- Email: [email protected]
Influence of Dietary Tallow on the Utilization of Calcium by the Laying Hen*
Influence of Dietary Tallow on the Utilization of Calcium by the Laying Hen* J. R. H U N T , J. R. A I T K E N AND W. G. HTJNSAKER Canada Department of Agriculture, Ottawa, Ont. (Received for publication October 31, 1960)
T
On the other hand, Boyd el al. (1932) noted that dietary fats increased calcium utilization in rats through its acidifying effect on the intestinal tract. Jones (1940) observed that addition of fat to a fat-free rachitogenic diet increased calcification. He also attributed the beneficial effect of fat to its influence on intestinal p H . Studies on humans by Steggerda and Mitchell (1951) demonstrated that high levels of milk fat did not interfere with calcium utilization, while Fugua and P a t t o n (1953) observed t h a t neither animal nor vegetable fat in the diet influenced calcium balance in humans. The
two experiments
reported
here
* Cont. No. 52, Animal Research Institute, Research Branch, Ottawa, Ont.
were designed to test whether fat in the diet affects calcium utilization in the laying hen. EXPERIMENT Experiment 1. In the first experiment the effects of adding tallow to a diet low in calcium (1.75%) and to a diet considered to be adequate in calcium (2.25%) were measured in terms of egg production, specific gravity of the eggs and level of calcium in the blood of laying hens. Three levels of fat (0, 3 % and 6%) were tested with each diet, giving 6 treatments in all. Additions of tallow or limestone to the basal diet (Table 1) were made at the expense of wheat and soybean oil meal to keep the protein content of all diets constant. Each treatment was imposed on 32 Single Comb White Leghorn hens in individual cages for a period of 112 days. The hens were 10 months old and had been treated uniformly before being placed on test. Treatments were allotted to the birds in a random manner. Before starting the treatments, specific gravity of all eggs laid by each hen over a two-week period, and plasma-calcium of each individual hen were determined to establish pretest values for these criteria. During the test, egg production was recorded for each hen and specific gravity was measured on 5 days' eggs each week by the flotation method using salt solutions varying in specific gravity from 1.066 to 1.102 in increments of 0.004. Plasma-calcium levels were determined individually on 12 randomly selected
1193
Downloaded from http://ps.oxfordjournals.org/ at D H Hill Library - Acquis Dept S on March 18, 2015
H E use of tallow in laying rations has prompted some concern over its possible effect on calcium utilization, as reflected in egg shell quality. The possibility t h a t fat in the feed may adversely affect calcium utilization is suggested by the results of published experiments with laying hens, chicks and rats. Hochreich el al. (1958) observed a decrease in shell thickness when 6.6% yellow grease was incorporated in a laying ration fed to hens receiving oyster shell ad libitum. Using chicks, Pepper et al. (1955) and Edwards el al. (1958) demonstrated an increase in calcium requirement when fat was incorporated in the diet. There are also reports that calcium utilization in rats decreases with increasing levels of dietary fat (French, 1942; and French and Elliot, 1943).
1194
J. R. H U N T , J. R. A I T K E N AND W.
TABLE 1.—Composition oj basal ration, Experiment 1
41.5 10.0 30.0 3.0 6.6 1.0 3.0 1.40 2.98 0.40
Vit. A Suppl. (10,000 IU/lb.) Vit. D s Suppl. (750,000 ICU/lb.) Riboflavin Suppl. (4 gm./lb.) MnS0 4 (70%)
Gm./lOO lb. 10 15 6 6
Calculated Analysis Protein, % Productive energy, Cal./lb. Calcium, % Phosphorus, %
15.0 788 1.75 0.66
birds from each treatment except those receiving 3 % tallow in the diet. Determinations were made at 4-week intervals using a modification of the method of P a t t o n and Reeder (1956). Results. The results of this experiment are presented in Table 2. Performance on the low-calcium diet was significantly different from t h a t on the high-calcium diet, in that egg production was lower and specific gravity of the eggs was lower. Differences in plasma-calcium levels were not significant. The addition of fat to either diet had no significant effect on performance. Even on the low-calcium diet, fat did not depress TABLE 2.—Performance Calcium level, % Supplementary tallow, % Egg production (survivor), % Feed/doz. eggs, lb. Mean specific gravity, final period* Mean plasma calcium, final period, mg-%
Duration of the test was 78 days. In addition to records on egg production, specific gravity of eggs, and feed consumption, bone ash was determined at end of test on tibia removed from 10 birds on each treatment except t h a t receiving 12% tallow. Calcium balance was also determined for two 10-day periods during the test, the first commencing 2 days after the birds were placed on treatment, and the second 38 days later. Each block of
of kens fed different levels of calcium and tallow
1.75 0
1.75 3
1.75 6
2.25 0
2.25 3
2.25 6
54.9 6.29 81
58.6 6.05 81
65.2 5.27 81
62.8 5.80 84
69.3 5.24 83
63.2 5.76 84
22.4
—
22.3
24.6
—
26.8
* Expressed as (specific gravityX 103) —103.
Downloaded from http://ps.oxfordjournals.org/ at D H Hill Library - Acquis Dept S on March 18, 2015
Ground wheat Pulverized oats Ground barley Fish meal (65% protein) Soybean oil meal (44% protein) Dried skim milk Dehydrated alfalfa meal Steamed bone meal Ground limestone Iodized salt
HUNSAKER
egg production or specific gravity of the eggs, as would be expected if it were interfering with calcium absorption. Instead, egg production appeared to be stimulated by the presence of tallow in the low-calcium diet, but the differences did not prove to be statistically significant. Experiment 2. In this experiment a higher level of fat was fed (0, 6 and 12%) as well as 6 % tallow as the calcium soap. Tallow was added to the basal diet (Table 3) at the expense of sucrose, so t h a t the protein level of the diet was unaffected. Calciu m soap was added at the expense of sucrose and limestone so t h a t both protein and calcium levels were unaltered. T h e calcium content of all diets was 1.8%. Hens in laying batteries were arbitrarily divided into blocks of 4 birds housed in adjoining individual cages. Each diet was randomly assigned to six blocks of 4 birds. The hens were of the same strain as those employed in the first experiment, and had been treated uniformly before being placed on test at 12 months of age.
%
Ingredients
G.
1195
T A L L O W AND CALCIUM UTILIZATION
Results. The results of this experiment are shown in Table 4. Egg production was affected only when tallow was fed as the calcium soap. This drop in production was probably a result of the 2 5 % reduction in food consumption. Neither specific gravity of the eggs nor bone ash were significantly affected by adding fat to the diet. Calcium retention appeared to be reduced on diets containing tallow in both trial periods, but the reduction did not prove to be statistically significant. The figures for calcium retention obtained in this experiment are considerably higher than those obtained by other workers (Common and Hale, 1941; and Mueller, 1959). These high figures may have been the result of loss of liquid from the fecal material, which could not be entirely prevented with the facilities employed. There was also some slight feed wastage, which would tend to give erroneously high retention values. DISCUSSION Dietary fat could affect absorption of calcium if free fatty acids and calcium ions
TABLE 3.—Composition of basal ration, Experiment 2
%
Ingredients
10.0 20.0 35.3 2.0 2.0 9.3 1.5 1.5 1.5 0.63 0.4
Ground barley Pulverized oats Ground wheat Fish meal (65% protein) Meat meal (50% protein) Soybean oil meal (44% protein) Skim milk powder Dehydrated cereal grass Dehydrated alfalfa meal Dicalcium phosphate Iodized salt Manganese sulfate Vit. A (10,000 IU/gm.) Vit. D 3 (750,000 ICU/lb.) Riboflavin supplement (4 gm./lb.)
Gm./lOO lb. 6 10 41 10
Total Calculated Analysis Protein, % Productive energy, Cal./lb. Calcium, % Phosphorus, %
84.2% 15.4 706 0.61 0.61
Experimental rations, Experiment 2 Ration Ingredients A 84.2 Basal Sucrose 12.4 Tallow — Tallow as calcium soap — 3.39 Ground limestone
B 84.2 6.4 6.0
—
3.39
C 84.2 0.4 12.0
—
3.39
D 84.2 6.6
— 9.23
—
NOTE: 9.23% calcium soap supplies 1.18% calcium and 6.0% fat.
were present at the right p H for insoluble calcium soap formation in the area of calcium absorption. As French and Elliot (1943) point out, the formation of readily absorbable bile-fatty acid-calcium complexes must also be considered. The effect of free fatty acid was tested by feeding the calcium soap of tallow on the assumption t h a t the p H of the gizzard was between 2.6 and 4.0 (Sturkie, 1954) and would dissociate the soap to the free fatty acid. Dissociation of the calcium tallow, in vitro, occurred between p H 4.8 and 6.4. The p H of the duodenum and
Downloaded from http://ps.oxfordjournals.org/ at D H Hill Library - Acquis Dept S on March 18, 2015
4 birds was treated as a single replicate for the calcium balance studies, and excreta collections and feed consumption were pooled within each replicate block. The balance trials were started and stopped a t the same hour of the day. No markers were employed and no a t t e m p t was made to determine whether an egg was present in the uterus at the time of starting or ending the trial. Calcium contents of feed and feces were determined by a modification of the method of Corley and Denis (1925) and egg shell calcium was determined by the method of Tyler and Geake (1953). A standard value of 31 mg. (Romanoff and Romanoff, 1949) was allotted to each egg for the calcium content of yolk and albumin.
1196
J. R. H U N T , J. R. A I T K E N AND W. G. HUNSAKF.R
TABLE 4.—The influence of tallow and calcium soap in Hie diet of the hen on calcium balance, feed consumption, egg shell quality, bone ash, and egg production Supplement to basal Criterion measured None Mean calcium balance,1 Period l 2 Period 2 Feed consumption1,
2 3
12% tallow
6% tallow as Ca soap
0.227 0.321
0.206 0.287
0.223 0.149
Period 1 Period 2
112 109
107 96
104 93
74 79
Mean specific gravity3, Period 1 Period 2
83 83
82 81
82 80
79 81
Bone ash, %
61.94
59.94
Egg production, hen days, %
56.0
53.7
— 55.2
59.58 45.2
Gm./bird/day. Period 1 was from 0-10 days on test and Period 2 from 38-48 davs on test. Expressed as (specific gravityX 103) —103.
jejunum is between 5.6 and 6.3 (Sturkie, 1954) and insoluble calcium soaps might have re-formed in these portions of the gut. From the absence of a measurable effect on calcium balance it is concluded that if insoluble soaps did form they were changed to an absorbable bile-fatty acid-calcium complex, or t h a t other mechanisms aided in the absorption of calcium. SUMMARY
The effect of dietary tallow on the utilization of calcium was tested by means of its effect on egg shell formation and calcium balance. Shell quality, indicated by specific gravity of the eggs, was not affected by the addition of tallow to the diet at levels up to 1 2 % . Shell quality was depressed by low dietary calcium, b u t tallow did not augment this effect. Calcium retention in laying hens was reduced more by 6 % calcium soap in the diet than by 12% tallow, but in neither case did the reduction prove to be statistically significant. Bone ash was not affected by 6 % tallow or 6 % calcium soap in the diet but the inclusion
of calcium soap or decreasing the calcium in the diet to 1.75% significantly depressed egg production. ACKNOWLEDGMENT
The authors are indebted to Mr. E. Moreau for technical assistance in various phases of this work. REFERENCES Boyd, O. F., C. L. Crum and J. R. Lyman, 1932. The absorption of calcium soaps and the relationship of dietary fat to calcium utilization in the white rat. J. Biol. Chem. 95: 29-41. Common, R. H., and R. W. Hale, 1941. Observations on the mineral metabolism of pullets. VI. The mobilization of body calcium for shell formation. J. Agr. Sci. 31:415-437. Corley, R. C , and W. Denis, 1925. The determination of calcium in tissue, feces and milk. J. Biol. Chem. 66: 601-608. Edwards, H. M., W. S. Dunahoo and H. L. Fuller, 1958. Effect of protein and calorie content of the diet on the calcium requirement of chickens. Poultry Sci. 37: 1201. French, C. E., 1942. The interrelationship of calcium and fat utilization in the growing albino rat. J. Nutrition, 23:375-384. French, C. E., and R. F. Elliot, 1943. The interrelationship of calcium and fat utilization. J. Nutrition, 25: 17-21. Fugua, M. E., and M. B. Palton, 1953. Effect of
Downloaded from http://ps.oxfordjournals.org/ at D H Hill Library - Acquis Dept S on March 18, 2015
1
0.395 0.371
6% tallow
T A L L O W AND CALCIUM UTILIZATION
Pepper, W. F., S. J. Slinger and I. Motzok, 1955. The effect of animal fat on the calcium and phosphorus requirements of the chicks. Poultry Sci. 34: 1216. Romanoff, A. L., and A. J. Romanoff, 1949. The Avian Egg. John Wiley and Sons, Inc., New York. Steggerda, F. R., and H. H. Mitchell, 1951. The calcium balance of adult human subjects on high- and low-fat (butter) diets. J. Nutrition, 45: 201-211. Sturkie, P. D., 1954. Avian Physiology. Comstock Pub. Co., Ithaca, N. Y. Tyler, C , and F. H. Geake, 1953. Studies on egg shells. III. Some physical and chemical characteristics of the egg shells of domestic hens. J. Sci. Food Agr. 12:587-596.
Relation of Serum Vitamin A Activity Levels of Hens to Reserves in Their Progeny 1 R O B E R T L. S Q U I B B
Disease and Environmental Stress Laboratories, Rutgers, the Stale University, New Brunswicji, New Jersey (Received for publication October 31, 1960)
T
H E physiology of vitamin A activity storage in the chick has been studied by Rubin and Bird (1941). During the period of development, reserves are accumulated in the egg via the blood stream of the hen and are utilized in p a r t by the growing embryo. Prior to hatching, excess yolk is drawn into the body cavity where it is absorbed from the sac over a 10-day period (Heywang, 1940). Bearse and Miller (1937) and Baumann et al. (1939) have correlated vitamin A reserves of the newborn chick to the content of this essential in the hen's diet.
The present studies were initiated to evaluate parental vitamin A stores in the chick, and to establish the relationship of the vitamin A activity of the hen's serum to these reserves. Variations between and 1 Paper of the Journal Series, Rutgers, the State University, New Brunswick, New Jersey.
within hens in transfer of vitamin A activity to the chick were observed. METHODS AND RESULTS Experiment 1.—Estimation of Parental Vitamin A Activity Reserves of Chicks. Vitamin A and total carotenoids transferred by the hen to the chick via the egg were estimated by determining the content of these nutrients in the sera, livers and yolk sacs of 25 newly hatched White Leghorn chicks obtained from a local hatchery. The chicks were from a breeder flock fed a diet containing a minimum of 3,000 IU's of vitamin A per pound of feed. The birds were weighed and bled by heart puncture, then sacrificed and the yolk sacs and livers removed and weighed. Vitamin A and total carotenoids were determined by the method of Bessey et al. (1946).
Downloaded from http://ps.oxfordjournals.org/ at D H Hill Library - Acquis Dept S on March 18, 2015
three levels of fat intake on calcium metabolism. J. Am. Dietet. Assoc. 29: 1010-1013. Hochreich, H. J., C. R. Douglas, I. H. Kidd and R. H. Harms, 1958. The effect of dietary protein and energy levels upon production of Single Comb White Leghorn hens. Poultry Sci. 37: 949953. Jones, J. H., 1940. The influence of fat on calcium and phosphorus metabolism. J. Nutrition, 20: 367-376. Mueller, W. J., 1959. The effect of environmental temperature and humidity on the calcium balance and serum calcium of laying pullets. Poultry Sci. 38: 1296-1301. Patton, J., and W. Reeder, 1956. New indicator for titration of calcium with (ethylenedinitrilo) tetraacetate. Anal. Chem. 28: 1026-1028.
1197
T
On the other hand, Boyd el al. (1932) noted that dietary fats increased calcium utilization in rats through its acidifying effect on the intestinal tract. Jones (1940) observed that addition of fat to a fat-free rachitogenic diet increased calcification. He also attributed the beneficial effect of fat to its influence on intestinal p H . Studies on humans by Steggerda and Mitchell (1951) demonstrated that high levels of milk fat did not interfere with calcium utilization, while Fugua and P a t t o n (1953) observed t h a t neither animal nor vegetable fat in the diet influenced calcium balance in humans. The
two experiments
reported
here
* Cont. No. 52, Animal Research Institute, Research Branch, Ottawa, Ont.
were designed to test whether fat in the diet affects calcium utilization in the laying hen. EXPERIMENT Experiment 1. In the first experiment the effects of adding tallow to a diet low in calcium (1.75%) and to a diet considered to be adequate in calcium (2.25%) were measured in terms of egg production, specific gravity of the eggs and level of calcium in the blood of laying hens. Three levels of fat (0, 3 % and 6%) were tested with each diet, giving 6 treatments in all. Additions of tallow or limestone to the basal diet (Table 1) were made at the expense of wheat and soybean oil meal to keep the protein content of all diets constant. Each treatment was imposed on 32 Single Comb White Leghorn hens in individual cages for a period of 112 days. The hens were 10 months old and had been treated uniformly before being placed on test. Treatments were allotted to the birds in a random manner. Before starting the treatments, specific gravity of all eggs laid by each hen over a two-week period, and plasma-calcium of each individual hen were determined to establish pretest values for these criteria. During the test, egg production was recorded for each hen and specific gravity was measured on 5 days' eggs each week by the flotation method using salt solutions varying in specific gravity from 1.066 to 1.102 in increments of 0.004. Plasma-calcium levels were determined individually on 12 randomly selected
1193
Downloaded from http://ps.oxfordjournals.org/ at D H Hill Library - Acquis Dept S on March 18, 2015
H E use of tallow in laying rations has prompted some concern over its possible effect on calcium utilization, as reflected in egg shell quality. The possibility t h a t fat in the feed may adversely affect calcium utilization is suggested by the results of published experiments with laying hens, chicks and rats. Hochreich el al. (1958) observed a decrease in shell thickness when 6.6% yellow grease was incorporated in a laying ration fed to hens receiving oyster shell ad libitum. Using chicks, Pepper et al. (1955) and Edwards el al. (1958) demonstrated an increase in calcium requirement when fat was incorporated in the diet. There are also reports that calcium utilization in rats decreases with increasing levels of dietary fat (French, 1942; and French and Elliot, 1943).
1194
J. R. H U N T , J. R. A I T K E N AND W.
TABLE 1.—Composition oj basal ration, Experiment 1
41.5 10.0 30.0 3.0 6.6 1.0 3.0 1.40 2.98 0.40
Vit. A Suppl. (10,000 IU/lb.) Vit. D s Suppl. (750,000 ICU/lb.) Riboflavin Suppl. (4 gm./lb.) MnS0 4 (70%)
Gm./lOO lb. 10 15 6 6
Calculated Analysis Protein, % Productive energy, Cal./lb. Calcium, % Phosphorus, %
15.0 788 1.75 0.66
birds from each treatment except those receiving 3 % tallow in the diet. Determinations were made at 4-week intervals using a modification of the method of P a t t o n and Reeder (1956). Results. The results of this experiment are presented in Table 2. Performance on the low-calcium diet was significantly different from t h a t on the high-calcium diet, in that egg production was lower and specific gravity of the eggs was lower. Differences in plasma-calcium levels were not significant. The addition of fat to either diet had no significant effect on performance. Even on the low-calcium diet, fat did not depress TABLE 2.—Performance Calcium level, % Supplementary tallow, % Egg production (survivor), % Feed/doz. eggs, lb. Mean specific gravity, final period* Mean plasma calcium, final period, mg-%
Duration of the test was 78 days. In addition to records on egg production, specific gravity of eggs, and feed consumption, bone ash was determined at end of test on tibia removed from 10 birds on each treatment except t h a t receiving 12% tallow. Calcium balance was also determined for two 10-day periods during the test, the first commencing 2 days after the birds were placed on treatment, and the second 38 days later. Each block of
of kens fed different levels of calcium and tallow
1.75 0
1.75 3
1.75 6
2.25 0
2.25 3
2.25 6
54.9 6.29 81
58.6 6.05 81
65.2 5.27 81
62.8 5.80 84
69.3 5.24 83
63.2 5.76 84
22.4
—
22.3
24.6
—
26.8
* Expressed as (specific gravityX 103) —103.
Downloaded from http://ps.oxfordjournals.org/ at D H Hill Library - Acquis Dept S on March 18, 2015
Ground wheat Pulverized oats Ground barley Fish meal (65% protein) Soybean oil meal (44% protein) Dried skim milk Dehydrated alfalfa meal Steamed bone meal Ground limestone Iodized salt
HUNSAKER
egg production or specific gravity of the eggs, as would be expected if it were interfering with calcium absorption. Instead, egg production appeared to be stimulated by the presence of tallow in the low-calcium diet, but the differences did not prove to be statistically significant. Experiment 2. In this experiment a higher level of fat was fed (0, 6 and 12%) as well as 6 % tallow as the calcium soap. Tallow was added to the basal diet (Table 3) at the expense of sucrose, so t h a t the protein level of the diet was unaffected. Calciu m soap was added at the expense of sucrose and limestone so t h a t both protein and calcium levels were unaltered. T h e calcium content of all diets was 1.8%. Hens in laying batteries were arbitrarily divided into blocks of 4 birds housed in adjoining individual cages. Each diet was randomly assigned to six blocks of 4 birds. The hens were of the same strain as those employed in the first experiment, and had been treated uniformly before being placed on test at 12 months of age.
%
Ingredients
G.
1195
T A L L O W AND CALCIUM UTILIZATION
Results. The results of this experiment are shown in Table 4. Egg production was affected only when tallow was fed as the calcium soap. This drop in production was probably a result of the 2 5 % reduction in food consumption. Neither specific gravity of the eggs nor bone ash were significantly affected by adding fat to the diet. Calcium retention appeared to be reduced on diets containing tallow in both trial periods, but the reduction did not prove to be statistically significant. The figures for calcium retention obtained in this experiment are considerably higher than those obtained by other workers (Common and Hale, 1941; and Mueller, 1959). These high figures may have been the result of loss of liquid from the fecal material, which could not be entirely prevented with the facilities employed. There was also some slight feed wastage, which would tend to give erroneously high retention values. DISCUSSION Dietary fat could affect absorption of calcium if free fatty acids and calcium ions
TABLE 3.—Composition of basal ration, Experiment 2
%
Ingredients
10.0 20.0 35.3 2.0 2.0 9.3 1.5 1.5 1.5 0.63 0.4
Ground barley Pulverized oats Ground wheat Fish meal (65% protein) Meat meal (50% protein) Soybean oil meal (44% protein) Skim milk powder Dehydrated cereal grass Dehydrated alfalfa meal Dicalcium phosphate Iodized salt Manganese sulfate Vit. A (10,000 IU/gm.) Vit. D 3 (750,000 ICU/lb.) Riboflavin supplement (4 gm./lb.)
Gm./lOO lb. 6 10 41 10
Total Calculated Analysis Protein, % Productive energy, Cal./lb. Calcium, % Phosphorus, %
84.2% 15.4 706 0.61 0.61
Experimental rations, Experiment 2 Ration Ingredients A 84.2 Basal Sucrose 12.4 Tallow — Tallow as calcium soap — 3.39 Ground limestone
B 84.2 6.4 6.0
—
3.39
C 84.2 0.4 12.0
—
3.39
D 84.2 6.6
— 9.23
—
NOTE: 9.23% calcium soap supplies 1.18% calcium and 6.0% fat.
were present at the right p H for insoluble calcium soap formation in the area of calcium absorption. As French and Elliot (1943) point out, the formation of readily absorbable bile-fatty acid-calcium complexes must also be considered. The effect of free fatty acid was tested by feeding the calcium soap of tallow on the assumption t h a t the p H of the gizzard was between 2.6 and 4.0 (Sturkie, 1954) and would dissociate the soap to the free fatty acid. Dissociation of the calcium tallow, in vitro, occurred between p H 4.8 and 6.4. The p H of the duodenum and
Downloaded from http://ps.oxfordjournals.org/ at D H Hill Library - Acquis Dept S on March 18, 2015
4 birds was treated as a single replicate for the calcium balance studies, and excreta collections and feed consumption were pooled within each replicate block. The balance trials were started and stopped a t the same hour of the day. No markers were employed and no a t t e m p t was made to determine whether an egg was present in the uterus at the time of starting or ending the trial. Calcium contents of feed and feces were determined by a modification of the method of Corley and Denis (1925) and egg shell calcium was determined by the method of Tyler and Geake (1953). A standard value of 31 mg. (Romanoff and Romanoff, 1949) was allotted to each egg for the calcium content of yolk and albumin.
1196
J. R. H U N T , J. R. A I T K E N AND W. G. HUNSAKF.R
TABLE 4.—The influence of tallow and calcium soap in Hie diet of the hen on calcium balance, feed consumption, egg shell quality, bone ash, and egg production Supplement to basal Criterion measured None Mean calcium balance,1 Period l 2 Period 2 Feed consumption1,
2 3
12% tallow
6% tallow as Ca soap
0.227 0.321
0.206 0.287
0.223 0.149
Period 1 Period 2
112 109
107 96
104 93
74 79
Mean specific gravity3, Period 1 Period 2
83 83
82 81
82 80
79 81
Bone ash, %
61.94
59.94
Egg production, hen days, %
56.0
53.7
— 55.2
59.58 45.2
Gm./bird/day. Period 1 was from 0-10 days on test and Period 2 from 38-48 davs on test. Expressed as (specific gravityX 103) —103.
jejunum is between 5.6 and 6.3 (Sturkie, 1954) and insoluble calcium soaps might have re-formed in these portions of the gut. From the absence of a measurable effect on calcium balance it is concluded that if insoluble soaps did form they were changed to an absorbable bile-fatty acid-calcium complex, or t h a t other mechanisms aided in the absorption of calcium. SUMMARY
The effect of dietary tallow on the utilization of calcium was tested by means of its effect on egg shell formation and calcium balance. Shell quality, indicated by specific gravity of the eggs, was not affected by the addition of tallow to the diet at levels up to 1 2 % . Shell quality was depressed by low dietary calcium, b u t tallow did not augment this effect. Calcium retention in laying hens was reduced more by 6 % calcium soap in the diet than by 12% tallow, but in neither case did the reduction prove to be statistically significant. Bone ash was not affected by 6 % tallow or 6 % calcium soap in the diet but the inclusion
of calcium soap or decreasing the calcium in the diet to 1.75% significantly depressed egg production. ACKNOWLEDGMENT
The authors are indebted to Mr. E. Moreau for technical assistance in various phases of this work. REFERENCES Boyd, O. F., C. L. Crum and J. R. Lyman, 1932. The absorption of calcium soaps and the relationship of dietary fat to calcium utilization in the white rat. J. Biol. Chem. 95: 29-41. Common, R. H., and R. W. Hale, 1941. Observations on the mineral metabolism of pullets. VI. The mobilization of body calcium for shell formation. J. Agr. Sci. 31:415-437. Corley, R. C , and W. Denis, 1925. The determination of calcium in tissue, feces and milk. J. Biol. Chem. 66: 601-608. Edwards, H. M., W. S. Dunahoo and H. L. Fuller, 1958. Effect of protein and calorie content of the diet on the calcium requirement of chickens. Poultry Sci. 37: 1201. French, C. E., 1942. The interrelationship of calcium and fat utilization in the growing albino rat. J. Nutrition, 23:375-384. French, C. E., and R. F. Elliot, 1943. The interrelationship of calcium and fat utilization. J. Nutrition, 25: 17-21. Fugua, M. E., and M. B. Palton, 1953. Effect of
Downloaded from http://ps.oxfordjournals.org/ at D H Hill Library - Acquis Dept S on March 18, 2015
1
0.395 0.371
6% tallow
T A L L O W AND CALCIUM UTILIZATION
Pepper, W. F., S. J. Slinger and I. Motzok, 1955. The effect of animal fat on the calcium and phosphorus requirements of the chicks. Poultry Sci. 34: 1216. Romanoff, A. L., and A. J. Romanoff, 1949. The Avian Egg. John Wiley and Sons, Inc., New York. Steggerda, F. R., and H. H. Mitchell, 1951. The calcium balance of adult human subjects on high- and low-fat (butter) diets. J. Nutrition, 45: 201-211. Sturkie, P. D., 1954. Avian Physiology. Comstock Pub. Co., Ithaca, N. Y. Tyler, C , and F. H. Geake, 1953. Studies on egg shells. III. Some physical and chemical characteristics of the egg shells of domestic hens. J. Sci. Food Agr. 12:587-596.
Relation of Serum Vitamin A Activity Levels of Hens to Reserves in Their Progeny 1 R O B E R T L. S Q U I B B
Disease and Environmental Stress Laboratories, Rutgers, the Stale University, New Brunswicji, New Jersey (Received for publication October 31, 1960)
T
H E physiology of vitamin A activity storage in the chick has been studied by Rubin and Bird (1941). During the period of development, reserves are accumulated in the egg via the blood stream of the hen and are utilized in p a r t by the growing embryo. Prior to hatching, excess yolk is drawn into the body cavity where it is absorbed from the sac over a 10-day period (Heywang, 1940). Bearse and Miller (1937) and Baumann et al. (1939) have correlated vitamin A reserves of the newborn chick to the content of this essential in the hen's diet.
The present studies were initiated to evaluate parental vitamin A stores in the chick, and to establish the relationship of the vitamin A activity of the hen's serum to these reserves. Variations between and 1 Paper of the Journal Series, Rutgers, the State University, New Brunswick, New Jersey.
within hens in transfer of vitamin A activity to the chick were observed. METHODS AND RESULTS Experiment 1.—Estimation of Parental Vitamin A Activity Reserves of Chicks. Vitamin A and total carotenoids transferred by the hen to the chick via the egg were estimated by determining the content of these nutrients in the sera, livers and yolk sacs of 25 newly hatched White Leghorn chicks obtained from a local hatchery. The chicks were from a breeder flock fed a diet containing a minimum of 3,000 IU's of vitamin A per pound of feed. The birds were weighed and bled by heart puncture, then sacrificed and the yolk sacs and livers removed and weighed. Vitamin A and total carotenoids were determined by the method of Bessey et al. (1946).
Downloaded from http://ps.oxfordjournals.org/ at D H Hill Library - Acquis Dept S on March 18, 2015
three levels of fat intake on calcium metabolism. J. Am. Dietet. Assoc. 29: 1010-1013. Hochreich, H. J., C. R. Douglas, I. H. Kidd and R. H. Harms, 1958. The effect of dietary protein and energy levels upon production of Single Comb White Leghorn hens. Poultry Sci. 37: 949953. Jones, J. H., 1940. The influence of fat on calcium and phosphorus metabolism. J. Nutrition, 20: 367-376. Mueller, W. J., 1959. The effect of environmental temperature and humidity on the calcium balance and serum calcium of laying pullets. Poultry Sci. 38: 1296-1301. Patton, J., and W. Reeder, 1956. New indicator for titration of calcium with (ethylenedinitrilo) tetraacetate. Anal. Chem. 28: 1026-1028.
1197