. All quail were individually wingbanded at 14 days of age. Day-old quail were grouped at random. When older quail (17 or 18 days old) were divided into subgroups or cages, they were first weighed, then distributed on a weight basis according to the method of Gardiner and Wehr (1950).
1437
1438
RUFF ET AL.
Feed and Medication. The basal ration used in all studies was a standard turkey starter ration containing 30% protein. The ration was mixed fresh for each trial. The medication used in these studies was received in the form of Coban 45 (Lot number 7LD44, shipment #84,022, 45 g monensin/lb) from Eli Lilly, Greenfield, IN, Bio-Cox (Lot number 84-499-06, 30 g salinomycin/lb) from A. H. Robins Co., Richmond, VA, and Amprol (Lot number 09,561, 25% amprolium) from Merck Sharp & Dohme, Rah way, NJ. The medication was mixed with the basal ration at levels based on the experimental design, which follows. After mixing, medicated ration was placed in individual, lidded waterproof cans, color coded to each specific drug level. Identical color codes were used on each of the feeders on the battery cages to indicate medication level and ration to be fed. Samples for medication assay were taken at random from several places within the individual cans and sent for assay to Eli Lilly (monensin), Agri-Bio (salinomycin), and Merck Sharp & Dohme (amprolium). Amprolium for water medication was Amprol 50 (20% soluble powder). Coccidia. Quail were inoculated with .5 cc of a mixture of coccidia. This dosage contained 5 x 105 sporulated oocysts each of Eimeria dispersa and E. lettyae except in the inoculation dose titration trials. The former species was added from a pure, laboratory-isolated culture. The latter species was added from a field culture originally from Pennsylvania that contained >90% E. lettyae. Other species in the field culture were not identified. Cultures were stored in 2.5% dichromate (K2CrO) and used within 5 mo of harvest. The dichromate was replaced with water before inoculation. Counts of sporulated oocysts were made using a hemocytometer. Experimental Design Titration of Inoculation Dosage. This trial was run to establish the inoculation dosage to be used in the drug trials. One hundred twenty five quail, 17 days old, were weighed, and divided into five groups of 25 quail each. Each group was further divided into five pens of five quail each. Quail were inoculated with 0, 105, 5 x 105, 106, or 2 x 106 sporulated oocysts/ quail, one group of five pens at each dosage. The inoculum contained equal numbers of E. dispersa and the mixed E. lettyae field culture
as described above. Mortality was recorded daily and 6 days later quail were weighed by pen. Efficacy Studies, Experiments 1 to 7. These seven experiments were identical in design except for medication levels and were performed in order to determine the effective drug level. In each trial, 125 quail, 1-day-old, were divided into five groups of 25 quail each. Two of these groups were fed unmedicated ration. The remaining three groups were given ration containing .008%, .010%, or .012% monensin, (Experiments 1 and 2), salinomycin (Experiments 3, 4, and 5), or .0125%, .0175%, .025% amprolium (Experiments 6 and 7), one group at each level. At 18 days of age each group was further divided into five cages of five quail each. All quail in the medicated groups and one of the unmedicated groups were inoculated with 106 sporulated oocysts. The remaining unmedicated group was used as an uninoculated control. Quail were weighed by cage on Day 24 (6 days after inoculation). Coccidial infections were confirmed by microscopic examination for parasites in the duodenum (the majority of which were E. lettyae) and ileum (the majority of which were E. dispersa). Numbers of parasites (gametes or oocysts) were scored based on the number of parasites in a representative microscopic field (100 x) of an average fresh intestinal scraping. These scores were 0 = no parasites, 1 = 1 to 10, 2 = 11 to 40, 3 = 41 to 100, and 4 = over 100 parasites/field. These scores were based on samples from two quail selected at random from each cage (10 from each group). Water Versus Feed Medication, Experiment 8. This experiment was designed to test if the route of administering amprolium (water vs. feed) would influence drug efficacy. Forty 1day-old quail were divided into four groups of 10 quail each. Two groups were unmedicated. At 12 days of age, one group was given water containing .0240% amprolium. A second group was fed rations containing .0250% amprolium. Two days later, quail in these two groups plus one unmedicated group were inoculated with 106 sporulated oocysts. Six days after inoculation, quail were weighed. Scrappings of the duodenum and ileum were examined microscopically to confirm the presence of parasites. Target Animal Safety, Experiment 9 and 10. These experiments were run to determine the safety of monensin or salinomycin in uninoculated quail. In each experiment, 100 1-day-old quail were divided into four groups of 25 quail each. One group was kept as unmedicated con-
PREVENTION OF COCCIDIOSIS IN BOBWHITES
trols. The remaining three groups were given rations containing .008%, .012%, or .016% monensin (Experiment 9) or .0055%, .00825%, or .011% salinomycin (Experiment 10), one level to each group. At 14 days of age, each group was subdivided into five cages of five quail/cage. Each cage of quail were weighed at 14 and 28 days. At 28 days, all surviving quail were killed and necropsied. Tissue Residues, Experiments 11 and 12. These experiments were designed to determine if tissue residues of monensin and salinomycin would exceed allowable limits. Tissue residue studies were conducted under the standards of Good Laboratory Practices or Guidelines (Code of Federal Regulations, 1984). Thirty quail were fed a ration containing .008% monensin beginning at 1 day of age. Medication was continued until termination of the experiment at 8 wk of age. Livers were collected separately from each sex, blotted on damp filter paper, then pooled to give samples weighing at least 15 g wet weight (Table 7). Pooled livers were frozen immediately on dry ice, then placed in plastic bags for shipment to Eli Lilly for residue assay. Assays were performed by P. R. Handy of the Lilly Research Laboratories, Greenfield, IN. Twenty quail were fed a ration containing .0044% salinomycin beginning at 1 day of age. An equal number of unmedicated quail were used. Medication was continued until termination of the experiment at 8 wk of age. Quail were killed, dry plucked, and samples of skin with adhering fat were collected separately from each sex. Sufficient skin and fat were collected from each quail to give a sample of at least 2.5
1439
g (Table 7). Samples were frozen immediately on dry ice, then placed in plastic bags for shipment to A. H. Robins Company for residue assay. Assays were performed by G. P. Dimenna of the A. H. Robins Company, Richmond, VA. Statistical Analysis. Data were analyzed by one-way analysis of variance to test for significance at P^.05. Differences between means were tested using Duncan's multiple range test. RESULTS
Titration of Inoculation Dosage. No quail died in this experiment. There was a direct relationship between increasing inoculation dose and depressed weight gain (Table 1). Efficacy Studies. In Experiment 1, one quail in the group receiving .012% monensin died of unknown causes prior to inoculation. Accordingly, one cage in this group contained only four quail. One uninoculated control and one inoculated, unmedicated quail died after Day 18, the latter apparently from coccidiosis. In Experiment 2, one inoculated, unmedicated quail died from coccidiosis. In Experiment 1, body weights prior to inoculation of quail given lower levels of monensin (.008% and .010%) were significantly greater than those of unmedicated quail or of quail given .012% monensin (Table 2). This difference was not seen in Experiment 2. In both experiments, the best protection based on body weight gain was obtained with .008% monensin. The number of parasites was significantly reduced in the duodenum in both experiments compared with the numbers in unmedicated inoculated quail (Table 2). Parasite numbers in the ileum
TABLE 1. Effect on body weight of different inciculation dosages of coccidia given to quail at 18 days iof age1''1 Body weight Oocysts pe r quail
18 days
0 10 s 5 X 10 s 10 6 2 X 10 6
40.7 40.7 40.7 40.6 40.6
± .9a + .9a ± ,9a ± .9a ± .9a
24 days
Gain
vs; 61.9 55.6 49.8 45.4 40.6
± ± ± ± ±
1.2a .9b 1.4C 1.3 d 1.3 e
21.2 14.8 9.1 4.8 0
± ± ± ± ±
.6 a .6b .8 C 1.0d .8e
Values within a column followed by different superscripts are significantly different (P<.05). 1
Values = mean ± standard error of the mean.
2 Dosages were based on a mixture of equal numbers of sporulated oocysts from a pure culture of Eimeria dispersa and a field culture of E. lettyae.
.008 .010 .012
.008 .010 .012
+ + + +
-
-
+ + + +
given
± ± ± ± ±
40.8 ± 40.4 ± 41.4 ± 41.0± 40.4 ±
39.5 39.3 43.1 40.2 30.5
bc
.2ab .2b .4a .3ab .lb
.4 .3bc .4a .3b .5C
Day 18
59.4 41.1 59.3 56.7 56.6
3.3 l.ld .8a 1.8bc 2.3C
ab
± .6a ± 1.8 b ± .5a ± .5a ± 1.4 a
58.6 ± 36.4+ 60.3 ± 54.1 + 50.6 ±
Day 24
18.6 .7 17.9 15.6 16.2
19.1 -2.8 17.2 13.9 12.1
3.3 1.3 C ,6ab 1.8b 2.1b
a
± .5a ± 1.6 C ab ± .5 ± ,6b ± 1.3ab
± ± ± ± ±
Weight gain
0 96 83 86
0 91 76 68
(%)
Pre Protection
.1 ± . 1 L
1.4 ± A"
0C ?. 3 ± 4 a 1 6 ± 3ab 1.5 + 2 a b
0b 1.3 ± . 2 a
+ 3a 1 3 + ?bc 1 3 + ,bc .6 ± 2 c d
o3 u0 2.2 ± . 2 a ..2±.lb .2±.lb .2±.lb
0U
I
Parasite score 2
2 Parasite numbers were based on microscopic examination of fresh intestinal scrapings of the duodenum (D) and ileum (I). Scores assigned ranged from 0 = no parasites to 4 = numerous parasites.
Each quail was given a mixture containing 5 X 10 s sporulated oocysts of E. lettyae and 5 X 10 s of E. dispersa at Day 18. Values are mean ± standard error of the mean. Percent protection is based on weight gain compared with the respective controls.
Values within a column and experiment followed by different superscripts are significantly different (P<.05).
0 0
2
1
0 0
(%)
Monensin
1
Experiment
B o d y weight
TABLE 2. Efficacy of monensin against a mixed inoculum of Etmena lettyae and E. dispersa in quail as measured by body weight and parasite numbers, Experiments 1 and 21
> r
C -n
PREVENTION OF COCCIDIOSIS IN BOBWHITES
of medicated quail were significantly reduced compared to unmedicated quail in Experiment 1 but not in Experiment 2 except at .012% monensin. In Experiment 3, eight quail in the group receiving .0055% salinomycin escaped from the cage prior to inoculation and were found loose on the floor. These were killed based on standard procedures for any birds found to be out of their cages and accordingly, three pens in this group contained only four quail and a forth pen contained five quail (four replicates total). One uninoculated control and one inoculated, unmedicated quail died after Day 18, the latter apparently from coccidiosis. In Experiment 4, one quail in the group receiving .0044% salinomycin died from undetermined causes prior to inoculation. In Experiment 5, one unmedicated quail died before inoculation, and three died after inoculation from coccidiosis. In Experiment 3, body weights, prior to inoculation, of quail given lower levels of salinomycin (.0044% and .0055%) were significantly greater than those of unmedicated quail or of quail given .0066% salinomycin (Table 3). This difference was not significant in Experiment 4 but was significant at .0044% salinomycin in Experiment 5. In Experiments 3 and 4, the best protection based on body weight gain was obtained with .0055% salinomycin. In Experiment 5, .0066% gave the best protection. The number of parasites was significantly reduced in the duodenum and ileum of medicated quail in all three experiments compared with the numbers in duodenum and ileum of unmedicated inoculated quail. In Experiment 6, one inoculated, unmedicated and one inoculated, .0175% amproliummedicated quail died after Day 18, but before Day 24, apparently from coccidiosis. Two quail were found dead on the morning of Day 24 and were included in final body weight analyses. In Experiment 7, one uninoculated control quail died from unknown causes the morning of Day 24. In Experiment 6, body weights between groups prior to inoculation showed slight but significant differences that were not related to medication level (Table 4). This difference was not seen in Experiment 7. In both experiments, amprolium gave no protection, based on body weight gain. The number of parasites in the duodenum was not significantly lower in medicated birds in Experiment 6 but was lower in
1441
Experiment 7, compared with the numbers in unmedicated, inoculated quail. Parasites in the ileum of medicated quail were not reduced by medication in Experiment 6, but were significantly reduced by levels of .0125% amprolium treatment in Experiment 7 compared with parasites in unmedicated, inoculated quail. In both experiments a low level of coccidial contamination was found in some uninoculated controls (2/10 and 3/10 in Experiments 6 and 7, respectively). No quail died during Experiment 8. There were no differences in efficacy between amprolium given in the feed or in drinking water (Table 5). All inoculated quail had numerous oocysts and meronts in the duodenum and ileum. Target Animal Safety. In Experiment 9, one quail died in each of the four groups between Day 14 and Day 28. Monensin medication significantly reduced body weight at 14 days compared with weight of unmedicated controls, especially at .016% (Table 6). By 28 days, this difference was still evident but was not statistically significant. There was a progressive suppression of body weight at 28 days with increasing levels of monensin. No abnormalities were found in any of the medicated quail at necropsy. In Experiment 10, no quail died. Salinomycin medication progressively and significantly reduced body weight at 14 days compared with the weight of unmedicated controls (Table 6). By 28 days this difference was no longer present at .0055%, was not statistically significant at .00825%, but was still significant at .011%. There was a progressive suppression of body weight at 28 days with increasing levels of salinomycin. No abnormalities were found in any of the medicated quail at necropsy. Tissue Residues. Daily observations of the quail in Experiments 11 and 12 showed no visible abnormalities. One medicated and one unmedicated quail died of undetermined causes during both experiments. No monensin residues were detected in any of the liver samples (Table 7). Salinomycin residues were all within the acceptable finite tolerance level of .68 ppm for skin and fat (Table 7). Feed Assays. All medication levels were within the acceptable variance in the assay procedure, except for two samples in Experiment 10. The assayed levels of these samples (.00638% and .00835%) were less than the expected levels (.00825% and .011%, respectively).
3 5 . 0 + :L i b 32.6 ± . 2 C 38.2 ± . 2 a 35.6 ± . 2 b 34.1 ± 2 b c
.0044 .0055 .0066
.0044 .0055 .0066
.3a .2a .3a .4a .2b
+ ± ± + ±
41.2 41.0 40.7 41.1 33.2
.4U .3b ,4a ,6a .6b
3.3 a l.lb 2.1 a .8a 1.5a
C 41.1 + .7 a 2.0 58.0 ± b 54.1 ± 1.8 54.5 + yal
a 62.0: , 5 C 44.4: 1.4 C 55.9: 2.1 7 ab 57.9: 46.2 ± 2.1 c 55.7 + 1.3 ab
(g) 58.6 ± 36.4 ± 61.9 ± 64.0 ± 58.4 ±
Day 24
Body weight
.0044 .0055 .0066
Day 18
± ± ± ± ±
Cocci given
39.5 39.3 42.8 44.0 40.3
(%)
Salinomycin
± ± ± ± ±
3.3 a 1.3 b 1.8a .3a 1.0a
20.9 ± .4 a 3.4 ± 1.6C 15.2+ 2.1 L ±ab 16.9: 13.1 : 2.1 C a 20.7 1.0 8.5 + . 9 b 19.8 1. a a 18.5 1.8 «a 20.4
19.1 -2.8 19.1 20.0 18.1
Weight gain
0 93 82 98
0 67 77 55
0 100 104 95
(%)
Protection
0e 2.9 ± . 2 a 2.4±.3ab 1.7±.5b 1.6 ± . 2 b 0C 2.7 ± . 3 a 1.5±.3b 1.0 ± . 4 b e .5 ± . 3 b e
0b 2.9 ± . 2 a .8±.3b .4±.3b .1 ± . l b
1.3±.3De .7 + . 3 c d
3.4±.3a 1.7 ± .4 b
0C 3.0 ± . 3 a 1.5±.5b .7 + . 2 b c .9±.3bc
.l + . l b
2.2 ± .2 a .5 + . 3 b .3+ .2°
Parasite score
Values within a column and experiment followed by different superscripts are significantly different (P<.05). ' Each quail was given a mixture containing 5 X 10 s sporulated oocysts of E. lettyae and 5 X 10 s of E. dispersa at Day 18. Values are mean ± standard error of the mean. Percent protection is based on weight gain compared with the respective controls. 2 Parasite numbers were based on microscopic examination of fresh intestinal scrapings of the duodenum (D) and ileum (I). Scores assigned ranged from 0 = no parasites to 4 = numerous parasites.
a—d
Experiment
TABLE 3. Efficacy of salinomycin against a mixed inoculum of Eimeria lettyae and E. dispersa in quail as measured by body weight and parasite numbers, Experiments 3 to 5 1
•73
>
UFFET
42.2 42.1 42.4 42.3 42.2
0 0 .0125 .0175 .0250 ± ± ± ± ±
± ± ± ± ± .l ,2a .la .2a .2a
a
.2C .2b .3a .3C
ab 2^i
63.9: 47.1 : 45.6 : 1.01be 43.8 : 7 bc 45.0:
— (g) 62.1 + . 5 a b 42.5 ± 1.6 b 1.8 41.7 : b 42.5 : 1.0 b 4 2 . 0 : 1.2
Day 24
1.1L
.4 a 1.7 b 1.6b
21.7 ± 4.9 ± 3.3 ± 1.1 be 1.5 ± 2.8 ±
21.2 ± 2.5 ± 1.3 ± 1.2 ± 2.2 ±
Weight gain
Values within a column and experiment followed by different superscripts are significantly different (P<.05).
40.9 40.0 40.4 41.3 39.8
Day 18
0 0 .0125 .0175 .0250
(%)
Amprolium
Body weight
0 0 0 0
0 0 0 0
(%)
Protection
.lu .2a .2a .4a .3a
1.1 ± .1be 1.8 ± . 3 C ibe 1.0:
± ± ± ± +
. 7 + .4 C 2.7 ± . 4 a
.1 2.8 2.6 2.0 2.4
± ± ± ±
.3ab .2a .4ab .3b .2 ± . 2 e 2.9 ± . 4 a 1.9 ± . 3 b 2.3 ± . 4 a b 1.6±.3b
2.6 3.3 2.6 1.9
Parasite score 2
J Parasite numbers were based on microscopic examination of fresh intestinal scrapings of the duodenum (D) and ileum (I). Scores assigned ranged from 0 = no parasites to 4 = numerous parasites.
Each quail was given a mixture containing 5 X 10 s sporulated oocysts of E. lettyae and 5 X 10 s of E. dispersa. Values are mean ± standard error of one mean. Percent protection is based on weight gain compared with the respective controls.
1
Experiment
Cocci given
TABLE 4. Efficacy of atnprolium against a mixed inoculum of Eimeria lettyae and E. dispersa in quail as measured by body weight and parasite numbers, Experiments 6 and 71
z H 5 z
tn
<
tn
•v
-^ -^
H tn
X
O
CO
OF COCCIDIOSIS IN
1444
RUFF ET AL. TABLE 5. Efficacy of amprolium in feed (.025%) or water (.024%) against a mixed inoculum of Eimeria lettyae and E. dispersa in quail, Experiment 81
Day 18
1 + + +
Body weight
Cocci given
41.3 45.0 44.2 41.5
Amprolium
Weight gain
Day 24
Protection
(%)
(%) 0 0 .025 (in feed) .024 (in water)
± ± ± ±
1.4 a l.la 1.3 a 1.3 a
60.7 51.6 52.3 50.5
± ± ± ±
2.0a 1.8b 1.7 b 1.8 b
19.4 6.5 8.2 9.0
± .8a ± 1.4 b ± 1.3b ± 1.0 b
0 13.2 19.4
a—b.Values within a column and experiment followed by different superscripts are significantly different (P«.05). 1 Each quail was given a mixture containing 5 X 10 s sporulated oocysts of E. lettyae and 5 X 10 s of E. dispersa at Day 18. Values are mean ± standard error of the mean.
DISCUSSION
against coccidia of the pheasant but Norton and Wise (1981) did not. Liquid or soluble amprol is often the medication of choice by gamebird producers because it is readily available and does not require feed milling. The results of Experiment 8 indicate that water medication is no more effective than feed medication. Birds generally consume twice as much water as feed and thus would have received almost twice the total dose of amprolium with the water medication. Both of the coccidial species used in these studies are pathogenic. E. dispersa is more severe in young quail chicks and can produce mortality and depressed weight gain (Tyzzer, 1929). E. lettyae (Ruff, 1985) likewise produces mortality only in young bobwhites but can cause a
The results of these studies indicate that both monensin (.008%) and salinomycin (.0055%) were effective for the prevention of coccidiosis in bobwhites based on body weight. These levels are lower than the levels (.010% to .0121% and .0066% for monensin and salinomycin, respectively) approved for prevention of coccidiosis in chickens (Feed Additive Compendium, 1986). This further emphasizes the need to test each medication in the target species. Amprolium was not effective for the control of coccidiosis in the present studies. Similarly, Ruff (1986) reported that it was ineffective for control of coccidiosis in Japanese quail. Patton et al. (1984) found amprolium to be effective
TABLE 6. Effect
of;monensin
and salinomycin
on! body
weight of- uninoculated
Body weight Mec iication
Day 14
Day 2 8
0
None Salinomycin Salinomycin Salinomycin
0
Gain (Day 14 t o Day 28)
(g)
(%) None Monensin Monensin Monensin
quail, Experiment
9 and
101
Weight suppression
(%)
.008 .012 .016
34.9 33.2 33.7 31.1
±.2a ±.2b ±.3b ±.2C
84.7 81.5 79.3 76.7
± l.la ±4.3a ± 2.9a ± 2.8a
49.8 48.3 45.6 45.6
± 1.2 a ±4.2a + 3.1a + 2.9a
.0055 .00825 .011
41.2 38.3 36.3 32.5
±.la ±.lb ±.3^ ±.2d
87.1 87.4 81.8 72.7
± 2.7a ± 1.9 a ± .6a ± 3.5b
45.9 49.1 45.5 40.2
+ 2.7ab +1.9a ± .6ab +3.5b
0 3.8 6.4 9.4 0 0 6.1 16.5
Values within a column and medication trial followed by different superscripts are significantly different (P«.05). 1
Values are mean + standard error of the mean.
PREVENTION OF COCCIDIOSIS IN BOBWHITES
1445
TABLE 7. Residue levels in the liver of quail fed ration containing .008% monensin (Experiment 11) or the skin and adhering fat of quail fed ration containing .0044% salinomycin (Experiment 12) for 8 wk
Treatment
Sex
No. samples
Weight per sample
Salinomycin residue
Control
M F
2 3
16.0 to 17.2 16.4 to 18.4
NDR 1 NDR
Monensin (.008%)
M F
2 3
15.6 to 16.2 17.3 to 17.9
NDR NDR
Control
M
6
8.4, 6.3, 6.6, 5.6, 6.4, 8.9
BQL 2 , BQL, BQL, BQL, BQL, BQL
F
6
6.0, 6.5, 4.9, 5.6,6.9, 5.8
.120, BQL, BQL, BQL, BQL, BQL
M
6
4.8, 8.2, 6.6, 5.0, 5.6, 6.8
.26, .11, .28, .20, .11, .13
F
6
5.1, 7.0, 6.7, 6.2,6.5, 7.3
.14, .14, BQL, .14, .13, BQL
(g)
Salinomycin (.0044%)
'NDR = No detectable residue. Limit of quantification was .04 ppm. Assays performed by Lilly Research Laboratories, Greenfield, IN. 2
BQL = Below quantifiable limits (<.l ppm). Assays performed by A. H. Robins Company, Richmond, Virginia.
depression of weight gain and poor reproduction in older birds (Ruff and Wilkins, 1986). The lack of consistent gross lesions with both these species prevents the development of a system for lesion scores analogous to that used in chicken coccidiosis. The oocyst scores in Experiment 1 to 5, however, indicate that both monensin and salinomycin may be more effective against E. lettyae than against E. dispersa. Both monensin and salinomycin had good safety margins of 1.5 times the proposed use level. The tissue residue studies also indicated that no drug withdrawal was necessary. In Experiment 10, the lower than expected level of salinomycin in two feed samples may have been due to an inadvertent delay in submitting the samples for assay. Those samples were not assayed until 7 mo after mixing. Assayed levels of salinomycin in finished feed decrease after 6 mo of storage, (Don Gilbert, A. H. Robins, Richmond, VA, personal communication).
REFERENCES Code of Federal Regulations, 1984. Title 21, Part 58, Good Laboratory Practices on Guidelines. Office of the Federal Register, Washington, DC. Feed Additive Compendium, 1986. Miller Publishing Co., Minneapolis, MN. Gardiner, J. L., and E. E. Wehr, 1950. Selecting experimental groups of chicks by weight. Proc. Helminfhol. Soc. Wash. 17:25-26. Norton, C. C , and D. R. Wise, 1981. Anticoccidial drugs for preventive therapy in intensively reared pheasants. Vet. Rec. 109:554-596. Patton, W. H., L. D. Schwartz, J. G. Babish, and D. J. I.isk, 1984. Use of amprolium for the control of coccidiosis in pheasants. Avian dis. 28:693-699. Ruff, M. D., 1985. Eimeria lettyae Sp. N. (Protozoa: Eimeriidae): Description of the life cycle and biology from the northern bobwhite, Colinus virginianus (L.). J. Wildl. Dis. 21:361-370. Ruff, M. D., 1986. Coccidiosis in gallinaceous gamebirds. In: Research in Avian Coccidiosis. L. R. McDougald, L. P. Joyner, and P. L. Long, ed. Univ. of Georgia, Athens, GA. Ruff, M. D., and G. C. Wilkins, 1986. Pathogenicity of Eimeria lettyae (Ruff, 1985) in the northern bobwhite (Colinusvirginianus, L.), J. Wildl. Dis. 23:121-126. Tyzzer, E. E., 1929. Coccidiosis in gallinaceous birds. Am. J. Hyg. X:l-115.
MATERIALS AND METHODS
Coccidiosis causes frequent and often severe problems in commercially reared gamebirds. Relatively few drugs are approved by the US Food and Drug Administration (FDA) for use in gamebirds and none for the control of coccidiosis in bobwhite quail. In the past, the relatively low market potential for gamebird medication has not made it economical for pharmaceutical companies to request FDA approval for such uses. More recently, however, some financial relief has been obtained under the IR-4 program, a joint project of FDA and US Department of Agriculture that is administered at Cook College, Rutgers University, by Robert Kupelian. This program allows for the facilitated approval of medications after IR-4-sponsored experiments showing efficacy, safety, and acceptable residues in the target animal species. One medication, amprolium, has already been cleared for use in pheasants based on data collected for this program (Patton et al., 1984). Trials reported here tested the efficacy and safety of monensin, salinomycin, and amprolium for the prevention of coccidiosis in the bobwhite quail.
Quail. Straight run bobwhites (Colinus virginianus) were used in all studies. These quail were hatched at the Animal Parasitology Institute from eggs collected from breeding flocks at the institute. Quail were housed in battery brooders with wire floors. These brooders were cleaned and sterilized in a steam chamber between trails. Unmedicated, uninoculated quail were examined and weighed at weekly intervals to ensure general health and expected growth. All quail were given feed and water ad libitum. Quail were housed under constant lighting. Access to experimental buildings was limited to essential personnel and a record of all persons entering the building was kept. Quail were checked twice daily throughout the experimental period. Any mortality was recorded and dead quail were examined for cause of death. All quail were individually wingbanded at 14 days of age. Day-old quail were grouped at random. When older quail (17 or 18 days old) were divided into subgroups or cages, they were first weighed, then distributed on a weight basis according to the method of Gardiner and Wehr (1950).
1437
1438
RUFF ET AL.
Feed and Medication. The basal ration used in all studies was a standard turkey starter ration containing 30% protein. The ration was mixed fresh for each trial. The medication used in these studies was received in the form of Coban 45 (Lot number 7LD44, shipment #84,022, 45 g monensin/lb) from Eli Lilly, Greenfield, IN, Bio-Cox (Lot number 84-499-06, 30 g salinomycin/lb) from A. H. Robins Co., Richmond, VA, and Amprol (Lot number 09,561, 25% amprolium) from Merck Sharp & Dohme, Rah way, NJ. The medication was mixed with the basal ration at levels based on the experimental design, which follows. After mixing, medicated ration was placed in individual, lidded waterproof cans, color coded to each specific drug level. Identical color codes were used on each of the feeders on the battery cages to indicate medication level and ration to be fed. Samples for medication assay were taken at random from several places within the individual cans and sent for assay to Eli Lilly (monensin), Agri-Bio (salinomycin), and Merck Sharp & Dohme (amprolium). Amprolium for water medication was Amprol 50 (20% soluble powder). Coccidia. Quail were inoculated with .5 cc of a mixture of coccidia. This dosage contained 5 x 105 sporulated oocysts each of Eimeria dispersa and E. lettyae except in the inoculation dose titration trials. The former species was added from a pure, laboratory-isolated culture. The latter species was added from a field culture originally from Pennsylvania that contained >90% E. lettyae. Other species in the field culture were not identified. Cultures were stored in 2.5% dichromate (K2CrO) and used within 5 mo of harvest. The dichromate was replaced with water before inoculation. Counts of sporulated oocysts were made using a hemocytometer. Experimental Design Titration of Inoculation Dosage. This trial was run to establish the inoculation dosage to be used in the drug trials. One hundred twenty five quail, 17 days old, were weighed, and divided into five groups of 25 quail each. Each group was further divided into five pens of five quail each. Quail were inoculated with 0, 105, 5 x 105, 106, or 2 x 106 sporulated oocysts/ quail, one group of five pens at each dosage. The inoculum contained equal numbers of E. dispersa and the mixed E. lettyae field culture
as described above. Mortality was recorded daily and 6 days later quail were weighed by pen. Efficacy Studies, Experiments 1 to 7. These seven experiments were identical in design except for medication levels and were performed in order to determine the effective drug level. In each trial, 125 quail, 1-day-old, were divided into five groups of 25 quail each. Two of these groups were fed unmedicated ration. The remaining three groups were given ration containing .008%, .010%, or .012% monensin, (Experiments 1 and 2), salinomycin (Experiments 3, 4, and 5), or .0125%, .0175%, .025% amprolium (Experiments 6 and 7), one group at each level. At 18 days of age each group was further divided into five cages of five quail each. All quail in the medicated groups and one of the unmedicated groups were inoculated with 106 sporulated oocysts. The remaining unmedicated group was used as an uninoculated control. Quail were weighed by cage on Day 24 (6 days after inoculation). Coccidial infections were confirmed by microscopic examination for parasites in the duodenum (the majority of which were E. lettyae) and ileum (the majority of which were E. dispersa). Numbers of parasites (gametes or oocysts) were scored based on the number of parasites in a representative microscopic field (100 x) of an average fresh intestinal scraping. These scores were 0 = no parasites, 1 = 1 to 10, 2 = 11 to 40, 3 = 41 to 100, and 4 = over 100 parasites/field. These scores were based on samples from two quail selected at random from each cage (10 from each group). Water Versus Feed Medication, Experiment 8. This experiment was designed to test if the route of administering amprolium (water vs. feed) would influence drug efficacy. Forty 1day-old quail were divided into four groups of 10 quail each. Two groups were unmedicated. At 12 days of age, one group was given water containing .0240% amprolium. A second group was fed rations containing .0250% amprolium. Two days later, quail in these two groups plus one unmedicated group were inoculated with 106 sporulated oocysts. Six days after inoculation, quail were weighed. Scrappings of the duodenum and ileum were examined microscopically to confirm the presence of parasites. Target Animal Safety, Experiment 9 and 10. These experiments were run to determine the safety of monensin or salinomycin in uninoculated quail. In each experiment, 100 1-day-old quail were divided into four groups of 25 quail each. One group was kept as unmedicated con-
PREVENTION OF COCCIDIOSIS IN BOBWHITES
trols. The remaining three groups were given rations containing .008%, .012%, or .016% monensin (Experiment 9) or .0055%, .00825%, or .011% salinomycin (Experiment 10), one level to each group. At 14 days of age, each group was subdivided into five cages of five quail/cage. Each cage of quail were weighed at 14 and 28 days. At 28 days, all surviving quail were killed and necropsied. Tissue Residues, Experiments 11 and 12. These experiments were designed to determine if tissue residues of monensin and salinomycin would exceed allowable limits. Tissue residue studies were conducted under the standards of Good Laboratory Practices or Guidelines (Code of Federal Regulations, 1984). Thirty quail were fed a ration containing .008% monensin beginning at 1 day of age. Medication was continued until termination of the experiment at 8 wk of age. Livers were collected separately from each sex, blotted on damp filter paper, then pooled to give samples weighing at least 15 g wet weight (Table 7). Pooled livers were frozen immediately on dry ice, then placed in plastic bags for shipment to Eli Lilly for residue assay. Assays were performed by P. R. Handy of the Lilly Research Laboratories, Greenfield, IN. Twenty quail were fed a ration containing .0044% salinomycin beginning at 1 day of age. An equal number of unmedicated quail were used. Medication was continued until termination of the experiment at 8 wk of age. Quail were killed, dry plucked, and samples of skin with adhering fat were collected separately from each sex. Sufficient skin and fat were collected from each quail to give a sample of at least 2.5
1439
g (Table 7). Samples were frozen immediately on dry ice, then placed in plastic bags for shipment to A. H. Robins Company for residue assay. Assays were performed by G. P. Dimenna of the A. H. Robins Company, Richmond, VA. Statistical Analysis. Data were analyzed by one-way analysis of variance to test for significance at P^.05. Differences between means were tested using Duncan's multiple range test. RESULTS
Titration of Inoculation Dosage. No quail died in this experiment. There was a direct relationship between increasing inoculation dose and depressed weight gain (Table 1). Efficacy Studies. In Experiment 1, one quail in the group receiving .012% monensin died of unknown causes prior to inoculation. Accordingly, one cage in this group contained only four quail. One uninoculated control and one inoculated, unmedicated quail died after Day 18, the latter apparently from coccidiosis. In Experiment 2, one inoculated, unmedicated quail died from coccidiosis. In Experiment 1, body weights prior to inoculation of quail given lower levels of monensin (.008% and .010%) were significantly greater than those of unmedicated quail or of quail given .012% monensin (Table 2). This difference was not seen in Experiment 2. In both experiments, the best protection based on body weight gain was obtained with .008% monensin. The number of parasites was significantly reduced in the duodenum in both experiments compared with the numbers in unmedicated inoculated quail (Table 2). Parasite numbers in the ileum
TABLE 1. Effect on body weight of different inciculation dosages of coccidia given to quail at 18 days iof age1''1 Body weight Oocysts pe r quail
18 days
0 10 s 5 X 10 s 10 6 2 X 10 6
40.7 40.7 40.7 40.6 40.6
± .9a + .9a ± ,9a ± .9a ± .9a
24 days
Gain
vs; 61.9 55.6 49.8 45.4 40.6
± ± ± ± ±
1.2a .9b 1.4C 1.3 d 1.3 e
21.2 14.8 9.1 4.8 0
± ± ± ± ±
.6 a .6b .8 C 1.0d .8e
Values within a column followed by different superscripts are significantly different (P<.05). 1
Values = mean ± standard error of the mean.
2 Dosages were based on a mixture of equal numbers of sporulated oocysts from a pure culture of Eimeria dispersa and a field culture of E. lettyae.
.008 .010 .012
.008 .010 .012
+ + + +
-
-
+ + + +
given
± ± ± ± ±
40.8 ± 40.4 ± 41.4 ± 41.0± 40.4 ±
39.5 39.3 43.1 40.2 30.5
bc
.2ab .2b .4a .3ab .lb
.4 .3bc .4a .3b .5C
Day 18
59.4 41.1 59.3 56.7 56.6
3.3 l.ld .8a 1.8bc 2.3C
ab
± .6a ± 1.8 b ± .5a ± .5a ± 1.4 a
58.6 ± 36.4+ 60.3 ± 54.1 + 50.6 ±
Day 24
18.6 .7 17.9 15.6 16.2
19.1 -2.8 17.2 13.9 12.1
3.3 1.3 C ,6ab 1.8b 2.1b
a
± .5a ± 1.6 C ab ± .5 ± ,6b ± 1.3ab
± ± ± ± ±
Weight gain
0 96 83 86
0 91 76 68
(%)
Pre Protection
.1 ± . 1 L
1.4 ± A"
0C ?. 3 ± 4 a 1 6 ± 3ab 1.5 + 2 a b
0b 1.3 ± . 2 a
+ 3a 1 3 + ?bc 1 3 + ,bc .6 ± 2 c d
o3 u0 2.2 ± . 2 a ..2±.lb .2±.lb .2±.lb
0U
I
Parasite score 2
2 Parasite numbers were based on microscopic examination of fresh intestinal scrapings of the duodenum (D) and ileum (I). Scores assigned ranged from 0 = no parasites to 4 = numerous parasites.
Each quail was given a mixture containing 5 X 10 s sporulated oocysts of E. lettyae and 5 X 10 s of E. dispersa at Day 18. Values are mean ± standard error of the mean. Percent protection is based on weight gain compared with the respective controls.
Values within a column and experiment followed by different superscripts are significantly different (P<.05).
0 0
2
1
0 0
(%)
Monensin
1
Experiment
B o d y weight
TABLE 2. Efficacy of monensin against a mixed inoculum of Etmena lettyae and E. dispersa in quail as measured by body weight and parasite numbers, Experiments 1 and 21
> r
C -n
PREVENTION OF COCCIDIOSIS IN BOBWHITES
of medicated quail were significantly reduced compared to unmedicated quail in Experiment 1 but not in Experiment 2 except at .012% monensin. In Experiment 3, eight quail in the group receiving .0055% salinomycin escaped from the cage prior to inoculation and were found loose on the floor. These were killed based on standard procedures for any birds found to be out of their cages and accordingly, three pens in this group contained only four quail and a forth pen contained five quail (four replicates total). One uninoculated control and one inoculated, unmedicated quail died after Day 18, the latter apparently from coccidiosis. In Experiment 4, one quail in the group receiving .0044% salinomycin died from undetermined causes prior to inoculation. In Experiment 5, one unmedicated quail died before inoculation, and three died after inoculation from coccidiosis. In Experiment 3, body weights, prior to inoculation, of quail given lower levels of salinomycin (.0044% and .0055%) were significantly greater than those of unmedicated quail or of quail given .0066% salinomycin (Table 3). This difference was not significant in Experiment 4 but was significant at .0044% salinomycin in Experiment 5. In Experiments 3 and 4, the best protection based on body weight gain was obtained with .0055% salinomycin. In Experiment 5, .0066% gave the best protection. The number of parasites was significantly reduced in the duodenum and ileum of medicated quail in all three experiments compared with the numbers in duodenum and ileum of unmedicated inoculated quail. In Experiment 6, one inoculated, unmedicated and one inoculated, .0175% amproliummedicated quail died after Day 18, but before Day 24, apparently from coccidiosis. Two quail were found dead on the morning of Day 24 and were included in final body weight analyses. In Experiment 7, one uninoculated control quail died from unknown causes the morning of Day 24. In Experiment 6, body weights between groups prior to inoculation showed slight but significant differences that were not related to medication level (Table 4). This difference was not seen in Experiment 7. In both experiments, amprolium gave no protection, based on body weight gain. The number of parasites in the duodenum was not significantly lower in medicated birds in Experiment 6 but was lower in
1441
Experiment 7, compared with the numbers in unmedicated, inoculated quail. Parasites in the ileum of medicated quail were not reduced by medication in Experiment 6, but were significantly reduced by levels of .0125% amprolium treatment in Experiment 7 compared with parasites in unmedicated, inoculated quail. In both experiments a low level of coccidial contamination was found in some uninoculated controls (2/10 and 3/10 in Experiments 6 and 7, respectively). No quail died during Experiment 8. There were no differences in efficacy between amprolium given in the feed or in drinking water (Table 5). All inoculated quail had numerous oocysts and meronts in the duodenum and ileum. Target Animal Safety. In Experiment 9, one quail died in each of the four groups between Day 14 and Day 28. Monensin medication significantly reduced body weight at 14 days compared with weight of unmedicated controls, especially at .016% (Table 6). By 28 days, this difference was still evident but was not statistically significant. There was a progressive suppression of body weight at 28 days with increasing levels of monensin. No abnormalities were found in any of the medicated quail at necropsy. In Experiment 10, no quail died. Salinomycin medication progressively and significantly reduced body weight at 14 days compared with the weight of unmedicated controls (Table 6). By 28 days this difference was no longer present at .0055%, was not statistically significant at .00825%, but was still significant at .011%. There was a progressive suppression of body weight at 28 days with increasing levels of salinomycin. No abnormalities were found in any of the medicated quail at necropsy. Tissue Residues. Daily observations of the quail in Experiments 11 and 12 showed no visible abnormalities. One medicated and one unmedicated quail died of undetermined causes during both experiments. No monensin residues were detected in any of the liver samples (Table 7). Salinomycin residues were all within the acceptable finite tolerance level of .68 ppm for skin and fat (Table 7). Feed Assays. All medication levels were within the acceptable variance in the assay procedure, except for two samples in Experiment 10. The assayed levels of these samples (.00638% and .00835%) were less than the expected levels (.00825% and .011%, respectively).
3 5 . 0 + :L i b 32.6 ± . 2 C 38.2 ± . 2 a 35.6 ± . 2 b 34.1 ± 2 b c
.0044 .0055 .0066
.0044 .0055 .0066
.3a .2a .3a .4a .2b
+ ± ± + ±
41.2 41.0 40.7 41.1 33.2
.4U .3b ,4a ,6a .6b
3.3 a l.lb 2.1 a .8a 1.5a
C 41.1 + .7 a 2.0 58.0 ± b 54.1 ± 1.8 54.5 + yal
a 62.0: , 5 C 44.4: 1.4 C 55.9: 2.1 7 ab 57.9: 46.2 ± 2.1 c 55.7 + 1.3 ab
(g) 58.6 ± 36.4 ± 61.9 ± 64.0 ± 58.4 ±
Day 24
Body weight
.0044 .0055 .0066
Day 18
± ± ± ± ±
Cocci given
39.5 39.3 42.8 44.0 40.3
(%)
Salinomycin
± ± ± ± ±
3.3 a 1.3 b 1.8a .3a 1.0a
20.9 ± .4 a 3.4 ± 1.6C 15.2+ 2.1 L ±ab 16.9: 13.1 : 2.1 C a 20.7 1.0 8.5 + . 9 b 19.8 1. a a 18.5 1.8 «a 20.4
19.1 -2.8 19.1 20.0 18.1
Weight gain
0 93 82 98
0 67 77 55
0 100 104 95
(%)
Protection
0e 2.9 ± . 2 a 2.4±.3ab 1.7±.5b 1.6 ± . 2 b 0C 2.7 ± . 3 a 1.5±.3b 1.0 ± . 4 b e .5 ± . 3 b e
0b 2.9 ± . 2 a .8±.3b .4±.3b .1 ± . l b
1.3±.3De .7 + . 3 c d
3.4±.3a 1.7 ± .4 b
0C 3.0 ± . 3 a 1.5±.5b .7 + . 2 b c .9±.3bc
.l + . l b
2.2 ± .2 a .5 + . 3 b .3+ .2°
Parasite score
Values within a column and experiment followed by different superscripts are significantly different (P<.05). ' Each quail was given a mixture containing 5 X 10 s sporulated oocysts of E. lettyae and 5 X 10 s of E. dispersa at Day 18. Values are mean ± standard error of the mean. Percent protection is based on weight gain compared with the respective controls. 2 Parasite numbers were based on microscopic examination of fresh intestinal scrapings of the duodenum (D) and ileum (I). Scores assigned ranged from 0 = no parasites to 4 = numerous parasites.
a—d
Experiment
TABLE 3. Efficacy of salinomycin against a mixed inoculum of Eimeria lettyae and E. dispersa in quail as measured by body weight and parasite numbers, Experiments 3 to 5 1
•73
>
UFFET
42.2 42.1 42.4 42.3 42.2
0 0 .0125 .0175 .0250 ± ± ± ± ±
± ± ± ± ± .l ,2a .la .2a .2a
a
.2C .2b .3a .3C
ab 2^i
63.9: 47.1 : 45.6 : 1.01be 43.8 : 7 bc 45.0:
— (g) 62.1 + . 5 a b 42.5 ± 1.6 b 1.8 41.7 : b 42.5 : 1.0 b 4 2 . 0 : 1.2
Day 24
1.1L
.4 a 1.7 b 1.6b
21.7 ± 4.9 ± 3.3 ± 1.1 be 1.5 ± 2.8 ±
21.2 ± 2.5 ± 1.3 ± 1.2 ± 2.2 ±
Weight gain
Values within a column and experiment followed by different superscripts are significantly different (P<.05).
40.9 40.0 40.4 41.3 39.8
Day 18
0 0 .0125 .0175 .0250
(%)
Amprolium
Body weight
0 0 0 0
0 0 0 0
(%)
Protection
.lu .2a .2a .4a .3a
1.1 ± .1be 1.8 ± . 3 C ibe 1.0:
± ± ± ± +
. 7 + .4 C 2.7 ± . 4 a
.1 2.8 2.6 2.0 2.4
± ± ± ±
.3ab .2a .4ab .3b .2 ± . 2 e 2.9 ± . 4 a 1.9 ± . 3 b 2.3 ± . 4 a b 1.6±.3b
2.6 3.3 2.6 1.9
Parasite score 2
J Parasite numbers were based on microscopic examination of fresh intestinal scrapings of the duodenum (D) and ileum (I). Scores assigned ranged from 0 = no parasites to 4 = numerous parasites.
Each quail was given a mixture containing 5 X 10 s sporulated oocysts of E. lettyae and 5 X 10 s of E. dispersa. Values are mean ± standard error of one mean. Percent protection is based on weight gain compared with the respective controls.
1
Experiment
Cocci given
TABLE 4. Efficacy of atnprolium against a mixed inoculum of Eimeria lettyae and E. dispersa in quail as measured by body weight and parasite numbers, Experiments 6 and 71
z H 5 z
tn
<
tn
•v
-^ -^
H tn
X
O
CO
OF COCCIDIOSIS IN
1444
RUFF ET AL. TABLE 5. Efficacy of amprolium in feed (.025%) or water (.024%) against a mixed inoculum of Eimeria lettyae and E. dispersa in quail, Experiment 81
Day 18
1 + + +
Body weight
Cocci given
41.3 45.0 44.2 41.5
Amprolium
Weight gain
Day 24
Protection
(%)
(%) 0 0 .025 (in feed) .024 (in water)
± ± ± ±
1.4 a l.la 1.3 a 1.3 a
60.7 51.6 52.3 50.5
± ± ± ±
2.0a 1.8b 1.7 b 1.8 b
19.4 6.5 8.2 9.0
± .8a ± 1.4 b ± 1.3b ± 1.0 b
0 13.2 19.4
a—b.Values within a column and experiment followed by different superscripts are significantly different (P«.05). 1 Each quail was given a mixture containing 5 X 10 s sporulated oocysts of E. lettyae and 5 X 10 s of E. dispersa at Day 18. Values are mean ± standard error of the mean.
DISCUSSION
against coccidia of the pheasant but Norton and Wise (1981) did not. Liquid or soluble amprol is often the medication of choice by gamebird producers because it is readily available and does not require feed milling. The results of Experiment 8 indicate that water medication is no more effective than feed medication. Birds generally consume twice as much water as feed and thus would have received almost twice the total dose of amprolium with the water medication. Both of the coccidial species used in these studies are pathogenic. E. dispersa is more severe in young quail chicks and can produce mortality and depressed weight gain (Tyzzer, 1929). E. lettyae (Ruff, 1985) likewise produces mortality only in young bobwhites but can cause a
The results of these studies indicate that both monensin (.008%) and salinomycin (.0055%) were effective for the prevention of coccidiosis in bobwhites based on body weight. These levels are lower than the levels (.010% to .0121% and .0066% for monensin and salinomycin, respectively) approved for prevention of coccidiosis in chickens (Feed Additive Compendium, 1986). This further emphasizes the need to test each medication in the target species. Amprolium was not effective for the control of coccidiosis in the present studies. Similarly, Ruff (1986) reported that it was ineffective for control of coccidiosis in Japanese quail. Patton et al. (1984) found amprolium to be effective
TABLE 6. Effect
of;monensin
and salinomycin
on! body
weight of- uninoculated
Body weight Mec iication
Day 14
Day 2 8
0
None Salinomycin Salinomycin Salinomycin
0
Gain (Day 14 t o Day 28)
(g)
(%) None Monensin Monensin Monensin
quail, Experiment
9 and
101
Weight suppression
(%)
.008 .012 .016
34.9 33.2 33.7 31.1
±.2a ±.2b ±.3b ±.2C
84.7 81.5 79.3 76.7
± l.la ±4.3a ± 2.9a ± 2.8a
49.8 48.3 45.6 45.6
± 1.2 a ±4.2a + 3.1a + 2.9a
.0055 .00825 .011
41.2 38.3 36.3 32.5
±.la ±.lb ±.3^ ±.2d
87.1 87.4 81.8 72.7
± 2.7a ± 1.9 a ± .6a ± 3.5b
45.9 49.1 45.5 40.2
+ 2.7ab +1.9a ± .6ab +3.5b
0 3.8 6.4 9.4 0 0 6.1 16.5
Values within a column and medication trial followed by different superscripts are significantly different (P«.05). 1
Values are mean + standard error of the mean.
PREVENTION OF COCCIDIOSIS IN BOBWHITES
1445
TABLE 7. Residue levels in the liver of quail fed ration containing .008% monensin (Experiment 11) or the skin and adhering fat of quail fed ration containing .0044% salinomycin (Experiment 12) for 8 wk
Treatment
Sex
No. samples
Weight per sample
Salinomycin residue
Control
M F
2 3
16.0 to 17.2 16.4 to 18.4
NDR 1 NDR
Monensin (.008%)
M F
2 3
15.6 to 16.2 17.3 to 17.9
NDR NDR
Control
M
6
8.4, 6.3, 6.6, 5.6, 6.4, 8.9
BQL 2 , BQL, BQL, BQL, BQL, BQL
F
6
6.0, 6.5, 4.9, 5.6,6.9, 5.8
.120, BQL, BQL, BQL, BQL, BQL
M
6
4.8, 8.2, 6.6, 5.0, 5.6, 6.8
.26, .11, .28, .20, .11, .13
F
6
5.1, 7.0, 6.7, 6.2,6.5, 7.3
.14, .14, BQL, .14, .13, BQL
(g)
Salinomycin (.0044%)
'NDR = No detectable residue. Limit of quantification was .04 ppm. Assays performed by Lilly Research Laboratories, Greenfield, IN. 2
BQL = Below quantifiable limits (<.l ppm). Assays performed by A. H. Robins Company, Richmond, Virginia.
depression of weight gain and poor reproduction in older birds (Ruff and Wilkins, 1986). The lack of consistent gross lesions with both these species prevents the development of a system for lesion scores analogous to that used in chicken coccidiosis. The oocyst scores in Experiment 1 to 5, however, indicate that both monensin and salinomycin may be more effective against E. lettyae than against E. dispersa. Both monensin and salinomycin had good safety margins of 1.5 times the proposed use level. The tissue residue studies also indicated that no drug withdrawal was necessary. In Experiment 10, the lower than expected level of salinomycin in two feed samples may have been due to an inadvertent delay in submitting the samples for assay. Those samples were not assayed until 7 mo after mixing. Assayed levels of salinomycin in finished feed decrease after 6 mo of storage, (Don Gilbert, A. H. Robins, Richmond, VA, personal communication).
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