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The Phosphorus Requirements of Growing Chickens as Related to Age
T h e Phosphorus Requirements of Growing Chickens as Related to Age W. F. O'ROURKE, P. H. PHILLIPS AND W. W. CRAVENS Departments of Poultry Husbandry and Biochemistry, University of Wisconsin, Madison
T
HE phosphorus requirements for growing chickens have been studied chiefly by means of rations containing considerable cereal products. This has complicated the estimation of the requirement for phosphorus by the growing chicken due to the poor availability of phytin phosphorus as shown by Lowe, Steenbock and Krieger (1939) and Heuser, Norris, McGinnis and Scott (1943). Mitchell and McClure (1937) and Mitchell (1947) have assessed the phosphorus requirements of poultry and have shown that the requirements should decrease with increasing body size. However, most experiments on phosphorus requirement of chickens have consisted of feeding the same levels of phosphorus for the entire experimental period, thus masking any change in the actual requirements with advancing age or increasing body size. In considering the comparative nutritional requirements of different classes of farm animals, Guilbert and Loosli (1951) observed that the recommended allowances of phosphorus for growing chickens remain constant with advancing
Published with the approval of the Director of the Wisconsin Agricultural Experiment Station. Supported in part by a grant from the Murphy Products Co., Burlington, Wisconsin. We are indebted to Wilson and Company, Chicago, Illinois for the gelatin and to the Lederle Laboratories for folacin, and the vitamin Bi2 and antibiotic feed supplement.
age whereas other farm animals showed a decreased need for this element. They explained part of the difference in total requirement by the fact that phytin phosphorus, found in all practical rations, is less available than inorganic phosphorus to the chicken. Experiments were in progress in our laboratory dealing with this point when the above paper appeared and we wish to present data showing that the principle of decreasing phosphorus requirements during the growing period, established with other species, also applies to the chicken. A purified diet was employed thus eliminating the problem of inefficient utilization of phosphorus from cereal sources. EXPERIMENTAL Straight run (N.H.XS.C.W.L.) chicks were placed in conventional battery brooders with feed and water supplied ad libitum. The composition of the purified basal ration used in all experiments was as follows in percent: autoclaved corn starch 60.5, hot alcohol extracted casein 18.0, gelatin 10.0, soybean oil 4.0, L cystine 0.3, vitamin A and D feeding oil (300 ICU, D-2,000 A) 0.5, vitamin B i 2 and antibiotic feed supplement 0.25. Other vitamins were added as follows in milligrams per kilogram: riboflavin 6, thiamine HCl 3, Ca pantothenate 20, niacin 50, pyridoxine HCl 4, 2 methyl 1-4 962
Downloaded from http://ps.oxfordjournals.org/ at University of Massachusetts Medical School on April 11, 2015
(Received for publication March 22, 1952)
PHOSPHORUS REQUIREMENTS OF CHICKS
TABLE 1. Composition of soli mixtures ' Salts V CaCOa CaHPCV2H20 K2HPO* MgS04-7H20 K2COs NaCl Fe(C6H507V6H20 KI MnS04-H20 ZnCl2 CuS04-5H20
600 S19 645 204 335 55 1.6 15.8 0.5 0.6
Salts 12 600 204 700 335 55 1.6 10 0.5 0.6
Day old chicks were used in experiments 1, 2, and 3. The experimental period was three weeks. In experiment 4, day old chicks were fed the purified basal ration containing Salts V for 14 days, at which time they were weighed and divided on the basis of weight into groups of 15 chicks each. In experiments 5 and 6 the chicks were raised to 4 weeks of age on the purified basal ration containing Salts V and then they were weighed and divided by weight into groups containing 15 chicks in experiments 5 and 12 chicks in experiment 6. Blood samples were obtained by the heart probe method of Sloan and Wilgus (1930) at the termination of experiment 6. Two ml. samples of blood were removed and mixed with 8 ml. of 10 percent trichloroacetic acid. The trichloroacetic acid treated blood samples from single
birds of an experimental group were pooled and filtered through Whatman 42 filter paper'. Serum phosphorus was determined by means of the method of Fiske and Subba-Row (1925) adapted for the use of an Evelyn photoelectric colorimeter. Bone ash determinations were made by the AOAC (1945) method. RESULTS AND DISCUSSION
Experiments 1, 2, and 3, which were designed to determine the phosphorus requirement of chicks during the early growth period, are summarized in Table 2. The data show that 0.51 percent phosphorus was optimum for growth and calcification as measured by bone ash. However, 0:43 percent phosphorus appeared to be almost optimal and will be considered the marginal level of phosphorus required to this age. This is 0.1— 0.2 percent lower than recommended by the National Research Council. However, the recommended allowances differ from actual requirements in that a margin of safety is provided in the allowances. Since, under these conditions, 0.43 percent phosphorus was marginal for early chick growth and calcification, as measured by bone ash, a fourth experiment was conducted in which day old chicks were raised to two weeks of age on the basal ration with Salts V as the salts mixture. They were weighed and divided into six groups on the basis of weight and fed the experimental rations until they were five weeks of age. The results of this experiment are given in Table 3. It will be noted that at the end of the three week feeding period greatest rate of growth was obtained at a phosphorus level of 0.43 percent. The data also indicate that the chicks receiving the ration containing 0.35 percent phosphorus grew at a near maximum rate. Thus the requirement would appear to be about .35 percent. It
Downloaded from http://ps.oxfordjournals.org/ at University of Massachusetts Medical School on April 11, 2015
naphthoquinone 0.5, biotin 0.2, m-inositol 1,000, choline chloride 2,000, folacin 4, alpha tocopherol 3, para-aminobenzoic acid 100. Six percent of Salts 12 was added to all experiments. However, in experiment 4 Salts V replaced Salts 12 in the ration containing 0.69 percent phosphorus. The level of phosphorus, its source and the replacement of Salts 12 by Salts V are indicated in the tables of results. The composition of the salt mixtures is given in Table 1.
963
964
W.
F. O ' R O U R K E , P. H. P H I L L I P S AND W.
W.
CRAVENS
TABLE 2.—Relation of the phosphorus content of the ration to growth and hone ash of chicks from hatching to three weeks of age Weeks Percent Percent T, ;„„* C a H P ( V 2 H 2 0 phosphorus E ^ X T added to basal in ration number
Percent bone ash Exp. 1 Weight in grams
0.16 0.16 0.16
1 2 3
47.3 39.6 32.8
57.5 56.7 51.0
86.5 75.5 59.3
103.9 96.3 74.8
42.7
0.6 0.6 0.78
0.27 0.27 0.30
1 2 3
48.8 39.9 31.9
58.2 54.2 57.1
95.9 82.6 95.5
135.3 114.2 141.8
45.8
l.OS l.OS 1.33
0.35 0.35 0.40
1 2 3
47.8 38.0 32.5
62.0 52.7 60.3
113.1 89.2 111.7
179.0 184.0 133.3
51.9
1.50 1.50 1.89
0.43 0.43 0.50
1 2 3
48.4 38.1 32.0
67.5 57.3 68.1
133.5 101.2 131.0
193.8 137.1 212.0
52.4
1.95 1.95 2.44
0.51 0.51 0.60
1 2 3
47.5 38.7 32.1
75.7 59.2 61.0
151.8 114.9 112.6
228.0 156.3 190.5
55.3
2.6 2.6 3.27
0.62 0.62 0.75
1 2 3
45.8 37.5 32.1
68.9 60.2 64.0
135.7 109.9 126.7
214.1 148.8 203.0
52.4
is obvious, if the results, of experiment 4 are compared with those of experiments 1, 2, and 3, that a decrease in requirement has attended an increased age. To ascertain if a drop in requirement of phosphorus by the chick takes place with a further increase in age, experiments 5 and 6 were conducted. In these experiments day old chicks were raised to four weeks of age on the basal ration plus Salts V and then weighed and divided into 6 groups on the basis of weight. Percent bone ash and serum phosphorus were TABLE 3.—Relation of the phosphorus content of the ration to growth from two to five weeks of age Percent Percent Exp. CaHPOr 2H:IO phosphorus added to in ration ber • basal None 0.6 1.05 1.50 1.95 Salts V
0.16 0.27 0.35 0.43 0.51 0.69
4 4 4 4 4 4
Weeks 2
3
4
5
Weight in grams 143 140 143 143 140 141
200 200 222 231 229 237
254 261 312 330 318 342
291 362 434 478 448 476
determined in experiment 6. The results of experiments 5 and 6 are given in Table 4. The group of chickens fed 0.35 percent phosphorus in experiment 5 suffered a set back the first week of the experiment. The cause for this was undetermined. The data on growth indicate that about 0.27 percent phosphorus meets the requirement for the 4 to 10 week growth period of the chick. However, the bone ash and inorganic phosphorus data indicate that 0.35 percent of phosphorus was required for optimum results. Admittedly this is a long period of experimentation and we realize that the requirement may have decreased at an earlier age than represented by the data. Mitchell and McClure (1937) and Mitchell (1947) have shown that the phosphorus requirement should decrease with age. However, in their analysis of the
Downloaded from http://ps.oxfordjournals.org/ at University of Massachusetts Medical School on April 11, 2015
None None None
965
PHOSPHORUS REQUIREMENTS OF CHICKS TABLE ^.—Relation of the phosphorus content of the ration to growth, percent bone ash and serum phosphorus from four to ten weeks of age
Mg. of inorganic blood Percent phosphorus bone ash per 100 cc. Exp. 6 of bloodExp. 6
^ ^ J?*™" .Pno™s in ration
Exp. number
None
0.16
5 6
268 366 417 566 681 294 403 528 601 732
836 978
3.5
46.9
5 6
267 398 543 709 835 1,057 1,137 967 1,135 295 424 556 664 824
5.6
52.5
5 6
268 391 523 678 846 1,035 1,142 870 1,027 296 270 401 529 708
6.3
54.9
5 6
267 389 528 677 809 296 423 553 669 834
957 1,060 988 1,136
6.5
57.9
5 6
267 407 551 714 869 1,073 1,179 296 433 571 700 865 1,020 1,153
6.5
55.6
5 6
267 403 545 702 858 1,021 294 443 582 709 857 1,023
6.5
55.7
0.60 1.05 1.50 1.95
2.6
0.27 0.35 0.43 0.51 0.62
10
problem they indicated that the growing chick initially has a low requirement which then increases and subsequently decreases with increasing body weight. Our data do not confirm the initial low requirement suggested by these workers but do show a decreased requirement with advancing age. Guilbert and Loosli (1951) have analyzed data for farm animals and have drawn curves that show a decrease in requirement with increasing body weight. They were unable to show a decreased requirement for chickens and turkeys. Rather the data on these species indicate that the requirement for phosphorus remains constant with age. They explain the indicated high requirement by phytin phosphorus unavailability but were unable to explain why the requirements do not drop with age. In fact they indicate that the constant requirement which available data suggests requires "verification and/or explanation." Our data would imply that the reason for the constant requirement suggested by previous investigators is due to the
825 850
1,152 1,167
5r R*c 4
-E N T
Q437.
LP
0.357.
H o S
0.27/.
UP
H o R U r- S
WEEKS
I
2
3
4
5 FIG.
^
7
8
9
10
1
time element or age in the experimental design. Since the interval used by most investigators has been from hatching to various ages, the differential in phosphorus requirement for the more rapid period of growth was masked. If we take a minimum phosphorus requirement for the periods studied in our experiments as 0.43 percent to 3 weeks, 0.35 percent for 2 to 5 weeks, 0.27 percent for 4 to 10 weeks and plot against age in weeks the decreasing requirement is
Downloaded from http://ps.oxfordjournals.org/ at University of Massachusetts Medical School on April 11, 2015
Percent CaHPCV2H 2 0 added to basal
966
H. J. ALMQUIST
plainly evident as shown in Figure 1. It may be that more extensive investigation would show a precise requirement differing somewhat from those indicated but the principle of decreasing requirement with advancing age appears to be justified. SUMMARY
Amino Acid Requirements of Chickens and Turkeys—A Review H. J. ALMQUIST The Grange Company, Modesto, California (Received for publication June 24, 1952)
1. CHICKS
T
HE amino acid requirements of the young chick were previously reviewed by the writer, (Almquist, 1947). The present review will include information reported since this date on the quantitative requirements of fowls for certain amino acids. a. Methionine A ration containing approximately 20% protein, furnished largely as casein plus arginine and glycine, was fed to White
Leghorn chicks (Briggs et al., 1942). The methionine and cystine contents of these rations have been recalculated using more recent analytical values. The diet probably contained 0.52% methionine and was optimally supplemented when cystine was added to make a total of 0.39%. The sulfur amino acid requirement was approximately 4.5% of the protein. An investigation of the methionine, choline and betaine utilization in White Leghorn chicks reaffirmed the previously
Downloaded from http://ps.oxfordjournals.org/ at University of Massachusetts Medical School on April 11, 2015
Experiments were conducted to determine the phosphorus requirements of the chick at different stages of growth. A purified ration was used to prevent complication due to the question of phytin phosphorus availability. It was established for the conditions of the experiments that the phosphorus required by the chick decreases with increasing age. The minimum levels of phosphorus required were .43 percent to 3 weeks, .35 percent from 2 to 5 weeks and .27 percent from 4 to 10 weeks.
REFERENCES Association of Official Agricultural Chemists, 1945. Official and Tentative Methods of Analysis: 625626. Fiske, C. H., and Y. Subba Row, 1925. The colorimetric determination of phosphorus. J. Biol. Chem. 66: 375-400. Guilbert, H. R., and J. K. Loosli, 1951. Comparative nutrition of farm animals. J. Animal Sci. 10: 2241. Heuser, G. F., L. C. Nbrris, J. McGinnis and M. L. Scott, 1943. Further evidence of the need for supplementing soybean meal chick rations with phosphorus. Poultry Sci. 22: 269-270. Lowe, J. R., H. Steenbock and C. H. Krieger, 1939. Cereals and rickets. I X The availability of phytin-P to the chick. Poultry Sci. 18: 40-44. Mitchell, H. H., 1947. The mineral requirements of farm animals. J. Animal Sci. 6: 365-377. Mitchell, H. H., and F. J. McClure, 1937. Mineral nutrition of farm animals. Bull. National Research Council, No. 99. Sloan, H. J., and H. S. Wilgus, Jr., 1930. Heart probe—A method for obtaining blood samples from chickens. Poultry Sci. 10: 10-16.
T
HE phosphorus requirements for growing chickens have been studied chiefly by means of rations containing considerable cereal products. This has complicated the estimation of the requirement for phosphorus by the growing chicken due to the poor availability of phytin phosphorus as shown by Lowe, Steenbock and Krieger (1939) and Heuser, Norris, McGinnis and Scott (1943). Mitchell and McClure (1937) and Mitchell (1947) have assessed the phosphorus requirements of poultry and have shown that the requirements should decrease with increasing body size. However, most experiments on phosphorus requirement of chickens have consisted of feeding the same levels of phosphorus for the entire experimental period, thus masking any change in the actual requirements with advancing age or increasing body size. In considering the comparative nutritional requirements of different classes of farm animals, Guilbert and Loosli (1951) observed that the recommended allowances of phosphorus for growing chickens remain constant with advancing
Published with the approval of the Director of the Wisconsin Agricultural Experiment Station. Supported in part by a grant from the Murphy Products Co., Burlington, Wisconsin. We are indebted to Wilson and Company, Chicago, Illinois for the gelatin and to the Lederle Laboratories for folacin, and the vitamin Bi2 and antibiotic feed supplement.
age whereas other farm animals showed a decreased need for this element. They explained part of the difference in total requirement by the fact that phytin phosphorus, found in all practical rations, is less available than inorganic phosphorus to the chicken. Experiments were in progress in our laboratory dealing with this point when the above paper appeared and we wish to present data showing that the principle of decreasing phosphorus requirements during the growing period, established with other species, also applies to the chicken. A purified diet was employed thus eliminating the problem of inefficient utilization of phosphorus from cereal sources. EXPERIMENTAL Straight run (N.H.XS.C.W.L.) chicks were placed in conventional battery brooders with feed and water supplied ad libitum. The composition of the purified basal ration used in all experiments was as follows in percent: autoclaved corn starch 60.5, hot alcohol extracted casein 18.0, gelatin 10.0, soybean oil 4.0, L cystine 0.3, vitamin A and D feeding oil (300 ICU, D-2,000 A) 0.5, vitamin B i 2 and antibiotic feed supplement 0.25. Other vitamins were added as follows in milligrams per kilogram: riboflavin 6, thiamine HCl 3, Ca pantothenate 20, niacin 50, pyridoxine HCl 4, 2 methyl 1-4 962
Downloaded from http://ps.oxfordjournals.org/ at University of Massachusetts Medical School on April 11, 2015
(Received for publication March 22, 1952)
PHOSPHORUS REQUIREMENTS OF CHICKS
TABLE 1. Composition of soli mixtures ' Salts V CaCOa CaHPCV2H20 K2HPO* MgS04-7H20 K2COs NaCl Fe(C6H507V6H20 KI MnS04-H20 ZnCl2 CuS04-5H20
600 S19 645 204 335 55 1.6 15.8 0.5 0.6
Salts 12 600 204 700 335 55 1.6 10 0.5 0.6
Day old chicks were used in experiments 1, 2, and 3. The experimental period was three weeks. In experiment 4, day old chicks were fed the purified basal ration containing Salts V for 14 days, at which time they were weighed and divided on the basis of weight into groups of 15 chicks each. In experiments 5 and 6 the chicks were raised to 4 weeks of age on the purified basal ration containing Salts V and then they were weighed and divided by weight into groups containing 15 chicks in experiments 5 and 12 chicks in experiment 6. Blood samples were obtained by the heart probe method of Sloan and Wilgus (1930) at the termination of experiment 6. Two ml. samples of blood were removed and mixed with 8 ml. of 10 percent trichloroacetic acid. The trichloroacetic acid treated blood samples from single
birds of an experimental group were pooled and filtered through Whatman 42 filter paper'. Serum phosphorus was determined by means of the method of Fiske and Subba-Row (1925) adapted for the use of an Evelyn photoelectric colorimeter. Bone ash determinations were made by the AOAC (1945) method. RESULTS AND DISCUSSION
Experiments 1, 2, and 3, which were designed to determine the phosphorus requirement of chicks during the early growth period, are summarized in Table 2. The data show that 0.51 percent phosphorus was optimum for growth and calcification as measured by bone ash. However, 0:43 percent phosphorus appeared to be almost optimal and will be considered the marginal level of phosphorus required to this age. This is 0.1— 0.2 percent lower than recommended by the National Research Council. However, the recommended allowances differ from actual requirements in that a margin of safety is provided in the allowances. Since, under these conditions, 0.43 percent phosphorus was marginal for early chick growth and calcification, as measured by bone ash, a fourth experiment was conducted in which day old chicks were raised to two weeks of age on the basal ration with Salts V as the salts mixture. They were weighed and divided into six groups on the basis of weight and fed the experimental rations until they were five weeks of age. The results of this experiment are given in Table 3. It will be noted that at the end of the three week feeding period greatest rate of growth was obtained at a phosphorus level of 0.43 percent. The data also indicate that the chicks receiving the ration containing 0.35 percent phosphorus grew at a near maximum rate. Thus the requirement would appear to be about .35 percent. It
Downloaded from http://ps.oxfordjournals.org/ at University of Massachusetts Medical School on April 11, 2015
naphthoquinone 0.5, biotin 0.2, m-inositol 1,000, choline chloride 2,000, folacin 4, alpha tocopherol 3, para-aminobenzoic acid 100. Six percent of Salts 12 was added to all experiments. However, in experiment 4 Salts V replaced Salts 12 in the ration containing 0.69 percent phosphorus. The level of phosphorus, its source and the replacement of Salts 12 by Salts V are indicated in the tables of results. The composition of the salt mixtures is given in Table 1.
963
964
W.
F. O ' R O U R K E , P. H. P H I L L I P S AND W.
W.
CRAVENS
TABLE 2.—Relation of the phosphorus content of the ration to growth and hone ash of chicks from hatching to three weeks of age Weeks Percent Percent T, ;„„* C a H P ( V 2 H 2 0 phosphorus E ^ X T added to basal in ration number
Percent bone ash Exp. 1 Weight in grams
0.16 0.16 0.16
1 2 3
47.3 39.6 32.8
57.5 56.7 51.0
86.5 75.5 59.3
103.9 96.3 74.8
42.7
0.6 0.6 0.78
0.27 0.27 0.30
1 2 3
48.8 39.9 31.9
58.2 54.2 57.1
95.9 82.6 95.5
135.3 114.2 141.8
45.8
l.OS l.OS 1.33
0.35 0.35 0.40
1 2 3
47.8 38.0 32.5
62.0 52.7 60.3
113.1 89.2 111.7
179.0 184.0 133.3
51.9
1.50 1.50 1.89
0.43 0.43 0.50
1 2 3
48.4 38.1 32.0
67.5 57.3 68.1
133.5 101.2 131.0
193.8 137.1 212.0
52.4
1.95 1.95 2.44
0.51 0.51 0.60
1 2 3
47.5 38.7 32.1
75.7 59.2 61.0
151.8 114.9 112.6
228.0 156.3 190.5
55.3
2.6 2.6 3.27
0.62 0.62 0.75
1 2 3
45.8 37.5 32.1
68.9 60.2 64.0
135.7 109.9 126.7
214.1 148.8 203.0
52.4
is obvious, if the results, of experiment 4 are compared with those of experiments 1, 2, and 3, that a decrease in requirement has attended an increased age. To ascertain if a drop in requirement of phosphorus by the chick takes place with a further increase in age, experiments 5 and 6 were conducted. In these experiments day old chicks were raised to four weeks of age on the basal ration plus Salts V and then weighed and divided into 6 groups on the basis of weight. Percent bone ash and serum phosphorus were TABLE 3.—Relation of the phosphorus content of the ration to growth from two to five weeks of age Percent Percent Exp. CaHPOr 2H:IO phosphorus added to in ration ber • basal None 0.6 1.05 1.50 1.95 Salts V
0.16 0.27 0.35 0.43 0.51 0.69
4 4 4 4 4 4
Weeks 2
3
4
5
Weight in grams 143 140 143 143 140 141
200 200 222 231 229 237
254 261 312 330 318 342
291 362 434 478 448 476
determined in experiment 6. The results of experiments 5 and 6 are given in Table 4. The group of chickens fed 0.35 percent phosphorus in experiment 5 suffered a set back the first week of the experiment. The cause for this was undetermined. The data on growth indicate that about 0.27 percent phosphorus meets the requirement for the 4 to 10 week growth period of the chick. However, the bone ash and inorganic phosphorus data indicate that 0.35 percent of phosphorus was required for optimum results. Admittedly this is a long period of experimentation and we realize that the requirement may have decreased at an earlier age than represented by the data. Mitchell and McClure (1937) and Mitchell (1947) have shown that the phosphorus requirement should decrease with age. However, in their analysis of the
Downloaded from http://ps.oxfordjournals.org/ at University of Massachusetts Medical School on April 11, 2015
None None None
965
PHOSPHORUS REQUIREMENTS OF CHICKS TABLE ^.—Relation of the phosphorus content of the ration to growth, percent bone ash and serum phosphorus from four to ten weeks of age
Mg. of inorganic blood Percent phosphorus bone ash per 100 cc. Exp. 6 of bloodExp. 6
^ ^ J?*™" .Pno™s in ration
Exp. number
None
0.16
5 6
268 366 417 566 681 294 403 528 601 732
836 978
3.5
46.9
5 6
267 398 543 709 835 1,057 1,137 967 1,135 295 424 556 664 824
5.6
52.5
5 6
268 391 523 678 846 1,035 1,142 870 1,027 296 270 401 529 708
6.3
54.9
5 6
267 389 528 677 809 296 423 553 669 834
957 1,060 988 1,136
6.5
57.9
5 6
267 407 551 714 869 1,073 1,179 296 433 571 700 865 1,020 1,153
6.5
55.6
5 6
267 403 545 702 858 1,021 294 443 582 709 857 1,023
6.5
55.7
0.60 1.05 1.50 1.95
2.6
0.27 0.35 0.43 0.51 0.62
10
problem they indicated that the growing chick initially has a low requirement which then increases and subsequently decreases with increasing body weight. Our data do not confirm the initial low requirement suggested by these workers but do show a decreased requirement with advancing age. Guilbert and Loosli (1951) have analyzed data for farm animals and have drawn curves that show a decrease in requirement with increasing body weight. They were unable to show a decreased requirement for chickens and turkeys. Rather the data on these species indicate that the requirement for phosphorus remains constant with age. They explain the indicated high requirement by phytin phosphorus unavailability but were unable to explain why the requirements do not drop with age. In fact they indicate that the constant requirement which available data suggests requires "verification and/or explanation." Our data would imply that the reason for the constant requirement suggested by previous investigators is due to the
825 850
1,152 1,167
5r R*c 4
-E N T
Q437.
LP
0.357.
H o S
0.27/.
UP
H o R U r- S
WEEKS
I
2
3
4
5 FIG.
^
7
8
9
10
1
time element or age in the experimental design. Since the interval used by most investigators has been from hatching to various ages, the differential in phosphorus requirement for the more rapid period of growth was masked. If we take a minimum phosphorus requirement for the periods studied in our experiments as 0.43 percent to 3 weeks, 0.35 percent for 2 to 5 weeks, 0.27 percent for 4 to 10 weeks and plot against age in weeks the decreasing requirement is
Downloaded from http://ps.oxfordjournals.org/ at University of Massachusetts Medical School on April 11, 2015
Percent CaHPCV2H 2 0 added to basal
966
H. J. ALMQUIST
plainly evident as shown in Figure 1. It may be that more extensive investigation would show a precise requirement differing somewhat from those indicated but the principle of decreasing requirement with advancing age appears to be justified. SUMMARY
Amino Acid Requirements of Chickens and Turkeys—A Review H. J. ALMQUIST The Grange Company, Modesto, California (Received for publication June 24, 1952)
1. CHICKS
T
HE amino acid requirements of the young chick were previously reviewed by the writer, (Almquist, 1947). The present review will include information reported since this date on the quantitative requirements of fowls for certain amino acids. a. Methionine A ration containing approximately 20% protein, furnished largely as casein plus arginine and glycine, was fed to White
Leghorn chicks (Briggs et al., 1942). The methionine and cystine contents of these rations have been recalculated using more recent analytical values. The diet probably contained 0.52% methionine and was optimally supplemented when cystine was added to make a total of 0.39%. The sulfur amino acid requirement was approximately 4.5% of the protein. An investigation of the methionine, choline and betaine utilization in White Leghorn chicks reaffirmed the previously
Downloaded from http://ps.oxfordjournals.org/ at University of Massachusetts Medical School on April 11, 2015
Experiments were conducted to determine the phosphorus requirements of the chick at different stages of growth. A purified ration was used to prevent complication due to the question of phytin phosphorus availability. It was established for the conditions of the experiments that the phosphorus required by the chick decreases with increasing age. The minimum levels of phosphorus required were .43 percent to 3 weeks, .35 percent from 2 to 5 weeks and .27 percent from 4 to 10 weeks.
REFERENCES Association of Official Agricultural Chemists, 1945. Official and Tentative Methods of Analysis: 625626. Fiske, C. H., and Y. Subba Row, 1925. The colorimetric determination of phosphorus. J. Biol. Chem. 66: 375-400. Guilbert, H. R., and J. K. Loosli, 1951. Comparative nutrition of farm animals. J. Animal Sci. 10: 2241. Heuser, G. F., L. C. Nbrris, J. McGinnis and M. L. Scott, 1943. Further evidence of the need for supplementing soybean meal chick rations with phosphorus. Poultry Sci. 22: 269-270. Lowe, J. R., H. Steenbock and C. H. Krieger, 1939. Cereals and rickets. I X The availability of phytin-P to the chick. Poultry Sci. 18: 40-44. Mitchell, H. H., 1947. The mineral requirements of farm animals. J. Animal Sci. 6: 365-377. Mitchell, H. H., and F. J. McClure, 1937. Mineral nutrition of farm animals. Bull. National Research Council, No. 99. Sloan, H. J., and H. S. Wilgus, Jr., 1930. Heart probe—A method for obtaining blood samples from chickens. Poultry Sci. 10: 10-16.