Zinc Requirement of the Chick: Factors Affecting Requirement

1584

J. O. ANDERSON, D. C. DOBSON AND R. K. WAGSTAFF

and J. McGinnis, 1960a. Influence of geographical area of production on the response of different barley samples to enzyme supplements or water treatment. Poultry Sci. 39: 103-108.

Willingham, H. E., J. McGinnis, F. Nelson and L. S. Jensen, 1960b. Relation of superiority of water-treated barley over enzyme supplements to antibiotics. Poultry Sci. 39: 1307.

Zinc Requirement of the Chick: Factors Affecting Requirement T. R. ZEIGLER, R. M. LEACH, JR., 1 L. C. NORRIS AND M. L. SCOTT Department of Poultry Husbandry, Cornell University, Ithaca, N.Y, (Received for publication January 27, 1961)

ARLY experiments by Titus (1932), Insko, Lyons and Martin (1938) and Lyons, Insko and Martin (1938) failed to show zinc to be a dietary essential for the chick. More recently, Mehring, Brumbaugh and Titus (1956) observed no beneficial effect upon growth of chicks from increasing the amount of zinc consumed from 42 to 820 mg. of zinc per kg. of diet. In studies on perosis, Wilgus, Norris and Heuser (1937), found that zinc as well as manganese had a beneficial effect upon the incidence of perosis, but under the conditions of their experiments manganese was shown to be the primary deficiency. Therefore, it was not until 1957, as a result of studies by O'Dell and Savage, that a true zinc deficiency was recognized in the chick. Edwards, Young and Gillis (1958), Moeller and Scott (1958), Morrison and Sarett (1958), Patrick (1958), and Roberson and Schaible (1958) have confirmed the original results showing that zinc deficiency in the chick results in retarded growth, abnormal bone development, poor feathering, dermatosis of the squamous epithelium and decreased efficiency of feed utilization. These studies indicated the requirement of the four-week-old chick to be 55 mg. of total zinc or less per kg. of diet. In earlier work in this laboratory, Zeigler, Leach and Norris "Present address: U. S. Plant, Soil and Nutrition Laboratory, Ithaca, New York.

(1958) produced a zinc deficiency in the chick, and suggested that the requirement of the chick for available zinc lies between 15 and 20 mg. of zinc per kg. of diet. The requirement could not be stated more precisely because it appeared to be increased when isolated soybean protein replaced casein as the source of protein in the purified diets used. The current report presents more precise information on the requirement of the chick for zinc, and also considers certain dietary factors which affect this requirement. MATERIALS AND METHODS

The composition of the purified basal diet used in these investigations is given in Table 1. Either isolated soybean protein or casein, supplemented with necessary amino acids, was used as the protein source in these diets. The soybean protein was purified by five washings in tap water at pH 4.6 with a final washing in demineralized water at the same pH. This was followed by pressing to remove as much water as possible, with subsequent drying in a forced draft electric oven at 65°C. The casein was washed twice with tap water, followed by five acid-salt washings with tap water at pH 2.5, after which it was washed with demineralized water at pH 4.75. The casein was then pressed and dried according to the same procedure used with the soybean protein.

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E

1585

ZINC REQUIREMENTS TABLE 1.—Composition of purified basal diets

TABLE 2.—Composition of practical type diets

Diets

Diets

Ingredients

Ingredients D 0/

%

%

— 27.00 58.16 3.00 3.00 1.22 5.72 0.30 0.80 0.80

— 30.00 46.78 10.00 3.27 1.33 6.22 0.33 0.87 1.20

59.06 3.00 3.00 1.22 5.72 0.70 0.30

48.09 10.00 3.27 1.33 6.22 0.76 0.33

Metabolizable energy, Cal/gm. 3.18 Protein content, % 25.86

3.81 28.97

3.05 24.90

3.52 27.64

%

27.00 30.00

1 Drackett Assay Protein C-l, purified by repeated washings. 2 Sheftene High Nitrogen Casein, purified by repeated washings. 3 One kilogram of mineral mixture contains 377 gm. CaPH0 4 , 261 gm. CaCOu, 152 gm. KH 2 P0 4 , 105 gm. NaCl, 49.8 gm. KC1, 43. 7 gm. MgS0 4 , 5.83 gm. FeS0 4 -7H 2 0, 5.83 gm. MnS0 4 H 2 0,0.0455 gm. KI, 0.292 gm. CuSCv5H 2 0, 0.0297 gm. CoCl2 •6H 2 0, 0.145 gm. NaMo0 4 -2H 2 0. All salts are analytical reagent grade. 4 Five kilograms of vitamin mixture contain: 10 mg. vitamin Bi2, 100 mg. biotin, 480 mg. menadione sodium bisulfite, 2.25 gm. pyridoxine HC1, 2 gm. folic acid, 5 gm. thiamine, 5 gm. riboflavin, 10 gm. calcium pantothenate, 25 gm. niacin, 125 gm. inositol, 163 gm. vitamin D 3 source (3,000 ICU/gm.), 300 gm. vitamin E source (50,000 IU/lb.), 250 gm. vitamin A source (10,000 IU/gm.), 11 gm. diphenyl-paraphenylene diamine, 1,100 gm. choline chloride (70% solution), 3,000 gm. glucose.

Diets A and B contained casein, the essential difference between them being in the amount of added fat, 3 % in diet A and 10% in diet B. Purified isolated soybean protein was used in diets C and D, with added fat in the amounts of 3% in diet C and 10% in diet D. Protein and all other nutrients were increased in diets B and D in proportion to their increased energy content. Three practical diets also were used in these investigations. These are described in Table 2. Diet E was formulated to represent a more complex broiler ration containing both animal and plant proteins with

Corn 51.05 Soybean oil meal, 50% protein 23.00 Fat (Grease) 5.00 Corn gluten meal 5.00 Meat and bone scraps, 50% protein 5.00 Fish meal, 60% protein 2.50 Fish solubles — Corn distillers solubles 2.00 Dried whey 2.00 Alfalfa meal 2.50 Dicalcium phosphate 0.60 Limestone 1.00 MnS0 4 0.02 NaCl 0.25 DL-Methionine 0.05 Butylated hydroxytoluene 0.025

%

%

48.42

53.19

28.50 5.00 5.00

37.50 5.00 —

2.00 2.50 2.00 2.50 2.05 1.66 0.02 0.25 0.08

2 21 1.70 0.02 0.25 0.10

0.025

0.025

Per 100 Per 100 Per 100 gm. gm. gm. Riboflavin, mg. 0.110 Niacin, mg. 0.660 Calcium pantothenate, mg. 0.441 Vitamin B 12 , Mg. 0.441 Vitamin D 3 , ICU 37.5 Vitamin A, IU — Vitamin E, IU 1.10 Menadione sodium bisulfite, mg. 0.50 Metabolizable energy, Cal./gm. 3.24 Protein content, % 23.80 Zinc content, /tg./gm. (calculated) 43

0.132 0.441

0.242 1.321

0.264 0.529 0.441 0.916 37.5 37.5 — 661 1.10 1.10 0.50

0.50

3.13 22.90

3.25 23.90

36

37

added sources of unidentified factors. Diet F was similar to diet E except that most of the animal protein supplements were removed. Diet G represented a simplified practical diet consisting largely of corn and soybean oil meal. Protein and energy in these diets were adjusted to be approximately equal, and an attempt also was made to equalize the amounts of essential vitamins and minerals. The energy values used in all calculations were those of Hill (1958). Analytical values for the zinc content of the ingredients used in all diets are presented in Table 3. These ingredients and

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/o

Purified soybean protein 1 Purified casein2 Glucose Corn oil Cellulose Vitamin mixture 3 Mineral mixture 4 DL-Methionine Glycine L-Arginine HC1

1S86

T. R. ZEIGLER, R. M. LEACH, JR., L. C. NOEEIS AND M. L. SCOTT

TABLE 3.—Zinc content of dietary ingredients Ingredients

Dry matter Mgm./gm. 3.5

Washed casein1 Crude isolated soybean protein 2 Washed isolated soybean protein

31 2

Cellulose3

28 4.8 72 71 102 185

Ground corn Distillers dried solubles

26 101

Alfalfa meal Dried whole whey Wheat Corn gluten meal Fish solubles Dried brewers yeast Dicalcium phosphate 4

20 7.5 35 69 34 49 2.4

1 Sheftene high nitrogen casein, Sheffield Chemical Company. 2 Drackett C-l Assay Protein, Archer-DanielsMidland Company 3 Solka-Floc, Grade BW-40, Brown Company. 4 International Minerals and Chemical Corporation. Note: Each value represents the average of duplicate determinations on a composite sample for each ingredient.

the purified diets were analyzed by the single-color method of the Association of Official Agricultural Chemists (1955), following an initial wet-ashing of the samples with a mixture of nitric, sulfuric and perchloric acids. Duplicate lots of 15 one-day-old White Plymouth Rock male chicks were used for each treatment in all experiments. The chicks were placed in electrically-heated battery brooders with raised wire screen floors, and were supplied the experimental diets and demineralized water ad libitum. Individual weights were recorded at weekly intervals during the four week experimental periods. Feed consumption was recorded at the time the chicks were weighed. Several precautions were taken to eliminate zinc intake by the chicks from extra-

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Soybean oil meal, 44% protein Soybean oil meal, 50% protein Menhaden fish meal, 60% protein Meat scrap, 50% protein

dietary sources. The galvanized battery brooders were painted with a plastic resin, and the diets were stored in tin-coated cans. The wire screen floors of the pens were made of stainless steel, and the diets and the demineralized water were supplied in stainless steel feeders and waterers. All diets were mixed in 26 kilogram quantities in a large metal bowl. Care was taken to avoid contact with zinc-coated surfaces. The basal diets contained no added zinc. For the experimental lots, zinc was added as a zinc chloride solution containing 2 5 mg. of zinc per ml. Since the chicks receiving zinc-deficient diets consistently showed severe hock enlargement which was markedly improved as the zinc level in the diet was increased, an empirical method was devised for indexing this deficiency symptom. In view of the fact slipped tendon, or perosis, did not occur, it was possible at the end of each experiment to score the chicks individually, simply according to severity of the hock enlargement, with scores of 0, 1, 2 or 3 in increasing order of severity. These values were totaled for individual lots and divided by the value representative of the maximum possible severity score for that lot. In the case of lots containing 15 chicks at the end of the experiment, the divisor was 45 (3 X 15). When the four-week average weights of the chicks receiving each treatment within an experiment were plotted against the logarithm of the total zinc content of the corresponding diet, the data were found to lie on a straight line for all treatments where growth was limited by the level of dietary zinc. Therefore, in these experiments, the requirement was calculated by finding the intercept of two regression lines, the first (y = mx + b) representing the relationship between chick growth and deficient levels of total dietary zinc, the second (y' = b') representing the average growth of chose lots of chicks fed diets in which zinc

1587

ZINC REQUIREMENTS

TAELE 4.—Effect

mg./kg. 0 5 10 15 20 25 30 60 90 120

26 day weight

Feed/ gain

%

gm. 165 (29) 300 (27) 356 (28) 327 (28) 350 (28) 353 (29)

2.00 1.92 1.71 1.75 1.70 1.75

Feed/ gain

gm. 303 (30)l

2.02

36

422 (27)

1.91

0

414 409 397 417

1.91 1.94 1.88 1.84

5 0 1 6

Zinc content of basal diet (by;inalysis) , mg./kg. Zinc requirement (calculated) mg./kg. diet Mg./gm. gain 1

Experiment 3A, Diet A

Hock score

28 day weight

(29) (28) (29) (29)

Studies using casein diets. The results of experiments conducted using purified diets containing casein are summarized in Table 4. Diet A supplemented with five levels of added zinc, from 0 to 120 mg. of added zinc per kg. of diet, was fed in Experiment 1. In this experiment the intervals between levels of added zinc were of such a magnitude that the requirement could not be precisely resolved. This experiment showed, however, that the requirement was more than 5.2 but less than 20.2 mg. of total zinc per kg. of diet. Experiment 3A was conducted to determine the requirement more precisely. Experiment 3A (Table 4) and Experiment 3B (Table 5) are actually two parts of the same experiment; their results therefore may be compared directly. In Experiment 3A, six levels of zinc, in 5 mg. increments from 0 to 25 mg. of added zinc per kg. of diet, were included. From an examination of the results, the first two treatments, 0 and 5 mg. of added zinc per kg. of diet, were selected for the calculation of the re-

of adding graded amounts of zinc to casein diets

Experiment 1, Diet A Added zinc

EXPERIMENTAL

Experiment 4A, Diet B

Hock score

28 day weight

Feed/ gain

%

gm. 154 (26) 407 (30) 495 (28) 492 (29) 510 (28) 502 (30)

2.28 1.54 1.47 1.48 1.49 1.48

51 19 3 4 5 10

Hock score

% 85 29 9 6 15 11

Experiment 1

Experiment 3A

Experiment 4A

5.2

4.8

6.5

5.2-20.2

12.7 22.0

14.2 21.0

—

Mean and number of survivors from duplicate lots of 15 male chicks per lot.

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was not a limiting factor (y and y' = weight of chicks at end of experiment; b and b' = intercept of regression line on y axis; x = logarithm of total zinc content of diet; m = slope of line). In separating those treatments that were deficient in zinc from those which were fed adequate amounts of zinc for use in the calculations of regression, three criteria of evaluation were employed as follows: (1) the weights were plotted on semi-logarithm paper as previously described; (2) feed efficiencies were considered; (3) the hock scores were carefully evaluated. After data from each experiment were carefully evaluated by these three criteria, the treatments were assigned to the particular regression in which they appeared to belong. This procedure resolved the treatments to the proper regressions more appropriately than could be done by any statistical treatment of the data. At best, specfic requirements, calculated by any manner, must be recognized as average values representing expression of a range, since requirements vary among individual chicks.

1588

T. R. ZEIGLER, R. M. LEACH, JR., L. C. NORRIS AND M. L. SCOTT TABLE 5.—Effect

of adding graded amounts of zinc to isolated soybean protein diets Experiment 3B, Diet C

Experiment 4B, Di et D

Hock score

26 day weight

Hock score

28 day weight

%

gm.

°7 /o

gm.

86 68 46 32 16 22 16

204 (28)

1.81

76

425 493 541 572

(29) (29) (30) (30)

1.50 1.46 1.40 1.40

57 59 30 27

609 (27)

1.36

11

Experiment 2, Diet C Added zinc

28 day weight

Feed/ gain

mg./kg. 0

gm. 163 (29)1

2.42

99

3

412 (29)

1.80

40

461 435 469 428

1.76 1.73 1.76 1.73

5 11 8 9

(28) (28) (29) (29)

238 (28) 318 (24) 358 (28) 408 (30) 439 (29) 427 (28) 412 (29) 413 (26) 389 (30)

1.82 1.73 1.71 1.62 1.66 1.66 1.67 1.64 1.70

1

Hock score

%

20 21 Experiment 3B

Experiment 4B

9.0

6.9

8.6

27.5 48.1

29.2 48.5

40.8 55.5

Experiment 2 Zinc conte nt of basal diet (by analysis), mg •Ag. Zinc requirement (calculated) mg./kg. diet Mg./gm. gam

Feed/ gain

Mean and number of survivors from duplicate lots of 15 male chicks per lot.

gression line representing the relationship between chick weight and log dose of zinc in those chicks fed zinc deficient diets. The 26 day weights of four lots receiving the higher zinc treatments were averaged and represented the growth of chicks showing optimum response to supplemental zinc. Calculation of the intercept of the two lines indicated a zinc requirement under these conditions of 12.7 mg. of total zinc per kg. of diet. Experiment 4A was conducted using diet B to determine what effect increased dietary energy (fat) would have upon the chick's requirement for zinc. Again Experiment 4A (Table 4) and Experiment 4B (Table 5) may be directly compared since they are parts of one large experiment. In Experiment 4A, six levels of zinc in 5 mg. increments from 0 to 25 mg. of added zinc per kg. of diet were included in the experimental design. The first two treatments, 0 and 5 mg. of added zinc per kg. of diet, were selected for the calculation of the regression line representing those chicks fed zinc deficient

diets. The 28-day weights of the four higher zinc treatments were averaged and represented the growth of chicks showing optimum response to supplemental zinc. Calculation of the intercept of the two lines gave the requirement under these conditions as 14.2 mg. of total zinc per kg. of diet. Studies using isolated soybean protein diets. The results of experiments conducted using purified diets containing isolated soybean protein are summarized in Table 5. Diet C, supplemented with five levels of added zinc, from 0 to 120 mg. of added zinc per kg. of diet, was fed in Experiment 2. From this experiment, the results of the first two treatments, 0 and 15 mg. of added zinc per kg. of diet, were selected for the calculation of the regression line representing those chicks fed zinc-deficient diets. The 28-day weights of the chicks receiving the four higher zinc levels were averaged and represented the growth of chicks showing optimum response to supplemental zinc. Calculation of the intercept of the two lines

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10 IS 20 25 30 60 90 120 500 1,000

Feed/ gain

ZINC REQUIREMENTS

calculation of the intercept of the two lines indicated a requirement, under these conditions, of 40.8 mg. of total zinc per kg. of diet. The level of 90 mg. of zinc per kg. of diet was presumed to be adequate because it was three times the maximum requirement found in previous experiments and this treatment produced four-week chick weights which were obviously representative of an optimum response. The hock score for this treatment also was comparable to the minimum value found in the previous experiments in which the isolated soybean protein diet was supplemented with adequate quantities of zinc. It is possible that the results obtained with 30 mg of added zinc per kg. of diet were such that they could be used in the calculation of either regression line. Again, observation of a graphic representation of these data illustrated that the four week weights produced by this treatment fell on the regression representing those chicks receiving deficient quantities of zinc, and also by increasing the amount of dietary zinc from 30 to 90, gave a reduction in the hock score. This evidence supports the calculations as previously made. Should, however, the treatment containing 30 mg. of added zinc per kg. of diet be included in the optimum response curve, the calculated value for the zinc requirement under these conditions is 37.5 mg. of total zinc per kg. of diet, which is only slightly lower than the preferred estimate of 40.8. Studies using practical broiler diets. One experiment was conducted to determine if diets composed of practical ingredients contained sufficient amounts of zinc to meet requirements of young chicks. Diets E, F and G (Table 2) were used in this experiment. These diets contained by calculation 43, 36 and 37 mg. of zinc per kg. of diet, respectively. Each diet was fed alone and with 100 mg. of added zinc per kg. of diet, making a total of six treatments. The experiment was conducted under the same

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indicated a zinc requirement, under these conditions, of 27.5 mg. of total zinc per kg. of diet. Diet C was also fed in Experiment 3B. In this experiment, seven graded amounts of zinc, from 5 to 60 mg. of added zinc per kg. of diet, were fed. In addition, this experiment contained two high-zinc treatments, 500 and 1000 mg. of added zinc per kg. of diet, in an attempt to determine if these quantities of zinc are toxic to chicks. Upon examination of these data, the results of the first four treatments—5, 10, 15 and 20 mg. of added zinc per kg. of diet—were selected for calculation of the regression line representing the weights of chicks fed zinc deficient diets. The weights of the chicks receiving the four higher zinc treatments, excluding the lot receiving 1000 mg. per kg. of diet, were averaged and represented the growth of chicks in which optimum response to supplemental zinc was obtained. Calculation of the intercept of the two lines indicated a zinc requirement, under these conditions, of 29.2 mg. of total zinc per kg. of diet. The last treatment in this experiment was excluded from the calculations because both chick growth and red blood cell counts were reduced when 1000 mg. of zinc as the chloride was added per kg. of diet. Experiment 4B was conducted using diet D to determine the effect of increased dietary energy (fat) upon the chick's requirement for zinc. This experiment consisted of six treatments representing the addition of 5, 15, 20, 25, 30 and 90 mg. of zinc per kg. of diet. In this experiment all treatments except the top level of 90 mg. added zinc per kg. of diet were used in the calculation of the regression line representing the weights of the chicks fed zinc deficient diets. The average weight of the chicks fed the high zinc treatment was taken as representative of the growth of chicks receiving adequate supplemental zinc. The

1589

1S90

T. R. ZEIGLER, R. M. LEACH, JR., L. C. NORRIS AND M. L. SCOTT TABLE 6.—Effect

of increasing the zinc content of practical broiler diets

Diet E

Diet F

Diet G

28 day weight Feed/gain

28 day weight Feed/gain

28 day weight Feed/gain

Supplement gm.

gm.

gm.

None

f2l 631(27)i \ -77l 1.79

632 633(28) J ; | | 1.84

100 mg./kg. zinc

673

650 667 (30) 683

m

(3Q)

1.78 j

„

1.79 1.76 1.77

.^

635 (30) J;|J 1.86

« * 668(29) J ; | | 1-79

Analysis of variance Source

M.S.

F

P

M.S.

F

P

3.30 <1.00 14.60 <1.00

<.10 >.10 <.01 >.10

.00323 .00323 .00908 .00030

1.90 1.90 5.34 1.70

>.10 >.10 <.10 >.10

11

Treatments Diets Zinc DXZ

5 2 1 2

1,196.8 129.0 5,292.0 217.0

Error

6

362.5

1

Efficiency of feed utilizations

28 day weights

.00170

Lot means, treatment mean and number of survivors from duplicate lots of 15 male chicks per lot.

special environmental conditions used in the previous experiments. The results of this experiment are summarized in Table 6. Analysis of variance conducted to determine the effects of zinc upon average chick weights and efficiency of feed conversion showed that the addition of 100 mg. of zinc per kg. of diet significantly increased (P < 0.01) the weight of the chicks fed these supplemented diets. The effects of added zinc upon efficiency of feed conversion approach significance (P < 0.10). A few chicks in all treatments showed a slight degree of hock enlargement but addition of zinc had no effect upon this condition. DISCUSSION When a purified diet containing casein was fed to young chicks, the total zinc requirement was 12-14 mg. of total zinc per kg. of diet. This requirement was independent of the dietary changes in energy and nutrient concentration brought about by increasing the level of fat in the diet from 3% to 10% and appears to be in good

agreement with that reported previously by others. Using a casein-gelatin diet, Pensack, Henson and Bogdonoff (1958) found the requirement to be not more than 20 mg. of total zinc per kg. of diet; Moeller and Scott (1958) reported the requirement to be not more than 10 mg. of added zinc per kg. of diet when heated egg white was used as the source of protein. When isolated soybean protein replaced the casein in the present studies, the requirement was increased to 27-29 mg. of total zinc per kg. of diet. In close agreement with these results are those of Moeller and Scott (1958) and Roberson and Schaible (1958), who reported the requirement to be 33 and 30 mg. of total zinc per kg. of diet, respectively. Young, Edwards and Gillis (1958), on the other hand, determined the requirement of chicks fed a similar diet to be 55 mg. of total zinc per kg. of diet. This apparent higher requirement may be due to genetic differences in breeds of chicks, to the higher amount of isolated soybean protein used in their diets, or to differences in

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Total (corrected)

df

ZINC REQUIREMENTS

1591

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analytical procedures used for determina- (fat) upon the zinc requirement when casein is used; whereas (4) Comparing the tion of zinc. When the level of fat was increased from results of Experiment 4B with those of Ex3 to 10% in the isolated soybean protein periment 2 and Experiment 3B (55.5 |xg. diets, the zinc requirement appeared to be Zn/gm. gain vs. 48.1 |xg. Zn/gm. gain and increased to about 41 mg. of total zinc per 48.5 [/.g. Zn/gm. gain) strongly suggests kg. of diet. This amounts to an increase in that the increase in requirement when the the requirement of about 45%. Since this fat (energy) was added to the isolated soyincrease was not observed when the casein bean diet was due to the simultaneous indiets were fed, it appears not to be due to crease in the amount of isolated soybean a specific effect of the increased energy protein, since this effect was absent when (fat) content of the diets, but rather to an the casein diet was fed. This 15% increase increase in the isolated soybean protein in requirement corresponds favorably to the 11% increase of isolated soybean protein per se. in the 10% fat diets. To further evaluate the zinc requirement when the purified diets were fed, calcuIn a practical broiler study, Supplee et al. lations were made so that it could be ex- (1958) reported that the addition of 48 mg. pressed also in terms of zinc required per of zinc per kg. of diet did not improve the unit of chick gain. By multiplying the growth or feed conversion of chicks. In the average feed conversion (feed/gain) of experiment which we conducted using pracchicks fed diets containing adequate zinc, tical diets, added zinc had a significant times the calculated requirement (fJig.Zn/ effect on the four week weights and nugm. feed), the requirement may be ex- merically improved the feed conversion; pressed as [xg. zinc per gm. gain. Expression however, the latter differences were not of the zinc requirement in this way brings statistically significant. This experiment out some interesting relationships as fol- indicates, however, that in practical diets lows: (1) When the results of Experiment containing 36 to 43 mg. total zinc per kg. 2 were compared with those of Experiment of diet, this zinc may not be sufficiently 3B it was found that the chicks in these available to meet the demands of the experiments required 48.1 |xg. Zn/gm. gain growing chick. and 48.5 jjt-g. Zn/gm. gain, respectively. The Both the experiments presented herein, consistency of these results suggests that and those of others previously discussed, this may be a more accurate method of des- suggest some specific property or properties ignating the requirement, and furthermore, of soybean protein which increases the points out the excellent reproducibility of chick's requirement for this trace element. results between experiments. (2) Compar- It has been suggested that soybean oil meal ing the results of Experiment 3A and Ex- and soybean protein contain a substance or periment 3B (22.0 [>.g. Zn/gm. gain and substances capable of reducing the availa48.5 [Ag. Zn/gm. gain respectively), the bility of zinc for chicks. O'Dell and Savage zinc requirement on the basis of unit of gain (1960) have suggested that phytic acid is also 2.2 times greater when isolated soy- present in the isolated soybean protein may bean protein was fed, as compared to casein. render the zinc unavailable. Inasmuch as (3) Comparing the results of Experiment certain amino acids possess sequestering 3A with Experiment 4A (22.0 [Ag. Zn/gm. properties, it is possible that the high level gain vs. 21.0 |xg. Zn/gm. gain) shows the of arginine (0.8-1.2%) added to the casein absence of an effect of increased energy diets used in these experiments helped to

1592

T. R. ZEIGLEE, R. M. LEACH, JR., L. C. NORMS AND M. L. SCOTT

increase zinc availability. Whether the variation in requirement between the two types of diet may be completely explained in terms of some property such as the phytic acid content of the soybean protein diets which decreases the availability of the dietary zinc, or whether the alternate hypothesis, which suggests that some property of the casein diets may aid by increasing the metabolic efficiency of the dietary zinc remains to be resolved.

1. The zinc requirement of chicks fed a purified diet containing casein was shown to be 12-14 mg. of total zinc per kg. of diet. 2. Chicks fed a similar diet in which the casein protein was replaced by isolated soybean protein required 27-29 mg. of total dietary zinc per kg. of diet. 3. Increasing the energy (fat) content of the diet from 3 to 10% had no observable effect upon the zinc requirement, whereas the requirement was increased as the level of soybean protein in the diet was increased. 4. Practical diets may not contain sufficient zinc for maximum growth when chicks are raised under zinc-free environmental conditions. 5. Soybean protein appears to possess a specific factor or property which increases the chick's requirement for zinc. Casein may contain a specific factor or property which increases the efficiency of utilization of zinc. 6. Calculations are made which suggest that the zinc requirement of the chick, expressed as |xg. Zn/gm. gain, is a more accurate expression of requirement than is mg. Zn/kg. of diet. ACKNOWLEDGMENTS The authors wish to acknowledge the very capable assistance of Mrs. Margaret

REFERENCES Association of Official Agricultural Chemists, 1955. Official Methods of Analysis, ed. 8, Washington, D. C. p. 382. Edwards, H. M., Jr., R. J. Young and M. B. Gillis. 1958. Studies on zinc in poultry nutrition. 1. The effect of feed, water and environment on zinc deficiency in chicks. Poultry Sci. 37: 1094-1099. Hill, F. W., 1958. Metabolizable energy values of practical and purified ingredients. Unpublished results, Cornell University. Insko, W. M., Jr., M. Lyons and J. H. Martin, 1938. The effect of manganese, zinc, aluminum and iron salts on the incidence of perosis in chicks. Poultry Sci. 17 : 264-269. Lyons, M., W. M. Insko, Jr. and J. H. Martin, 1938. The effect of intraperitoneal injections of manganese, zinc, aluminum and iron salts on the occurrence of slipped tendon in chicks. Poultry Sci. 17: 12-16. Mehring, A. L., Jr., J. H. Brumbaugh and H. W. Titus, 1956. A comparison of the growth of chicks fed diets containing different quantities of zinc. Poultry Sci. 35: 956-958. Moeller, M. W., and H. M. Scott, 1958. Studies with purified diets. 3. Zinc requirement. Poultry Sci. 37: 1227-1228. Morrison, A. B., and H. P. Sarett, 1958. Studies of zinc deficiency in the chick. J. Nutrition, 65: 267-280. O'Dell, B. L., and J. E. Savage, 1957. Symptoms of zinc deficiency in the chick. Federation Proc. 16: 394. O'Dell, B. L., and J. E. Savage, 1960. Effect of phytic acid on zinc availability. Proc. Soc. Exp. Biol. Med. 103: 304-306. Patrick, H., 1958. Zinc deficiency in chicks. Federation Proc. 17: 487. Pensack, J. M., J. N. Henson and P. D. Bogdonoff, 1958. The effects of calcium and phosphorus on the zinc requirements of growing chickens. Poultry Sci. 37: 1232. Roberson, R. H., and P. J. Schaible, 1958. The zinc requirement of the chick. Poultry Sci. 37: 1321-1323. Supplee, W. C , D. L. Blamberg, O. D. Keene, G. F. Combs and G. L. Romoser, 1958. Obser-

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CONCLUSIONS

Smith in the analytical determinations for zinc. This work was supported in part by the Distillers Feed Research Council, Cincinnati, Ohio.

1593

ZINC REQUIREMENTS vations on zinc supplementation of poultry rations. Poultry Sci. 37: 1245-1246. Titus, H. W., 1932. Perosis, or deforming leg weakness in the chicken. Poultry Sci. 11: 117125. Wilgus, H. S., Jr., L. C. Norris and G. F. Heuser, 1937. The role of manganese and certain other trace elements in the prevention of perosis.

J. Nutrition, 14: 155-167. Young, R. J., H. M. Edwards, Jr. and M. B. Gillis, 1958. Studies on zinc in poultry nutrition. 2. Zinc requirement and deficiency symptoms of chicks. Poultry Sci. 37: 1100-1107. Zeigler, T. R., R. M. Leach, Jr., and L. C. Norris, 1958. Zinc requirement of the chick. Federation Proc. 17: 498.

Studies on the Vitamin K Requirements of Young Pheasants and Quail

EARL

R.

N.Y.

HOLM

New York State Conservation Department, Albany,

N.Y.

AND R.

E.

REYNOLDS

New York State Game Farm, Ithaca, N. Y. (Received for publication January 27, 1961)

E

ARLIER reports from this laboratory have dealt with the protein, calcium, phosphorus, vitamin D, manganese, zinc, riboflavin, niacin, choline, sodium, chlorine, and iodine requirements of pheasants (Scott et al., 1954, 1958a, 1959, 1960); and the phosphorus, sodium, chlorine, and iodine requirements of young Bobwhite quail (Scott et al., 1958b, 1960). Since little is known about the vitamin K requirements and relative vitamin K activities of vitamin Ki, menadione, and menadione sodium bisulfite for young pheasants and quail, the studies were undertaken which are the subject of this report. EXPERIMENTAL

All experiments were conducted at the Ithaca Game Farm of the New York State Conservation Department. Both the pheasants and quail were housed in wire pens with raised wire floors. The pens were equipped with thermostatically-controlled electric hovers. Each experimental lot contained 50 Ringnecked pheasants or 25 Bob-

white quail of mixed sex at the start of the experiment. All treatments were conducted in duplicate. The pheasants were distributed among 32 6' X 6' pens; the quail treatments were distributed among 24 4' X 4' pens. Feed and water were supplied ad libitum. The basic vitamin K-deficient diet used in all experiments is presented in Table 1. In each experiment, one series of treatments (Series 1) was added directly to this diet, while for the second series of treatments (Series 2) the diet was modified by the addition of 0.1% sulfaquinoxaline prior to supplementation with the various vitamin K-active materials. Vitamin Ki and menadione were dissolved in 95% ethyl alcohol for addition to the diet; pure menadione sodium bisulfite was dissolved in 50% ethyl alcohol. Prothrombin time determinations were used to measure vitamin K activity. The method was a modification of that of Hoffman and Custer (1942) as described by Nelson and Norris (1960). Individual pro-

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M. L. SCOTT Department of Poultry Husbandry, Cornell University, Ithaca,