Pirimiphos-methyl

Toxicity to birds

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to birds: dietary toxicity test

Remarks:

reproduction

Type of information:

experimental study

Adequacy of study:

key study

Study period:

April 1975 to May 1975

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

The studied laying hens were allowed a 28-day acclimatisation period prior to the start of egg production. This was followed by a 30-day period to ensure the birds had reached maximum egg production before the start of the 42-day experimental period. The birds were dietary exposed to the test substance for 28-day experimental period which followed by a 14-day recovery period. The number of eggs laid, quality and grade, fertility of eggs and their hatchability, chick (F1 generation) bodyweight and mortality up to 10 days of age and bodyweight and food consumption of parent birds were studied during this test.

GLP compliance:

no

Dose method:

feed

Analytical monitoring:

yes

Remarks:

See Methods used for determining residues in 'Any other information on materials and methdos incl. tables'

Vehicle:

yes

Remarks:

feed

Details on preparation and analysis of diet:

PREPARATION OF THE DIET
The commercial basic ration contain no additives. This ration was used for all birds with the required amount of test material added and the ration's composition was listed below:
- Wheat meal: 30%
- Maize meal: 20%
- Ex. soya meal: 20%
- Fish meal: 10%
- Maize starch: 10%
- Grass meal: 5%
- Limestone flour: 2.5%
- Coopers BTA40: 2.5%
The same ration was used for the chicks.

For the experimental diets a small premix was made after incorporating the required amount of the test substance in 0.5 kg of basal diet, This was mixed in a tumble mixer for 20 minutes, The premix was then added to the basal diet and incorporated mechanically. Fresh batches of experimental diet were prepared weekly.

Test organisms (species):

other: Laying hen

Details on test organisms:

TEST ORGANISM
- Common name: Laying hen
- Source: Local breeder
- Age at arrival: 146 point-of lay (approximately 18 weeks old) pullets and sixteen 30 weeks old cockerels. On arrival the birds were examined to ensure there were no clinical signs of ill health, and they were allocated to pens- in treatment groups.

Limit test:

no

Total exposure duration (if not single dose):

42 d

Remarks:

28-day experimental period on test diets with eggs collected for residue analysis and incubation and 14-day period with eggs collected for residue analysis only (all birds on control diet)

Post exposure observation period:

14 days

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

- Group 1 (Basal diet only): 4 males + 37 females
- Group 2 (Basal diet + 4 mg test substance/kg diet): 4 males + 35 females
- Group 3 (Basal diet + 12 mg test substance/kg diet): 4 males + 37 females
- Group 4 (Basal diet + 40 mg test substance/kg diet): 4 males + 37 females

Control animals:

yes, plain diet

Nominal and measured doses / concentrations:

- Nominal doses: 0 (negative control), 4, 12 and 40 mg test substance/kg diet.
- Measured doses: 4.1 – 5.2, 12.2 – 15.1 and 40.8 - 45.2 mg/kg diet, respectively.

Details on test conditions:

ACCLIMATION
- Acclimation period: Four-week prior to the start of egg production. This was followed by a 30-day period to ensure that the birds had reached maximum egg production before the test stared.

PEN SIZE AND CONSTRUCTION MATERIALS (F0 generation)
- Description: The pens measured 2½ x 3 m and each pen housed one treatment group. Each pen contained an automatic drinker, food container, grit oontainer and nest boxes.
- Floor covering: The bedding used was wood shavings and these were replenished weekly,

NO. OF BIRDS PER SEX PER GROUP : See 'No.of animal per sex oer dose and/or stage'

NO. OF REPLICATES PER GROUP
- For vehicle control: 1
- For treated: 1

TEST CONDITIONS (F0 generation)
- Room temperature: The ambient temperature of thebuilding was 15 ˚C
- Photoperiod: 17 hours light and 7 hours darness
- Ventilation: Ventilation fans were adjusted to allow twelve air changes per hour.
- Feeding: The birds had access to food and water ad llbitum throughout the study.

EXPERIMENTAL PERCEDURE (F0 generation)
The cockerels were moved to a different treatment group after each 7-day experimental period. This was done to reduce possible effects of male infertility and meant that each group of 4 cockerels was placed with each group of hens for 7 days. This applied to the 28-day period of the study when eggs were collected for incubation. For the last 14-day period of the study when eggs were collected for residue analysis only, the cockerels were moved to the pens they occupied for the first 7-day period of the study.
All groups of birds were treated similarly, the only difference being in the diets offered.

TREATMENT OF CHICKS (F1 generation)
On hatching, the chicks remained in the incubator for approximately 12 hours before being transferred in treatment groups to a five-tiered brooder.
- Cage description: The birds were housed in groups in cages of metal construction measuring 80 x 36 x 24 cm.
- Room temperature: The ambient temperature of the brooder was maintained at 32 ˚C by means of thermostatically controlled heater units.
- Ventilation: The ventilation fans were adjusted to give eight air changes per hour.
- Feeding: The diet offered was similar to that offered to the parent generation and was given ad libitum. Water was available at all times.

Details on examinations and observations:

MORTALITY / CLINICAL SIGNS
Recorded as they occurred.

BODY WEIGHT
The birds were weighed in groups on days 0, 7, 14, 21, 28 and 35 of the study.

FOOD CONSUMPTION
This was recorded over 7-day periods. The food consumption was that of the male and female birds combined.

BIRD HEALTH
All birds were examined daily for any toxic signs.

Details on reproductive parameters:

- Eggs incubation: All suitable eggs laid on days 1, 2, 4, 6, 8, 9, 11, 13, 15, 16, 18, 20, 22, 23, 25 and 27 of the study were incubated. After collection, selected eggs were stored at room temperature for 7 days and then placed in a incubator for 21 days at a temperature of 37 ˚C. On day 19 all eggs were moved into hatching trays in the bottom compartment of the incubator.

- Egg Production: This was recorded dally for the acclimatisation and test periods.

- Eggs quality: Each egg was examined for cracks and abnormal shape. Each egg was also graded using a modification of the weights specified by the 'Egg Marketing Board'. The eggs were weighed and allocated by weight to one of the following grades:
> Small: 0 - 42 g
> Medoum: 42 - 63 g
> Large: 64 - 112 g

- Candling: All eggs set in the incubator were candled for signs of fertility on days 7 and 18 of the incubation period,

- Hatching: The following results were recorded: 1) Number hatched alive; 2) Number dead in shell; 3) Number infertile; 4) Number broken during incubation and 5) Any abnormalities

- Chick rearing: All birds hatched were reared to 10 days of age and the following results were recorded: 1) Weight of chicks within 24 hours of hatching (day 0) and again on day 10 approximately, from which the bodyweight gain was obtained; 2) Mortalities and 3) Any abnormalities

Reference substance (positive control):

no

Key result

Duration (if not single dose):

28 d

Dose descriptor:

NOEL

Effect level:

40 mg/kg diet

Conc. / dose based on:

test mat.

Basis for effect:

reproductive parameters

Mortality and sub-lethal effects:

An overview of the results is provided in Table 2 - Table 3 in 'Any other information on results incl. tables'.

- Food consuption (F0 generation): The food consumption of the four treatment groups varied over the 7-day periods of the study. The results covering the 28-day inclusion period suggested that diets containing the test substance might be less palatable than the control diet. As only total food consumption figures for each group of birds over weekly periods were available for analysis and as time is a systematic factor and not a random factor, and also as the observations taken over different time periods on the same birds are not independent, it is not possible to do a strictly valid statistical analysis of the data. However, both non-parametric and classical two way analyses of variance were carried out on the data. No significant differences were obtained. Food consumption in all the groups was similar during the 2-week post-inclusion period when all groups were offered basal diet only.

- Bodyweight (F0 generation): The mean bodyweights of all groups increased over the test period. All bodyweight changes were considered to be within normal limits and the results indicate that no adverse effects on bodyweight resulted from the inclusion of the test substance in the diet of laying hens at concentrations up to 40 mg/kg diet.

- Mortality: One bird in the control group died on day 35 of the study. No other mortalities were recorded.

- Bird health: All surviving birds appeared to remain in good health and no signs of stress or abnormal behaviour were observed.

Effects on reproduction:

An overview of the results is provided in Table 4 - Table 8 in 'Any other information on results incl. tables'.

- Egg production: All groups of birds offered diet containing the test substance laid more eggs than the control group. Results were analysed statistically by the two-way analysis of variance, the factors in the analysis being treatment groups and day of collection. Treatment with 4 mg/kg diet, 12 mg/kg diet and 40 mg/kg diet produced significantly more eggs than the control group (P < 0.001, P < 0.001 and P < 0.001 respectively).

- Egg quality: There was no marked difference between treatments in the number of cracked or broken eggs recorded. The results were confirmed statistically using non-parametric methods. From these results it appears that the inclusion of the test substance in the diet of laying hens had no adverse effects on egg quality. Results were confirmed statistically using Friedman's two-way analysis of variance.
(a) % of eggs laid that were grade S (small). There was no significant trend associated with dose.
(b) % of eggs laid that were grade M (medium). There was no significant trend associated with dose.
(c) % of eggs laid that were grade L (large). Group treated with 12 mg/kg diet was statistically different from the control group (P < 0.05) producing fewer grade L eggs. This result complements the fact that group treated with 12 mg/kg diet produced more grade M eggs than the control group.

- Fertility and hatchabillty:
(a) % of eggs incubated that were infertile: statistical analysis of the results indicate that there was no statistical difference between treatments.
(b) % of eggs incubated in which there were embryonic mortalities: statistical analysis of the results indicate that there was no statistical difference between treatments.
(c) % of eggs incubated which were hatched alive: statistical analysis of the results indicate that there was no statistical difference between treatments.
The fertility and hatchability results indicate that the inclusion of the test substance in the diet of laying hens had no adverse effects on the parameters measured.

- Chick weights (F1 generation): The results were analysed by non-parametric methods. No significant difference between treatments was observed. The group mean bodyweight increases of the four groups were as follows:
(a) Control: 37.1 g
(b) 4 mg/kg diet test substance treated group: 36.3 g
(c) 12 mg/kg diet test substance treated group: 37.2 g
(d) 40 mg/kg diet test substance treated group: 37.2 g

- Chick mortalities (F1 generation): The % mortalities in the four groups were as follows:
(a) Control: 11.2
(b) 4 mg/kg diet test substance treated group: 10.8
(c) 12 mg/kg diet test substance treated group: 11.1
(d) 40 mg/kg diet test substance treated group: 12.3
The mortalities of the four groups were considered to be within normal limits.

Analytical data

- Egg yolk: There were indications that the test substance concentrations in egg yolks in 40 mg/kg diet reached a plateau level by day 7, as the concentrations on days 7, 14 and 21 were similar. The day 28 concentration was only slightly higher. Following the 7-day withdrawal periods, values were below the level of detection. The results for the other three groups following analysis for the test substance were on or below the level of detection. The results for all groups following analysis for the metabolites of the test substance were below the levels of detection.

- Egg white, liver and flesh: The measured test substance levels in egg white, liver and mixed flesh were below the levels of detection.

 

Table 2. Group mean food consumption (F0 generation)

Group	Inclusion level (mg test substance/kg diet)	Food consumption (kg/bird)
		Period of study						Total
		0 - 7 days	8 - 14 days	15 - 21 days	22 - 28 days	29 - 35 days	36 - 42 days	0 - 28 days	29 - 42 days	0 - 42 days
1	0	1.14	1.03	1.03	0.98	1.15	0.83	4.18	1.98	6.16
2	4	0.89	0.97	1.03	0.95	1.05	0.77	3.84	1.82	5.66
3	12	0.99	1.26	0.83	0.95	1.12	0.86	4.03	1.98	6.01
4	40	0.95	0.96	1.10	0.82	1.13	0.79	3.83	1.92	5.75

 

Table 3. Group mean body weight (F0 generation, females only)

Group	Inclusion level (mg test substance/kg diet)	0	7	14	21	28	35	Increased (g/bird)
1	0	1925	1930	1989	2019	1996	1930	5
2	4	1957	1911	1940	1969	1984	1975	18
3	12	1920	1971	1969	1961	1967	1977	57
4	40	1933	1926	1928	1950	1938	1999	66

 Table 4. Summary of reproduction parameters

Group	Treatment level (mg/kg diet)	Egg quality as % of egg laid				Total eggs laid	Total egg incubated	F1 generation
								Hatched alive %	Embryonic mortalities %	Infertile %	Body weights (g)			Mortalities % of eggs incubated
		Rejected	small	Medium	Large						0 days	10 days	Increased 1 - 10 days
1	0	6.8	3.6	80.5*	7.4	365	182	63.5	22.1	14.3	41.3	78.4	37.1	11.2
2	4	6.3	2	84.4*	5.9	507	270	66.3	20.8	13.0	41	77.3	36.3	10.8
3	12	3.7	4.8	89	2.5	481	278	61.9	23.4	14.7	40.5	77.7	37.2	11.1
4	40	6	3.4	83.8	6.8	498	268	68.3	21.3	10.4	40.6	77.8	37.2	12.3

Table 5. Number of eggs laid/group (0-28 days)

Group	Inclusion level (mg test substance/kg diet)	Eggs laid				Total eggs laid
		Week 1	Week 2	Week 3	Week 4
1	0	96	77	114	78	365
2	4	101	119	154	133	507
3	12	136	123	121	101	481
4	40	124	121	150	103	498

 

Table 6. Number of cracked or broken eggs

Group	Inclusion level (mg test substance/kg diet)	Total eggs laid (days 0 -28)	Eggs broken		Eggs cracked
			actual	%	actual	%
1	0	365	6	1.6	19	5.2
2	4	507	11	2.2	21	4.1
3	12	481	6	1.2	12	2.5
4	40	498	8	1.6	22	4.4

 

Table 7. Number of eggs in each weight range

Group	Inclusion level (mg test substance/kg diet)	Total eggs laid (days 0 -28)	Egg rejected		Small		Medium		Large
			actual	%	actual	%	actual	%	actual	%
1	0	365*	25	6.8	13	3. 6	294	80.5	27	7.4
2	4	507*	32	6.3	10	2	428	84.4	30	5.9
3	12	481	18	3. 7	23	4.8	428	89.0	12	2.5
4	40	498	30	6.0	17	3.4	417	83.8	34	6.8

* Some eggs were broken after collection and prior to grading (Group 1: 6 eggs, Group 2: 7 eggs).

 

Table 8. Summary of hatchability results (actual and %)

Group			Hatched alive		Embryonic mortalities						Infertile
	Inclusion level (mg test substance/kg diet)	Egg incubated	actual	%	Early		Fully formed		Total		actual	%
					actual	%	actual	%	actual	%
1	0	181*	115	63.5	24	13.3	16	8.8	40	22.1	26	14.3
2	4	270	179	66.3	34	12.6	22	8.1	46	20.7	35	13
3	12	278	172	61.9	30	10.8	35	12.6	65	23.4	41	14.7
4	40	268	183	68.3	34	12.7	23	8.6	57	21.3	28	10.4

* Results from day 15 not included in calculation of means as only one egg was incubated.

Validity criteria fulfilled:

not specified

Conclusions:

Based on the findings, the NOEL was determined to be 40 mg/kg diet.

Executive summary:

 The effects of the test substance to birds (laying hen) was investigated in 28-day exposure study. The study did not follow any internationally established guidelines and was not in compliance with GLP criteria. However, the study was well documented and meets generally accepted scientific principles. The study was therefore considered to have a Klimisch 2 reliability score and was acceptable for assessment. 146 hens, purchased at 18 weeks of age, and 16 30-week-old cockerels were used in this study. The birds were allowed a 28-day acclimation period prior to the start of egg production. This was followed by a 30-day period to ensure the birds had reached maximum egg production before the start of the 28-day treatment plus 14-day recovery experimental period. The nominal doses were 0 (control, on plain diet only), 4, 12 and 40 mg/kg diet. The diet samples were analytically verified by gas chromatography and the mean measured doses were determined to be 4.1 – 5.2, 12.2 – 15.1 and 40.8 - 45.2 mg/kg diet, respectively. The measured test substance levels in egg white, liver and mixed flesh were below the levels of detection. For biological effect, the number of eggs laid, quality and grade, fertility of eggs and their hatchability, chick (F1 generation) bodyweight and mortality up to 10 days of age and bodyweight and food consumption of parent birds were studied in this test.

 

F0 generation: Birds offered diet containing the test substance laid more eggs than the control group. But there was no statistical difference between treatments. The number of cracked and broken eggs was recorded. All other eggs were graded according to weight. The results indicate that the dietary inclusion of the test substance had no adverse effects on egg quality and egg weight. The number of large eggs produced by 12 mg/kg diet treated group was lower than the other groups (significant at the P < 0.05 level). None of the other results were statistically significant. The three groups offered diet containing the test substance consumed less food than the control group over the 28-day inclusion period, although this difference was not statistically significant. The food consumptions of the three test groups and the control group were similar over the two-week post-inclusion period. The mean bodyweights of all groups increased over the test period. All bodyweight changes were considered to be within normal limits. The results indicate that the inclusion of the test substance in the diet at various levels had no adverse effects on bodyweight. One bird in the control group died on day 35 of the study. No other mortalities were recorded. All surviving birds appeared to remain in good health and no signs of stress or abnormal behaviour were observed. The results of all groups were considered to be within normal limits. Statistical evaluation of the results revealed no significant difference between treatments. No adverse effects were observed that could be related to treatment.

F1 generation: All results of chick mortality were considered to be within normal limits and there was no significant difference between treatments. There was no significant difference of chick bodyweights between treatments. Overall, all results were considered to be within normal limits and there was no significant difference between treatments. Therefore, the NOEL was determined to be 40 mg/kg diet.

Description of key information

All available data was assessed and the study representing the worst-case effects was included here as key studies. These results are selected for the CSA.

28-d NOEL = 40 mg/kg diet, laying hen, reproduction parameters, no guideline followed, Ross 1978

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for birds:

40 mg/kg food

Additional information

The effects of the test substance to birds (laying hen) were investigated in a 28-day exposure study. The study did not follow any internationally established guidelines and was not in compliance with GLP criteria. However, the study was well documented and meets generally accepted scientific principles. The study was therefore considered to have a Klimisch 2 reliability score and was acceptable for assessment. 146 hens, purchased at 18 weeks of age, and 16 30-week-old cockerels were used in this study. The birds were allowed a 28-day acclimation period prior to the start of egg production. This was followed by a 30-day period to ensure the birds had reached maximum egg production before the start of the 28-day treatment plus 14-day recovery experimental period. The nominal doses were 0 (control, on plain diet only), 4, 12 and 40 mg/kg diet. The diet samples were analytically verified by gas chromatography and the mean measured doses were determined to be 4.1 – 5.2, 12.2 – 15.1 and 40.8 - 45.2 mg/kg diet, respectively. The measured test substance levels in egg white, liver and mixed flesh were below the levels of detection. For biological effect, the number of eggs laid, quality and grade, fertility of eggs and their hatchability, chick (F1 generation) bodyweight and mortality up to 10 days of age and bodyweight and food consumption of parent birds were studied in this test.

 

F0 generation: Birds offered diet containing the test substance laid more eggs than the control group. But there was no statistical difference between treatments. The number of cracked and broken eggs was recorded. All other eggs were graded according to weight. The results indicate that the dietary inclusion of the test substance had no adverse effects on egg quality and egg weight. The number of large eggs produced by 12 mg/kg diet treated group was lower than the other groups (significant at the P < 0.05 level). None of the other results were statistically significant. The three groups offered diet containing the test substance consumed less food than the control group over the 28-day inclusion period, although this difference was not statistically significant. The food consumptions of the three test groups and the control group were similar over the two-week post-inclusion period. The mean bodyweights of all groups increased over the test period. All bodyweight changes were considered to be within normal limits. The results indicate that the inclusion of the test substance in the diet at various levels had no adverse effects on bodyweight. One bird in the control group died on day 35 of the study. No other mortalities were recorded. All surviving birds appeared to remain in good health and no signs of stress or abnormal behaviour were observed. The results of all groups were considered to be within normal limits. Statistical evaluation of the results revealed no significant difference between treatments. No adverse effects were observed that could be related to treatment.

F1 generation: All results of chick mortality were considered to be within normal limits and there was no significant difference between treatments. There was no significant difference of chick bodyweights between treatments. Overall, all results were considered to be within normal limits and there was no significant difference between treatments. Therefore, the NOEL was determined to be 40 mg/kg diet.