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Biological Availability of Feed Grade Phosphates Using a Corn-Soybean Meal Basal Diet
366
RESEARCH
ferences are not necessarily proportional to differences in T.M.E. For example dehydrated alfalfa has a greater gross energy value than corn (4.13 vs. 3.89 kcal./g.) but the corn has a greater T.M.E. value (3.55 vs. 1.39 kcal./g.). Nevertheless the differences between the gross energy values add weight to the conclusion that the differences between the T.M.E. values were random. It is concluded that the T.M.E. values of the feedingstuffs studied in this experiment were additive. It is reasonable to assume that T.M.E. values can be used successfully in feed formulation. ACKNOWLEDGMENTS The author wishes to thank Mrs. S. Tobin for her able technical assistance and K. Price for his suggestions respecting data interpretation. REFERENCE Sibbald, I. R., 1976. A bioassay for true metabolizable energy in feedingstuffs. Poultry Sci. 55: 303-308.
BIOLOGICAL AVAILABILITY OF FEED GRADE PHOSPHATES USING A CORN-SOYBEAN MEAL BASAL DIET L. A. WOZNIAK, J. M. PENSACK, V. STRYESKI AND R. D. WILBUR
American Cyanamid Company, Agricultural Division, Princeton, New Jersey 08540 (Received for publication July 23, 1976)
ABSTRACT Experiments were conducted to evaluate the biological availability of feed phosphates (dicalcium phosphate and def luorinated rock phosphate) to chicks using a corn-soybean meal diet and the tibia bone ash assay. Phosphoric acid was used as the reference standard. At equal levels of phosphorus supplementation, dicalcium phosphate (18.5 percent P) was significantly (p = 0.05) more bioavailable than defluorinated rock phosphate (18 percent P). POULTRY SCIENCE 56: 366-369,
INTRODUCTION
T
HE investigations of Gillis et al. (1954), Nelson and Walker (1964), and Pensack
Cyphos®—Registered trademark of American Cyanamid Company for its brand of feed phosphates (mixture of dicalcium and monocalcium phosphate).
1977
(1974) have shown that the chick tibia bone ash assay was a sensitive and reproducible method to determine phosphorus bioavailability from inorganic feed phosphate when added to a basal diet containing blood fibrin. The purpose of this study was to determine the bioavailability of feed phosphates to
Downloaded from http://ps.oxfordjournals.org/ at Swinburne University of Technology on May 17, 2015
noted that these data describe the ingredients at the time at which they were incorporated into the 10 experimental diets. The comparison of observed and calculated T.M.E. values is presented in Table 2. The two sets of values are in reasonable agreement with differences ranging from —0.09 to +0.13 kcal./g. of diet. The mean difference is 0.02 kcal./g. which is equivalent to 0.6% of the meanof the observed T.M.E. means. A series of t-tests showed that none of the differences between observed and calculated T.M.E. values was significant at the 5% level of probability. Part of the difference between observed and calculated values may be attributable to slight errors in mixing. This was examined by comparing the observed and calculated gross energy values of the diets (Table 2). The mean difference is 0.04 kcal./g. which is twice the mean difference between the two sets of T.M.E. data. The correlation between the two sets of differences is only 0.414 at 8 degrees of freedom; however, the errors in mixing implied by the gross energy dif-
NOTES
367
RESEARCH NOTES
chicks substituting blood fibrin with soybean meal which is more typical of a practical-type diet and is considerably less expensive. Nelson and Peeler (1961) reported a similar study, but they used a constant calcium-phosphorus ratio instead of a constant calcium concentration as used in this study. MATERIALS AND METHODS
TABLE 1.—Basal diet
Ingredient Ground yellow corn Soybean meal (48% protein) Iodized salt DL methionine Choline chloride (50% supplement) Calcium carbonate' Solka Floe 1 Vitamin A (30,000 I.U./g.) Vitamin D 3 (200,000 I.C.U./g.) Vitamin E ( 4 4 U . / g . ) Vitamin K (menadione) Parvo (3%) folic acid Riboflavin Proferm (0.132 mg./g.) B l 2 Niacinamide Ca pantothenate BHT (butylated hydroxy toluene) Manganese (manganous oxide) Iron (ferrous carbonate) Zinc (zinc oxide) Copper (copper oxide) Iodine (calcium iodate) Cobalt (cobalt carbonate)
Per kilogram diet Grams 604.6 350.0 3.0 1.5 1.0 21.2 17.9 Milligrams 331 5.5 50 2.2 47 13 83.3 27 22 125 62.5 30.0 25.0 3.25 1.75 1.25
'The amounts of calcium carbonate and/or Solka Floe are adjusted when the diet is supplemented with phosphoric acid or inorganic phosphates. The concentration of calcium (1 percent) was kept constant in all of the diets. The concentration of phosphorus in the unsupplemented diet was 0.43 percent.
% P added' % P total % Bone ash2 OTTO (L53 37.3 ± 0.58 0.20 0.63 48.7 ± 0.49 0.30 0.73 52.8 ± 0.42 1 Each treatment consisted of four groups of birds with ten birds per group. 2 Values are means ± standard error. females per pen) with raised wire floors, in a room held at 24° C. Feed and water were supplied ad libitum. The composition of the basal diet is shown in Table 1. Supplementation of the diet with phosphoric acid or feed phosphates was carried out as indicated in Table 2. Total calcium in the final diets was maintained at 1 percent by the addition of calcium carbonate; therefore, the Ca:P ratio was not constant and varied from 1.4:1 to 2.1:1. The chicks were administered the different diets for a period of 20 days, then weighed, sacrificed, and the right tibia was removed for bone ash determination as described for A.O.A.C. vitamin D assay (1970). The biological availability of each feed phosphate was calculated from the phosphoric acid reference curve obtained by plotting percent bone ash against the logarithm of the percentage of added dietary phosphorus (0.1, 0.2, and 0.3 percent added P from phosphoric acid). A lower level (0.05 percent P) of supplementation with phosphoric acid was not included in the linear regression analysis due to a 27 percent mortality associated with a phosphorus deficiency. Phosphoric acid was considered to be 100 percent available. RESULTS AND DISCUSSION The effect of supplementation of the basal corn-soybean meal diet with different levels of phosphoric acid on bone ash of chicks is reported in Table 2 and Figure 1. The dose
Downloaded from http://ps.oxfordjournals.org/ at Swinburne University of Technology on May 17, 2015
Hubbard x Hubbard broiler chicks (dayold) were randomly assigned to electrically heated starting batteries (five males and five
TABLE 2.—Effect of phosphorus levels added as phosphoric acid to corn-soybean meal diet on bone ash of chicks
368
RESEARCH NOTES
60
50
40
• Phosphoric acid - 100%
• Cyphos® £ 4 | x 100 = 93% U.15
< c 30 o
•
Defluorinated phosphate 0.11 x100 - 73% 0.15
20
10
0.10 0.11
_L 0.14 0.15
0.20
0.30
0.40
% Supplementary phosphate added to diet FIG. 1. Determination of bioavailability of inorganic feed phosphates to chicks as measured by bone ash using phosphoric acid as the reference standard.
response curve (Figure 1) obtained with this basal diet is similar to the reference curve reported by Pensack (1974) using a basal diet containing blood fibrin as a protein source. The values for percent bone ash obtained from chicks fed the basal diet supplemented with Cyphos® (dicalcium phosphate—18.5 percent P) or defluorinated rock phosphate (18 percent P) are shown in Table 3. Dicalcium phosphate produced significantly higher bone ash (42.2 percent) than defluorinated rock
phosphate (39.0 percent). Biological availability of the phosphorus in these two feed phosphates was determined using the phosphoric acid reference curve as indicated in Figure 1. At a level equivalent to 0.15 percent added phosphorus, Cyphos® (dicalcium phosphate) was found to be 93 percent as available as phosphoric acid. At the same percentage of added phosphorus (0.15 percent), the defluorinated rock phosphate was only 75 percent as available as
Downloaded from http://ps.oxfordjournals.org/ at Swinburne University of Technology on May 17, 2015
-i-A
369
RESEARCH NOTES
TABLE 3.—Effect of supplementation of corn-soybean meal diet with inorganic feed phosphates on bone ash of chicks Supplement' Cyphos® (dicalciumphosphate 18.5% P) Defluorinated rock phosphate
%P added
%P total
% Bone ash 2
demonstrating that biological values of different phosphorus sources determined with a practical diet are similar to those reported with a purified diet. REFERENCES
0.15
0.58
42.2 ± 0.62a
0.15
0.58
39.0 ± 0.93b
phosphoric acid and also significantly (P = 0.05) less available than dicalcium phosphate. These results confirm and extend those of Pensack (1974) and Nelson and Peeler (1961),
Downloaded from http://ps.oxfordjournals.org/ at Swinburne University of Technology on May 17, 2015
' Each treatment consisted of four groups of birds with ten birds per group. 2 Values are means ± standard error. Averages without common letters are significantly different at P = 0.05.
Association of Official Agricultural Chemists, 1970. Official Methods of Analysis, 11th ed., Washington, D.C. Gillis, M. B., L. C. Norris and G. F. Heuser, 1954. Studies on the biological value of inorganic phosphates. J. Nutr. 52: 115-125. Nelson, T. S., and H. T. Peeler, 1961. The availability of phosphorus from single and combined phosphates to chicks. Poultry Sci. 40: 1321-1328. Nelson, T. S., and A. C. Walker, 1964. The biological evaluation of phosphorus compounds. Poultry Sci. 43: 94-98. Pensack, J. M., 1974. Feed phosphates: biological availability of feed grade phosphates. Poultry Sci. 53: 143-148.
RESEARCH
ferences are not necessarily proportional to differences in T.M.E. For example dehydrated alfalfa has a greater gross energy value than corn (4.13 vs. 3.89 kcal./g.) but the corn has a greater T.M.E. value (3.55 vs. 1.39 kcal./g.). Nevertheless the differences between the gross energy values add weight to the conclusion that the differences between the T.M.E. values were random. It is concluded that the T.M.E. values of the feedingstuffs studied in this experiment were additive. It is reasonable to assume that T.M.E. values can be used successfully in feed formulation. ACKNOWLEDGMENTS The author wishes to thank Mrs. S. Tobin for her able technical assistance and K. Price for his suggestions respecting data interpretation. REFERENCE Sibbald, I. R., 1976. A bioassay for true metabolizable energy in feedingstuffs. Poultry Sci. 55: 303-308.
BIOLOGICAL AVAILABILITY OF FEED GRADE PHOSPHATES USING A CORN-SOYBEAN MEAL BASAL DIET L. A. WOZNIAK, J. M. PENSACK, V. STRYESKI AND R. D. WILBUR
American Cyanamid Company, Agricultural Division, Princeton, New Jersey 08540 (Received for publication July 23, 1976)
ABSTRACT Experiments were conducted to evaluate the biological availability of feed phosphates (dicalcium phosphate and def luorinated rock phosphate) to chicks using a corn-soybean meal diet and the tibia bone ash assay. Phosphoric acid was used as the reference standard. At equal levels of phosphorus supplementation, dicalcium phosphate (18.5 percent P) was significantly (p = 0.05) more bioavailable than defluorinated rock phosphate (18 percent P). POULTRY SCIENCE 56: 366-369,
INTRODUCTION
T
HE investigations of Gillis et al. (1954), Nelson and Walker (1964), and Pensack
Cyphos®—Registered trademark of American Cyanamid Company for its brand of feed phosphates (mixture of dicalcium and monocalcium phosphate).
1977
(1974) have shown that the chick tibia bone ash assay was a sensitive and reproducible method to determine phosphorus bioavailability from inorganic feed phosphate when added to a basal diet containing blood fibrin. The purpose of this study was to determine the bioavailability of feed phosphates to
Downloaded from http://ps.oxfordjournals.org/ at Swinburne University of Technology on May 17, 2015
noted that these data describe the ingredients at the time at which they were incorporated into the 10 experimental diets. The comparison of observed and calculated T.M.E. values is presented in Table 2. The two sets of values are in reasonable agreement with differences ranging from —0.09 to +0.13 kcal./g. of diet. The mean difference is 0.02 kcal./g. which is equivalent to 0.6% of the meanof the observed T.M.E. means. A series of t-tests showed that none of the differences between observed and calculated T.M.E. values was significant at the 5% level of probability. Part of the difference between observed and calculated values may be attributable to slight errors in mixing. This was examined by comparing the observed and calculated gross energy values of the diets (Table 2). The mean difference is 0.04 kcal./g. which is twice the mean difference between the two sets of T.M.E. data. The correlation between the two sets of differences is only 0.414 at 8 degrees of freedom; however, the errors in mixing implied by the gross energy dif-
NOTES
367
RESEARCH NOTES
chicks substituting blood fibrin with soybean meal which is more typical of a practical-type diet and is considerably less expensive. Nelson and Peeler (1961) reported a similar study, but they used a constant calcium-phosphorus ratio instead of a constant calcium concentration as used in this study. MATERIALS AND METHODS
TABLE 1.—Basal diet
Ingredient Ground yellow corn Soybean meal (48% protein) Iodized salt DL methionine Choline chloride (50% supplement) Calcium carbonate' Solka Floe 1 Vitamin A (30,000 I.U./g.) Vitamin D 3 (200,000 I.C.U./g.) Vitamin E ( 4 4 U . / g . ) Vitamin K (menadione) Parvo (3%) folic acid Riboflavin Proferm (0.132 mg./g.) B l 2 Niacinamide Ca pantothenate BHT (butylated hydroxy toluene) Manganese (manganous oxide) Iron (ferrous carbonate) Zinc (zinc oxide) Copper (copper oxide) Iodine (calcium iodate) Cobalt (cobalt carbonate)
Per kilogram diet Grams 604.6 350.0 3.0 1.5 1.0 21.2 17.9 Milligrams 331 5.5 50 2.2 47 13 83.3 27 22 125 62.5 30.0 25.0 3.25 1.75 1.25
'The amounts of calcium carbonate and/or Solka Floe are adjusted when the diet is supplemented with phosphoric acid or inorganic phosphates. The concentration of calcium (1 percent) was kept constant in all of the diets. The concentration of phosphorus in the unsupplemented diet was 0.43 percent.
% P added' % P total % Bone ash2 OTTO (L53 37.3 ± 0.58 0.20 0.63 48.7 ± 0.49 0.30 0.73 52.8 ± 0.42 1 Each treatment consisted of four groups of birds with ten birds per group. 2 Values are means ± standard error. females per pen) with raised wire floors, in a room held at 24° C. Feed and water were supplied ad libitum. The composition of the basal diet is shown in Table 1. Supplementation of the diet with phosphoric acid or feed phosphates was carried out as indicated in Table 2. Total calcium in the final diets was maintained at 1 percent by the addition of calcium carbonate; therefore, the Ca:P ratio was not constant and varied from 1.4:1 to 2.1:1. The chicks were administered the different diets for a period of 20 days, then weighed, sacrificed, and the right tibia was removed for bone ash determination as described for A.O.A.C. vitamin D assay (1970). The biological availability of each feed phosphate was calculated from the phosphoric acid reference curve obtained by plotting percent bone ash against the logarithm of the percentage of added dietary phosphorus (0.1, 0.2, and 0.3 percent added P from phosphoric acid). A lower level (0.05 percent P) of supplementation with phosphoric acid was not included in the linear regression analysis due to a 27 percent mortality associated with a phosphorus deficiency. Phosphoric acid was considered to be 100 percent available. RESULTS AND DISCUSSION The effect of supplementation of the basal corn-soybean meal diet with different levels of phosphoric acid on bone ash of chicks is reported in Table 2 and Figure 1. The dose
Downloaded from http://ps.oxfordjournals.org/ at Swinburne University of Technology on May 17, 2015
Hubbard x Hubbard broiler chicks (dayold) were randomly assigned to electrically heated starting batteries (five males and five
TABLE 2.—Effect of phosphorus levels added as phosphoric acid to corn-soybean meal diet on bone ash of chicks
368
RESEARCH NOTES
60
50
40
• Phosphoric acid - 100%
• Cyphos® £ 4 | x 100 = 93% U.15
< c 30 o
•
Defluorinated phosphate 0.11 x100 - 73% 0.15
20
10
0.10 0.11
_L 0.14 0.15
0.20
0.30
0.40
% Supplementary phosphate added to diet FIG. 1. Determination of bioavailability of inorganic feed phosphates to chicks as measured by bone ash using phosphoric acid as the reference standard.
response curve (Figure 1) obtained with this basal diet is similar to the reference curve reported by Pensack (1974) using a basal diet containing blood fibrin as a protein source. The values for percent bone ash obtained from chicks fed the basal diet supplemented with Cyphos® (dicalcium phosphate—18.5 percent P) or defluorinated rock phosphate (18 percent P) are shown in Table 3. Dicalcium phosphate produced significantly higher bone ash (42.2 percent) than defluorinated rock
phosphate (39.0 percent). Biological availability of the phosphorus in these two feed phosphates was determined using the phosphoric acid reference curve as indicated in Figure 1. At a level equivalent to 0.15 percent added phosphorus, Cyphos® (dicalcium phosphate) was found to be 93 percent as available as phosphoric acid. At the same percentage of added phosphorus (0.15 percent), the defluorinated rock phosphate was only 75 percent as available as
Downloaded from http://ps.oxfordjournals.org/ at Swinburne University of Technology on May 17, 2015
-i-A
369
RESEARCH NOTES
TABLE 3.—Effect of supplementation of corn-soybean meal diet with inorganic feed phosphates on bone ash of chicks Supplement' Cyphos® (dicalciumphosphate 18.5% P) Defluorinated rock phosphate
%P added
%P total
% Bone ash 2
demonstrating that biological values of different phosphorus sources determined with a practical diet are similar to those reported with a purified diet. REFERENCES
0.15
0.58
42.2 ± 0.62a
0.15
0.58
39.0 ± 0.93b
phosphoric acid and also significantly (P = 0.05) less available than dicalcium phosphate. These results confirm and extend those of Pensack (1974) and Nelson and Peeler (1961),
Downloaded from http://ps.oxfordjournals.org/ at Swinburne University of Technology on May 17, 2015
' Each treatment consisted of four groups of birds with ten birds per group. 2 Values are means ± standard error. Averages without common letters are significantly different at P = 0.05.
Association of Official Agricultural Chemists, 1970. Official Methods of Analysis, 11th ed., Washington, D.C. Gillis, M. B., L. C. Norris and G. F. Heuser, 1954. Studies on the biological value of inorganic phosphates. J. Nutr. 52: 115-125. Nelson, T. S., and H. T. Peeler, 1961. The availability of phosphorus from single and combined phosphates to chicks. Poultry Sci. 40: 1321-1328. Nelson, T. S., and A. C. Walker, 1964. The biological evaluation of phosphorus compounds. Poultry Sci. 43: 94-98. Pensack, J. M., 1974. Feed phosphates: biological availability of feed grade phosphates. Poultry Sci. 53: 143-148.