Prometryn

Toxicity to birds

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to birds: reproduction test

Type of information:

experimental study

Adequacy of study:

key study

Study period:

8 Apr 1988 to 6 Oct 1988

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 71-4 (Avian Reproduction Test)

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Dose method:

feed

Analytical monitoring:

yes

Vehicle:

yes

Remarks:

feed

Details on preparation and analysis of diet:

- Preparation of diet: All groups received the same basal feeds. Test diets were prepared weekly. The test substance was incorporated directly into the feed without employment of a vehicle. Test diet concentrations were adjusted to correct for the 98.1% purity value supplied by the sponsor. All diets were prepared approximately 24 hours prior to administration using an upright mixer. All diets were mixed for 10 - 15 minutes each. The Control diet was prepared simply by adding basal feed to the mixer bowl and blending for 10-15 minutes.
- Analysis of diet: One hundred gram samples of prepared diets from all groups were collected and shipped frozen with dry ice approximately every six weeks throughout the project for confirmation of dietary levels. A total of four sets was shipped. One set consisted of 0, 50, 250, and 500 ppm a.i. diet levels.

Test organisms (species):

Anas platyrhynchos

Details on test organisms:

TEST ORGANISM
- Common name: Mallard ducks
- Age at test initiation: 26-27 weeks old (hatched on October 5, 1987 and had received Bacterin vaccinations at 7 and 14 days of age.) The ducks were phenotypically indistinguishable from wild birds and were 17-18 weeks old when they were received.
- Quarantine period: All birds were placed on a 66 day quarantine period to determine their suitability as test units and to acclimate them to the laboratory conditions. All birds were fed with commercial feed during the quarantine period.
- Breeding population: All birds were approaching their first breeding season.

Limit test:

no

Total exposure duration (if not single dose):

20 wk

No. of animals per sex per dose and/or stage:

16 males and 16 females per dose

Control animals:

yes, plain diet

Nominal and measured doses / concentrations:

- Nominal concentrations: 0 (control), 50, 250, and 500 mg a.i./kg
- Measured concentrations: <1.0 (control), 52.3, 251.8, 520.5 mg a.i./kg
Table 1 in 'Any other informations on materials and methods incl. tables'

Details on test conditions:

QUARANTINE PERIOD
- Period: 66 days
- Room temperature: 48°F to 68°F
- Humidity: 78% and 100%
- Health condition: One female bird was sacrificed on 2/05/88 (day 3 of the quarantine period ). It had gotten caught in the cage and injured itself. All other birds were normal and active throughout the quarantine period. Prior to initiation of the project, all birds were examined and their suitability for testing ( based on general physical condition) was determined.

PEN SIZE AND CONSTRUCTION MATERIALS
- Description: 2' x 4' x 2' wire pens. Pens and pans were rinsed daily.

NO. OF BIRDS PER REPLICATE
- For negative control: 2 (1 male and 1 female)
- For treated group: 2 (1 male and 1 female)
- No. of replicates per negative control: 16
- No. of replicates per treated concentration: 16

TEST CONDITIONS (range, mean, SD as applicable)
- Temperature: 52 - 96 °F
- Relative humidity (%): 82%
- Photoperiod: 8 hours light of 16 hours darkness (first six weeks); Increased 4 hours light every week until a maximum of 16 hours per day was achieved. Then the photoperiod remained 16 hours per day until the end of the study.
- Light intensity: fluorescent lights (first 6 weeks); 75 watt bulbs suspended and centered between two pens, producing between 9 and 20 foot-candles at bird's eye level (after 6 weeks)
- Other: Basal ration and natural well water with no additives were available at all times. There are no known or suspected contaminants in the drinking water which is analysed every three months for such substances.
- Hatching: After the birds had been on test feed for nine weeks, all normal eggs were selected for hatching. These eggs were placed in a refrigerator maintained at average daily maximum and minimum temperatures of 51°F and 40°F, respectively, and 80% relative humidity. The eggs were turned once daily during each 7-day collection period. Following each 7-day collection period, the eggs were placed in an incubator maintained at 99.0°F to 99.9°F with a wet bulb reading of 84°F to 92°F. All eggs were turned automatically while in the incubator every four hours until placed in the hatching trays on incubation day 24. This procedure was followed for eleven 7-day collection periods from the control and each test group.

- F1 generation: The F1 generation birds were housed in a building separate from their parents. They were placed in 45.7 cm x 61 cm x 45.7 cm wire cages divided by group and pen number. All ducklings were observed daily.

Details on examinations and observations:

- Body weight: The birds were randomised, arbitrarily assigned to test groups, and weighed individual. All ducks were weighed biweekly thereafter except during the egg production period (test weeks 9 through 20). Technicians did not weigh the birds during this period in an effort to promote egg production and decrease the amount of stress that additional handling places on the birds.

- Food consumption: All birds were allowed natural well water with no additives and their respective diets at all times, Test diet feeding began 9 weeks before eggs were collected for incubation and continued until the termination of the project. Food consumption was determined biweekly.

- Pathological examinations: Observations were made daily to ascertain the presence (or absence) of clinical signs of toxicity indicative of test material effect. A gross pathological examination was conducted on the one bird that died during the investigation. Gross pathological examinations were conducted on half of all surviving adult birds at termination.

Details on reproductive parameters:

- Egg production and quality: Eggs were collected and candled daily during the production period. The first eggs were collected on 5/30/88 in the T-II and T-III Test groups, on 6/07/88 in the Control group, and on 6/11/88 in the T-I Test group. The total number of eggs collected, the total number of uncracked and unbroken eggs, and the total number of cracked or broken eggs were recorded for each group.
- Hatchability: The following hatchability data were recorded for each hatch:
a. number hatched,
b. number unhatched,
c. fertility,
d. embryo life at 15-20 days (based on candling),
e. examination of unhatched eggs for stage of development.

- Egg shell thickness: After group egg production had reached approximately 20%, all eggs collected the first day of every other week (1, 3, 5, 7, 9 , and 11) were examined to determine the thickness of the shells at the equatorial circumference (3 measurements/egg).

- Residue studies: All eggs that were examined for eggshell thickness measurements were quick-frozen and retained. After hatching results were available from all hatches (A through K) and with the approval of the sponsor, the remaining parental birds in each group were sacrificed. Half of the remaining Control and Test birds were subjected to gross pathological examinations. Individually pooled samples of muscle, liver, and fat from half of the remaining birds in each group were collected and quick-frozen.

- F1 generation: The following data were recorded for each hatch:
a. weight of ducklings on days 1 and 14,
b. viability of ducklings over a 14 day period (clean diet),
c. gross pathological examinations of selected ducklings on day 14.

Reference substance (positive control):

no

Key result

Duration (if not single dose):

20 wk

Dose descriptor:

NOEL

Effect level:

500 mg/kg diet

Conc. / dose based on:

act. ingr.

Basis for effect:

reproductive parameters

Mortality and sub-lethal effects:

An overview of the results is provided in Table 2 – Table 4 in ‘Any other information on results incl. tables’
- Body weight: No statistically significant differences were noted at any of the weighing intervals.
- Food consumption: No statistically significant differences were noted at any time during the investigation.
- Mortality and behavioural reactions: One mortality was recorded in the T-II Test group during
test week 13 of the investigation. There were no abnormal behavioural reactions noted during the investigation which could be attributed to the ingestion of the test substance.
- Gross pathological examinations: A gross pathological examination of the one T-II Test bird that died during the investigation revealed clotted blood present in the lungs, oral cavity, and oesophagus and around the heart. A 2 cm x 1 cm firm nodule was found on the lobe of the right lung. Gross pathological examinations of half of the surviving adult birds in each group at the final sacrifice revealed findings in only seven birds.

Effects on reproduction:

An overview of the results is provided in Table 5 – Table 7 in ‘Any other information on results incl. tables’
- Eggs: No statistically significant differences were noted with respect to eggshell thicknesses, number of defective eggs, number of viable embryos, number of live 15-20 day embryos, number of normal hatchlings, number of 14 day-old survivors, and number of eggs laid.
- F1 generation body weight: Although some statistically significant differences in mean body weights on days 1 and 14 were noted for various groups within the hatches, these differences were not consistent. Hence, they were not considered to be attributable to the test substance.
- F1 generation viability: No statistically significant differences were noted. The viability data (average from all hatches) of the ducklings from the C, T-I, T-II, and T-III Test groups were essentially the same.
- F1 generation behavioural reaction and gross pathological examinations: There were no abnormal behavioural reactions or systemic signs of toxicity noted during the 14 day observation periods which could be attributed to ingestion of the test substance by the parental generation. Gross pathological examinations of ducklings found dead during the 14 day observation periods and selected ducklings sacrificed on day 14 from each group and hatch revealed no abnormal pathological findings.

Reported statistics and error estimates:

See Statistical analyses in 'Any other information on materials and methods incl. tables'

Table 2. Body Weight and Food Consumption Data (grams)

	Control		50 ppm a.i.		250 ppm a.i.		500 ppm a.i.
Initiation	B.W.	F.C.	B.W.	F.C.	B.W.	F.C.	B.W.	F.C.
2	1153	109	1157	113	1141	104	1175	106
4	1145	105	1158	106	1131	97	1164	103
6	1169	110	1173	115	1139	107	1184	110
8	1161	109	1164	118	1139	107	1180	118
10 12	N/A N/A	141 148	N/A N/A	139 145	N/A N/A	134 152	N/A N/A	139 150
14 16	N/A N/A	142 144	N/A N/A	144 147	N/A N/A	146 138	N/A N/A	145 147
18 20	N/A 1278	137 140	N/A 1268	141 139	N/A 1254	131 127	NIA 1288	136 140

The body weight data are presented as a group mean, The food consumption data are presented as the group mean food consumed per bird per day.

B.W.=Body Weight

F.C.=Food Consumption

No statistically significant differences were noted.

 

Table 3. Mean duckling body weight (g)

Group	Nominal concentration	Day 1	Day 14
Control	0 ppm a.i.	36	154
T-I	50 ppm a.i.	35	168
T-II	250 ppm a.i.	36	147
T-III	500 ppm a.i.	36	135

No statistically significant differences were noted.

Table 4. 14 Day-Old Survivors By Week

Week #	1	2	3	4	5	6	7	8	9	10	11	Total
Control	17	52	56	62	65	30	57	23	49	21	20	452
50 ppm a.i.	3	28	40	55	57	35	55	27	45	25	18	388
250 ppm a.i.	24	58	52	62	65	37	58	22	30	24	4	436
500 ppm a.i.	18	40	66	58	72	45	46	19	26	21	16	427

No statistically significant differences were noted.

Table 5.Reproductive data

	Control	50 ppm a.i.	250 ppm a.i.	500 ppm a.i.
Eggs laid	722	711	661	704
Eggs defective	29	19	17	22
Eggs set	638	606	586	617
Viable Embryos	573	537	556	561
Live 15-20 day embryos	570	532	551	557
Normal hatchings	467	401	450	440
14 day-old survivors	452	388	436	427

No statistically significant differences were noted.

Table 6. Reproductive success data

	Control	50 ppm a.i.	250 ppm a.i.	500 ppm a.i.
Eggs laid per hen in 13 weeks	45	44	41	44
Eggs defective of egg laid (%)	4.0	2.7	2.6	3.1
Viable embryos of eggs set (%)	89.8	88.6	94.9	91.0
Live 15 -20 day embryos of viable embryos (%)	99.5	99.1	99.1	99.3
Normal hatchings of live 15 -20 day embryos (%)	81.9	75.4	81.7	79.0
14 day-old survivors of Normal hatchings (%)	96.8	96.8	96.9	97.0
14 day-old survivors per hen	28	24	27	27

 

Table 7. Egg shell thickness

	Control	50 ppm a.i.	250 ppm a.i.	500 ppm a.i.
No. of Eggs Analysed	52	55	48	49
Mean shell thickness (mm)	0.393	0.390	0.393	0.397

No statistically significant differences were noted.

Validity criteria fulfilled:

yes

Conclusions:

There were no treatment related mortalities, pathological effect, body weight or food consumption at any of the concentrations tested. In addition, there were no apparent treatment-related effects upon any of the reproductive parameters measured at the 50, 250 or 500 mg a.i./kg diet treatments. Therefore, the NOEL was determined to be 500 mg a.i./kg diet, the highest concentration tested.

Executive summary:

The effects of the test substance on the mallard ducks (Anas platyrhynchos) were determined in a one generation reproduction test. The test was conducted according to EPA 71-4 guideline and in compliance with GLP. The test substance was administered in the diet to groups of 16 pairs of 26 - 27 weeks old (at test initiation) Mallard ducks approaching their first breeding season. Ducks received the test substance at nominal dietary concentrations of 50, 250 and 500 mg/kg diet for 20 weeks. A control group was maintained concurrently with the treatment groups. All ducks were weighted biweekly except during the egg production period. Food consumption were determined biweekly. The birds were observed daily for mortality, abnormal behaviour, and signs of toxicity. Gross pathological examinations were conducted on half of all surviving adult birds at termination. For the first six weeks of the test, the birds were held under a photoperiod of eight hours of light per day. After that, the photoperiod was increased 4 hours every week, until reach the maximum 16 hours of light per day. The adults continued on a photoperiod of 16 hours of light per day until the end of the study. Eggs were collected daily during the production period. The total number of eggs collected, the total number of uncracked and unbroken eggs, and the total number of cracked or broken eggs were recorded for each group. After group egg production had reached approximately 20%, all eggs collected the first day of every other week were examined the thickness of the shell. After the birds had been on test feed for nine weeks, all normal eggs were selected for hatching. The following hatchability data were recorded for each hatch on number (un)hatched, fertility, embryo life at 15-20 days (based on candling), and examination of unhatched eggs for stage of development.

The results showed that there were no treatment related mortalities, pathological effect, body weight or food consumption at any of the concentrations tested. In addition, there were no apparent treatment related effects upon any of the reproductive parameters measured at the 50, 2500 or 500 mg a.i./kg diet treatments. Therefore, the NOEL was determined to be 500 mg a.i./kg diet, the highest concentration tested.

Description of key information

All available data was assessed and the study representing the worst-case effects was included here as key studies. The other study is included as supporting information. The key study is selected for the CSA.

20-wk NOEC = 500 mg a.i./kg diet, Anas platyrhynchos, reproduction, EPA 71-4, Fletcher, 1989

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for birds:

500 mg/kg food

Additional information

The effects of the test substance on the mallard ducks (Anas platyrhynchos) were determined in a one generation reproduction test. The test was conducted according to EPA 71-4 guideline and in compliance with GLP. The test substance was administered in the diet to groups of 16 pairs of 26 - 27 weeks old (at test initiation) Mallard ducks approaching their first breeding season. Ducks received the test substance at nominal dietary concentrations of 50, 250 and 500 mg/kg diet for 20 weeks. A control group was maintained concurrently with the treatment groups. All ducks were weighted biweekly except during the egg production period. Food consumption were determined biweekly. The birds were observed daily for mortality, abnormal behaviour, and signs of toxicity. Gross pathological examinations were conducted on half of all surviving adult birds at termination. For the first six weeks of the test, the birds were held under a photoperiod of eight hours of light per day. After that, the photoperiod was increased 4 hours every week, until reach the maximum 16 hours of light per day. The adults continued on a photoperiod of 16 hours of light per day until the end of the study. Eggs were collected daily during the production period. The total number of eggs collected, the total number of uncracked and unbroken eggs, and the total number of cracked or broken eggs were recorded for each group. After group egg production had reached approximately 20%, all eggs collected the first day of every other week were examined the thickness of the shell. After the birds had been on test feed for nine weeks, all normal eggs were selected for hatching. The following hatchability data were recorded for each hatch on number (un)hatched, fertility, embryo life at 15-20 days (based on candling), and examination of unhatched eggs for stage of development.

The results showed that there were no treatment related mortalities, pathological effect, body weight or food consumption at any of the concentrations tested. In addition, there were no apparent treatment related effects upon any of the reproductive parameters measured at the 50, 2500 or 500 mg a.i./kg diet treatments. Therefore, the NOEL was determined to be 500 mg a.i./kg diet, the highest concentration tested.