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Tissue Residues of Mercury in Broilers Fed Fish Meals Containing Different Concentrations of Mercury
2181
HG EXPOSURE
afforded of the higher mercury concentration in the eggs laid by the Br. birds.
Tissue Residues of Mercury in Broilers Fed Fish Meals Containing Different Concentrations of Mercury B . E . M A R C H AND RAYMOND SOONG
Department of Poultry Science, The University of British Columbia, Vancouver, British Canada V6T 1WS
Columbia,
AND E . BruNSKi AND R . E . E . JONAS
Vancouver Laboratory, Fisheries Research Board of Canada, 6640 N. W. Marine Drive, British Columbia, Canada V6T 1X2
Vancouver,
(Received for publication March 15, 1974)
ABSTRACT Two herring meals containing 0.17 and 0.22 p.p.m. of mercury respectively were fed to broilers at dietary levels of 5, 10 and 17.1%. The amounts of mercury present in the diet from this source thus varied from 0.0085 to 0.0376 p.p.m. Growth rate and mortality to eight weeks of age were unaffected by the level or source of herring meal in the diet. The amount of mercury ingested by the birds fed any of the diets resulted in negligible effects on the concentration of mercury present in breast or leg muscle. There was, however, significant accumulation of mercury in liver, kidney, claw and feather tissue, which reflected the dietary concentration of mercury. The amount present in the feathers was high as 0.845 p.p.m. This amount may be sufficiently high to warrant concern when feathers are processed into meal. POULTRY SCIENCE 53: 2181-2185, 1974
T
HE finding that herring meals contain sufficient mercury to result in measurable tissue residues in laying birds fed 8% herring meal in the diet (March et al., 1974) suggested the advisability of conducting a further ex-
periment with broilers. Most previous studies of mercury residues in poultry meat and tissues have dealt with the feeding of diets containing mercury added in the form of various compounds, generally at levels in
Downloaded from http://ps.oxfordjournals.org/ by guest on June 14, 2015
Mercury retention in several strains and strain crosses of chickens. Poultry Sci. 49: 1101-1104. Peakall, D. B., and J. L. Lincer, 1972. Methyl mercury: ACKNOWLEDGMENT its effect on eggshell thickness. Bull. Environ. Contain. Toxicol. 8: 89-90. We thank Mr. Y. C. Lau for his expert Platonow, N. S., and H. S. Funnell, 1971. The accuassistance with the analyses for mercury. mulation of mercury in chickens following the prolonged administration of low levels of an inorganic REFERENCES mercurial. Vet. Rec. 88: 503-504. Gaskin, D. E., K. Ishida and R. Frank, 1972. Mercury Smart, N. A., and M. K. Lloyd, 1963. Mercury in harbour porpoises (Phocoena phocoena) from the residues in eggs, flesh and livers of hens fed wheat Bay of Fundy region. J. Fish. Res. Bd. Can. 29: treated with methylmercury dicyandiamide. J. Sci. 1644-1646. Food. Agr. 14: 734-740. Kiwimae, A., A. Swennson, U. Ulfrarson and G. Stainton, M. P., 1971. Syringe procedure for transfer Westoo, 1969. Methylmercury compounds in eggs of nanogram quantities of mercury vapour for from hens after oral administration of mercury flameless atomic absorption spectrophotometry. compounds. J. Agric. Food Chem. 17: 1014-1016. Anal. Chem. 43: 625-627. Miller, V. L., G. E. Bearse and K. E. Hammermeister, Uthe, J. F., F. A. J. Armstong and M. P. Stainton, 1959. Mercury retention, a trait of chickens. Poultry 1970. Mercury determination in fish samples by wet Sci. 38: 1037-1039. digestion and flameless atomic absorption spectroMiller, V. L., G. E. Bearse and E. Csonka, 1970. photometry. J. Fish. Res. Bd. Can. 27: 805-811.
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B. E. MARCH, R. SOONG, E. BUJNSKI AND R. E. E. JONAS
TABLE 1.—Composition of experimental diets 1
2
3
4
5
6
7
Ingredient
%
%
%
%
%
%
%
Ground wheat Soybean meal Atlantic herring meal Pacific herring meal Iodized salt Limestone Bonemeal DL-methionine Vegetable oil Corn starch Micronutrients
61.0 29.0
64.5 20.5 5.0
64.5 20.5
68.0 12.0 10.0
68.0 12.0
72.9
72.9
—
—
17.1
— —
— —
—
0.5 1.0 2.0 0.25 6.0
0.5 1.0 1.8 0.12 6.0
—
5.0 0.5 1.0 1.8 0.12 6.0
0.5 0.9 1.6 0.07 6.0
—
10.0 0.5 0.9 1.6 0.07 6.0
0.5 0.9 1.3 0.03 6.0
—
17.1 0.5 0.9 1.3 0.03 6.0
— *
t*
t*
t*
t*
t*
t*
*Micronutrients per kg. of diet: manganese sulphate 132 mg., riboflavin 3.3 mg., calcium pantothenate 6.6 mg., niacin 13.2 mg., folacin 0.77 mg., biotin 0.088 mg., choline chloride 250 mg., vitamin B I 2 0.013 mg., menadione 0.55 mg., vitamin D 3 750 I.C.U., vitamin A 11000 I.U., vitamin E 25 I.U. tCorn starch to adjust to 100%
TABLE 2.—Average body weights of chicks (males and females) at 4 and 8 weeks of age Dietary protein supplement Soybean meal (SBM) SBM, 5% Atlantic herring meal, 8.5 p.p.b. dietary Hg** SBM, 5% Pacific herring meal, 11.0 p.p.b. dietary Hg SBM, 10% Atlantic herring meal, 17.0 p.p.b. dietary Hg SBM, 10% Pacific herring meal, 22.0 p.p.b. dietary Hg 17.1% Atlantic herring meal, 29.1 p.p.b. dietary Hg 17.1% Pacific herring meal, 37.6% p.p.b. dietary Hg
Average* body weights 4 weeks 8 weeks gg700 1743 718 1695 745
1803
756
1837
740
1842
730
1706
735
1696
*Average of four and of two replicate lots at 4 and 8 weeks of age respectively. **From herring meal.
feathers respectively. During the period when mercurial compounds were used extensively for seed dressing there were numerous reports of mercury accumulation in the tissues of domestic and wild birds that had consumed treated grain (Berg et al., 1966; Tejning and Vesterberg, 1964; Fimreite et al., 1970). There are also reports regarding toxicity and tissue residues resulting from the direct feeding of mercurial compounds to young birds (Gardiner et al., 1971; Parkhurst and Thaxton, 1973, Thaxton and Parkhurst, 1973). Fimreite (1970) concluded that methyl mercury may be more toxic for growing birds than for adults. In the following study mercury accumulation was measured in various tissues of broilers fed diets in which the source of supplementary protein was soybean meal and/or herring meal. EXPERIMENTAL Two sources of herring meal were used in the study. The meals were manufactured from fish caught off the Atlantic and the Pacific coasts of Canada. The two meals were from the same manufacturing lots as were used in the separate study with adult birds mentioned above (March et al., 1974) and contained 0.17 and 0.22 p.p.m. respectively of mercury.
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excess of those likely to be encountered through the use of natural feedstuffs. Soares et al. (1973), however, fed chicks diets containing fish meals with the concentrations of 0.3 p.p.m. and 0.42 p.p.m. of mercury over a three-week period and reported accumulation of 0.11, 0.14, 0.23 and 0.44 p.p.m. of mercury in breast muscle, liver, kidney and
H G RESIDUES IN TISSUES
The formulae of the experimental diets are shown in Table 1. The control diet 1 contained soybean meal as the source of supplementary protein. Diets 2-5 contained the herring meals at levels of 5 and 10% and lesser amounts of soybean meal. Diets 6 and 7 contained 17.1% of the respective herring meals as the sole sources of supplementary protein. All diets contained 22% of protein. Diet 1 was supplemented with 0.25% of DL-methionine and the other diets with methionine at levels
2183
calculated to adjust the total concentration to 0.5% of the diet. Each diet was fed to four replicate lots of 14 day-old broiler chicks (mixed males and females). The chicks were reared in battery brooders. At four weeks of age the chicks were weighed. Two replicate lots from each dietary treatment were killed and tissues were sampled for mercury analysis. The remaining two replicate lots from each dietary treatment were fed the experimental diets
Dietary protein supplement Soybean meal (SBM)
SBM, 5% Atlantic herring meal 8.5 p.p.b. dietary Hg***
SBM, 5% Pacific herring meal 11.0 p.p.b. dietary Hg
SBM, 10% Atlantic herring meal 17.0 p.p.b. dietary Hg
SBM, 10% Pacific herring meal 22.0 p.p.b. dietary Hg
17.1% Atlantic herring meal 29.1 p.p.b. dietary Hg
17.1% Pacific herring meal, 37.6 p.p.b. dietary Hg
Tissue Age, wks. 4 (J 9 8
Feather* 100 120 80 70 93 300 290 260 330 295 320 330 280 290 305 360 410 410 550 433 560 570 540 590 565 640 790 760 720 728 860 870 900 750 845
Average Hg concentration , p.p.b. Breast Leg Claw* Kidney** Liver** muscle** muscle** 60 50 40 80 70 70 50 40 80 90 50 50 40 70 70 50 80 40 70 90 80 75 58 58 40 200 130 100 80 80 140 140 100 70 80 150 230 100 70 100 190 130 80 60 70 83 170 158 95 70 190 140 130 70 80 180 100 140 80 80 160 190 140 70 90 160 140 110 60 80 83 173 143 130 70 250 220 170 90 200 240 200 140 100 110 270 250 200 110 70 230 220 150 70 80 115 248 223 165 93 290 250 170 330 110 280 260 170 150 110 220 430 220 60 80 390 240 210 70 80 295 295 193 95 153 440 250 240 150 90 460 240 240 70 110 480 280 240 70 80 420 270 230 100 80 90 450 260 238 98 560 290 290 160 200 510 290 320 130 110 470 430 340 70 70 600 350 310 70 80 535 340 315 115 108
*air-dry basis. **dry-weight basis, these tissues contain approximately 75% moisture. ***from herring meal.
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TABLE 3.—Mercury concentrations in tissues from chickens fed diets containing different concentrations of mercury from fishmeal
2184
B. E. MARCH, R. SOONG, E. BILINSKI AND R. E. E. JONAS
until 8 weeks of age. The chicks were weighed and killed for tissue sampling. The tissues sampled were feather (secondary wing), claw (horny portion only), kidney, liver, mixed breast muscle and mixed leg muscle. Samples of each tissue from males and females were pooled separately. Mercury analyses were carried out as described previously (March et al, 1974). RESULTS AND DISCUSSION
ACKNOWLEDGMENT We thank Mr. Y. C. Lau for his expert assistance with the analyses for mercury. REFERENCES Berg, W., A. Johnels, B. Sjostrand and T. Westermark, 1966. Mercury content in feathers of Swedish birds from the past 100 years. Oikos, 17: 71-83. Fimreite, N., R. W. Fyfe and J. A. Keith, 1970. Mercury contamination of Canadian prairie seed eaters and their avian predators. Canadian FieldNaturalist, 84: 269-276. Fimreite, N., 1970. Effects of methyl mercury-treated feed on the mortality and growth of Leghorn cockerels. Can. J. Anim. Sci. 50: 387-389. Gardiner, E. E., R. Hironaka and S. B. Slen, 1971. Growth, feed efficiency and levels of mercury in tissues of two breeds of chickens fed methyl mercury dicyandiamide. Can. J. Anim. Sci. 51: 657-662. March, B. E., R. Soong, E. Belinski and R. E. E. Jonas, 1974. Effects on chickens of chronic exposure to mercury at low levels through dietary fishmeal. Poultry Sci. 53:2175-2181. Parkhurst, C. R., and P. Thaxton, 1973. Toxicity of mercury to young chickens. 1. Effect on growth and mortality. Poultry Sci. 52: 273-276. Snedecor, G. W., 1956. Statistical Methods, fifth edition. Iowa State College Press, Ames, Iowa.
Downloaded from http://ps.oxfordjournals.org/ by guest on June 14, 2015
The average weights of the chicks at 4 and 8 weeks of age are shown in Table 2. There were no statistically significant differences among the average weights at either age according to the results of analysis of variance (Snedecor, 1956). There was little mortality and none ascribable to the level of herring meal in the diet. The results of the analyses for mercury concentrations in the various tissues are summarized in Table 3. Each value is the average of duplicate determinations. The concentrations found in the tissues of the birds receiving no herring meal were consistently low and represent the lower limits of sensitivity of the analytical technique. Muscle accumulated very little mercury even when the diet contained 17.1% of herring meal. The feathers from the birds fed this level of herring meal contained an average of 730 or 840 p.p.b. of mercury depending upon the origin of the herring meal. Claws from the birds contained 450 and 530 p.p.b. of mercury. Even with only 5% of herring meal in the diet some accumulation of mercury occurred in the feathers and claws of the birds. At all dietary levels of herring meal the difference in the mercury concentration of the two meals resulted in differences in mercury concentration in the feathers, claws and livers. Mercury concentration in the kidney reflected the mercury concentration of the herring meal only at the two higher levels of dietary inclusion. The above data are in general agreement with those reported by Soares et
al. (1973) allowing for the fact that these investigators fed fish meal to three-week old chicks for a period of five weeks rather than continuously from the time of hatching as in the present experiment. The only significant sex difference in mercury level in the tissue was the higher (p < 0.01) concentration in the kidney of the male birds at eight weeks of age. Average concentration of mercury was higher (p < 0.01) in the kidney at eight weeks of age than at four weeks. Average concentration of mercury in both breast and leg muscle was significantly (p < 0.05) higher at four weeks of age than at eight weeks. Concentrations of mercury induced in the edible tissues were not so high as to be considered hazardous. The concentrations in the feathers were, on the other hand, sufficiently high to be of concern when feathers are processed into meal.
2185
H G RESIDUES IN TISSUES
Soares, J. H., Jr., D. Miller, H. Lagally, B. R. Stillings, P. Bauersfeldand S. Cuppett, 1973. The comparative effect of oral ingestion of methyl mercury on chicks and rats. Poultry Sci. 52: 452-458. Tejning, S., and R. Vesterberg, 1964. Alkyl mercurytreated seed in food grain. Mercury in tissues and
eggs from hens fed with grain containing methyl mercury dicyandiamide. Poultry Sci. 43: 6-11. ITiaxton, P., and C. R. Parkhurst, 1973. Toxicity of mercury to young chickens. 2. Gross changes in organs. Poultry Sci. 52: 277-281.
Tissue Selenium Content and Serum Tocopherols as Influenced by Dietary Type, Selenium and Vitamin E 1,2 R.
L.
ARNOLD,3 O. E.
O L S O N 4 AND C . W .
CARLSON 4
Brookings,
(Received for publication March 15, 1974)
ABSTRACT A study was conducted using 672 pullets of the Regional Control and DeKalb 131 laying type strains fed either a corn-soy type diet or a semi-purified type diet supplemented with high (10 p.p.m.) or low (0 or 2 p.p.m.) amounts of vitamin E and 0, 0.1 and 1.0 p.p.m. of selenium (Se) fed as sodium selenite. There were no significant differences in rates of egg production due to Se or vitamin E supplements. The DeKalb strain produced larger eggs of higher interior quality (Haugh units). Supplementing the corn-soy diet which contained 0.48 p.p.m. Se with 1 p.p.m. of Se resulted in the production of slightly smaller eggs. Mortality was significantly (P < 0.01) higher in hens fed the semi-purified diet, and their body weights were significantly (P < 0.01) less than those of hens fed the corn-soy diet. The Regional Controls were heavier than the DeKalb strain. Slightly less feed was consumed with added Se or with the purified diet. Fertility and percent hatchability of eggs were higher with the corn-soy diet but were not influenced by vitamin E. Selenium at 0.1 p.p.m. enhanced hatchability of fertile eggs. The Se contents of eggs and tissues were most consistently increased with the 1.0 p.p.m. supplement of sodium selenite. A greater proportion of supplemental Se was deposited in tissues and eggs when feeding the semi-purified diet which contained very low natural levels of the element (ca 0.05 p.p.m.). Vitamin E singly or in combination did not influence Se deposited in eggs and tissues, but did increase serum tocopherol levels. POULTRY SCIENCE 53: 2185-2192, 1974
INTRODUCTION HOMPSON and Scott's (1969) evidence for the essentiality of selenium for chicks has prompted the study of effects of dietary
T
1. Published with the approval of the Director of the South Dakota Agricultural Experiment Station as Paper No. 1263 of the Journal Series. 2. A portion of the thesis submitted to the Graduate School of South Dakota State University by the senior author in partial fulfillment for the requirements of the Ph.D. Degree. 3. Former graduate student, Department of Animal Science, now with Thompson-Hayward Chemical Company, Kansas City, Kansas 66110. 4. Professors, Departments of Station Biochemistry and Animal Science, respectively.
additions of the element on its content in edible poultry products. Studies involving effects of selenium additions on the blood and tissues of the chick (Scott and Cantor, 1971), turkey (Cantor and Scott, 1972) and pig (Ku et al., 1972) have been reported. In general an increase in blood and tissue selenium levels was found as dietary levels increased, but a tapering-off effect with selenium supplements of 0.4 p.p.m. or greater was also reported. Due to the sparing effects of selenium and vitamin E upon each other, it could be postulated that vitamin E might influence selenium levels in blood and tissues or vice versa. However, although selenium has been shown
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Departments of Animal Science and Station Biochemistry, South Dakota State University, South Dakota 57006
HG EXPOSURE
afforded of the higher mercury concentration in the eggs laid by the Br. birds.
Tissue Residues of Mercury in Broilers Fed Fish Meals Containing Different Concentrations of Mercury B . E . M A R C H AND RAYMOND SOONG
Department of Poultry Science, The University of British Columbia, Vancouver, British Canada V6T 1WS
Columbia,
AND E . BruNSKi AND R . E . E . JONAS
Vancouver Laboratory, Fisheries Research Board of Canada, 6640 N. W. Marine Drive, British Columbia, Canada V6T 1X2
Vancouver,
(Received for publication March 15, 1974)
ABSTRACT Two herring meals containing 0.17 and 0.22 p.p.m. of mercury respectively were fed to broilers at dietary levels of 5, 10 and 17.1%. The amounts of mercury present in the diet from this source thus varied from 0.0085 to 0.0376 p.p.m. Growth rate and mortality to eight weeks of age were unaffected by the level or source of herring meal in the diet. The amount of mercury ingested by the birds fed any of the diets resulted in negligible effects on the concentration of mercury present in breast or leg muscle. There was, however, significant accumulation of mercury in liver, kidney, claw and feather tissue, which reflected the dietary concentration of mercury. The amount present in the feathers was high as 0.845 p.p.m. This amount may be sufficiently high to warrant concern when feathers are processed into meal. POULTRY SCIENCE 53: 2181-2185, 1974
T
HE finding that herring meals contain sufficient mercury to result in measurable tissue residues in laying birds fed 8% herring meal in the diet (March et al., 1974) suggested the advisability of conducting a further ex-
periment with broilers. Most previous studies of mercury residues in poultry meat and tissues have dealt with the feeding of diets containing mercury added in the form of various compounds, generally at levels in
Downloaded from http://ps.oxfordjournals.org/ by guest on June 14, 2015
Mercury retention in several strains and strain crosses of chickens. Poultry Sci. 49: 1101-1104. Peakall, D. B., and J. L. Lincer, 1972. Methyl mercury: ACKNOWLEDGMENT its effect on eggshell thickness. Bull. Environ. Contain. Toxicol. 8: 89-90. We thank Mr. Y. C. Lau for his expert Platonow, N. S., and H. S. Funnell, 1971. The accuassistance with the analyses for mercury. mulation of mercury in chickens following the prolonged administration of low levels of an inorganic REFERENCES mercurial. Vet. Rec. 88: 503-504. Gaskin, D. E., K. Ishida and R. Frank, 1972. Mercury Smart, N. A., and M. K. Lloyd, 1963. Mercury in harbour porpoises (Phocoena phocoena) from the residues in eggs, flesh and livers of hens fed wheat Bay of Fundy region. J. Fish. Res. Bd. Can. 29: treated with methylmercury dicyandiamide. J. Sci. 1644-1646. Food. Agr. 14: 734-740. Kiwimae, A., A. Swennson, U. Ulfrarson and G. Stainton, M. P., 1971. Syringe procedure for transfer Westoo, 1969. Methylmercury compounds in eggs of nanogram quantities of mercury vapour for from hens after oral administration of mercury flameless atomic absorption spectrophotometry. compounds. J. Agric. Food Chem. 17: 1014-1016. Anal. Chem. 43: 625-627. Miller, V. L., G. E. Bearse and K. E. Hammermeister, Uthe, J. F., F. A. J. Armstong and M. P. Stainton, 1959. Mercury retention, a trait of chickens. Poultry 1970. Mercury determination in fish samples by wet Sci. 38: 1037-1039. digestion and flameless atomic absorption spectroMiller, V. L., G. E. Bearse and E. Csonka, 1970. photometry. J. Fish. Res. Bd. Can. 27: 805-811.
2182
B. E. MARCH, R. SOONG, E. BUJNSKI AND R. E. E. JONAS
TABLE 1.—Composition of experimental diets 1
2
3
4
5
6
7
Ingredient
%
%
%
%
%
%
%
Ground wheat Soybean meal Atlantic herring meal Pacific herring meal Iodized salt Limestone Bonemeal DL-methionine Vegetable oil Corn starch Micronutrients
61.0 29.0
64.5 20.5 5.0
64.5 20.5
68.0 12.0 10.0
68.0 12.0
72.9
72.9
—
—
17.1
— —
— —
—
0.5 1.0 2.0 0.25 6.0
0.5 1.0 1.8 0.12 6.0
—
5.0 0.5 1.0 1.8 0.12 6.0
0.5 0.9 1.6 0.07 6.0
—
10.0 0.5 0.9 1.6 0.07 6.0
0.5 0.9 1.3 0.03 6.0
—
17.1 0.5 0.9 1.3 0.03 6.0
— *
t*
t*
t*
t*
t*
t*
*Micronutrients per kg. of diet: manganese sulphate 132 mg., riboflavin 3.3 mg., calcium pantothenate 6.6 mg., niacin 13.2 mg., folacin 0.77 mg., biotin 0.088 mg., choline chloride 250 mg., vitamin B I 2 0.013 mg., menadione 0.55 mg., vitamin D 3 750 I.C.U., vitamin A 11000 I.U., vitamin E 25 I.U. tCorn starch to adjust to 100%
TABLE 2.—Average body weights of chicks (males and females) at 4 and 8 weeks of age Dietary protein supplement Soybean meal (SBM) SBM, 5% Atlantic herring meal, 8.5 p.p.b. dietary Hg** SBM, 5% Pacific herring meal, 11.0 p.p.b. dietary Hg SBM, 10% Atlantic herring meal, 17.0 p.p.b. dietary Hg SBM, 10% Pacific herring meal, 22.0 p.p.b. dietary Hg 17.1% Atlantic herring meal, 29.1 p.p.b. dietary Hg 17.1% Pacific herring meal, 37.6% p.p.b. dietary Hg
Average* body weights 4 weeks 8 weeks gg700 1743 718 1695 745
1803
756
1837
740
1842
730
1706
735
1696
*Average of four and of two replicate lots at 4 and 8 weeks of age respectively. **From herring meal.
feathers respectively. During the period when mercurial compounds were used extensively for seed dressing there were numerous reports of mercury accumulation in the tissues of domestic and wild birds that had consumed treated grain (Berg et al., 1966; Tejning and Vesterberg, 1964; Fimreite et al., 1970). There are also reports regarding toxicity and tissue residues resulting from the direct feeding of mercurial compounds to young birds (Gardiner et al., 1971; Parkhurst and Thaxton, 1973, Thaxton and Parkhurst, 1973). Fimreite (1970) concluded that methyl mercury may be more toxic for growing birds than for adults. In the following study mercury accumulation was measured in various tissues of broilers fed diets in which the source of supplementary protein was soybean meal and/or herring meal. EXPERIMENTAL Two sources of herring meal were used in the study. The meals were manufactured from fish caught off the Atlantic and the Pacific coasts of Canada. The two meals were from the same manufacturing lots as were used in the separate study with adult birds mentioned above (March et al., 1974) and contained 0.17 and 0.22 p.p.m. respectively of mercury.
Downloaded from http://ps.oxfordjournals.org/ by guest on June 14, 2015
excess of those likely to be encountered through the use of natural feedstuffs. Soares et al. (1973), however, fed chicks diets containing fish meals with the concentrations of 0.3 p.p.m. and 0.42 p.p.m. of mercury over a three-week period and reported accumulation of 0.11, 0.14, 0.23 and 0.44 p.p.m. of mercury in breast muscle, liver, kidney and
H G RESIDUES IN TISSUES
The formulae of the experimental diets are shown in Table 1. The control diet 1 contained soybean meal as the source of supplementary protein. Diets 2-5 contained the herring meals at levels of 5 and 10% and lesser amounts of soybean meal. Diets 6 and 7 contained 17.1% of the respective herring meals as the sole sources of supplementary protein. All diets contained 22% of protein. Diet 1 was supplemented with 0.25% of DL-methionine and the other diets with methionine at levels
2183
calculated to adjust the total concentration to 0.5% of the diet. Each diet was fed to four replicate lots of 14 day-old broiler chicks (mixed males and females). The chicks were reared in battery brooders. At four weeks of age the chicks were weighed. Two replicate lots from each dietary treatment were killed and tissues were sampled for mercury analysis. The remaining two replicate lots from each dietary treatment were fed the experimental diets
Dietary protein supplement Soybean meal (SBM)
SBM, 5% Atlantic herring meal 8.5 p.p.b. dietary Hg***
SBM, 5% Pacific herring meal 11.0 p.p.b. dietary Hg
SBM, 10% Atlantic herring meal 17.0 p.p.b. dietary Hg
SBM, 10% Pacific herring meal 22.0 p.p.b. dietary Hg
17.1% Atlantic herring meal 29.1 p.p.b. dietary Hg
17.1% Pacific herring meal, 37.6 p.p.b. dietary Hg
Tissue Age, wks. 4 (J 9 8
Feather* 100 120 80 70 93 300 290 260 330 295 320 330 280 290 305 360 410 410 550 433 560 570 540 590 565 640 790 760 720 728 860 870 900 750 845
Average Hg concentration , p.p.b. Breast Leg Claw* Kidney** Liver** muscle** muscle** 60 50 40 80 70 70 50 40 80 90 50 50 40 70 70 50 80 40 70 90 80 75 58 58 40 200 130 100 80 80 140 140 100 70 80 150 230 100 70 100 190 130 80 60 70 83 170 158 95 70 190 140 130 70 80 180 100 140 80 80 160 190 140 70 90 160 140 110 60 80 83 173 143 130 70 250 220 170 90 200 240 200 140 100 110 270 250 200 110 70 230 220 150 70 80 115 248 223 165 93 290 250 170 330 110 280 260 170 150 110 220 430 220 60 80 390 240 210 70 80 295 295 193 95 153 440 250 240 150 90 460 240 240 70 110 480 280 240 70 80 420 270 230 100 80 90 450 260 238 98 560 290 290 160 200 510 290 320 130 110 470 430 340 70 70 600 350 310 70 80 535 340 315 115 108
*air-dry basis. **dry-weight basis, these tissues contain approximately 75% moisture. ***from herring meal.
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TABLE 3.—Mercury concentrations in tissues from chickens fed diets containing different concentrations of mercury from fishmeal
2184
B. E. MARCH, R. SOONG, E. BILINSKI AND R. E. E. JONAS
until 8 weeks of age. The chicks were weighed and killed for tissue sampling. The tissues sampled were feather (secondary wing), claw (horny portion only), kidney, liver, mixed breast muscle and mixed leg muscle. Samples of each tissue from males and females were pooled separately. Mercury analyses were carried out as described previously (March et al, 1974). RESULTS AND DISCUSSION
ACKNOWLEDGMENT We thank Mr. Y. C. Lau for his expert assistance with the analyses for mercury. REFERENCES Berg, W., A. Johnels, B. Sjostrand and T. Westermark, 1966. Mercury content in feathers of Swedish birds from the past 100 years. Oikos, 17: 71-83. Fimreite, N., R. W. Fyfe and J. A. Keith, 1970. Mercury contamination of Canadian prairie seed eaters and their avian predators. Canadian FieldNaturalist, 84: 269-276. Fimreite, N., 1970. Effects of methyl mercury-treated feed on the mortality and growth of Leghorn cockerels. Can. J. Anim. Sci. 50: 387-389. Gardiner, E. E., R. Hironaka and S. B. Slen, 1971. Growth, feed efficiency and levels of mercury in tissues of two breeds of chickens fed methyl mercury dicyandiamide. Can. J. Anim. Sci. 51: 657-662. March, B. E., R. Soong, E. Belinski and R. E. E. Jonas, 1974. Effects on chickens of chronic exposure to mercury at low levels through dietary fishmeal. Poultry Sci. 53:2175-2181. Parkhurst, C. R., and P. Thaxton, 1973. Toxicity of mercury to young chickens. 1. Effect on growth and mortality. Poultry Sci. 52: 273-276. Snedecor, G. W., 1956. Statistical Methods, fifth edition. Iowa State College Press, Ames, Iowa.
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The average weights of the chicks at 4 and 8 weeks of age are shown in Table 2. There were no statistically significant differences among the average weights at either age according to the results of analysis of variance (Snedecor, 1956). There was little mortality and none ascribable to the level of herring meal in the diet. The results of the analyses for mercury concentrations in the various tissues are summarized in Table 3. Each value is the average of duplicate determinations. The concentrations found in the tissues of the birds receiving no herring meal were consistently low and represent the lower limits of sensitivity of the analytical technique. Muscle accumulated very little mercury even when the diet contained 17.1% of herring meal. The feathers from the birds fed this level of herring meal contained an average of 730 or 840 p.p.b. of mercury depending upon the origin of the herring meal. Claws from the birds contained 450 and 530 p.p.b. of mercury. Even with only 5% of herring meal in the diet some accumulation of mercury occurred in the feathers and claws of the birds. At all dietary levels of herring meal the difference in the mercury concentration of the two meals resulted in differences in mercury concentration in the feathers, claws and livers. Mercury concentration in the kidney reflected the mercury concentration of the herring meal only at the two higher levels of dietary inclusion. The above data are in general agreement with those reported by Soares et
al. (1973) allowing for the fact that these investigators fed fish meal to three-week old chicks for a period of five weeks rather than continuously from the time of hatching as in the present experiment. The only significant sex difference in mercury level in the tissue was the higher (p < 0.01) concentration in the kidney of the male birds at eight weeks of age. Average concentration of mercury was higher (p < 0.01) in the kidney at eight weeks of age than at four weeks. Average concentration of mercury in both breast and leg muscle was significantly (p < 0.05) higher at four weeks of age than at eight weeks. Concentrations of mercury induced in the edible tissues were not so high as to be considered hazardous. The concentrations in the feathers were, on the other hand, sufficiently high to be of concern when feathers are processed into meal.
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Soares, J. H., Jr., D. Miller, H. Lagally, B. R. Stillings, P. Bauersfeldand S. Cuppett, 1973. The comparative effect of oral ingestion of methyl mercury on chicks and rats. Poultry Sci. 52: 452-458. Tejning, S., and R. Vesterberg, 1964. Alkyl mercurytreated seed in food grain. Mercury in tissues and
eggs from hens fed with grain containing methyl mercury dicyandiamide. Poultry Sci. 43: 6-11. ITiaxton, P., and C. R. Parkhurst, 1973. Toxicity of mercury to young chickens. 2. Gross changes in organs. Poultry Sci. 52: 277-281.
Tissue Selenium Content and Serum Tocopherols as Influenced by Dietary Type, Selenium and Vitamin E 1,2 R.
L.
ARNOLD,3 O. E.
O L S O N 4 AND C . W .
CARLSON 4
Brookings,
(Received for publication March 15, 1974)
ABSTRACT A study was conducted using 672 pullets of the Regional Control and DeKalb 131 laying type strains fed either a corn-soy type diet or a semi-purified type diet supplemented with high (10 p.p.m.) or low (0 or 2 p.p.m.) amounts of vitamin E and 0, 0.1 and 1.0 p.p.m. of selenium (Se) fed as sodium selenite. There were no significant differences in rates of egg production due to Se or vitamin E supplements. The DeKalb strain produced larger eggs of higher interior quality (Haugh units). Supplementing the corn-soy diet which contained 0.48 p.p.m. Se with 1 p.p.m. of Se resulted in the production of slightly smaller eggs. Mortality was significantly (P < 0.01) higher in hens fed the semi-purified diet, and their body weights were significantly (P < 0.01) less than those of hens fed the corn-soy diet. The Regional Controls were heavier than the DeKalb strain. Slightly less feed was consumed with added Se or with the purified diet. Fertility and percent hatchability of eggs were higher with the corn-soy diet but were not influenced by vitamin E. Selenium at 0.1 p.p.m. enhanced hatchability of fertile eggs. The Se contents of eggs and tissues were most consistently increased with the 1.0 p.p.m. supplement of sodium selenite. A greater proportion of supplemental Se was deposited in tissues and eggs when feeding the semi-purified diet which contained very low natural levels of the element (ca 0.05 p.p.m.). Vitamin E singly or in combination did not influence Se deposited in eggs and tissues, but did increase serum tocopherol levels. POULTRY SCIENCE 53: 2185-2192, 1974
INTRODUCTION HOMPSON and Scott's (1969) evidence for the essentiality of selenium for chicks has prompted the study of effects of dietary
T
1. Published with the approval of the Director of the South Dakota Agricultural Experiment Station as Paper No. 1263 of the Journal Series. 2. A portion of the thesis submitted to the Graduate School of South Dakota State University by the senior author in partial fulfillment for the requirements of the Ph.D. Degree. 3. Former graduate student, Department of Animal Science, now with Thompson-Hayward Chemical Company, Kansas City, Kansas 66110. 4. Professors, Departments of Station Biochemistry and Animal Science, respectively.
additions of the element on its content in edible poultry products. Studies involving effects of selenium additions on the blood and tissues of the chick (Scott and Cantor, 1971), turkey (Cantor and Scott, 1972) and pig (Ku et al., 1972) have been reported. In general an increase in blood and tissue selenium levels was found as dietary levels increased, but a tapering-off effect with selenium supplements of 0.4 p.p.m. or greater was also reported. Due to the sparing effects of selenium and vitamin E upon each other, it could be postulated that vitamin E might influence selenium levels in blood and tissues or vice versa. However, although selenium has been shown
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Departments of Animal Science and Station Biochemistry, South Dakota State University, South Dakota 57006