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Calcium, Phosphorus, and Vitamin D Interrelationships in the Nutrition of the Growing Chick*
Calcium, Phosphorus, and Vitamin D Interrelationships in the Nutrition of the Growing Chick* J. S. CARVER, ROBERT JOHN EVANS, AND JAMES MCGINNIS Divisions of Poultry and Chemistry, Washington Agricultural Experiment Station, Pullman, Washington (Received for publication January 5, 1946)
T
HE shortage of animal protein concentrates during the war years and their replacement by vegetable protein supplements containing much less calcium and phosphorus accompanied by a shortage of bone meal made it desirable to further study the interrelationships of calcium, phosphorus and vitamin D in chick nutrition. Bethke et al. (1929) and Hart et al. (1930) showed the optimum calcium: phosphorus ratio to be between 3:1 and 4:1 when low levels of vitamin D were fed. When larger amounts of vitamin D were added to the diet, Hart et al. (1930) observed less difference between various calcium: phosphorus ratios and found that lower levels of calcium and phosphorus could be used. Nowatarski and Bird (1943) found that smaller amounts of vitamin D were required when the calcium and phosphorus levels in the diet were increased. Evans and Brant (1945) using turkey poults secured similar results. They reported that lower levels of calcium and phosphorus could be used when high levels of vitamin D were fed and that when higher levels of calcium and phosphorus were used con* Published as Scientific Paper No. 667, College of Agriculture and Agricultural Experiment Stations, State College of Washington, Pullman, Washington.
siderably lower levels of vitamin D gave good growth and calcification. The object of this study was to determine the influence of the level of vitamin D and the calcium:phosphorus ratio on the growth and calcification in chicks. EXPERIMENTAL Nine hundred day-old White Leghorn cockerels were divided into forty-five groups of twenty each. The chicks were brooded in electric battery brooders for four weeks. The percentage composition of the basal diet used was: ground wheat 40.0, ground yellow corn 30.9, herring fish meal 3.0, solvent process soybean oil meal 19.0, dehydrated alfalfa meal 5.0, riboflavin concentrate 1.0, salt 1.0, choline chloride 0.1, manganese sulfate 0.0125. All diets contained 19 percent protein. Calcium and phosphorus were supplied by oyster shell flour and dicalcium phosphate. These were added in varying amounts to give the levels of calcium and phosphorus indicated in Table 1. The vitamin D added to the different diets at the levels indicated in Table 1 was a corn oil solution of irradiated 7-dehydrocholesterol. The chicks and feed were weighed weekly. At four weeks of age all of the chicks remaining were killed and the left tibia of each chick was removed and cleaned of
294
CALCIUM, PHOSPHORUS, AND VITAMIN D. INTERRELATIONSHIPS
295
TABLE 1.—The effect of vitamin D, level of phosphorus, and calcium:phosphorus ratio on average weight and percentage of bone ash* at four weeks Phosphorus level Ca:P
Vitamin D
A.O.A.C. units/lOO gm. diet
Body wt.
Bone ash
Body wt.
Bone . ash
Body wt.
gm.
%
gm.
%
gm.
146 0
161
239
250
263 41.2
247
205
36.7 271
247
1:1 35.3 316
280
40.5
41.0 290
2:1 243
45.2 255
48.4
47.3 286
299
3:1 43.2
36.8 252
266
47.0
46.7 263
4:1 41.7
36.6 306
292
45.3 312
303
1:1 44.2 298
45.0 304
44.6
45.9 293
313
2:1 44.8 262
46.1 269
47.0
47.1 270
286
3:1 43.6 227
60
39.7
38.7
36.5
38.9
60
268
244
267
60
269 37.1
36.2
34.9
60
28.2
4:1 215
20
%
174
263
263
30.5
20
gm.
3:1 241
20
Bone ash
30.4
34.9
32.9
20
Body wt..
2:1 247
0
%
178 26.5
32.4
0
Bone ash
1:1 25.8
0
1-0%
0.8%
0.6%
0.5% Ratio
46.3
46.8
46.7
251
233
4:1 42.9
44.9
45.8
* Least significant difference was 1.3 for bone ash.
adhering tissue for the bone ash determination. The tibiae were extracted with 95 percent ethyl alcohol for 24 hours and
with ethyl ether for 24 hours. They were then dried at 110°C. for twenty hours and ashed at 550°C. for sixteen hours. Each
296
J. S. CARVER, ROBERT JOHN EVANS, AND JAMES MCGINNIS
group of bones was divided ,at random into two parts and ashed separately. The bone ash data were subjected to statistical treatment by analysis of variance. RESULTS AND DISCUSSION
The growth and bone ash results obtained with the forty-five different diets are summarized in Table 1. When no vitamin D was added to the diet, the best bone ash results were secured at the 3:1 calcium:phosphorus ratio with a 1.0 percent level of phosphorus. The fastest growth rates and the highest percentages of bone ash were obtained at either the 2:1 or 3:1 ratio of calcium to phosphorus. At either of these ratios there was a progressive increase in bone ash with an increase in the phosphorus content of the diet, up to the maximum level of 1.0 percent. The 1:1 ratio of calcium to phosphorus gave poorer results in growth and bone ash at all levels of phosphorus fed. No improvement in growth or bone ash was obtained by increasing the calcium: phosphorus ratio above the 3:1 level. Both growth rate and percentage of bone ash were decreased at the 0.8 percent phosphorus level when the calcium was increased to a 4:1 ratio. These effects were probably due to the high mineral content of this diet. The only group in the entire experiment in which any appreciable mortality occurred was the one fed the diet containing 0.5 percent phosphorus and a calcium to phosphorus ratio of 1:1 with no vitamin D. At a 20 A.O.A.C. unit level of vitamin D per one hundred grams of diet, the 2:1 calcium:phosphorus ratio fed at any level of phosphorus gave better results than any other ratio. The greatest growth rates and the highest percentages of bone ash were obtained when a 2:1 ratio of calcium to phosphorus was fed at levels of 0.8 and 1.0 percent phosphorus. Even though the
results on bone ash and growth were the highest with the 2:1 ratio at the 0.8 and 1.0 percent phosphorus levels, the differences between the 3:1 and 2:1 ratios were small. The results obtained were improved by the addition of 20 units of vitamin D per hundred grams of diet. This addition of vitamin D significantly increased the percentage of bone ash as compared to the corresponding lots receiving no vitamin D. When 60 A.O.A.C. units of vitamin D were fed, the best growth was obtained with calcium:phosphorus ratios of 1:1 and 2:1 at all levels ofphosphorus fed. All ratios of calcium to phosphorus gave satisfactory bone ash except at the 0.5 percent level of phosphorus. As the calcium:phosphorus ratio was increased to 3:1 and 4:1, growth was progressively depressed at all levels of phosphorus until the growth at the 4:1 ratio was about the same as that obtained in the corresponding groups fed no vitamin D. The 0.5 percent level of phosphorus at all calcium:phosphorus ratios gave lower bone ash than the higher levels of phosphorus. When the bone ash data obtained with the different levels of vitamin D were compared, better calcification was obtained with 60 A.O.A.C. chick units of vitamin D than with 20 units when the diet contained 0.5 or 0.6 percent phosphorus. No improvement in bone ash or growth occurred when vitamin D was increased from 20 to 60 A.O.A.C. chick units where the diet contained 0.8 or 1.0 percent phosphorus at the 2:1 or 3:1 ratios of calcium to phosphorus. At the 1:1 ratio, 60 units of vitamin D gave increased growth and calcification as compared to the same diets containing 20 units. From the results of this experiment it is apparent that both the level and ratio of calcium to phosphorus are important if the best growth and calcification are to be obtained. The lower the level of vitamin
CALCIUM, PHOSPHORUS, AND VITAMIN D INTERRELATIONSHIPS
D fed, the greater was the importance of having correct amounts and ratio's of calcium to phosphorus. Good growth and calcification were secured when 20 A.O.A.C. chick units of vitamin D per 100 grams of diet were used with adequate amounts of calcium and phosphorus. These results are in agreement with those reported by Carver et al, (1934). Where an inadequate amount of phosphorus or an unbalanced ratio of calcium to phosphorus was used, it was necessary to add higher levels of vitamin D in order to obtain satisfactory growth and calcification. Similar results were reported by McGinnis, Norris, and Heuser (1944) and Singsen and Mitchell (1945) who found that a higher percentage of bone ash was obtained when higher levels of vitamin D were added to a low-phosphorus diet. SUMMARY AND CONCLUSIONS
An interrelationship was observed between the levels of calcium, phosphorus, and vitamin D in the diet of chicks. The results show that the amounts of calcium and phosphorus as well as their ratios are of importance if optimum growth and bone ash are to be obtained. When no supplementary vitamin D was added to the diets, a progressive improvement in growth and percentage of bone ash were obtained by increasing the phosphorus content of the diet from 0.5 to 0.8 percent at calcium:phosphorus ratios of 2:1 and 3:1. At all levels of phosphorus, a 4:1 calcium:phosphorus ratio caused a depression in both growth and percentage of bone ash. When vitamin D was added to the diet, a level of 20 A.O.A.C. chick units gave
297
satisfactory growth and bone ash with the 0.8 and 1.0 percent levels of phosphorus at calcium:phosphorus ratios of 2:1 and 3:1. Increasing the vitamin D to 60 A.O. A. C. chick units at the above phosphorus levels and calcium:phosphorus ratios did not improve growth or bone ash. On the other hand, at the 1:1 calcium:phosphorus ratio and at all levels of phosphorus fed, 60 A.O.A.C. chick units gave better growth and calcification then 20 units. At a 2:1 ratio and 0.5 and 0.6 percent phosphorus levels, 60 units gave better growth and calcification than 20 units. Neither the 20 nor the 60 unit level of vitamin D improved growth at the 4:1 ratio of calcium to phosphorus over the corresponding groups fed no vitamin D. REFERENCES
Bethke, R. M., D. C. Kennard, C. H. Kick, and G. Zinzalian, 1929.' The calcium phosphorus relationship in the nutrition of the growing chick. Poultry Sci. 8: 257-265. Carver, J. S.,. E. I. Robertson, D. Brazie, R. H. Johnson, and J. L. St. John, 1934. The vitamin D requirements of chickens. Wash. Agr. Exp. Sta. Bui. 299: 1^0. Evans, R. J., and A. Wade Brant, 1945. Calcium, phosphorus and vitamin D interrelationships in turkey poult nutrition. Poultry Sci. 24:404-407. Hart, E. B., H . T. Scott, O. L. Kline, and J. G. Halpin, 1930. The calcium phosphorus ratio in the nutrition of growing chicks. Poultry Sci. 9: 296-306. McGinnis, James, L. C. Norris, and G. F . Heuser, 1944. Poor utilisation of phosphorus in cereals and legumes by chickens for bone development. Poultry Sci. 23:157-159. Nowotarski, J. S., and H. R. Bird, 1943. Dietary calcium and phosphorus levels and the vitamin D requirement of the chick. Poultry Sci. 22: 72-78. Singsen, E. P., and H. H. Mitchell, 1945. Phosphorus in poultry nutrition. Poultry Sci. 24: 479-480.
T
HE shortage of animal protein concentrates during the war years and their replacement by vegetable protein supplements containing much less calcium and phosphorus accompanied by a shortage of bone meal made it desirable to further study the interrelationships of calcium, phosphorus and vitamin D in chick nutrition. Bethke et al. (1929) and Hart et al. (1930) showed the optimum calcium: phosphorus ratio to be between 3:1 and 4:1 when low levels of vitamin D were fed. When larger amounts of vitamin D were added to the diet, Hart et al. (1930) observed less difference between various calcium: phosphorus ratios and found that lower levels of calcium and phosphorus could be used. Nowatarski and Bird (1943) found that smaller amounts of vitamin D were required when the calcium and phosphorus levels in the diet were increased. Evans and Brant (1945) using turkey poults secured similar results. They reported that lower levels of calcium and phosphorus could be used when high levels of vitamin D were fed and that when higher levels of calcium and phosphorus were used con* Published as Scientific Paper No. 667, College of Agriculture and Agricultural Experiment Stations, State College of Washington, Pullman, Washington.
siderably lower levels of vitamin D gave good growth and calcification. The object of this study was to determine the influence of the level of vitamin D and the calcium:phosphorus ratio on the growth and calcification in chicks. EXPERIMENTAL Nine hundred day-old White Leghorn cockerels were divided into forty-five groups of twenty each. The chicks were brooded in electric battery brooders for four weeks. The percentage composition of the basal diet used was: ground wheat 40.0, ground yellow corn 30.9, herring fish meal 3.0, solvent process soybean oil meal 19.0, dehydrated alfalfa meal 5.0, riboflavin concentrate 1.0, salt 1.0, choline chloride 0.1, manganese sulfate 0.0125. All diets contained 19 percent protein. Calcium and phosphorus were supplied by oyster shell flour and dicalcium phosphate. These were added in varying amounts to give the levels of calcium and phosphorus indicated in Table 1. The vitamin D added to the different diets at the levels indicated in Table 1 was a corn oil solution of irradiated 7-dehydrocholesterol. The chicks and feed were weighed weekly. At four weeks of age all of the chicks remaining were killed and the left tibia of each chick was removed and cleaned of
294
CALCIUM, PHOSPHORUS, AND VITAMIN D. INTERRELATIONSHIPS
295
TABLE 1.—The effect of vitamin D, level of phosphorus, and calcium:phosphorus ratio on average weight and percentage of bone ash* at four weeks Phosphorus level Ca:P
Vitamin D
A.O.A.C. units/lOO gm. diet
Body wt.
Bone ash
Body wt.
Bone . ash
Body wt.
gm.
%
gm.
%
gm.
146 0
161
239
250
263 41.2
247
205
36.7 271
247
1:1 35.3 316
280
40.5
41.0 290
2:1 243
45.2 255
48.4
47.3 286
299
3:1 43.2
36.8 252
266
47.0
46.7 263
4:1 41.7
36.6 306
292
45.3 312
303
1:1 44.2 298
45.0 304
44.6
45.9 293
313
2:1 44.8 262
46.1 269
47.0
47.1 270
286
3:1 43.6 227
60
39.7
38.7
36.5
38.9
60
268
244
267
60
269 37.1
36.2
34.9
60
28.2
4:1 215
20
%
174
263
263
30.5
20
gm.
3:1 241
20
Bone ash
30.4
34.9
32.9
20
Body wt..
2:1 247
0
%
178 26.5
32.4
0
Bone ash
1:1 25.8
0
1-0%
0.8%
0.6%
0.5% Ratio
46.3
46.8
46.7
251
233
4:1 42.9
44.9
45.8
* Least significant difference was 1.3 for bone ash.
adhering tissue for the bone ash determination. The tibiae were extracted with 95 percent ethyl alcohol for 24 hours and
with ethyl ether for 24 hours. They were then dried at 110°C. for twenty hours and ashed at 550°C. for sixteen hours. Each
296
J. S. CARVER, ROBERT JOHN EVANS, AND JAMES MCGINNIS
group of bones was divided ,at random into two parts and ashed separately. The bone ash data were subjected to statistical treatment by analysis of variance. RESULTS AND DISCUSSION
The growth and bone ash results obtained with the forty-five different diets are summarized in Table 1. When no vitamin D was added to the diet, the best bone ash results were secured at the 3:1 calcium:phosphorus ratio with a 1.0 percent level of phosphorus. The fastest growth rates and the highest percentages of bone ash were obtained at either the 2:1 or 3:1 ratio of calcium to phosphorus. At either of these ratios there was a progressive increase in bone ash with an increase in the phosphorus content of the diet, up to the maximum level of 1.0 percent. The 1:1 ratio of calcium to phosphorus gave poorer results in growth and bone ash at all levels of phosphorus fed. No improvement in growth or bone ash was obtained by increasing the calcium: phosphorus ratio above the 3:1 level. Both growth rate and percentage of bone ash were decreased at the 0.8 percent phosphorus level when the calcium was increased to a 4:1 ratio. These effects were probably due to the high mineral content of this diet. The only group in the entire experiment in which any appreciable mortality occurred was the one fed the diet containing 0.5 percent phosphorus and a calcium to phosphorus ratio of 1:1 with no vitamin D. At a 20 A.O.A.C. unit level of vitamin D per one hundred grams of diet, the 2:1 calcium:phosphorus ratio fed at any level of phosphorus gave better results than any other ratio. The greatest growth rates and the highest percentages of bone ash were obtained when a 2:1 ratio of calcium to phosphorus was fed at levels of 0.8 and 1.0 percent phosphorus. Even though the
results on bone ash and growth were the highest with the 2:1 ratio at the 0.8 and 1.0 percent phosphorus levels, the differences between the 3:1 and 2:1 ratios were small. The results obtained were improved by the addition of 20 units of vitamin D per hundred grams of diet. This addition of vitamin D significantly increased the percentage of bone ash as compared to the corresponding lots receiving no vitamin D. When 60 A.O.A.C. units of vitamin D were fed, the best growth was obtained with calcium:phosphorus ratios of 1:1 and 2:1 at all levels ofphosphorus fed. All ratios of calcium to phosphorus gave satisfactory bone ash except at the 0.5 percent level of phosphorus. As the calcium:phosphorus ratio was increased to 3:1 and 4:1, growth was progressively depressed at all levels of phosphorus until the growth at the 4:1 ratio was about the same as that obtained in the corresponding groups fed no vitamin D. The 0.5 percent level of phosphorus at all calcium:phosphorus ratios gave lower bone ash than the higher levels of phosphorus. When the bone ash data obtained with the different levels of vitamin D were compared, better calcification was obtained with 60 A.O.A.C. chick units of vitamin D than with 20 units when the diet contained 0.5 or 0.6 percent phosphorus. No improvement in bone ash or growth occurred when vitamin D was increased from 20 to 60 A.O.A.C. chick units where the diet contained 0.8 or 1.0 percent phosphorus at the 2:1 or 3:1 ratios of calcium to phosphorus. At the 1:1 ratio, 60 units of vitamin D gave increased growth and calcification as compared to the same diets containing 20 units. From the results of this experiment it is apparent that both the level and ratio of calcium to phosphorus are important if the best growth and calcification are to be obtained. The lower the level of vitamin
CALCIUM, PHOSPHORUS, AND VITAMIN D INTERRELATIONSHIPS
D fed, the greater was the importance of having correct amounts and ratio's of calcium to phosphorus. Good growth and calcification were secured when 20 A.O.A.C. chick units of vitamin D per 100 grams of diet were used with adequate amounts of calcium and phosphorus. These results are in agreement with those reported by Carver et al, (1934). Where an inadequate amount of phosphorus or an unbalanced ratio of calcium to phosphorus was used, it was necessary to add higher levels of vitamin D in order to obtain satisfactory growth and calcification. Similar results were reported by McGinnis, Norris, and Heuser (1944) and Singsen and Mitchell (1945) who found that a higher percentage of bone ash was obtained when higher levels of vitamin D were added to a low-phosphorus diet. SUMMARY AND CONCLUSIONS
An interrelationship was observed between the levels of calcium, phosphorus, and vitamin D in the diet of chicks. The results show that the amounts of calcium and phosphorus as well as their ratios are of importance if optimum growth and bone ash are to be obtained. When no supplementary vitamin D was added to the diets, a progressive improvement in growth and percentage of bone ash were obtained by increasing the phosphorus content of the diet from 0.5 to 0.8 percent at calcium:phosphorus ratios of 2:1 and 3:1. At all levels of phosphorus, a 4:1 calcium:phosphorus ratio caused a depression in both growth and percentage of bone ash. When vitamin D was added to the diet, a level of 20 A.O.A.C. chick units gave
297
satisfactory growth and bone ash with the 0.8 and 1.0 percent levels of phosphorus at calcium:phosphorus ratios of 2:1 and 3:1. Increasing the vitamin D to 60 A.O. A. C. chick units at the above phosphorus levels and calcium:phosphorus ratios did not improve growth or bone ash. On the other hand, at the 1:1 calcium:phosphorus ratio and at all levels of phosphorus fed, 60 A.O.A.C. chick units gave better growth and calcification then 20 units. At a 2:1 ratio and 0.5 and 0.6 percent phosphorus levels, 60 units gave better growth and calcification than 20 units. Neither the 20 nor the 60 unit level of vitamin D improved growth at the 4:1 ratio of calcium to phosphorus over the corresponding groups fed no vitamin D. REFERENCES
Bethke, R. M., D. C. Kennard, C. H. Kick, and G. Zinzalian, 1929.' The calcium phosphorus relationship in the nutrition of the growing chick. Poultry Sci. 8: 257-265. Carver, J. S.,. E. I. Robertson, D. Brazie, R. H. Johnson, and J. L. St. John, 1934. The vitamin D requirements of chickens. Wash. Agr. Exp. Sta. Bui. 299: 1^0. Evans, R. J., and A. Wade Brant, 1945. Calcium, phosphorus and vitamin D interrelationships in turkey poult nutrition. Poultry Sci. 24:404-407. Hart, E. B., H . T. Scott, O. L. Kline, and J. G. Halpin, 1930. The calcium phosphorus ratio in the nutrition of growing chicks. Poultry Sci. 9: 296-306. McGinnis, James, L. C. Norris, and G. F . Heuser, 1944. Poor utilisation of phosphorus in cereals and legumes by chickens for bone development. Poultry Sci. 23:157-159. Nowotarski, J. S., and H. R. Bird, 1943. Dietary calcium and phosphorus levels and the vitamin D requirement of the chick. Poultry Sci. 22: 72-78. Singsen, E. P., and H. H. Mitchell, 1945. Phosphorus in poultry nutrition. Poultry Sci. 24: 479-480.