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Calcium and Phosphorus Requirements of Finishing Broilers Using Phosphorus Sources of Low and High Availability1
752
M. F. POOL
100
90
1
Control
£80
\
c V
_l
o70 •
—
- V^_____ Epinephrine Fig. 3
5? 6 0
1
50
1 10 Hours Post Mortem
I 15
i 20
25
FIG. 3. Changes in rest length with time post mortem.
1960a). The mechanism of this second effect and the basic change in the muscle fiber on tenderization or toughening represent the objective of Continuing studies. REFERENCES Bate-Smith, E. C , 1939. Changes in elasticity of mammalian muscle undergoing rigor mortis. J. Physiol. 96: 176-193. Bate-Smith, E. C , and J. R. Bendall, 1949. Factors determining the time course of rigor mortis. J. Physiol. 110: 47-65.
de Fremery, D., and M. F. Pool, 1960a. The tenderization pattern in adrenaline treated poultry. Technical program and abstracts of 20th Annual Meeting, Institute of Food Technologists. Abs. 165, p. 42. de Fremery, D., and M. F. Pool, 1960b. Biochemistry of chicken muscle as related to rigor mortis and tenderization. Food Res. 25: 73-87. de Fremery, D., M. F. Pool, and H. Lineweaver, 1962. Poultry tenderness and post-mortem glycolysis. Proc. 12th World's Poultry Congress, 418-421.
Calcium and Phosphorus Requirements of Finishing Broilers Using Phosphorus Sources of Low and High Availability1 P. W. WALDROUP, C. B. AMMERMAN AND R. H. HARMS Florida Agricultural Experiment Stations, Gainesville, Florida (Received for publication November 27, 1962)
T
HE National Research Council (1960) has suggested that the dietary calcium and phosphorus levels for broilers 0-8 weeks of age be 1.0 and 0.6 percent, 1 Florida Agricultural Journal Series No. 1615.
Experiment
Stations,
respectively. However, requirements as reported by various workers have been quite variable. Calcium requirements have ranged from 0.60 percent (Simco and Stephenson, 1960; Formica el al., 1961) to levels as high as 2.14 percent (Sherwood, 1932). Phosphorus requirements have
C A & P R E Q U I R E M E N T S OF F I N I S H I N G B R O I L E R S
been reported to range from 0.50 percent (Wilgus, 1931) to 0.87 percent (Sherwood, 1932). The experiments reported herein were conducted to study the calcium and phosphorus requirements of broiler type chicks for the period of four to eight weeks of age, and to study the effect of varying one mineral upon the requirement of the other. EXPERIMENTAL PROCEDURE Two experiments involving four trials were conducted. Two of these trials were designed to determine the requirements for calcium and phosphorus using a phosphorus source considered to be highly available, while two were designed to determine the requirements for these minerals when phosphate sources of both high and low availability were used. All chicks used in these trials were meat-type broilers obtained from a local hatchery. From one day old until four weeks of age, they were fed a basal diet which contained 0.6 percent phosphorus and 1.0 percent calcium. At the s t a r t of each of the trials, all chicks were randomly assigned to the experimental treatments, and all pens were adjusted as closely as possible for uniform body weight. Unheated b a t t e r y brooders with raised wire floors were used in each of the tests. Body weight gain and efficiency of feed utilization were used as criteria of calcium and phosphorus adequacy. The chicks were individually weighed at four and eight weeks of age, and feed consumption per pen was determined. From these measurements, body weight gains and feed required to produce a unit of gain were determined. The experimental diets were mixed at the beginning of each 4-week trial and used throughout the trial. These diets were kept iso-caloric and iso-nitrogenous
753
by varying the level of corn, soybean oil meal and animal fat. Values according to Titus (1955) were used in making these adjustments. The diets were mixed the day before the trial began, and stored in galvanized buckets in the battery room. Triplicate pens of 5 male and 5 female chicks were assigned to each dietary treatment in respective trials. The results of these trials were subjected to the analysis of variance as outlined by Snedecor (1956). Since there were no diet X trial interactions, data from the two trials in each experiment were combined for this presentation. Significant differences between treatment means were determined by the multiple range test of Duncan (1955). Experiment 1: This experiment, involving duplicate trials, was conducted to determine the calcium and phosphorus requirements of finishing broilers when the supplemental phosphorus was from a source considered to be highly available (feed grade dicalcium phosphate). A 3 X 4 factorial arrangement of treatments was used involving three phosphorus levels (0.50, 0.60, 0.70 percent total phosphorus) and four levels of calcium (0.60, 0.90, 1.20 and 1.50 percent). The experimental diets were produced by blending diets 1 through 4 (Table 1) in proportions necessary to attain the desired levels of calcium and phosphorus. Experiment 2: This experiment involved duplicate trials and was conducted to determine the calcium and phosphorus requirements of finishing broilers when using phosphorus sources of high and low availability. The experimental diets contained either soft phosphate (supplemented to 0.60 and 0.80 percent total phosphorus) or defluorinated phosphate (supplemented to 0.40 and 0.80 percent
754
P. W. WALDROUP, C. B. AMMERMAN AND R. H. HARMS TABLE 1.—Composition of Diets Ingredients
Yellow corn Soybean oil meal (50% protein) Stabilized animal fat Alfalfa meal (17% protein) Dicalcium phosphate (18% P + 2 6 % Ca) Defluorinated phos. (18% P + 3 4 % Ca) Soft phosphate (10% P + 2 0 % Ca) Ground limestone Iodized salt Micro-ingred. mix 1
54.24
58.29
53.59
62.43
52.64
58.74
45.
65.42
59.32
64.34
54.78
32.45 2,94
33.25 4.53
32.54 3.21
33.33 4.76
29.00 2.00
30.68 5.30
29.60 3.24
32.00 7.58
28.53 1.10
29.53 3.05
28.75 1.33
30.35 4.54
3.00
3.00
3.00
3.00
3.00
3.00
3.00
3.00
3.00
3.00
3.00
3.00
0.53
0.56
1.66
1.66 0.06
0.09
1.20
1.20
— 0.40 0.90
— 2.36 0.40 0.90
2.12 0.16 0.40 0.90
2.25 4.83 0.40 0.90
0.40 0.90
4.35 5.93 0.40 0.90
0.59 0.40 0.90
3.71 0.40 0.90
0.08 0.40 0.90
4.83 0.40 0.90
0.78 0.40 0.90
3.12 0.40 0.90
22.0 22.0 20.6 20.6 20.6 20.6 20.6 20.6 20.6 20.6 22.1 22.0 1,000. 11,000. 1[,000. 983. 981. 983. 985. 986. 984. 983. 983. 11,000. 0.50 0.70 0.70 0.60 0.60 0.80 0.80 0.40 0.40 0.60 0.60 0.50 1.50 0.60 1.50 0.60 2.40 0.80 3.20 0.40 1.60 0.60 2.40 0.60
% Protein Cal. Prod. Energy % Phosphorus % Calcium
1 Micro-ingredient mix supplied per pound of diet: 3,150 I.TJ. vitamin A, 350 mg. choline, 18 mg. niacin, 340 I.C.U. vitamin D3, 2 mg. riboflavin, 9 mg. calcium pantothenate, 10 meg. vitamin Biz, 80 mg. manganese sulfate, 0.0125% santoquin, 9 mg. ron, 0.9 mg. copper, 90 meg. cobalt, 5 mg. iodine, and 45 meg. zinc.
total phosphorus) with a range of calciumphosphorus ratios (1.0:1, 1.5:1, 2.0:1, and 4.0:1). The diets were prepared by blending diets 5 through 12 (Table 1) in proporTABLE 2.—Four to eight week weight gain of broilertype chicks fed various calcium and phosphorus levels (Exp. 1) % phosphi3 r u s
%
calcium
0.60
0.90
1.20
1.50
All
0.50
0.60
0.70
All
M F
(Body weight gain (grams)1 883 858 884 875 697 696 690 694
Av.
79Qabcd
777cd
787i>cd
785
M F
855 673
897 729
889 716
880 706
Av.
764d
813"
803 ab
793
M F
800 638
889 708
890 713
860 686
Av.
7193
798abc
802ab
773
M F
783 654
873 718
855 707
837 685
Av.
718s
795al,cd
769cd
761
M F
830 666
879 712
880 700
863 693
Av.
748
796
790
778
1 Means bearing the same superscripts do not differ significantly.
tions necessary to attain the desired level of calcium and phosphorus. RESULTS AND DISCUSSION Experiment 1: The results of these trials indicated that 0.50 percent total phosphorus using a highly available source (dicalcium phosphate) promoted the best growth for broilers during the period of four to eight weeks of age when the level of calcium was 0.6 percent (Table 2). However, with a level of 0.9, 1.2 or 1.5 percent calcium a level of 0.6 percent phosphorus was required for best growth. This is similar to levels which promoted the best growth as reported by Simco and Stephenson (1960), White-Stephens et al. (1960) and Formica et al. (1961). This level was adequate for both male and female chicks as evidenced by the lack of a phosphorus X sex interaction. A calcium level of 0.60 percent resulted in normal growth rate with a level of 0.50 percent phosphorus (Table 2). This agrees with the data reported by Simco and Stephenson (1960), White-Stephens et al. (1960), and Formica et al. (1961). However, levels of 0.90 and 1.2 percent calcium resulted in best growth when the diet contained 0.6 or 0.7 percent phosphorus
755
CA & P REQUIREMENTS OF FINISHING BROILERS TABLE 3.—Four to eight week feed utilization of broiler-type chicks fed various calcium and phosphorus levels (Exp. 1) % phosphorus
%
calcium
0.50
0.60
0.70
All
0.60 0.90 1.20 1.50
(Grams feed/gram gain) 1.95" 2.09 b 2.Wd 2.05 b 2.05 b 2.04 b 2.16<=d 2.04 b 2.05 b 2.19' 1 2.02 b 2.08 bc
All
2.09
2.05
2.08
1
2.06 2.05 2.08 2.10 2.07
1 Means bearing the same superscripts do not differ significantly.
which would agree with data reported by Watts and Davis (I960),and Edwards et al. (1960). When the phosphorus level was marginal (less than 0.6 percent), higher levels of calcium lowered weight gains as compared to the 0.60 percent level of calcium. This effect has been previously reported by Vandepopuliere et al. (1961).
Feed utilization, as measured by grams of feed required to produce a gram of gain, was improved each time an improvement in body weight gains was observed (Table 3). The level of 0.60 percent total phosphorus resulted in the most efficient feed utilization over all levels of phosphorus, while 0.90 percent calcium produced the most efficient utilization over all calcium levels. When both calcium and phosphorus levels were considered, the most efficient use of feed resulted when a diet containing 0.50 percent phosphorus and 0.60 percent calcium was fed. Experiment 2: Chicks fed diets supplemented with soft phosphate to a level of 0.60 percent total phosphorus gained significantly less as compared to those receiving the same level from defluorinated phosphate (Table 4). When the level of phosphorus in the diet was increased to
TABLE 4.—Four to eight week weight gain of broiler-type chicks fed different phosphorus sources at various calcium and phosphorus levels (Exp. 2) Phosphorus source
Calcium : Phosphorus ratio % phos. 1.0:1
1.5:1
2.0:1
4.0:1
All
:
Soft Phosphate
Soft Phosphate
Defluorinated Phosphate
Defluorinated Phosphate
0.60
0.80
0.40
0.60
All
(Body weight gain (grams) 728 760 • 625 674 630 507
M F
726 655
Av.
690d
701 d
695*
566"
663
M F
843 696
844 689
798 639
630 526
779 639
Av.
769°
767"
719
578"
709
M F
733 615
708 557
693 552
622 507
690 557
Av.
674°d
633b°
623b
565»
623
M F
820 723
880 721
920 704
756 647
844 699
Av.
771«
800"
812e
701 d
772
M F
781 672
790 660
793 631
658 547
756 628
Av.
727
725
712
603
692
Means bearing the same superscripts do not differ significantly.
710 617
756
P. W. W A L D R O U P , C. B. AMMERMAN AND R. H.
HARMS
TABLE 5.—Four lo eight week feed utilization of broiler-type chicks fed different phosphorus sources at various calcium and phosphorus levels {Exp. 2) Phosphorus source
Calcium: Phosphorus ratio % Phos.
1.0:1
1.5:1
2.0:1
(Grams feed/gram gain) 2.31* b 2.52»b 2.37 ab 2.37 ab
4.0:1
All
2.62" 2.55»b
2.46 2.41 2.49 2.33
1
Soft Phosphate
0.60 0.80
2.38»b 2.36a''
Defluorinated Phosphate
0.40 0.60
2.44»b 2.37*b
2.48ab 2.28 b
2.48»b 2.26 b
2.56»b 2.43»b
All
2.39
2.36
2.41
2.54
1
Means bearing the same superscript do not differ significantly.
0.80 percent using soft phosphate, weight gains of chicks were equal to those fed the 0.60 percent phosphorus diet using defluorinated phosphate, provided the calcium: phosphorus ratios did not exceed 1.5:1. These results are similar to findings of W a t t s and Davis (1960), who reported t h a t a 0.70% phosphorus diet using soft phosphate was comparable to equal levels from dicalcium phosphate. However, when the calcium:phosphorus ratio was increased to 2 : 1 , growth rate of birds receiving 0.6% phosphorus from defluorinated phosphate was significantly better than obtained with 0 . 8 % phosphorus from soft phosphate. Increased calcium: phosphorus ratios tended to restrict body weight gain of chicks (Table 4). Chicks grown on soft phosphate diets were more sensitive to increased calcium:phosphorus ratios than were those grown on defluorinated phosphate diets. This resulted in a highly significant phosphorus source X ratio interaction. As the phosphorus level of the diet approached the phosphorus requirement, less effect of increased calcium p h o s phorus ratios was noted, which resulted in a highly significant phosphorus level X ratio interaction. In all cases, a 4 : 1 calcium: phosphorus ratio restricted growth. The optimum calcium: phosphorus ratio
for chicks fed the diet containing 0.Suy o phosphorus using soft phosphate was between 1:1 and 1.5:1 (Table 4), or a calcium level between 0.80 and 1.20 percent. The body weight gain of chicks grown on these diets were numerically less than those grown on the 0.60 percent diet using defluorinated phosphate at comparable ratios but did not differ significantly. Higher calcium:phosphorus ratios significantly depressed body weight gains. When chicks were fed diets containing 0.60% phosphorus using defluorinated phosphate, calcium levels u p to 1.2% slightly increased body weight gains over those fed 0.6% calcium. However, this increase was not significant. Improvement in feed utilization was obtained each time an improvement in weight gains was observed (Table 5). In general, few significant differences were noted. SUMMARY AND CONCLUSIONS
Four trials were conducted to determine the calcium and phosphorus requirements of broilers from 4 to 8 weeks of age when using sources of highly available phosphorus (dicalcium phosphate and defluorinated phosphate) and a source of low availability (soft phosphate). Results of these trials indicate that 0.50
CA & P REQUIREMENTS OF FINISHING BROILERS
percent total phosphorus using highlyavailable sources was adequate for broilers during this period when the diet contained 0.6 percent calcium. However, better growth was obtained with a 0.6 percent total phosphorus when higher levels of calcium was used. A calcium level of 0.6 percent was adequate with 0.5 percent phosphorus, with 0.9 percent calcium giving better results with higher levels of phosphorus. It is concluded that the requirement for either calcium or phosphorus can not be stated without specifying the level of the other mineral. A level of 0.8 percent phosphorus from soft phosphate produced broilers numerically, but not significantly lighter than those grown on diets containing 0.6 percent phosphorus from defluorinated phosphate. The calcium:phosphorus ratio of the diet significantly affected body weight gains and feed utilization. Chicks on the lower phosphorus levels were affected to a greater degree by changes in the calcium : phosphorus ratio, while those on diets containing soft phosphate were affected to a greater degree than those containing defluorinated phosphate. ACKNOWLEDGMENTS
This work was supported in part by a grant-in-aid from Smith-Douglass Company. The dicalcium phosphate and defluorinated phosphate were furnished by Smith-Douglass Company and the soft
757
phosphate by the Soft Phosphate' Research Institute. REFERENCES Duncan, D. R., 1955. Multiple range and multiple F tests. Biometrics, 11: 1-12. Edwards, H. M., Jr., W. S. Dunahoo, J. L. Carmon and H. L. Fuller, 1960. Effect of protein, energy, and fat content of the ration on calcium utilization. Poultry Sci. 39: 1389-1394. Formica, S. D., M. J. Smidt, M. M. Bacharach, W. F. Davin and J. C. Fritz, 1961. Calcium and phosphorus requirements of growing turkeys and chickens. Poultry Sci. 40: 1402-1403. National Research Council, 1960. Nutrient requirements for domestic animals. Nutrient requirements for poultry. Washington, D. C. Sherwood, R. M., 1932. Lime and phosphoric acid requirements for chicks. Texas Agricultural Experiment Station Bulletin 462. Simco, T. F., E. L. Stephenson, 1960. Re-evaluation of the calcium and phosphorus requirements for chicks. Poultry Sci. 39: 1295. Snedecor, G. W., 1956. Statistical Methods. Iowa State College Press. Ames, Iowa. Titus, H. W., 1955. The Scientific Feeding of Chickens. The Interstate Printers and Publishers, Danville, Illinois. Watts, A. B., and B. H. Davis, 1960. The effect of level of calcium and source of phosphorus on growth of broilers. Poultry Sci. 39: 1304. White-Stephens, R. H., J. M. Pensack and E. L. R. Stokstad, 1960. The calcium and phosphorus requirement of the chick. Poultry Sci. 39: 1305. Wilgus, H. S., 1931. The quantitative requirements of the growing chick for calcium and phosphorus. Poultry Sci. 10: 108. Vandepopuliere, J. M., C. B. Ammerman and R. H. Harms, 1961. The relationship of calciumphosphorus ratios to the utilization of plant and inorganic phosphorus by the chick. Poultry Sci. 40: 951-957.
NEWS AND
NOTES
'rom page 731) left college as many returned veterans did (we had no G.I. Bill after our World War)." The next 7 months were spent working at an oil refinery and through the wheat harvest in Northwestern Oklahoma. "After getting a taste of hard physical work, he showed enough intelligence, or laziness, to return to A & M," graduating with a B.S. degree in 1922.
As an undergraduate he did some teaching, and worked and lived at the poultry farm for two years. On graduation he was appointed to the staff of the Poultry Department as Instructor, "even though he graduated in animal husbandry and had been on the livestock judging team. (Won $57.00 in the 1922 Intercollegiate Contest at Ft. Worth.)" During the
(Continued on page 769)
M. F. POOL
100
90
1
Control
£80
\
c V
_l
o70 •
—
- V^_____ Epinephrine Fig. 3
5? 6 0
1
50
1 10 Hours Post Mortem
I 15
i 20
25
FIG. 3. Changes in rest length with time post mortem.
1960a). The mechanism of this second effect and the basic change in the muscle fiber on tenderization or toughening represent the objective of Continuing studies. REFERENCES Bate-Smith, E. C , 1939. Changes in elasticity of mammalian muscle undergoing rigor mortis. J. Physiol. 96: 176-193. Bate-Smith, E. C , and J. R. Bendall, 1949. Factors determining the time course of rigor mortis. J. Physiol. 110: 47-65.
de Fremery, D., and M. F. Pool, 1960a. The tenderization pattern in adrenaline treated poultry. Technical program and abstracts of 20th Annual Meeting, Institute of Food Technologists. Abs. 165, p. 42. de Fremery, D., and M. F. Pool, 1960b. Biochemistry of chicken muscle as related to rigor mortis and tenderization. Food Res. 25: 73-87. de Fremery, D., M. F. Pool, and H. Lineweaver, 1962. Poultry tenderness and post-mortem glycolysis. Proc. 12th World's Poultry Congress, 418-421.
Calcium and Phosphorus Requirements of Finishing Broilers Using Phosphorus Sources of Low and High Availability1 P. W. WALDROUP, C. B. AMMERMAN AND R. H. HARMS Florida Agricultural Experiment Stations, Gainesville, Florida (Received for publication November 27, 1962)
T
HE National Research Council (1960) has suggested that the dietary calcium and phosphorus levels for broilers 0-8 weeks of age be 1.0 and 0.6 percent, 1 Florida Agricultural Journal Series No. 1615.
Experiment
Stations,
respectively. However, requirements as reported by various workers have been quite variable. Calcium requirements have ranged from 0.60 percent (Simco and Stephenson, 1960; Formica el al., 1961) to levels as high as 2.14 percent (Sherwood, 1932). Phosphorus requirements have
C A & P R E Q U I R E M E N T S OF F I N I S H I N G B R O I L E R S
been reported to range from 0.50 percent (Wilgus, 1931) to 0.87 percent (Sherwood, 1932). The experiments reported herein were conducted to study the calcium and phosphorus requirements of broiler type chicks for the period of four to eight weeks of age, and to study the effect of varying one mineral upon the requirement of the other. EXPERIMENTAL PROCEDURE Two experiments involving four trials were conducted. Two of these trials were designed to determine the requirements for calcium and phosphorus using a phosphorus source considered to be highly available, while two were designed to determine the requirements for these minerals when phosphate sources of both high and low availability were used. All chicks used in these trials were meat-type broilers obtained from a local hatchery. From one day old until four weeks of age, they were fed a basal diet which contained 0.6 percent phosphorus and 1.0 percent calcium. At the s t a r t of each of the trials, all chicks were randomly assigned to the experimental treatments, and all pens were adjusted as closely as possible for uniform body weight. Unheated b a t t e r y brooders with raised wire floors were used in each of the tests. Body weight gain and efficiency of feed utilization were used as criteria of calcium and phosphorus adequacy. The chicks were individually weighed at four and eight weeks of age, and feed consumption per pen was determined. From these measurements, body weight gains and feed required to produce a unit of gain were determined. The experimental diets were mixed at the beginning of each 4-week trial and used throughout the trial. These diets were kept iso-caloric and iso-nitrogenous
753
by varying the level of corn, soybean oil meal and animal fat. Values according to Titus (1955) were used in making these adjustments. The diets were mixed the day before the trial began, and stored in galvanized buckets in the battery room. Triplicate pens of 5 male and 5 female chicks were assigned to each dietary treatment in respective trials. The results of these trials were subjected to the analysis of variance as outlined by Snedecor (1956). Since there were no diet X trial interactions, data from the two trials in each experiment were combined for this presentation. Significant differences between treatment means were determined by the multiple range test of Duncan (1955). Experiment 1: This experiment, involving duplicate trials, was conducted to determine the calcium and phosphorus requirements of finishing broilers when the supplemental phosphorus was from a source considered to be highly available (feed grade dicalcium phosphate). A 3 X 4 factorial arrangement of treatments was used involving three phosphorus levels (0.50, 0.60, 0.70 percent total phosphorus) and four levels of calcium (0.60, 0.90, 1.20 and 1.50 percent). The experimental diets were produced by blending diets 1 through 4 (Table 1) in proportions necessary to attain the desired levels of calcium and phosphorus. Experiment 2: This experiment involved duplicate trials and was conducted to determine the calcium and phosphorus requirements of finishing broilers when using phosphorus sources of high and low availability. The experimental diets contained either soft phosphate (supplemented to 0.60 and 0.80 percent total phosphorus) or defluorinated phosphate (supplemented to 0.40 and 0.80 percent
754
P. W. WALDROUP, C. B. AMMERMAN AND R. H. HARMS TABLE 1.—Composition of Diets Ingredients
Yellow corn Soybean oil meal (50% protein) Stabilized animal fat Alfalfa meal (17% protein) Dicalcium phosphate (18% P + 2 6 % Ca) Defluorinated phos. (18% P + 3 4 % Ca) Soft phosphate (10% P + 2 0 % Ca) Ground limestone Iodized salt Micro-ingred. mix 1
54.24
58.29
53.59
62.43
52.64
58.74
45.
65.42
59.32
64.34
54.78
32.45 2,94
33.25 4.53
32.54 3.21
33.33 4.76
29.00 2.00
30.68 5.30
29.60 3.24
32.00 7.58
28.53 1.10
29.53 3.05
28.75 1.33
30.35 4.54
3.00
3.00
3.00
3.00
3.00
3.00
3.00
3.00
3.00
3.00
3.00
3.00
0.53
0.56
1.66
1.66 0.06
0.09
1.20
1.20
— 0.40 0.90
— 2.36 0.40 0.90
2.12 0.16 0.40 0.90
2.25 4.83 0.40 0.90
0.40 0.90
4.35 5.93 0.40 0.90
0.59 0.40 0.90
3.71 0.40 0.90
0.08 0.40 0.90
4.83 0.40 0.90
0.78 0.40 0.90
3.12 0.40 0.90
22.0 22.0 20.6 20.6 20.6 20.6 20.6 20.6 20.6 20.6 22.1 22.0 1,000. 11,000. 1[,000. 983. 981. 983. 985. 986. 984. 983. 983. 11,000. 0.50 0.70 0.70 0.60 0.60 0.80 0.80 0.40 0.40 0.60 0.60 0.50 1.50 0.60 1.50 0.60 2.40 0.80 3.20 0.40 1.60 0.60 2.40 0.60
% Protein Cal. Prod. Energy % Phosphorus % Calcium
1 Micro-ingredient mix supplied per pound of diet: 3,150 I.TJ. vitamin A, 350 mg. choline, 18 mg. niacin, 340 I.C.U. vitamin D3, 2 mg. riboflavin, 9 mg. calcium pantothenate, 10 meg. vitamin Biz, 80 mg. manganese sulfate, 0.0125% santoquin, 9 mg. ron, 0.9 mg. copper, 90 meg. cobalt, 5 mg. iodine, and 45 meg. zinc.
total phosphorus) with a range of calciumphosphorus ratios (1.0:1, 1.5:1, 2.0:1, and 4.0:1). The diets were prepared by blending diets 5 through 12 (Table 1) in proporTABLE 2.—Four to eight week weight gain of broilertype chicks fed various calcium and phosphorus levels (Exp. 1) % phosphi3 r u s
%
calcium
0.60
0.90
1.20
1.50
All
0.50
0.60
0.70
All
M F
(Body weight gain (grams)1 883 858 884 875 697 696 690 694
Av.
79Qabcd
777cd
787i>cd
785
M F
855 673
897 729
889 716
880 706
Av.
764d
813"
803 ab
793
M F
800 638
889 708
890 713
860 686
Av.
7193
798abc
802ab
773
M F
783 654
873 718
855 707
837 685
Av.
718s
795al,cd
769cd
761
M F
830 666
879 712
880 700
863 693
Av.
748
796
790
778
1 Means bearing the same superscripts do not differ significantly.
tions necessary to attain the desired level of calcium and phosphorus. RESULTS AND DISCUSSION Experiment 1: The results of these trials indicated that 0.50 percent total phosphorus using a highly available source (dicalcium phosphate) promoted the best growth for broilers during the period of four to eight weeks of age when the level of calcium was 0.6 percent (Table 2). However, with a level of 0.9, 1.2 or 1.5 percent calcium a level of 0.6 percent phosphorus was required for best growth. This is similar to levels which promoted the best growth as reported by Simco and Stephenson (1960), White-Stephens et al. (1960) and Formica et al. (1961). This level was adequate for both male and female chicks as evidenced by the lack of a phosphorus X sex interaction. A calcium level of 0.60 percent resulted in normal growth rate with a level of 0.50 percent phosphorus (Table 2). This agrees with the data reported by Simco and Stephenson (1960), White-Stephens et al. (1960), and Formica et al. (1961). However, levels of 0.90 and 1.2 percent calcium resulted in best growth when the diet contained 0.6 or 0.7 percent phosphorus
755
CA & P REQUIREMENTS OF FINISHING BROILERS TABLE 3.—Four to eight week feed utilization of broiler-type chicks fed various calcium and phosphorus levels (Exp. 1) % phosphorus
%
calcium
0.50
0.60
0.70
All
0.60 0.90 1.20 1.50
(Grams feed/gram gain) 1.95" 2.09 b 2.Wd 2.05 b 2.05 b 2.04 b 2.16<=d 2.04 b 2.05 b 2.19' 1 2.02 b 2.08 bc
All
2.09
2.05
2.08
1
2.06 2.05 2.08 2.10 2.07
1 Means bearing the same superscripts do not differ significantly.
which would agree with data reported by Watts and Davis (I960),and Edwards et al. (1960). When the phosphorus level was marginal (less than 0.6 percent), higher levels of calcium lowered weight gains as compared to the 0.60 percent level of calcium. This effect has been previously reported by Vandepopuliere et al. (1961).
Feed utilization, as measured by grams of feed required to produce a gram of gain, was improved each time an improvement in body weight gains was observed (Table 3). The level of 0.60 percent total phosphorus resulted in the most efficient feed utilization over all levels of phosphorus, while 0.90 percent calcium produced the most efficient utilization over all calcium levels. When both calcium and phosphorus levels were considered, the most efficient use of feed resulted when a diet containing 0.50 percent phosphorus and 0.60 percent calcium was fed. Experiment 2: Chicks fed diets supplemented with soft phosphate to a level of 0.60 percent total phosphorus gained significantly less as compared to those receiving the same level from defluorinated phosphate (Table 4). When the level of phosphorus in the diet was increased to
TABLE 4.—Four to eight week weight gain of broiler-type chicks fed different phosphorus sources at various calcium and phosphorus levels (Exp. 2) Phosphorus source
Calcium : Phosphorus ratio % phos. 1.0:1
1.5:1
2.0:1
4.0:1
All
:
Soft Phosphate
Soft Phosphate
Defluorinated Phosphate
Defluorinated Phosphate
0.60
0.80
0.40
0.60
All
(Body weight gain (grams) 728 760 • 625 674 630 507
M F
726 655
Av.
690d
701 d
695*
566"
663
M F
843 696
844 689
798 639
630 526
779 639
Av.
769°
767"
719
578"
709
M F
733 615
708 557
693 552
622 507
690 557
Av.
674°d
633b°
623b
565»
623
M F
820 723
880 721
920 704
756 647
844 699
Av.
771«
800"
812e
701 d
772
M F
781 672
790 660
793 631
658 547
756 628
Av.
727
725
712
603
692
Means bearing the same superscripts do not differ significantly.
710 617
756
P. W. W A L D R O U P , C. B. AMMERMAN AND R. H.
HARMS
TABLE 5.—Four lo eight week feed utilization of broiler-type chicks fed different phosphorus sources at various calcium and phosphorus levels {Exp. 2) Phosphorus source
Calcium: Phosphorus ratio % Phos.
1.0:1
1.5:1
2.0:1
(Grams feed/gram gain) 2.31* b 2.52»b 2.37 ab 2.37 ab
4.0:1
All
2.62" 2.55»b
2.46 2.41 2.49 2.33
1
Soft Phosphate
0.60 0.80
2.38»b 2.36a''
Defluorinated Phosphate
0.40 0.60
2.44»b 2.37*b
2.48ab 2.28 b
2.48»b 2.26 b
2.56»b 2.43»b
All
2.39
2.36
2.41
2.54
1
Means bearing the same superscript do not differ significantly.
0.80 percent using soft phosphate, weight gains of chicks were equal to those fed the 0.60 percent phosphorus diet using defluorinated phosphate, provided the calcium: phosphorus ratios did not exceed 1.5:1. These results are similar to findings of W a t t s and Davis (1960), who reported t h a t a 0.70% phosphorus diet using soft phosphate was comparable to equal levels from dicalcium phosphate. However, when the calcium:phosphorus ratio was increased to 2 : 1 , growth rate of birds receiving 0.6% phosphorus from defluorinated phosphate was significantly better than obtained with 0 . 8 % phosphorus from soft phosphate. Increased calcium: phosphorus ratios tended to restrict body weight gain of chicks (Table 4). Chicks grown on soft phosphate diets were more sensitive to increased calcium:phosphorus ratios than were those grown on defluorinated phosphate diets. This resulted in a highly significant phosphorus source X ratio interaction. As the phosphorus level of the diet approached the phosphorus requirement, less effect of increased calcium p h o s phorus ratios was noted, which resulted in a highly significant phosphorus level X ratio interaction. In all cases, a 4 : 1 calcium: phosphorus ratio restricted growth. The optimum calcium: phosphorus ratio
for chicks fed the diet containing 0.Suy o phosphorus using soft phosphate was between 1:1 and 1.5:1 (Table 4), or a calcium level between 0.80 and 1.20 percent. The body weight gain of chicks grown on these diets were numerically less than those grown on the 0.60 percent diet using defluorinated phosphate at comparable ratios but did not differ significantly. Higher calcium:phosphorus ratios significantly depressed body weight gains. When chicks were fed diets containing 0.60% phosphorus using defluorinated phosphate, calcium levels u p to 1.2% slightly increased body weight gains over those fed 0.6% calcium. However, this increase was not significant. Improvement in feed utilization was obtained each time an improvement in weight gains was observed (Table 5). In general, few significant differences were noted. SUMMARY AND CONCLUSIONS
Four trials were conducted to determine the calcium and phosphorus requirements of broilers from 4 to 8 weeks of age when using sources of highly available phosphorus (dicalcium phosphate and defluorinated phosphate) and a source of low availability (soft phosphate). Results of these trials indicate that 0.50
CA & P REQUIREMENTS OF FINISHING BROILERS
percent total phosphorus using highlyavailable sources was adequate for broilers during this period when the diet contained 0.6 percent calcium. However, better growth was obtained with a 0.6 percent total phosphorus when higher levels of calcium was used. A calcium level of 0.6 percent was adequate with 0.5 percent phosphorus, with 0.9 percent calcium giving better results with higher levels of phosphorus. It is concluded that the requirement for either calcium or phosphorus can not be stated without specifying the level of the other mineral. A level of 0.8 percent phosphorus from soft phosphate produced broilers numerically, but not significantly lighter than those grown on diets containing 0.6 percent phosphorus from defluorinated phosphate. The calcium:phosphorus ratio of the diet significantly affected body weight gains and feed utilization. Chicks on the lower phosphorus levels were affected to a greater degree by changes in the calcium : phosphorus ratio, while those on diets containing soft phosphate were affected to a greater degree than those containing defluorinated phosphate. ACKNOWLEDGMENTS
This work was supported in part by a grant-in-aid from Smith-Douglass Company. The dicalcium phosphate and defluorinated phosphate were furnished by Smith-Douglass Company and the soft
757
phosphate by the Soft Phosphate' Research Institute. REFERENCES Duncan, D. R., 1955. Multiple range and multiple F tests. Biometrics, 11: 1-12. Edwards, H. M., Jr., W. S. Dunahoo, J. L. Carmon and H. L. Fuller, 1960. Effect of protein, energy, and fat content of the ration on calcium utilization. Poultry Sci. 39: 1389-1394. Formica, S. D., M. J. Smidt, M. M. Bacharach, W. F. Davin and J. C. Fritz, 1961. Calcium and phosphorus requirements of growing turkeys and chickens. Poultry Sci. 40: 1402-1403. National Research Council, 1960. Nutrient requirements for domestic animals. Nutrient requirements for poultry. Washington, D. C. Sherwood, R. M., 1932. Lime and phosphoric acid requirements for chicks. Texas Agricultural Experiment Station Bulletin 462. Simco, T. F., E. L. Stephenson, 1960. Re-evaluation of the calcium and phosphorus requirements for chicks. Poultry Sci. 39: 1295. Snedecor, G. W., 1956. Statistical Methods. Iowa State College Press. Ames, Iowa. Titus, H. W., 1955. The Scientific Feeding of Chickens. The Interstate Printers and Publishers, Danville, Illinois. Watts, A. B., and B. H. Davis, 1960. The effect of level of calcium and source of phosphorus on growth of broilers. Poultry Sci. 39: 1304. White-Stephens, R. H., J. M. Pensack and E. L. R. Stokstad, 1960. The calcium and phosphorus requirement of the chick. Poultry Sci. 39: 1305. Wilgus, H. S., 1931. The quantitative requirements of the growing chick for calcium and phosphorus. Poultry Sci. 10: 108. Vandepopuliere, J. M., C. B. Ammerman and R. H. Harms, 1961. The relationship of calciumphosphorus ratios to the utilization of plant and inorganic phosphorus by the chick. Poultry Sci. 40: 951-957.
NEWS AND
NOTES
'rom page 731) left college as many returned veterans did (we had no G.I. Bill after our World War)." The next 7 months were spent working at an oil refinery and through the wheat harvest in Northwestern Oklahoma. "After getting a taste of hard physical work, he showed enough intelligence, or laziness, to return to A & M," graduating with a B.S. degree in 1922.
As an undergraduate he did some teaching, and worked and lived at the poultry farm for two years. On graduation he was appointed to the staff of the Poultry Department as Instructor, "even though he graduated in animal husbandry and had been on the livestock judging team. (Won $57.00 in the 1922 Intercollegiate Contest at Ft. Worth.)" During the
(Continued on page 769)