Aluminium sulphate

Toxicity to reproduction: other studies

Administrative data

Endpoint:

toxicity to reproduction: other studies

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Reliable without restrictions. Well-presented study, with relevant measurement of chemical concentrations

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: The General Linear Models and Duncan's multiple range test.

Principles of method if other than guideline:

Data analysis was conducted through the Statistical Analysis System (SAS) main tained at The Pennsylvania State University Computation Center.
The General Linear Models procedure was used to perform the analysis of variance and Duncan's multiple range test. Arcsin square root transformations were carried out on variables that were proportions. This transformation was developed to correct the lack of normality when there are unequal variances. Because this procedure is unlikely to produce noticeable changes in conclusions when proportions range between 30 and 70%, it was only performed on values, from zero to 30% and from 70 to 100% .Differences were considered statistically significant at p < 0.05).

GLP compliance:

not specified

Type of method:

in vivo

Test material

Test material information

Constituent 1

Reference substance name:

Aluminium sulphate

EC Number:

233-135-0

EC Name:

Aluminium sulphate

Cas Number:

10043-01-3

Molecular formula:

Al2(SO4)3

IUPAC Name:

Aluminium sulphate

Test material form:

solid: compact

Details on test material:

- Name of test material (as cited in study report): Aluminium sulfate

Test animals

Species:

other: hen

Strain:

other: White Leghorn laying hens

Sex:

male/female

Details on test animals or test system and environmental conditions:

White Leghorn laying hens (DeKalb XL strain, DeKalb Hatchery, Hellam, PA) were selected on the basis of consistent egg production and assigned to treatments (20 per treatment) so that initial production among groups was equal. They were housed in individual cages with feed and water supplied ad libitum.

Eggshell and contents.
Whole eggs were weighed at room temperature. Shells and contents were separated. Shells were rinsed, dried and weighed to determine percentage shell. The contents were pooled into four units of five in each treatment. Yolks and whites were homogenized and lyophilized in polypropylene sample jars. Lyophilized samples were stored at 4°C until analyzed.
For determination of aluminum concentration, 2-g samples were placed in quartz crucibles and wet-digested with 12 mol/L HNO3 (BakerReagent grade, Phillipsburg City, NJ).
The residue was dry-ashed at 600°C overnight. Samples were diluted to 50 mL with 0.5% HNO3. This solution was analyzed for aluminum using flameless atomic absorption spectrophotometry (Instrumentation Laboratory Model 775, Wilmington, MA).
All glassware for aluminum analyses was soaked in a 20% solution of nitric acid and rinsed thoroughly with distilled, deionized water. The validity of the aluminum analysis was verified using the Trace Metals 1 Standard obtained from the Environmental Protection Agency (Environmental Monitoring and Support Laboratory, Cincinnati, OH).

Blood.
Plasma phosphorus levels were determined using the inorganic phosphate assay of Fiske and Subbarow. Calcium levels were determined by flame atomic absorption spectrophotometry (Instrumenta tions Laboratory Model 551, Wilmington, MA) using a 0.5% lanthanum chloride diluent solution to prevent phosphate interference.

Bone.
Bone ash was determined using the procedure described by Nahorniak .Tibiae were cleaned and defatted in an ethanol/benzene extraction solution. The dry bones were then ashed at 600°C overnight in a muffle furnace to determine percent ash. Bone calcium and phosphorus contents were determined, using the previously cited methods, on 100-mg samples dissolved in 2mL 12mol/L HCl and diluted to 100mL. Aluminum determination was performed on 60-mg ash samples. Ash was dissolved in 1mL of 50% HNOs and diluted to 100 mL with deionized, distilled water. Samples were analyzed using flameless atomic absorption spectrophotometry.

Diets.
Ingredients were weighed and mixed using stainless steel or plastic equipment. Two-gram samples were weighed, ashed at 600°C overnight and analyzed for calcium, phosphorus and aluminum. The previously cited methods were used for calcium and phosphorus analysis. Aluminum concentrations were determined by flame absorption spectrophotometry after dissolving the entire ash in concentrated HNOs over heat and diluting to a volume containing an appropriate aluminum concentration. A diluent containing 2000 ng potassium/ mL (5.128 mg KNOs/L deionized H2O)was used to control matrix interference.

Administration / exposure

Route of administration:

oral: feed

Vehicle:

other: diet

Details on exposure:

White Leghorn laying hens (DeKalb XL strain, DeKalb Hatchery, Hellam, PA) were selected on the basis of consistent egg production and assigned to treatments (20 per treatment) so that initial production among groups was equal. They were housed in individual cages with feed and water supplied ad libitum.

The composition of the basal diet is shown in Table 1.
The source of added aluminum was A12(SO4)3, which was added in place of corn. Hens in production for 22 wk were fed diets containing 0.0, 0.15 or 0.30% added aluminum for 17 wk. Daily egg production was recorded, and percentage eggshell was determined weekly. Feed consumption was determined monthly.
Body weight data were recorded at the beginning and end of the experiment. During the experiment, blood was drawn from the brachial vein with heparinized syringes. At the conclusion of the experiment, blood samples were obtained by cardiac puncture. The hens were artificially inseminated weekly with pooled semen from Ross broiler breeder males.
Fertility and hatchability were determined by breaking out the unhatched eggs after 21 d of incubation. Male offspring from each hen dietary treatment group were wingbanded and assigned to dietary treatments (0.0, 0.15 or 0.30% AI; n = 182/treatment).
Chicks were arranged in batteries so that each pen contained two chicks from each hen treatment group. Body weights and feed in takes were recorded weekly, and samples of blood and bone were obtained at the conclusion of the experiment.

The composition of the diet used in the chick experiments is shown in Table 2

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

17 weeks

Frequency of treatment:

daily

Duration of test:

17 weeks, 22 weeks,

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 0.15 or 0.3% aluminium for 17 weeks.
Basis:
nominal in diet

No. of animals per sex per dose:

182

Control animals:

yes

Details on study design:

This study was performed to determine the long-term effects of dietary aluminum on egg production and reproductive parameters in the mature laying hen and on growth rate and feed efficiency in young chicks. The diets used in these studies were adequate in phosphorus and other essential nutrients. Aluminum added to constitute 0.30% of the diet severely depressed growth and reduced feed efficiency, bone ash and plasma phosphorus in male Ross x Leghorn chicks.
At the same time, 0.15% added aluminum mildly depressed growth, feed efficiency and bone ash but had no effect on plasma phosphorus levels. The reduction in bone ash was relatively mild, and no clinical signs of rickets were observed. In laying hens, diets containing 0.15% added aluminum did not affect egg production, but 0.30% added aluminum reduced production significantly. Long-term exposure to aluminum increased percent shell in both groups receiving aluminum, whereas egg weight remained similar to that in controls. There were no changes in hatchability or bone ash associated with dietary aluminum. Although dietary aluminum influenced bone aluminum content, egg aluminum content was not affected. These studies indicate that dietary aluminum interferes with systems in addition to phosphorus metabolism.

Statistics:

Statistical analysis.
Data analysis was conducted through the Statistical Analysis System (SAS) main tained at The Pennsylvania State University Computation Center.
The General Linear Models procedure was used to perform the analysis of variance and Duncan's multiple range test. Arcsin square root transformations were carried out on variables that were proportions. This transformation was developed to correct the lack of normality when there are unequal variances. Because this procedure is unlikely to produce noticeable changes in conclusions when proportions range between 30 and 70%, it was only performed on values, from zero to 30% and from 70 to 100% .Differences were considered statistically significant at p < 0.05).

Results and discussion

Effect levels

1

Dose descriptor:

LOAEL

Effect level:

187.5 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: 0.15% of aluminium sulphate corresponds to 1500 ppm (mg/l).1 ppm in the diet of chick is equavalent to 0.125 mg/kg bw per day. Consequently 1500 ppm is equavalent to 187.5 mg/kg bw per day (1500x 0.125).

2

Dose descriptor:

LOAEL

Effect level:

375 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: 0.3% of aluminium sulphate corresponds to 3000 ppm (mg/l).1 ppm in the diet of chick is equavalent to 0.125 mg/kg bw per day. Consequently 3000 ppm is equavalent to 375 mg/kg bw per day (3000x 0.125).

Observed effects

White leghorn laying hens were fed diets containing 0, 0.15% (187.5mg/kg bw Aluminium sulphate) or 0.3% aluminium (375 mg/kg bw Aluminium sulphate) for 17 weeks. The LOAEL was based on significantly depressed fertility and chick body weight at 0.15% and these effects plus significantly reduced total egg production and feed consumption at 0.3% aluminium. Egg hatchability was unaffected.

Any other information on results incl. tables

TABLE 3

Long-term (17 weeks) effect of dietary aluminum on laying hen performance

 

Added dietary Al	Total egg production	Feed consuption	weight	shell		fertility		hatchability
%	%	g (hen-day)	g	%		%		%
0.00	90.2	117.7	59.25	8.99	229	83.7	1847	59.0	1522
0.15	87.5	111.0	59.90	9.31	236	81.1	1801	60.5	1469
0.30	70.5	102.5	58.84	9.37	194	80.1	1352	63.6	1120

 

 

TABLE 4

Long-term (17 weeks) effect of dietary aluminum on parameters of mineral metabolism in laying hens

 

Added dietary Al	Plasma calcium	Plasma phosphorus	Bone ash	Bone calcium	Bone phosphorus
%	mg/100 ml	mg/100 ml	%	% of ash	% of ash
0.00	24.37	4.01	57.6	39.5	17.5
0.15	28.04	3.83	58.1	39.3	19.2
0.30	26.56	3.60	58.0	39.4	18.9

 

 

TABLE 5

Long-term (17 weeks) effect of dietary aluminum on

aluminum levels in bone and egg samples

Added dietary Al	Bone Al	Egg Al
%	mg/kg	mg/kg
0.00	8.3	11.9
0.15	11.7	11.6
0.30	19.1	11.8

 

TABLE 6

Influence of dietary aluminum on performance and mineral metabolism of chicks

 

Added dietary Al	Body weight	Feed efficiency	Plasma calcium	Plasma phosphorus	Bone ash	Bone Al
%	g	g feed/g body wt	mg/100 ml	mg/100 ml	%	mg/kg
0.00	312	1.42	9.82	6.60	44.5	1.49
0.15	276	1.47	9.60	6.40	42.5	6.21
0.30	187	1.79	9.66	6.06	40.6	9.73

 

 

Applicant's summary and conclusion

Conclusions:

White leghorn laying hens were fed diets containing 0, 0.15% (187.5mg/kg bw Aluminium sulphate) or 0.3% aluminium (375 mg/kg bw Aluminium sulphate) for 17 weeks. The LOAEL was based on significantly depressed fertility and chick body weight at 0.15% and these effects plus significantly reduced total egg production and feed consumption at 0.3% aluminium. Egg hatchability was unaffected.

Executive summary:

RESULTS

 

This experiment was conducted to evaluate the effect of aluminum exposure on productivity, fertility and hatchability. The results are presented in Table 3.

 By the second week of treatment, 0.30% added dietary aluminum significantly decreased egg output. However, afterthe initial drop in production, hens fed this diet maintained consistent output and did not show signs of induced molt. Overall, production was not affected by0.15% added dietary aluminum but was reduced significantly by 0.30% aluminum. Feed consumption wassignificantly reduced by 0.30% added dietary aluminum.

There was no change in egg weight associated withdietary aluminum, which is consistent with a preliminary study. However, an unexpected significant increasein percent shell occurred in both groups receiving addedaluminum.

The addition of 0.30% dietary aluminum slightly but significantly lowered fertility. However, percent hatchability showed no significant changes.

 

Plasma and bone mineral data are presented in Table4. Plasma calcium showed an inconsistent responsetodietary aluminum,- hens fed0.15% added aluminum hadsignificantly higher plasma calcium values than controlbirds. Hens receiving 0.30% aluminum had intermediate plasma calcium levels that were not significantlydifferent from those of control hens or of hens receiving0.15% added aluminum. No differences existed inplasma phosphorus levels. Bone analysis showed no differences in percentage ash or in calcium and phosphorus concentrations.

 

The results of aluminum analysis of bone and eggs are presented in Table 5. Aluminum concentrations indried, defatted bone increased with increasing levels ofdietaryaluminum, with the change being significant inhens receiving 0.30% aluminum. The aluminum content of eggs was not different across treatments. These results show that although the hen's bone accumulated aluminum, there was no detectable transfer to the egg.

 

The effect of aluminum in the diet of laying hens onthe performance of the progeny was also investigated. No trends in the incidence of deformities were noted athatching, and there was no significant effect of hen dieton chick response. Therefore, the data for each chickdiet are reported in a combined form in Table 6. By 1wk of age, dietary aluminum had significantly reduced body weight in a dose-dependent manner. Feed efficiency was significantly reduced among chicks receiving the highest level of aluminum. These levels of dietary aluminum had no effect on mortality. The plasma calcium level was not affected by dietary aluminum, but thephosphorus level was significantly lowered by 0.30%added dietary aluminum. Bone ash was significantlyreduced and bone aluminum was significantly increasedby added aluminum, both in a dose-dependent manner.Identical results were obtained in parallel experimentswith Hubbard x Hubbard broiler chicks.

 

To put these results into perspective, a survey of thealuminum content of diets and feed ingredients wasconducted. Commercial feeds for young chicks werefound to range between 0.003 and 0.01% aluminum (wt/wt), whereas diets for laying hens contained 0.01 to0.04% aluminum (wt/wt). It may be assumed that thehigher values obtained with the diets for laying henswere due to the higher level of mineral supplementationwith these diets. Of the individual feed ingredients,soybean meal was the major source of aluminum. Theaverage aluminum content of six samples of soybeanmeal was0.018%, with a range of 0.0009 to 0.04%.