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The Vitamin A Requirements of Breeding Turkeys and Their Progeny
The Vitamin A Requirements of Breeding Turkeys and Their Progeny G. S. STOEWSAND AND M. L. SCOTT Department of Poultry Husbandry, Cornell University, Ithaca, N. Y. (Received for publication November 4, 1960)
U
It is probable that the extreme variation in reported vitamin A requirements is due to variations in stability of the reference vitamin A preparations used in the different experiments. Recent studies in this laboratory (Scott et al., 1957; Hill et al., 1961) have shown that with the use of "stabilized" vitamin A produced by the new manufacturing processes for physically-stabilizing vitamin A supplements in poultry feeds, the minimum vitamin A requirements of chicks and hens are much lower than indicated by earlier experiments where unstabilized fish liver oils or carotene were used as the sources of vitamin A. In view of this, it was considered desirable to determine
the vitamin A requirements of breeding turkeys and their progeny, using a "stabilized" vitamin A supplement. The results of these studies are presented in this report. PROCEDURE AND RESULTS
The vitamin A requirement of breeding turkeys. Two experiments were conducted with Empire White Broad Breasted large breeding turkeys during two different years. The first experiment was conducted for approximately 130 days from December through April, eggs being collected during the last 77 days of the expejriment; the second experiment was conducted for 105 days from February through May, all eggs being collected throughout the experiment. The experimental breeder diets used both years are shown in Table 1. In the first experiment, four levels of vitamin A were used, 800, 1,600, 2,400 and 4,800 USP units per pound of feed; in the second experiment the basal diet contained 450 USP units of vitamin A activity due to the yellow corn present in the diet and was further supplemented with 350, 750 and 1,950 USP units of stabilized vitamin A to provide diets containing total vitamin A activities of 450, 800, 1,200 and 2,400 USP units per pound. The vitamin A supplement used in both studies was a commercially-prepared, gelatin-stabilized beadlet typifying the new "stabilized" vitamin A preparations for animal feeds, and containing 250,000 USP units of vitamin A per gram as the palmitate ester.
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PON evaluation of available information, the Committee on Animal Nutrition of the National Research Council (1954) set the minimum vitamin A requirements for breeding turkeys and for starting and growing turkeys at 2,400 USP units per pound of diet. The estimates are based upon research work in which carotene, fish liver oils or "unstabilized" vitamin A preparations were used to supply the vitamin. These studies showed extremely variable results and indicated requirements for the young poult, for example, ranging from the neighborhood of 2,400 USP units (Wilgus, 1940; Van Reen et al., 1951) to over 7,500 USP units of vitamin A per pound of diet (Wharton et al., 1949). Very limited published work is available upon which to base a minimum vitamin A requirement for breeding turkeys.
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G. S. STOEWSAND AND M. L. SCOTT
TABLK 1.—Basal diets for vitamin A studies with turkey breeders
Ingredients
Diet #1 Diet #2 (for ex- (for experiper'ment 1) ment 2)
%
%. — 30.0 35.0 18.0 5.0 2.0 2.0 2.5 1.0 4.0 0.5
+
1
Vitamins and minerals added per 100 lbs. of diet: 16.0 gms manganese sulfate (70% feed grade); 20.0 gms vitamin D 3 (3,000 ICU/gm.); 15.0 gms d-alpha-tocopheryl acetate (110 IU/gm.); 0.5 gm. Ca pantothenate; 0.2 gm. riboflavin; 0.4 mg. vitamin B12; 10 mg. menadione sodium bisulfite (Klotogen F). Calculated analysis: Protein, % 17.4 18.5 Fat, % 4.0 5.5 Calcium, % 2.4 2.6 Phosphorus, % 0.75 0.8 Metabolizable energy, Cal./lb. 1,400 1,375 Vitamin A activity, USP units/lb. trace 450
This vitamin A preparation was blended with soybean oil meal to produce supplements of 9,925 USP units per gram for use in Experiment 1, and most poult experiments, and of 10,000 USP units per gram for use in Experiment 2. A "doublecoated" vitamin A product, consisting of a gelatin coat around a hard fat vitamin A beadlet, was used in Experiment 6. The turkeys were housed in small pens on litter. In the first experiment, each treatment was fed to duplicate lots of 8 female turkeys per lot. Duplicate lots of 12 turkey hens each were used in the second experiment, except that quadruplicate lots of 12 hens each received the diet containing 2,400 USP units of vitamin A per pound. The turkeys were artificially in-
In view of the report by Scott (1937) of decreased mottling or spotted appearance in the shells of eggs of vitamin Adeficient turkey breeding hens, observations were made of the eggs from the hens receiving all vitamin A treatments in Experiment 2. Although, by and large, TABLE 2.—Results oj first experiment with Empire White breeding turkey hens Vitamin A in bree ier diet USP units/lb. 800
Production 1
Total feed consumed
Vitamin A content of turkey eggs 82 days 2
126 days 2
%
lbs.
5.1.3 40.0 Avg. 46.6
50.0 56.8 53.4
1,189
9.6
2.4
1,600
50.5 43.0 Avg. 46.8
45.4 42.0 43.7
1,373
10.2
6.3
2,400
61.3 47.3 Avg. 54.3
54.1 53.2 53.6
1,229
11.4
6.9
4,800
55.5 38.3 Avg. 46.9
56.4 51.9 54.2
1,203
14.0
15.0
1 1
%
Hatchability of fertile eggs
I U / g m . IU/gm.
Eight hens per lot. Days after breeders started on experiment.
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White corn meal 55.5 Yellow corn meal — 15.0 Wheat, ground 14.0 Soybean oil meal, 50% protein 4.5 Meat & bone scrap, 50% protein 2.0 Brewers dried yeast Whey, dried product, 55% lactose 2.5 1.0 Stabilized white tallow 1.0 Dicalcium phosphate 4.0 Calcium carbonate, ground 0.5 Salt, iodized Vitamins and minerals1 +
seminated 5 days before the first egg collection and about every 20 days for the duration of the collection periods. The results of Experiment 1 are summarized in Table 2; those of Experiment 2 in Table 3. The results of Experiment 1 showed no consistent effects of vitamin A level upon turkey breeder nutrition, indicating that the lowest level of 800 USP units of vitamin A per pound of diet was sufficient under the conditions of this experiment. The results of the second experiment, however, indicated that the addition of 350 USP units of "stabilized" vitamin A (a total of 800 USP units) per pound of diet was not sufficient, whereas the addition of 750 USP units of "stabilized" vitamin A (a total of 1,200 USP units) per pound of diet produced rates of production and hatchability of fertile eggs which were not improved by doubling this level of vitamin A in the breeder diet.
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V I T A M I N A R E Q U I R E M E N T S OF T U R K E Y S
TABLE 3.—Evidence on the vitamin A requirement of breeding turkeys Vitamin A per pound of breeder diet from stafrom yelbilized low corn vitamin A suppl.
Total hendays
%
%
%
%
589 497
1,184 1,155
49.8 43.0
46.4
56.3 65.9
61.1
Total
USP units USP units USP units 450 450 0
Production
Total eggs
Per
lot
Avg.
Hatcha Per lot
Avg.
350
800
519 615
1,215 1,208
42.7 50.9
46.8
63.2 72.0
67.6
450
750
1,200
661 616
1,188 1,191
55.6 51.7
53.7
72.8 68.7
70.8
450
1,950
2,400
679 555 719 690
1,155 1,237 1,216 1,193
58.8 44.9 59.1 57.8
eggs from the deficient hens showed somewhat lighter mottling than those fed adequate vitamin A, a number of eggs produced by hens fed the lowest level of vitamin A were as deeply mottled as those produced b y hens receiving the highest amount of the vitamin. Therefore, it appeared impossible to assess vitamin A nutrition of the turkey breeders on the basis of the degree of mottling of the eggs. Studies with turkey poults. Experiment 3. This experiment and Experiments 4 and 5, were conducted with poults which were the progeny of the hens receiving the various vitamin A treatments in Experiment 1. For the first experiment, poults were divided into two groups and fed two different diets, one a basal vitamin A-low diet, the composition of which is shown in Table 4, while the other group received this diet with a supplement of 800 USP of stabilized vitamin A per pound of diet. Diets and water were supplied ad libitum and the experiments were conducted in wire-floored battery brooders in a thermostatically-heated room. The results of the first experiment with poults are shown in
55.0
71.7 67.9 67.1 79.0
71.4
Table 5. These results show increased carry-over of vitamin A in the poults as the level of vitamin A in the diet of the TABLE 4.—Composition of basal diet used to study vitamin A requirements of young poults Ingredients
Amounts
% White corn Ground wheat Soybean oil meal (50% protein) Stripped lard Meat & bone scrap Dried brewers' yeast Whey, dried product, 55% lactose Limestone Salt Santoquin
38.4 14.0 29.0 1.6 11.0 2.0 2.0 1.5 0.35 0.0125
Additional vitamins & minerals used per 100 lb. of diet: Manganese sulfate (70% feed grade) Choline chloride (70%) ZnCl2 Niacin Vitamin D 3 (3,000 ICU/gm.) d-alpha-tocopheryl acetate (110 IU/gm.) Ca pantothenate Riboflavin Vitamin B12 Menadione sodium bisulfite (Klotogen F)
17.0 25.0 2.0 1.9 20.0
gms. gms. gms. gms. gms.
2.5 700.0 200.0 0.4
gms. mgs. mgs. mg.
40.0 mgs.
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450
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G. S. STOEWSAND AND M. L. SCOTT
TABLE 5.—Growth, feed conversion and survival of progeny of turkey breeding hens receiving various levels of vitamin A when fed diets containing no vitamin A or a moderately low level of the vitamin
Diet of dams
Diet of progeny
4 wk. avg.1 weights of progeny
USP units/lb.
USP units/lb.
gms.
Vitamin A content of:
Survival of2 progeny
Feed/gain
Started dying at 14th day—0/10
0
1,600
0
273
Started dying at 16th day—5/10
2,400
0
244
Started dying at 21st day—1/10
4,800
0
332
Started dying at 25th day—1/10
800 1,600 2,400 4,800
800 800 800 800
407 416 407 455
9/11 10/10 10/10 10/10
2.44 2.23 2.16 2.02
1
Expressed as the weighted mean of male and female poult weights. All surviving poults fed basal diet showed gross symptoms of vitamin A deficiency. Numerator of fraction shows number of poults alive at 4 weeks. 2
dams was increased. This is especially evident in terms of length of survival before onset of mortality on the vitamin A-free basal diet and in terms of efficiency of feed utilization by the poults receiving 800 USP units of vitamin A per pound of diet. Experiment 4. Since mortality was very heavy in the poults receiving the basal diet, and no appreciable mortality occurred in those receiving 800 U S P units of vitamin A per pound of diet in Experiment 3, a further experiment was conducted to determine the carry-over of vitamin A in the progeny of the hens receiving 800, 1,600 and 2,400 USP units of vitamin A per pound of breeder diet. For this experiment, progeny from each hen t r e a t m e n t were fed the starter diet supplemented with 100, 200 and 400 USP units of stabilized vitamin A per pound. The results of the experiment, presented in Table 6, show the importance of vitamin A carry-over in young poults receiving border-line vitamin A levels. Mortality
and ataxia of vitamin A deficiency were not prevented in poults receiving 400 USP units of vitamin A per pound of starter diet or less, when their dams were fed diets containing vitamin A levels of 800 and 1,600 U S P units per pound of breeder diet, b u t were almost completely prevented under these conditions in poults which were the progeny of dams receiving 2,400 USP units of stabilized vitamin A per pound of breeder diet. Experiment 5. In the third poult experiment, graded levels of vitamin A, 200, 400, 800 and 2,400 USP units per pound of starter diet, were fed to the progeny of the hens receiving the various vitamin A treatments. Observations were made on growth and survival to eight weeks of age as well as on feed utilization. Liver storage of vitamin A was determined at 6 and 8 weeks of age in poults receiving each vitamin A treatment. These analyses were conducted, however, only on the livers of the poults which were the progeny of the hens receiving the lowest vitamin A treat-
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800
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VITAMIN A REQUIREMENTS OF TURKEYS TABLE 6.—Survival of progeny of hens receiving graded levels of vitamin A
Diet of dams
Diet of progeny
9 wk. avg. weights
USP units/lb. 800
USP units/lb. 100
—
All poults dead by 5 wks. of age
200
—
All poults dead by 8 wks. of age
400 100
1,799
200 400 100 200 400
1,076 1,981
1,600
5/101—2 poults showed mild ataxia All dead by 5 wks. of age.
—
5/10—surviving poults showed severe ataxia 6/10—no ataxia in survivors All dead by 7 weeks of age 6/10—showed severe ataxia 9/10—one poult showed slight ataxia
— 1,488 1,876
No. survivors/no. started.
ment. The results of the experiment are presented in Table 7. These results show that growth and feed utilization were improved as the vitamin A nutrition of the poults was improved, whether the vitamin A was supplied as carry-over from the dams or via the poult starting diet.
Growth of poults from hens receiving only 800 USP units of the vitamin per pound of breeder diet was increased by each increasing level of vitamin A up to the level of 2,400 USP units per pound of starter diet. However, when the dams received 1,600 USP units of vitamin A
TABLE 7.—Growth, feed utilization and survival of poults in Experiment 5 Vitamin A content of: Diet of dams Diet of progeny USP units/lb.
1 2
8 wk. avg. weights of1 progeny
Survival of progeny
Liver storage of vitamin A Feed/g£ 6 wks.
USP units/lb.
gms.
800
200 400 800 2,400
861 1,457 1,547 1,696
5/9 2 9/9 7/8 8/8
3.23 2.41 2.12 2.19
1,600
200 400 800 2,400
1,024 1,463 1,805 1,683
8/8 6/7 9/9 9/10
2.62 2.34 2.19 2.25
2,400
200 400 800
1,068 1,592 1,567
8/10 9/10 8/10
2.35 2.35 2.18
4,800
200 400 800 2,400
1,109 1,691 1,640 1,782
6/9 8/9 8/9 8/8
2.57 2.17 2.05 2.20
Weighted means of males and females. No. surviving to eight weeks/no. started.
8 wks.
USP units per gram of liver 0 0 0 0 0.7-1.8 0.4-0.6 23-30 26-35
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2,400
Survival
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G. S. STOEWSAND AND M . L. SCOTT
TABLE 8.—Vitamin A requirement of poults hatched from hens receiving a commercial breeder diet Vitamin A content of poult starting
Liver vitamin A 8 wk. weighted mean weight
Feed/
;n
Week analys£s
Per gram
Per
Hver
Blood uric acid at 6 wks.1
were made USP units/lb. 200
gms. 8352
USP units
USP units
0 0 0
0 0 0 0 0 0 0
10.58 + 0.46
10.5 12.2 22.5 48.8
10.04 + 0.72
15.4 19.8 35.8 61.2
.32 + 0.91
1,617
2.09
0 0 0 0
1,000
1,627
2.19
0.9 0.9 1.2 1.3
1,200
1,584
2.04
2,400
1,614
2.03
9.1 16.7 13.8 34.0
4.4
+0.51
169 249 289
1 Averages of 10 blood uric acid determinations per treatment, except in lot receiving 200 USP units A/lb., where only 8 poults were alive at 6 weeks of age. 2 Only two poults alive at 8 weeks in this lot. Thirty poults per treatment at the start of the experiment. No mortality in the other lots. 3 Std. error of the mean.
per pound of breeder diet, or more, the requirement of their progeny for vitamin A for optimum growth and efficiency of feed utilization did not exceed 800 U S P units per pound of poult starting diet. Experiment 6. Experiments 3, 4 and 5 indicated the requirements of poults from hens receiving various levels of vitamin A. Nevertheless, it was considered desirable to determine the requirements of poults hatched from eggs laid by hens receiving a commercial turkey breeder diet. The experiment was conducted with duplicate lots of 15 poults per lot receiving 200, 800, 1,000, 1,200, and 2,400 USP units of vitamin A per pound of diet. Liver vitamin A analyses were conducted on two poults from each t r e a t m e n t a t 3, 4, 5 and 8 weeks of age. Blood uric acid
determinations were made on ten poult per t r e a t m e n t at 6 weeks of age, according to the method of Brown (1945). The results of the experiment, presented in Table 8, show t h a t the minimum vitamin A requirement of young poults for growth under the conditions of this experiment, was no greater than 800 USP units per pound of diet. This level of vitamin A, however, provided no carry-over of vitamin A in the livers of the poults. Vitamin A at 1,000 and 1,200 USP units per pound of diet, produced minimal liver storage. On the other hand, the 2,400 USP unit level of vitamin A per pound of poult diet produced an appreciable increase in liver storage of vitamin A. Vitamin A liver storage generally increased as the poults grew older. This observation con-
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800
mg. % 12.0 ± 0 . 7 6 3
V I T A M I N A R E Q U I R E M E N T S OP T U R K E Y S
DISCUSSION Upon supplementing a low-vitamin A turkey breeder diet with stabilized vitamin A, it was found t h a t the minimum vitamin A requirement was about 1,200 USP units per pound of diet. This is approximately equivalent to t h a t found by Hill et al. (1961) to be required b y laying and breeding chickens, and is much lower than the requirements previously indicated (Titus, 1939; N A S - N R C Bulletin 301, 1954). The vitamin A content of the eggs and carry-over in the poults increased with increasing levels of vitamin A in the breeding diet. Only in hens receiving 4,800 USP units of vitamin A per pound of diet was the vitamin A content of the eggs maintained at a high level throughout the entire experimental period. In poults fed vitamin A-deficient starting diets, the carry-over of vitamin A was demonstrated to be directly relited to the vitamin A treatments of the dams. Progeny of hens receiving each increment of vitamin A showed increasingly better survival and growth on the deficient starting diets. Thus, although normal egg production,
hatchability and maintenance of the breeders was obtained with vitamin A levels of 1,200 USP units per pound of breeder diet, levels of 2,400-4,800 USP units of stabilized vitamin A per pound of diet produced marked improvement in the carry-over reserves of vitamin A in the progeny. Decision as to the minimum vitamin A requirement of young poults depends upon whether the criterion of optimum requirement is based upon growth and feed utilization alone, or also takes into consideration liver storage and blood uric acid levels. Storage of vitamin A in the liver certainly appears to be desirable since under conditions of little or no liver storage, stresses and diseases may precipitate vitamin A deficiency (Erasmus, Scott and Levine, 1960). Furthermore, as first indicated b y Elvehjem and Neu (1932), high blood uric acid levels are indicative of insufficient vitamin A in the diet to maintain maximum integrity of the epithelium of the kidney tubules and probably of the gastro-intestinal tract. Thus, in poults which are the progeny of hens receiving 1,600 U S P units of vitamin A per pound of diet or more, and under excellent environmental conditions, a dietary level of 800 U S P units of stabilized vitamin A per pound of poult starter diets has been shown to be sufficient for optimum growth and efficiency of feed utilization. However, a vitamin A level of approximately 2,400 USP units per pound of diet was needed in order to produce satisfactory liver storage of vitamin A and minimum blood uric acid levels. The minimum requirement of 800 U S P units per pound of poult diet is slightly higher t h a n the level of 600 USP units of stabilized vitamin A found by Hill et al. (1961) to be required by starting chicks. Since recent work in our laboratory (Stoewsand and Scott, 1960) shows t h a t the vitamin A requirement is increased by
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firms t h a t previously made by Gurcay et al. (1950). Blood uric acid levels decreased with increasing vitamin A levels, reaching the lowest level only with the highest vitamin A treatment. Blood uric acid levels of normal poults receiving practical commercial rations were found to be approximately 4-5 m g . % . Thus, the minimum vitamin A requirement of young poults for minimal liver storage of the vitamin is approximately 1,000-1,200 USP units and the minimum requirement for lowest uric acid blood levels is greater than 1,200, and m a y be as high as 2,400 USP units of vitamin A per pound of diet, even when a stabilized source of the vitamin is used.
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G. S. STOEWSAND AND M. L. SCOTT
increasing the protein content of the diet, it is possible that the higher minimum vitamin A requirement of poults, as compared to chicks, is due to the higher protein content of the poult starting diet. SUMMARY
ACKNOWLEDGEMENTS
The authors are indebted to Distillation Products Industries, Rochester, N. Y., for financial assistance and for the vitamin A preparation, PGB-250, used in Experiments 1, 2, 3, 4 and 5; to Stabilized Vita-
REFERENCES Brown, H., 1945. The determination of uric acid in human blood. J. Biol. Chem. 158: 601-608. Elvehjem, C. A., and V. F. Neu, 1932. Studies in vitamin A avitaminosis in the chick. J. Biol. Chem. 97: 71-82. Erasmus, J., M. L. Scott and P. P. Levine, 1960. A relationship between coccidiosis and vitamin A nutrition in chicks. Poultry Sci. 39: 565-572. Gurcay, R., R. V. Boucher and E. W. Callenbach, 1950. Utilization of vitamin A by turkey poults. I. Crystalline carotene, crystalline vitamin A acetate and "black cod" liver oil. J. Nutrition, 41:565-582. Hill, F. W., M. L. Scott, L. C. Norris and G. F. Heuser, 1961. Reinvestigation of the vitamin A requirements of laying and breeding hens and their progeny. Poultry Sci. 40: 1245-1254. National Academy of Sciences-National Research Council, 1954. Nutrient requirements for poultry. Publication 301. Scott, H. M., 1937. Turkey production in Kansas. Kansas Sta. Coll. Bull. 276. Scott, M. L., F. W. Hill, L. C. Norris, G. F. Heuser, R. E. Reynolds, E. H. Parsons, Jr. and H. E. Butters, 1957. New information on the vitamin A requirements of chickens, ducks and pheasants. Proc. Cornell Nutr. Conf., pp. 132-136. Stoewsand, G. S., and M. L. Scott, 1960. An interrelationship between vitamin A requirement and the protein level in the chick diet. Poultry Sci. 39: 1297-1298. Titus, H. W., 1939. Practical nutritive requirements of poultry. U.S.D.A. Yearbook of Agric, p. 818. Van Reen, R., M. W. Taylor and W. C. Russell, 1951. The vitamin A requirement of the turkey poult fed a purified diet. J. Nutrition, 43: 235— 244. Wharton, F. D., L. D. Matterson, H. M. Scott and C. I. Bliss, 1949. The vitamin A requirement of growing turkeys. J. Nutrition, 39: 543-554. Wilgus, H. S., 1940. Experiments show that turkey poults need four times as much vitamin A as do chicks. Colorado Farm Bull. 2(1): 3.
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The results presented in this report show: (1) 1,200 USP units of stabilized vitamin A per pound of turkey breeder diet were sufficient for optimum egg production, hatchability of fertile eggs and maintenance of the breeding hens; (2) however, 4,800 USP units of vitamin A per pound of breeder diet were required in order to maintain the vitamin A content of the eggs at high levels over a prolonged period and to produce appreciable carry-over of vitamin A in the progeny at hatching, such that the poults could survive and grow normally to 8-9 weeks of age on marginal levels of vitamin A in the poult starting diet; (3) 800 USP units of stabilized vitamin A per pound of poult starting diet were required for normal growth and feed utilization of progeny of turkey hens receiving 1,600 USP units or more of vitamin A in the turkey breeder diet; (4) however, a vitamin A level of approximately 2,400 USP units per pound of starter diet was needed in order to produce satisfactory liver storage of vitamin A and minimum blood uric acid levels.
mins, Inc., Garfield, N. J., for financial assistance and for the vitamin A preparation, Perma-Dual, used in Experiment 6; and to Hoffmann-La Roche, Inc., Nutley, N. J., for financial assistance.
U
It is probable that the extreme variation in reported vitamin A requirements is due to variations in stability of the reference vitamin A preparations used in the different experiments. Recent studies in this laboratory (Scott et al., 1957; Hill et al., 1961) have shown that with the use of "stabilized" vitamin A produced by the new manufacturing processes for physically-stabilizing vitamin A supplements in poultry feeds, the minimum vitamin A requirements of chicks and hens are much lower than indicated by earlier experiments where unstabilized fish liver oils or carotene were used as the sources of vitamin A. In view of this, it was considered desirable to determine
the vitamin A requirements of breeding turkeys and their progeny, using a "stabilized" vitamin A supplement. The results of these studies are presented in this report. PROCEDURE AND RESULTS
The vitamin A requirement of breeding turkeys. Two experiments were conducted with Empire White Broad Breasted large breeding turkeys during two different years. The first experiment was conducted for approximately 130 days from December through April, eggs being collected during the last 77 days of the expejriment; the second experiment was conducted for 105 days from February through May, all eggs being collected throughout the experiment. The experimental breeder diets used both years are shown in Table 1. In the first experiment, four levels of vitamin A were used, 800, 1,600, 2,400 and 4,800 USP units per pound of feed; in the second experiment the basal diet contained 450 USP units of vitamin A activity due to the yellow corn present in the diet and was further supplemented with 350, 750 and 1,950 USP units of stabilized vitamin A to provide diets containing total vitamin A activities of 450, 800, 1,200 and 2,400 USP units per pound. The vitamin A supplement used in both studies was a commercially-prepared, gelatin-stabilized beadlet typifying the new "stabilized" vitamin A preparations for animal feeds, and containing 250,000 USP units of vitamin A per gram as the palmitate ester.
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PON evaluation of available information, the Committee on Animal Nutrition of the National Research Council (1954) set the minimum vitamin A requirements for breeding turkeys and for starting and growing turkeys at 2,400 USP units per pound of diet. The estimates are based upon research work in which carotene, fish liver oils or "unstabilized" vitamin A preparations were used to supply the vitamin. These studies showed extremely variable results and indicated requirements for the young poult, for example, ranging from the neighborhood of 2,400 USP units (Wilgus, 1940; Van Reen et al., 1951) to over 7,500 USP units of vitamin A per pound of diet (Wharton et al., 1949). Very limited published work is available upon which to base a minimum vitamin A requirement for breeding turkeys.
1256
G. S. STOEWSAND AND M. L. SCOTT
TABLK 1.—Basal diets for vitamin A studies with turkey breeders
Ingredients
Diet #1 Diet #2 (for ex- (for experiper'ment 1) ment 2)
%
%. — 30.0 35.0 18.0 5.0 2.0 2.0 2.5 1.0 4.0 0.5
+
1
Vitamins and minerals added per 100 lbs. of diet: 16.0 gms manganese sulfate (70% feed grade); 20.0 gms vitamin D 3 (3,000 ICU/gm.); 15.0 gms d-alpha-tocopheryl acetate (110 IU/gm.); 0.5 gm. Ca pantothenate; 0.2 gm. riboflavin; 0.4 mg. vitamin B12; 10 mg. menadione sodium bisulfite (Klotogen F). Calculated analysis: Protein, % 17.4 18.5 Fat, % 4.0 5.5 Calcium, % 2.4 2.6 Phosphorus, % 0.75 0.8 Metabolizable energy, Cal./lb. 1,400 1,375 Vitamin A activity, USP units/lb. trace 450
This vitamin A preparation was blended with soybean oil meal to produce supplements of 9,925 USP units per gram for use in Experiment 1, and most poult experiments, and of 10,000 USP units per gram for use in Experiment 2. A "doublecoated" vitamin A product, consisting of a gelatin coat around a hard fat vitamin A beadlet, was used in Experiment 6. The turkeys were housed in small pens on litter. In the first experiment, each treatment was fed to duplicate lots of 8 female turkeys per lot. Duplicate lots of 12 turkey hens each were used in the second experiment, except that quadruplicate lots of 12 hens each received the diet containing 2,400 USP units of vitamin A per pound. The turkeys were artificially in-
In view of the report by Scott (1937) of decreased mottling or spotted appearance in the shells of eggs of vitamin Adeficient turkey breeding hens, observations were made of the eggs from the hens receiving all vitamin A treatments in Experiment 2. Although, by and large, TABLE 2.—Results oj first experiment with Empire White breeding turkey hens Vitamin A in bree ier diet USP units/lb. 800
Production 1
Total feed consumed
Vitamin A content of turkey eggs 82 days 2
126 days 2
%
lbs.
5.1.3 40.0 Avg. 46.6
50.0 56.8 53.4
1,189
9.6
2.4
1,600
50.5 43.0 Avg. 46.8
45.4 42.0 43.7
1,373
10.2
6.3
2,400
61.3 47.3 Avg. 54.3
54.1 53.2 53.6
1,229
11.4
6.9
4,800
55.5 38.3 Avg. 46.9
56.4 51.9 54.2
1,203
14.0
15.0
1 1
%
Hatchability of fertile eggs
I U / g m . IU/gm.
Eight hens per lot. Days after breeders started on experiment.
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White corn meal 55.5 Yellow corn meal — 15.0 Wheat, ground 14.0 Soybean oil meal, 50% protein 4.5 Meat & bone scrap, 50% protein 2.0 Brewers dried yeast Whey, dried product, 55% lactose 2.5 1.0 Stabilized white tallow 1.0 Dicalcium phosphate 4.0 Calcium carbonate, ground 0.5 Salt, iodized Vitamins and minerals1 +
seminated 5 days before the first egg collection and about every 20 days for the duration of the collection periods. The results of Experiment 1 are summarized in Table 2; those of Experiment 2 in Table 3. The results of Experiment 1 showed no consistent effects of vitamin A level upon turkey breeder nutrition, indicating that the lowest level of 800 USP units of vitamin A per pound of diet was sufficient under the conditions of this experiment. The results of the second experiment, however, indicated that the addition of 350 USP units of "stabilized" vitamin A (a total of 800 USP units) per pound of diet was not sufficient, whereas the addition of 750 USP units of "stabilized" vitamin A (a total of 1,200 USP units) per pound of diet produced rates of production and hatchability of fertile eggs which were not improved by doubling this level of vitamin A in the breeder diet.
1257
V I T A M I N A R E Q U I R E M E N T S OF T U R K E Y S
TABLE 3.—Evidence on the vitamin A requirement of breeding turkeys Vitamin A per pound of breeder diet from stafrom yelbilized low corn vitamin A suppl.
Total hendays
%
%
%
%
589 497
1,184 1,155
49.8 43.0
46.4
56.3 65.9
61.1
Total
USP units USP units USP units 450 450 0
Production
Total eggs
Per
lot
Avg.
Hatcha Per lot
Avg.
350
800
519 615
1,215 1,208
42.7 50.9
46.8
63.2 72.0
67.6
450
750
1,200
661 616
1,188 1,191
55.6 51.7
53.7
72.8 68.7
70.8
450
1,950
2,400
679 555 719 690
1,155 1,237 1,216 1,193
58.8 44.9 59.1 57.8
eggs from the deficient hens showed somewhat lighter mottling than those fed adequate vitamin A, a number of eggs produced by hens fed the lowest level of vitamin A were as deeply mottled as those produced b y hens receiving the highest amount of the vitamin. Therefore, it appeared impossible to assess vitamin A nutrition of the turkey breeders on the basis of the degree of mottling of the eggs. Studies with turkey poults. Experiment 3. This experiment and Experiments 4 and 5, were conducted with poults which were the progeny of the hens receiving the various vitamin A treatments in Experiment 1. For the first experiment, poults were divided into two groups and fed two different diets, one a basal vitamin A-low diet, the composition of which is shown in Table 4, while the other group received this diet with a supplement of 800 USP of stabilized vitamin A per pound of diet. Diets and water were supplied ad libitum and the experiments were conducted in wire-floored battery brooders in a thermostatically-heated room. The results of the first experiment with poults are shown in
55.0
71.7 67.9 67.1 79.0
71.4
Table 5. These results show increased carry-over of vitamin A in the poults as the level of vitamin A in the diet of the TABLE 4.—Composition of basal diet used to study vitamin A requirements of young poults Ingredients
Amounts
% White corn Ground wheat Soybean oil meal (50% protein) Stripped lard Meat & bone scrap Dried brewers' yeast Whey, dried product, 55% lactose Limestone Salt Santoquin
38.4 14.0 29.0 1.6 11.0 2.0 2.0 1.5 0.35 0.0125
Additional vitamins & minerals used per 100 lb. of diet: Manganese sulfate (70% feed grade) Choline chloride (70%) ZnCl2 Niacin Vitamin D 3 (3,000 ICU/gm.) d-alpha-tocopheryl acetate (110 IU/gm.) Ca pantothenate Riboflavin Vitamin B12 Menadione sodium bisulfite (Klotogen F)
17.0 25.0 2.0 1.9 20.0
gms. gms. gms. gms. gms.
2.5 700.0 200.0 0.4
gms. mgs. mgs. mg.
40.0 mgs.
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450
1258
G. S. STOEWSAND AND M. L. SCOTT
TABLE 5.—Growth, feed conversion and survival of progeny of turkey breeding hens receiving various levels of vitamin A when fed diets containing no vitamin A or a moderately low level of the vitamin
Diet of dams
Diet of progeny
4 wk. avg.1 weights of progeny
USP units/lb.
USP units/lb.
gms.
Vitamin A content of:
Survival of2 progeny
Feed/gain
Started dying at 14th day—0/10
0
1,600
0
273
Started dying at 16th day—5/10
2,400
0
244
Started dying at 21st day—1/10
4,800
0
332
Started dying at 25th day—1/10
800 1,600 2,400 4,800
800 800 800 800
407 416 407 455
9/11 10/10 10/10 10/10
2.44 2.23 2.16 2.02
1
Expressed as the weighted mean of male and female poult weights. All surviving poults fed basal diet showed gross symptoms of vitamin A deficiency. Numerator of fraction shows number of poults alive at 4 weeks. 2
dams was increased. This is especially evident in terms of length of survival before onset of mortality on the vitamin A-free basal diet and in terms of efficiency of feed utilization by the poults receiving 800 USP units of vitamin A per pound of diet. Experiment 4. Since mortality was very heavy in the poults receiving the basal diet, and no appreciable mortality occurred in those receiving 800 U S P units of vitamin A per pound of diet in Experiment 3, a further experiment was conducted to determine the carry-over of vitamin A in the progeny of the hens receiving 800, 1,600 and 2,400 USP units of vitamin A per pound of breeder diet. For this experiment, progeny from each hen t r e a t m e n t were fed the starter diet supplemented with 100, 200 and 400 USP units of stabilized vitamin A per pound. The results of the experiment, presented in Table 6, show the importance of vitamin A carry-over in young poults receiving border-line vitamin A levels. Mortality
and ataxia of vitamin A deficiency were not prevented in poults receiving 400 USP units of vitamin A per pound of starter diet or less, when their dams were fed diets containing vitamin A levels of 800 and 1,600 U S P units per pound of breeder diet, b u t were almost completely prevented under these conditions in poults which were the progeny of dams receiving 2,400 USP units of stabilized vitamin A per pound of breeder diet. Experiment 5. In the third poult experiment, graded levels of vitamin A, 200, 400, 800 and 2,400 USP units per pound of starter diet, were fed to the progeny of the hens receiving the various vitamin A treatments. Observations were made on growth and survival to eight weeks of age as well as on feed utilization. Liver storage of vitamin A was determined at 6 and 8 weeks of age in poults receiving each vitamin A treatment. These analyses were conducted, however, only on the livers of the poults which were the progeny of the hens receiving the lowest vitamin A treat-
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800
1259
VITAMIN A REQUIREMENTS OF TURKEYS TABLE 6.—Survival of progeny of hens receiving graded levels of vitamin A
Diet of dams
Diet of progeny
9 wk. avg. weights
USP units/lb. 800
USP units/lb. 100
—
All poults dead by 5 wks. of age
200
—
All poults dead by 8 wks. of age
400 100
1,799
200 400 100 200 400
1,076 1,981
1,600
5/101—2 poults showed mild ataxia All dead by 5 wks. of age.
—
5/10—surviving poults showed severe ataxia 6/10—no ataxia in survivors All dead by 7 weeks of age 6/10—showed severe ataxia 9/10—one poult showed slight ataxia
— 1,488 1,876
No. survivors/no. started.
ment. The results of the experiment are presented in Table 7. These results show that growth and feed utilization were improved as the vitamin A nutrition of the poults was improved, whether the vitamin A was supplied as carry-over from the dams or via the poult starting diet.
Growth of poults from hens receiving only 800 USP units of the vitamin per pound of breeder diet was increased by each increasing level of vitamin A up to the level of 2,400 USP units per pound of starter diet. However, when the dams received 1,600 USP units of vitamin A
TABLE 7.—Growth, feed utilization and survival of poults in Experiment 5 Vitamin A content of: Diet of dams Diet of progeny USP units/lb.
1 2
8 wk. avg. weights of1 progeny
Survival of progeny
Liver storage of vitamin A Feed/g£ 6 wks.
USP units/lb.
gms.
800
200 400 800 2,400
861 1,457 1,547 1,696
5/9 2 9/9 7/8 8/8
3.23 2.41 2.12 2.19
1,600
200 400 800 2,400
1,024 1,463 1,805 1,683
8/8 6/7 9/9 9/10
2.62 2.34 2.19 2.25
2,400
200 400 800
1,068 1,592 1,567
8/10 9/10 8/10
2.35 2.35 2.18
4,800
200 400 800 2,400
1,109 1,691 1,640 1,782
6/9 8/9 8/9 8/8
2.57 2.17 2.05 2.20
Weighted means of males and females. No. surviving to eight weeks/no. started.
8 wks.
USP units per gram of liver 0 0 0 0 0.7-1.8 0.4-0.6 23-30 26-35
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2,400
Survival
1260
G. S. STOEWSAND AND M . L. SCOTT
TABLE 8.—Vitamin A requirement of poults hatched from hens receiving a commercial breeder diet Vitamin A content of poult starting
Liver vitamin A 8 wk. weighted mean weight
Feed/
;n
Week analys£s
Per gram
Per
Hver
Blood uric acid at 6 wks.1
were made USP units/lb. 200
gms. 8352
USP units
USP units
0 0 0
0 0 0 0 0 0 0
10.58 + 0.46
10.5 12.2 22.5 48.8
10.04 + 0.72
15.4 19.8 35.8 61.2
.32 + 0.91
1,617
2.09
0 0 0 0
1,000
1,627
2.19
0.9 0.9 1.2 1.3
1,200
1,584
2.04
2,400
1,614
2.03
9.1 16.7 13.8 34.0
4.4
+0.51
169 249 289
1 Averages of 10 blood uric acid determinations per treatment, except in lot receiving 200 USP units A/lb., where only 8 poults were alive at 6 weeks of age. 2 Only two poults alive at 8 weeks in this lot. Thirty poults per treatment at the start of the experiment. No mortality in the other lots. 3 Std. error of the mean.
per pound of breeder diet, or more, the requirement of their progeny for vitamin A for optimum growth and efficiency of feed utilization did not exceed 800 U S P units per pound of poult starting diet. Experiment 6. Experiments 3, 4 and 5 indicated the requirements of poults from hens receiving various levels of vitamin A. Nevertheless, it was considered desirable to determine the requirements of poults hatched from eggs laid by hens receiving a commercial turkey breeder diet. The experiment was conducted with duplicate lots of 15 poults per lot receiving 200, 800, 1,000, 1,200, and 2,400 USP units of vitamin A per pound of diet. Liver vitamin A analyses were conducted on two poults from each t r e a t m e n t a t 3, 4, 5 and 8 weeks of age. Blood uric acid
determinations were made on ten poult per t r e a t m e n t at 6 weeks of age, according to the method of Brown (1945). The results of the experiment, presented in Table 8, show t h a t the minimum vitamin A requirement of young poults for growth under the conditions of this experiment, was no greater than 800 USP units per pound of diet. This level of vitamin A, however, provided no carry-over of vitamin A in the livers of the poults. Vitamin A at 1,000 and 1,200 USP units per pound of diet, produced minimal liver storage. On the other hand, the 2,400 USP unit level of vitamin A per pound of poult diet produced an appreciable increase in liver storage of vitamin A. Vitamin A liver storage generally increased as the poults grew older. This observation con-
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800
mg. % 12.0 ± 0 . 7 6 3
V I T A M I N A R E Q U I R E M E N T S OP T U R K E Y S
DISCUSSION Upon supplementing a low-vitamin A turkey breeder diet with stabilized vitamin A, it was found t h a t the minimum vitamin A requirement was about 1,200 USP units per pound of diet. This is approximately equivalent to t h a t found by Hill et al. (1961) to be required b y laying and breeding chickens, and is much lower than the requirements previously indicated (Titus, 1939; N A S - N R C Bulletin 301, 1954). The vitamin A content of the eggs and carry-over in the poults increased with increasing levels of vitamin A in the breeding diet. Only in hens receiving 4,800 USP units of vitamin A per pound of diet was the vitamin A content of the eggs maintained at a high level throughout the entire experimental period. In poults fed vitamin A-deficient starting diets, the carry-over of vitamin A was demonstrated to be directly relited to the vitamin A treatments of the dams. Progeny of hens receiving each increment of vitamin A showed increasingly better survival and growth on the deficient starting diets. Thus, although normal egg production,
hatchability and maintenance of the breeders was obtained with vitamin A levels of 1,200 USP units per pound of breeder diet, levels of 2,400-4,800 USP units of stabilized vitamin A per pound of diet produced marked improvement in the carry-over reserves of vitamin A in the progeny. Decision as to the minimum vitamin A requirement of young poults depends upon whether the criterion of optimum requirement is based upon growth and feed utilization alone, or also takes into consideration liver storage and blood uric acid levels. Storage of vitamin A in the liver certainly appears to be desirable since under conditions of little or no liver storage, stresses and diseases may precipitate vitamin A deficiency (Erasmus, Scott and Levine, 1960). Furthermore, as first indicated b y Elvehjem and Neu (1932), high blood uric acid levels are indicative of insufficient vitamin A in the diet to maintain maximum integrity of the epithelium of the kidney tubules and probably of the gastro-intestinal tract. Thus, in poults which are the progeny of hens receiving 1,600 U S P units of vitamin A per pound of diet or more, and under excellent environmental conditions, a dietary level of 800 U S P units of stabilized vitamin A per pound of poult starter diets has been shown to be sufficient for optimum growth and efficiency of feed utilization. However, a vitamin A level of approximately 2,400 USP units per pound of diet was needed in order to produce satisfactory liver storage of vitamin A and minimum blood uric acid levels. The minimum requirement of 800 U S P units per pound of poult diet is slightly higher t h a n the level of 600 USP units of stabilized vitamin A found by Hill et al. (1961) to be required by starting chicks. Since recent work in our laboratory (Stoewsand and Scott, 1960) shows t h a t the vitamin A requirement is increased by
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firms t h a t previously made by Gurcay et al. (1950). Blood uric acid levels decreased with increasing vitamin A levels, reaching the lowest level only with the highest vitamin A treatment. Blood uric acid levels of normal poults receiving practical commercial rations were found to be approximately 4-5 m g . % . Thus, the minimum vitamin A requirement of young poults for minimal liver storage of the vitamin is approximately 1,000-1,200 USP units and the minimum requirement for lowest uric acid blood levels is greater than 1,200, and m a y be as high as 2,400 USP units of vitamin A per pound of diet, even when a stabilized source of the vitamin is used.
1261
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G. S. STOEWSAND AND M. L. SCOTT
increasing the protein content of the diet, it is possible that the higher minimum vitamin A requirement of poults, as compared to chicks, is due to the higher protein content of the poult starting diet. SUMMARY
ACKNOWLEDGEMENTS
The authors are indebted to Distillation Products Industries, Rochester, N. Y., for financial assistance and for the vitamin A preparation, PGB-250, used in Experiments 1, 2, 3, 4 and 5; to Stabilized Vita-
REFERENCES Brown, H., 1945. The determination of uric acid in human blood. J. Biol. Chem. 158: 601-608. Elvehjem, C. A., and V. F. Neu, 1932. Studies in vitamin A avitaminosis in the chick. J. Biol. Chem. 97: 71-82. Erasmus, J., M. L. Scott and P. P. Levine, 1960. A relationship between coccidiosis and vitamin A nutrition in chicks. Poultry Sci. 39: 565-572. Gurcay, R., R. V. Boucher and E. W. Callenbach, 1950. Utilization of vitamin A by turkey poults. I. Crystalline carotene, crystalline vitamin A acetate and "black cod" liver oil. J. Nutrition, 41:565-582. Hill, F. W., M. L. Scott, L. C. Norris and G. F. Heuser, 1961. Reinvestigation of the vitamin A requirements of laying and breeding hens and their progeny. Poultry Sci. 40: 1245-1254. National Academy of Sciences-National Research Council, 1954. Nutrient requirements for poultry. Publication 301. Scott, H. M., 1937. Turkey production in Kansas. Kansas Sta. Coll. Bull. 276. Scott, M. L., F. W. Hill, L. C. Norris, G. F. Heuser, R. E. Reynolds, E. H. Parsons, Jr. and H. E. Butters, 1957. New information on the vitamin A requirements of chickens, ducks and pheasants. Proc. Cornell Nutr. Conf., pp. 132-136. Stoewsand, G. S., and M. L. Scott, 1960. An interrelationship between vitamin A requirement and the protein level in the chick diet. Poultry Sci. 39: 1297-1298. Titus, H. W., 1939. Practical nutritive requirements of poultry. U.S.D.A. Yearbook of Agric, p. 818. Van Reen, R., M. W. Taylor and W. C. Russell, 1951. The vitamin A requirement of the turkey poult fed a purified diet. J. Nutrition, 43: 235— 244. Wharton, F. D., L. D. Matterson, H. M. Scott and C. I. Bliss, 1949. The vitamin A requirement of growing turkeys. J. Nutrition, 39: 543-554. Wilgus, H. S., 1940. Experiments show that turkey poults need four times as much vitamin A as do chicks. Colorado Farm Bull. 2(1): 3.
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The results presented in this report show: (1) 1,200 USP units of stabilized vitamin A per pound of turkey breeder diet were sufficient for optimum egg production, hatchability of fertile eggs and maintenance of the breeding hens; (2) however, 4,800 USP units of vitamin A per pound of breeder diet were required in order to maintain the vitamin A content of the eggs at high levels over a prolonged period and to produce appreciable carry-over of vitamin A in the progeny at hatching, such that the poults could survive and grow normally to 8-9 weeks of age on marginal levels of vitamin A in the poult starting diet; (3) 800 USP units of stabilized vitamin A per pound of poult starting diet were required for normal growth and feed utilization of progeny of turkey hens receiving 1,600 USP units or more of vitamin A in the turkey breeder diet; (4) however, a vitamin A level of approximately 2,400 USP units per pound of starter diet was needed in order to produce satisfactory liver storage of vitamin A and minimum blood uric acid levels.
mins, Inc., Garfield, N. J., for financial assistance and for the vitamin A preparation, Perma-Dual, used in Experiment 6; and to Hoffmann-La Roche, Inc., Nutley, N. J., for financial assistance.