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Effect of High Amounts of Dietary Zinc and Age Upon Tissue Zinc in Young Chicks
D. POLIN AND R. K. RINGER
1954
Dill, W. A., and A. J. Glazko, 1972. Fluorometric assay of diphenylhydantoin in plasma or whole blood. Clin. Chem. 18: 675-676. Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics, 11: 1-42. Dunnett, D. W., 1955. A multiple comparison procedure for comparing several treatments with a control. J. Amer. Statist. Assoc. 50: 1096-1121. Fries, G. F., G. S. Marrow, J. W. Lester and C. H. Gordon, 1971. Effect of microsomal enzyme inducing drugs on DDT and dieldrin elimination from cows. J. Dairy Sci. 54: 364-368. Polin, D., and R. K. Ringer, 1975. Withdrawal rates
of DDT from chickens treated with diphenylhydantoin. Can. J. Physiol. Pharmacol. 53: 166-173. Snedecor, G. W., and W. G. Cochran, 1967. Statistical Methods, 6th ed. Iowa State Univ. Press, Ames, Iowa. Villareale, M., L. V. Gould, R. H. Wasserman, A. Barr, R. T. Chiroff and W. H. Bergstrom, 1974. Diphenylhydantoin: Effects on calcium metabolism in the chick. Science, 183: 671-673. Watson, M., J. Gabicaand W. W. Benson, 1972. Serum organochlorine pesticides in mentally retarded patients on differing drug regimens. Clin. Pharmacol. Ther. 13: 186-192.
R. L . KINCAID, W . J. MILLER, L . S. JENSEN, D . L . HAMPTON, M. W. NEATHERY AND R. P . GENTRY
Animal and Dairy Science Department and Poultry Science Department, University of Georgia, Athens, Georgia, 30602 (Received for publication February 23, 1976)
ABSTRACT Weight gains of young broiler chicks were not reduced by up to 2400 p.p.m. added zinc fed to four weeks of age. Tissue zinc was not changed significantly by 600 or 1200 p.p.m. supplemental dietary zinc, but at 2400 p.p.m. added zinc, blood, kidney, and liver zinc were significantly elevated (P < 0.05). In the heart, zinc was not affected by the added dietary zinc but increased over time with all diets. Unlike the calf and weanling pig, the metabolism of zinc in the young chick does not appear to change appreciably with increasing maturity. Thus, the homeostatic control mechanisms of the young chick are effective for up to 1200 p.p.m. dietary zinc, but are partially overcome by 2400 p.p.m. added dietary zinc. POULTRY SCIENCE 55: 1954-1957, 1976
INTRODUCTION
T
diet, zinc in the liver and kidney is increased
HE necessity of zinc in animal nutrition
8- to 12-fold by 600 p.p.m. dietary zinc for
is well established (Miller, 1960; O'Dell
21 days, but no such effect occurs in mature
et al,
1958; Tucker and Salmon, 1955), but
cows (Stake et al, 1975; Kincaid et al, 1976).
like all essential elements, excessive zinc is
Chicks are able to consume diets containing
toxic. In some species, the homeostatic con-
1500 to 2000 p.p.m. zinc without reduced
trol mechanisms for high dietary zinc appear
growth (Roberson and Schaible, 1960). When
to be closely related to the physiological age
fed 2000 p.p.m. zinc for 10 weeks, the zinc
of the animal. Whereas, weanling pigs fed
content in the chick liver was increased 64%
greater than 1000 p.p.m. dietary zinc exhibit
(Johnson et al, 1962). Whether greater tissue
reduced weight gains, stiffness, and greatly
deposition of zinc occurs in chicks during
elevated liver zinc, older growing pigs are
the first few weeks of their life has not been
not affected materially by comparable zinc
reported. The objective of this study was
levels (Sampson et al,
1942; Brink et
al,
1959). With calves consuming a practical type
to determine the ability of young chicks to adjust, with time, to high zinc intakes.
Downloaded from http://ps.oxfordjournals.org/ at New York University on February 11, 2015
Effect of High Amounts of Dietary Zinc and Age Upon Tissue Zinc in Young Chicks
1955
HIGH ZINC INTAKE
MATERIALS AND METHODS
TABLE 1.—Composition of basal diet Ingredients
g. / 1 0 0 g . diet
Ground yellow corn Soybean meal (48.5% protein) Meat and bone meal (50% protein) Poultry oil Dehydrated alfalfa meal (17% protein) Ground limestone Defluorinated phosphate (18% P; 32% Ca) Salt Methionine (DL) Trace mineral mix 1 Vitamin premix 2 Lysine (L)
60.40 28.15 6.00 1.50 1.50 0.75 0.75 0.40 0.15 0.05 0.25 0.10
•Trace mineral mix provided (mg. per kg. diet): Mn, 60; Fe, 30; Cu, 5; Zn, 50; I, 1; Ca, 75 (min.) 90 (max.). 2 Vitamin premix provided (per kg. diet): vit. A, 4400 I.U.; vit. D 3 , 880 I.C.U.; vit. E, 11 I.U.; riboflavin, 4.4 mg.; Ca pantothenate, 8.8 mg.; nicotinic acid, 44 mg.; chlorine CI, 220 mg.; vit. B l 2 , 6.6 |j.g.; vit. B 6 , 2.2 mg.; menadione sodium bisulfite, 2.2 mg.; folic acid, 0.55 mg.; d-biotin, 0.11 mg.; thiamine HCl, 2.2 mg.; ethoxyquin, 125 mg.
RESULTS AND DISCUSSION Unlike the calf, feeding 600 p.p.m. supplemental zinc to the young chick did not affect tissue zinc levels (Figure 1). Likewise, 1200 p.p.m. added zinc did not significantly increase tissue zinc, although generally, average tissue zinc concentrations were slightly higher. Thus, zinc homeostatic control mechanisms protect the chick, for at least limited periods of time, against increased zinc in tissues from dietary zinc levels up to 1200 p.p.m. At 2400 p.p.m. added dietary zinc, tissue zinc levels were elevated significantly (P < 0.05) in the blood, liver, and kidney. Zinc concentration in the liver steadily increased with time, but that in kidney and blood was not substantially higher at four weeks than after the first week. In contrast to other tissues, zinc in the heart was not elevated in response to 2400 p.p.m. supplemental zinc, but, over time, increased with all diets. Although the increased tissue zinc of chicks fed 2400 p.p.m. added zinc indicates some breakdown in the homeostatic control mechanisms, growth was not adversely affected at this level. The weight gains of chicks receiving up to 2400 p.p.m. added dietary zinc were not significantly different from controls (Table 2). The effectiveness of zinc homeostatic control mechanisms varies among species of animals and is reflected by the differences in dietary zinc requirements (O'Dell et al, 1958; Smith et al, 1961; Forbes and Yohe, 1960) and in the tolerances for high dietary zinc (Ott et al., 1966; Ansari et al, 1975). For example, rats have lower dietary requirements for zinc than some species and can tolerate much higher dietary amounts. With increasing physiological age the zinc homeostatic control mechanisms become more
Downloaded from http://ps.oxfordjournals.org/ at New York University on February 11, 2015
Day old chicks (Cobb's broiler strain) of both sexes were randomly divided into 12 lots of 12 chicks each. Three of the lots were assigned to each of the following dietary treatments: 0, 600, 1200, and 2400 p.p.m. supplemental zinc as zinc oxide. Chicks were maintained in stainless steel batteries and fed a practical corn-soybean meal broiler ration (Table 1) containing 107 p.p.m. zinc. Feed and water were provided ad libitum. Weight gains were recorded weekly. Nine chicks from each treatment were sacrificed weekly, for four weeks, and liver, kidneys, heart, and blood removed for zinc analysis. Zinc analyses were by atomic absorption spectrophotometry after wet ashing the samples in a tertiary acid mixture (nitricperchloric-sulfuric). The data were subjected to analysis of variance according to procedures described by Steel and Torrie (1960). Significant differences among treatment
means were detected by Duncan's new multiple range test (Duncan, 1955).
1956
KlNCAlD ET AL.
• CONTROL 0 600
£180
A
PPM A D D E D
G
LIVER
BLOOD
ZN
• 1 2 0 0 PPM ADDED ZN « 2 4 0 0 PPM ZN
5 45>or Q 30
1 SE
120 o_ CL
CL 0_
X
15
60
Nl
I
SE
HEART
5135
5 90
90
60 CL CL
o_ 45
I
• CONTROL o 600 PPM ADDED ZN « 1200 PPM ADDED ZN ' 2400 PPM ADDED ZN
I
„-30
• o t a I
I I CONTROL 6 0 0 PPM ADDED Z N 1200 PPM A D D E D Z N 2 4 0 0 PPM A D D E D Z N SE .
1
2 WEEKS
2 WEEKS
FIG. 1. The effect of high levels of zinc fed to day old chicks for four weeks upon the concentration of zinc in the (a) liver, (b) kidney, (c) blood, and (d) heart. SE from error mean square, N = 9.
effective in some species. Calves and weanling pigs are more susceptible to tissue zinc deposition and zinc toxicity than their more mature counterparts (Kincaid et al., 1976; Sampson et al, 1942). The young chick is much more tolerant of excess dietary zinc than are the calf and weanling pig. In the chick, tissue zinc was TABLE 2.—The effect of high dietary zinc upon chick weights Amount of added dietary zinc (p.p.m.) 1 0 600 1200 2400 Week 1 2 3 4
Grams 91 215 393 579
94 217 403 589
99 227 423 643
97 219 407 633
' None of the values at each time period were significantly different (P > 0.05).
not significantly elevated until 2400 p.p.m. added zinc was fed with the greatest increases occurring the first week. These findings are, in general, consistent with those of Johnson et al. (1962) for chicks fed 2000 p.p.m. zinc for 10 weeks. Thus, high zinc metabolism in the young chick does not appear to differ significantly with increasing physiological maturity. With the calf fed a practical corn-soy diet with 600 p.p.m. added zinc, much of the several hundred-percent increased zinc of the liver and pancreas is associated with a lowmolecular-weight zinc-binding protein, but no such association occurs in the cow (Kincaid et al., 1976). A low-molecular-weight zincbinding protein is also associated with increased tissue zinc in rats fed high dietary zinc (Chen et al., 1974, 1975), although the
Downloaded from http://ps.oxfordjournals.org/ at New York University on February 11, 2015
B
CONTROL 6 0 0 PPM ADDED ZN 1 2 0 0 PPM ADDED ZN 2 4 0 0 PPM ADDED ZN
I I
KIDNEY
CL
• o ' a
H I G H ZINC INTAKE
buildup of zinc in rat tissue is less than in the calf. Thus, the relative ease of zinc transfer across the cell wall and the sensitivity of the mechanism(s) regulating the synthesis of a zinc-binding protein may account for much of the difference between species in tissue response to high dietary zinc. Studies on the role of this zinc-binding protein in the homeostatic control of zinc in chicks have not been reported.
Ansari, M. S., W. J. Miller, J. W. Lassiter, M. W. Neathery and R. P. Gentry, 1975. Effects of high but nontoxic dietary zinc on zinc metabolism and adaptations in rats. Proc. Soc. Exp. Biol. Med. 150: 534-536. Brink, M. F., D. E. Becker, S. W. Terrill and A. H. Jensen, 1959. Zinc toxicity in the weanling pig. J. Anim. Sci. 18: 836-842. Chen, R. W., D. J. Eakin and P. D. Whanger, 1974. Biological function of metallothionein. II. Its role in zinc metabolism in the rat. Nutr. Rep. Int. 10: 195-201. Chen, R. W., P. D. Whanger and P. H. Weswig, 1975. Biological function of metallothionein. I. Synthesis of degradation of rat liver metallothionein. Biochem. Med. 12: 95-105. Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics, 11: 1-42. Forbes, R. M., and M. Yohe, 1960. Zinc requirement and balance studies with the rat. J. Nutr. 70: 53-57. Johnson, D., Jr., A. L. Mehring, Jr., F. X. Savino and H. W. Titus, 1962. The tolerance of growing
chickens for dietary zinc. Poultry Sci. 41: 311-317. Kincaid, R. L., W. J. Miller, P. R. Fowler, D. L. Hampton, R. P. Gentry and M. W. Neathery, 1976. The effect of high dietary zinc upon zinc metabolism and intracellular distribution in cows and calves. (Unpublished data) Miller, J. K., and W. J. Miller, 1960. Development of zinc deficiency in Holstein calves fed a purified diet. J. Dairy Sci. 43: 1854-1856. O'Dell, B. L., P. M. Newberne and J. E. Savage, 1958. Significance of dietary zinc for the growing chick. J. Nutr. 65: 503-518. Ott, E. A., W. H. Smith, R. B. Harrington and W. M. Beeson, 1966. Zinc toxicity in ruminants. II. Effect of high levels of dietary zinc on gains, feed consumption, and feed efficiency of beef cattle. J. Anim. Sci. 25: 419-423. Roberson, R. H., and P. J. Schaible, 1960. The tolerance of growing chicks for high levels of different forms of zinc. Poultry Sci. 39: 893-896. Sampson, J., R. Graham and H. R. Hester, 1942. Studies on feeding zinc to pigs. Cornell Vet. 32: 225-236. Smith, W. H., M. P. Plumlee and W. M. Beeson, 1961. Zinc requirement of the growing pig fed isolated soybean protein semi-purified rations. J. Anim. Sci. 20: 128-132. Stake, P. E., W. J. Miller, R. P. Gentry and M. W. Neathery, 1975. Zinc metabolic adapations in calves fed a high but nontoxic zinc level for varying time periods. J. Anim. Sci. 40: 132-137. Steel, R. G. D., and J. H. Torrie, 1960. Principles and Procedures of Statistics. McGraw-Hill, New York. Tucker, H. F., and W. D. Salmon, 1955. Parakeratosis on zinc deficiency in the pig. Proc. Soc. Exp. Biol. Med. 88: 613-616.
NEWS AND NOTES (Continued from page 1932) encouraged organizations in the same state to meet prior to June 28, to decide on one nomination per state for consideration at the New Orleans caucus. Egg producer organizations, associations, and cooperatives were notified that they should submit requests for certification by May 28 if they wished to participate in nominating a new member to the Board. In their certification requests, each organization filed pertinent data as to the nature, size, stability, permanency, and function of its operations.
The U.S.D.A. has announced that revised poultry and rabbit grading regulations became effective July 15, 1976. The revised regulations eliminate all reference to voluntary inspection for wholesomeness of poultry and rabbits, remove obsolete portions of the regulations, and add standards for quality grading of rabbit parts. A.M.S. administers the voluntary grading program and U.S.D.A.'s A.P.H.I.S. provides voluntary in-
(Continued on page 1961)
Downloaded from http://ps.oxfordjournals.org/ at New York University on February 11, 2015
REFERENCES
1957
1954
Dill, W. A., and A. J. Glazko, 1972. Fluorometric assay of diphenylhydantoin in plasma or whole blood. Clin. Chem. 18: 675-676. Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics, 11: 1-42. Dunnett, D. W., 1955. A multiple comparison procedure for comparing several treatments with a control. J. Amer. Statist. Assoc. 50: 1096-1121. Fries, G. F., G. S. Marrow, J. W. Lester and C. H. Gordon, 1971. Effect of microsomal enzyme inducing drugs on DDT and dieldrin elimination from cows. J. Dairy Sci. 54: 364-368. Polin, D., and R. K. Ringer, 1975. Withdrawal rates
of DDT from chickens treated with diphenylhydantoin. Can. J. Physiol. Pharmacol. 53: 166-173. Snedecor, G. W., and W. G. Cochran, 1967. Statistical Methods, 6th ed. Iowa State Univ. Press, Ames, Iowa. Villareale, M., L. V. Gould, R. H. Wasserman, A. Barr, R. T. Chiroff and W. H. Bergstrom, 1974. Diphenylhydantoin: Effects on calcium metabolism in the chick. Science, 183: 671-673. Watson, M., J. Gabicaand W. W. Benson, 1972. Serum organochlorine pesticides in mentally retarded patients on differing drug regimens. Clin. Pharmacol. Ther. 13: 186-192.
R. L . KINCAID, W . J. MILLER, L . S. JENSEN, D . L . HAMPTON, M. W. NEATHERY AND R. P . GENTRY
Animal and Dairy Science Department and Poultry Science Department, University of Georgia, Athens, Georgia, 30602 (Received for publication February 23, 1976)
ABSTRACT Weight gains of young broiler chicks were not reduced by up to 2400 p.p.m. added zinc fed to four weeks of age. Tissue zinc was not changed significantly by 600 or 1200 p.p.m. supplemental dietary zinc, but at 2400 p.p.m. added zinc, blood, kidney, and liver zinc were significantly elevated (P < 0.05). In the heart, zinc was not affected by the added dietary zinc but increased over time with all diets. Unlike the calf and weanling pig, the metabolism of zinc in the young chick does not appear to change appreciably with increasing maturity. Thus, the homeostatic control mechanisms of the young chick are effective for up to 1200 p.p.m. dietary zinc, but are partially overcome by 2400 p.p.m. added dietary zinc. POULTRY SCIENCE 55: 1954-1957, 1976
INTRODUCTION
T
diet, zinc in the liver and kidney is increased
HE necessity of zinc in animal nutrition
8- to 12-fold by 600 p.p.m. dietary zinc for
is well established (Miller, 1960; O'Dell
21 days, but no such effect occurs in mature
et al,
1958; Tucker and Salmon, 1955), but
cows (Stake et al, 1975; Kincaid et al, 1976).
like all essential elements, excessive zinc is
Chicks are able to consume diets containing
toxic. In some species, the homeostatic con-
1500 to 2000 p.p.m. zinc without reduced
trol mechanisms for high dietary zinc appear
growth (Roberson and Schaible, 1960). When
to be closely related to the physiological age
fed 2000 p.p.m. zinc for 10 weeks, the zinc
of the animal. Whereas, weanling pigs fed
content in the chick liver was increased 64%
greater than 1000 p.p.m. dietary zinc exhibit
(Johnson et al, 1962). Whether greater tissue
reduced weight gains, stiffness, and greatly
deposition of zinc occurs in chicks during
elevated liver zinc, older growing pigs are
the first few weeks of their life has not been
not affected materially by comparable zinc
reported. The objective of this study was
levels (Sampson et al,
1942; Brink et
al,
1959). With calves consuming a practical type
to determine the ability of young chicks to adjust, with time, to high zinc intakes.
Downloaded from http://ps.oxfordjournals.org/ at New York University on February 11, 2015
Effect of High Amounts of Dietary Zinc and Age Upon Tissue Zinc in Young Chicks
1955
HIGH ZINC INTAKE
MATERIALS AND METHODS
TABLE 1.—Composition of basal diet Ingredients
g. / 1 0 0 g . diet
Ground yellow corn Soybean meal (48.5% protein) Meat and bone meal (50% protein) Poultry oil Dehydrated alfalfa meal (17% protein) Ground limestone Defluorinated phosphate (18% P; 32% Ca) Salt Methionine (DL) Trace mineral mix 1 Vitamin premix 2 Lysine (L)
60.40 28.15 6.00 1.50 1.50 0.75 0.75 0.40 0.15 0.05 0.25 0.10
•Trace mineral mix provided (mg. per kg. diet): Mn, 60; Fe, 30; Cu, 5; Zn, 50; I, 1; Ca, 75 (min.) 90 (max.). 2 Vitamin premix provided (per kg. diet): vit. A, 4400 I.U.; vit. D 3 , 880 I.C.U.; vit. E, 11 I.U.; riboflavin, 4.4 mg.; Ca pantothenate, 8.8 mg.; nicotinic acid, 44 mg.; chlorine CI, 220 mg.; vit. B l 2 , 6.6 |j.g.; vit. B 6 , 2.2 mg.; menadione sodium bisulfite, 2.2 mg.; folic acid, 0.55 mg.; d-biotin, 0.11 mg.; thiamine HCl, 2.2 mg.; ethoxyquin, 125 mg.
RESULTS AND DISCUSSION Unlike the calf, feeding 600 p.p.m. supplemental zinc to the young chick did not affect tissue zinc levels (Figure 1). Likewise, 1200 p.p.m. added zinc did not significantly increase tissue zinc, although generally, average tissue zinc concentrations were slightly higher. Thus, zinc homeostatic control mechanisms protect the chick, for at least limited periods of time, against increased zinc in tissues from dietary zinc levels up to 1200 p.p.m. At 2400 p.p.m. added dietary zinc, tissue zinc levels were elevated significantly (P < 0.05) in the blood, liver, and kidney. Zinc concentration in the liver steadily increased with time, but that in kidney and blood was not substantially higher at four weeks than after the first week. In contrast to other tissues, zinc in the heart was not elevated in response to 2400 p.p.m. supplemental zinc, but, over time, increased with all diets. Although the increased tissue zinc of chicks fed 2400 p.p.m. added zinc indicates some breakdown in the homeostatic control mechanisms, growth was not adversely affected at this level. The weight gains of chicks receiving up to 2400 p.p.m. added dietary zinc were not significantly different from controls (Table 2). The effectiveness of zinc homeostatic control mechanisms varies among species of animals and is reflected by the differences in dietary zinc requirements (O'Dell et al, 1958; Smith et al, 1961; Forbes and Yohe, 1960) and in the tolerances for high dietary zinc (Ott et al., 1966; Ansari et al, 1975). For example, rats have lower dietary requirements for zinc than some species and can tolerate much higher dietary amounts. With increasing physiological age the zinc homeostatic control mechanisms become more
Downloaded from http://ps.oxfordjournals.org/ at New York University on February 11, 2015
Day old chicks (Cobb's broiler strain) of both sexes were randomly divided into 12 lots of 12 chicks each. Three of the lots were assigned to each of the following dietary treatments: 0, 600, 1200, and 2400 p.p.m. supplemental zinc as zinc oxide. Chicks were maintained in stainless steel batteries and fed a practical corn-soybean meal broiler ration (Table 1) containing 107 p.p.m. zinc. Feed and water were provided ad libitum. Weight gains were recorded weekly. Nine chicks from each treatment were sacrificed weekly, for four weeks, and liver, kidneys, heart, and blood removed for zinc analysis. Zinc analyses were by atomic absorption spectrophotometry after wet ashing the samples in a tertiary acid mixture (nitricperchloric-sulfuric). The data were subjected to analysis of variance according to procedures described by Steel and Torrie (1960). Significant differences among treatment
means were detected by Duncan's new multiple range test (Duncan, 1955).
1956
KlNCAlD ET AL.
• CONTROL 0 600
£180
A
PPM A D D E D
G
LIVER
BLOOD
ZN
• 1 2 0 0 PPM ADDED ZN « 2 4 0 0 PPM ZN
5 45>or Q 30
1 SE
120 o_ CL
CL 0_
X
15
60
Nl
I
SE
HEART
5135
5 90
90
60 CL CL
o_ 45
I
• CONTROL o 600 PPM ADDED ZN « 1200 PPM ADDED ZN ' 2400 PPM ADDED ZN
I
„-30
• o t a I
I I CONTROL 6 0 0 PPM ADDED Z N 1200 PPM A D D E D Z N 2 4 0 0 PPM A D D E D Z N SE .
1
2 WEEKS
2 WEEKS
FIG. 1. The effect of high levels of zinc fed to day old chicks for four weeks upon the concentration of zinc in the (a) liver, (b) kidney, (c) blood, and (d) heart. SE from error mean square, N = 9.
effective in some species. Calves and weanling pigs are more susceptible to tissue zinc deposition and zinc toxicity than their more mature counterparts (Kincaid et al., 1976; Sampson et al, 1942). The young chick is much more tolerant of excess dietary zinc than are the calf and weanling pig. In the chick, tissue zinc was TABLE 2.—The effect of high dietary zinc upon chick weights Amount of added dietary zinc (p.p.m.) 1 0 600 1200 2400 Week 1 2 3 4
Grams 91 215 393 579
94 217 403 589
99 227 423 643
97 219 407 633
' None of the values at each time period were significantly different (P > 0.05).
not significantly elevated until 2400 p.p.m. added zinc was fed with the greatest increases occurring the first week. These findings are, in general, consistent with those of Johnson et al. (1962) for chicks fed 2000 p.p.m. zinc for 10 weeks. Thus, high zinc metabolism in the young chick does not appear to differ significantly with increasing physiological maturity. With the calf fed a practical corn-soy diet with 600 p.p.m. added zinc, much of the several hundred-percent increased zinc of the liver and pancreas is associated with a lowmolecular-weight zinc-binding protein, but no such association occurs in the cow (Kincaid et al., 1976). A low-molecular-weight zincbinding protein is also associated with increased tissue zinc in rats fed high dietary zinc (Chen et al., 1974, 1975), although the
Downloaded from http://ps.oxfordjournals.org/ at New York University on February 11, 2015
B
CONTROL 6 0 0 PPM ADDED ZN 1 2 0 0 PPM ADDED ZN 2 4 0 0 PPM ADDED ZN
I I
KIDNEY
CL
• o ' a
H I G H ZINC INTAKE
buildup of zinc in rat tissue is less than in the calf. Thus, the relative ease of zinc transfer across the cell wall and the sensitivity of the mechanism(s) regulating the synthesis of a zinc-binding protein may account for much of the difference between species in tissue response to high dietary zinc. Studies on the role of this zinc-binding protein in the homeostatic control of zinc in chicks have not been reported.
Ansari, M. S., W. J. Miller, J. W. Lassiter, M. W. Neathery and R. P. Gentry, 1975. Effects of high but nontoxic dietary zinc on zinc metabolism and adaptations in rats. Proc. Soc. Exp. Biol. Med. 150: 534-536. Brink, M. F., D. E. Becker, S. W. Terrill and A. H. Jensen, 1959. Zinc toxicity in the weanling pig. J. Anim. Sci. 18: 836-842. Chen, R. W., D. J. Eakin and P. D. Whanger, 1974. Biological function of metallothionein. II. Its role in zinc metabolism in the rat. Nutr. Rep. Int. 10: 195-201. Chen, R. W., P. D. Whanger and P. H. Weswig, 1975. Biological function of metallothionein. I. Synthesis of degradation of rat liver metallothionein. Biochem. Med. 12: 95-105. Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics, 11: 1-42. Forbes, R. M., and M. Yohe, 1960. Zinc requirement and balance studies with the rat. J. Nutr. 70: 53-57. Johnson, D., Jr., A. L. Mehring, Jr., F. X. Savino and H. W. Titus, 1962. The tolerance of growing
chickens for dietary zinc. Poultry Sci. 41: 311-317. Kincaid, R. L., W. J. Miller, P. R. Fowler, D. L. Hampton, R. P. Gentry and M. W. Neathery, 1976. The effect of high dietary zinc upon zinc metabolism and intracellular distribution in cows and calves. (Unpublished data) Miller, J. K., and W. J. Miller, 1960. Development of zinc deficiency in Holstein calves fed a purified diet. J. Dairy Sci. 43: 1854-1856. O'Dell, B. L., P. M. Newberne and J. E. Savage, 1958. Significance of dietary zinc for the growing chick. J. Nutr. 65: 503-518. Ott, E. A., W. H. Smith, R. B. Harrington and W. M. Beeson, 1966. Zinc toxicity in ruminants. II. Effect of high levels of dietary zinc on gains, feed consumption, and feed efficiency of beef cattle. J. Anim. Sci. 25: 419-423. Roberson, R. H., and P. J. Schaible, 1960. The tolerance of growing chicks for high levels of different forms of zinc. Poultry Sci. 39: 893-896. Sampson, J., R. Graham and H. R. Hester, 1942. Studies on feeding zinc to pigs. Cornell Vet. 32: 225-236. Smith, W. H., M. P. Plumlee and W. M. Beeson, 1961. Zinc requirement of the growing pig fed isolated soybean protein semi-purified rations. J. Anim. Sci. 20: 128-132. Stake, P. E., W. J. Miller, R. P. Gentry and M. W. Neathery, 1975. Zinc metabolic adapations in calves fed a high but nontoxic zinc level for varying time periods. J. Anim. Sci. 40: 132-137. Steel, R. G. D., and J. H. Torrie, 1960. Principles and Procedures of Statistics. McGraw-Hill, New York. Tucker, H. F., and W. D. Salmon, 1955. Parakeratosis on zinc deficiency in the pig. Proc. Soc. Exp. Biol. Med. 88: 613-616.
NEWS AND NOTES (Continued from page 1932) encouraged organizations in the same state to meet prior to June 28, to decide on one nomination per state for consideration at the New Orleans caucus. Egg producer organizations, associations, and cooperatives were notified that they should submit requests for certification by May 28 if they wished to participate in nominating a new member to the Board. In their certification requests, each organization filed pertinent data as to the nature, size, stability, permanency, and function of its operations.
The U.S.D.A. has announced that revised poultry and rabbit grading regulations became effective July 15, 1976. The revised regulations eliminate all reference to voluntary inspection for wholesomeness of poultry and rabbits, remove obsolete portions of the regulations, and add standards for quality grading of rabbit parts. A.M.S. administers the voluntary grading program and U.S.D.A.'s A.P.H.I.S. provides voluntary in-
(Continued on page 1961)
Downloaded from http://ps.oxfordjournals.org/ at New York University on February 11, 2015
REFERENCES
1957