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The Influence of Feed Efficiency on the Phosphorus Requirement for Growth and Bone Calcification in the Chick1
POULTRY SCIENCE September, 1953, Vol. 32, N o . 5 •
H. FISHER, 2 E. P. SINGSEN AND L. D. MATTERSON Storrs Agricultural Experiment Station, Poultry Department, University of Connecticut, Storrs, Connecticut (Received for publication October 30, 1952)
E
VER since the development and widespread use of high energy broiler and starter rations, the adequacy of many specific nutrients in those rations has been open to some questioning. On the basis of the greater gain per unit of feed consumed on the high energy rations over the standard type ration in use in 1944-45, a three pound bird consumes approximately three fourths the nutrients consumed by a three pound bird on older type rations. Singsen (1951) believed that today's birds are growing on the margin of safety provided in earlier nutrient recommendations. One of the nutrient recommendations of the National Research Council believed by Singsen (1951) to be critical is for the mineral phosphorus which has been the subject of the present investigation. Two exploratory experiments were conducted to find a low P ration that would support maximum growth and that could be changed in its 1 Supported in part by grants from the Yantic Grain & Products Co., Norwich, Connecticut, and Merck & Co., Inc., Rahway, New Jersey. 2 Present address, Department of Animal Science, University of Illinois, TJrbana, Illinois.
749
energy content without changing other nutrients so as to give the equivalent of both the high energy ration of today as well as the older type low energy ration. The approach used in the experiment to be presented was one of comparing growth and calcification at increasing levels of phosphorus on two rations that were alike except in their energy content and which were thought to represent the 1944-45 standard type ration, as well as the present day high energy type of ration. EXPERIMENTAL
The experimental design is given in Table 1. Three hundred male chicks from the University farm flock of New Hampshire males X Barred Rock females were randomly assigned into twelve lots of twenty-five birds each. The chicks were wingbanded, weighed and then placed in a metal chick starting battery unit, water and feed being supplied ad libitum. The birds were weighed individually at weekly intervals for four weeks; at two weeks seven birds were randomly removed from each lot and sacrificed for bone ash. At four weeks, the end of the experiment,
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The Influence of Feed Efficiency on the Phosphorus Requirement for Growth and Bone Calcification in the Chick1
750
H. FISHER, E. P. SINGSEN AND L. D. MATTERSON TABLE 1.—Experimental design
TABLE 2.—Percentage composition of basal rations
Level of P (%) Basal ration
0.24
0.35
0.40
0.45
Rations 0.50
Ingredients
0.60
Lot number High energy A Low energy B
1
4
5
6
7
10
11
12
B Parts by weight
67.07 11.00 2.00 2.50
42.07 25.00 11.00 .00 .50
2.00 2.00 8.00 1.00 0.50
00 00 8.00 1.00 0.50
0.25 0.0125
0.25 0.0125
Variable
Variable
* Per 100 lbs. of feed: choline chloride (25%) 200 gm., niacin 0.9 gm., calcium pantothenate 50 mg., vitamin B21 (Merck 12.5 mg./lb.) 26 gm., procaine penicillin 0.315 gm. Phosphorus analysis 0.24% for both rations Calcium analysis 0.20% for both rations f The Quaker Oats Co., Chicago, Illinois.
feed. Both basal rations analyzed to contain 0.24 percent P by the method of Gomori (1942), while their calcium contents were 0.20 by the A.O.A.C. method (1950). Each ration was fed at six levels of P, the added P being supplied as Sodium Acid Phosphate, C.P. A Ca:P ratio of 2:1 was maintained on all P levels.
TABLE 3.—The effect of ration and phosphorus level in the diet of chicks on growth, blood phosphorus and bone calcification Level of P
Lot
Basal ration
Av. wts. 2 weeks (gm.)
Av. wts. 4 weeks (gm.)
Av. % ash 2 wks.
Av. % ash 4 wks.
1 7 2 8 3 9 4 10 5 11 6 12
A B A B A B A B A B A B
153.44 127.60 157.68 134,12 150.79 128.28 146.60 134.75 153.29 125.25 150.13 123.50
385.47 307.33 407.33 303.47 407.53 295.47 406.53 341.13 407.27 303.60 387.73 299.07
30.39 37.76 38.02 40.40 39.47 41.71 40.01 42.07 40.63 41.86 42.35 39.73
34.43 40.69 42.40 42.59 42.71 43.44 42.74 44.07 44.77 43.73 43.46 44.47
% 0.24 0.35 0.40 0.45 0.50 0.60
Av. blood Av. total M g . P / P 4 weeks feed cons. 100 gm. (mg.%) 4 wks. (gm.) gain 3.37 4.87 5.19 5.17 5.29 5.16 5.12 5.21 5.42 5.26 5.14 5.05
616.50 637.62 634.85 647.31 655.85 624.02 632.35 691.79 667.62 638.67 654.65 666.90
4.30 5.76 6.19 8.40 7.25 9.63 7.95 10.44 9.08 12.45 11.30 15.75
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five birds from each lot were bled by heart puncture for blood phosphate determination, and then were sacrificed with the remaining birds from each lot for bone ash determination. After percent ash had been determined, several ash samples from lots 1 and 7 were also analyzed for P content. Care was taken not to place lots of corresponding P level (1 and 7, 2 and 8, etc.) on the same tier of the battery so as not to confound P level with position in the battery in the absence of replication. The two basal rations (Table 2) differed in energy content, 25 percent corn meal by weight in ration A being replaced with 25 percent oat huller feed in ration B. The energy values calculated from Fraps' (1946) table show ration A to contain approximately 968 Calories/lb. of feed while ration B calculated to contain approximately 683 Calories/lb. of
White corn meal, debranned, degerminatedf Oat huller feedf Soybean grits (50%) Liver meal Alfalfa Butyl solubles (500 Mg. ribo./gm.) Distillers solubles Casein—crude Wheat germ oil Salt Vitamin A & D oil (300 D—1,500 A) Manganese sulfate Vitamin supplement Calcium carbonate C.P.
A Parts by weight
751
P UTILIZATION ON HIGH AND LOW ENERGY RATIONS TABLE 4.—Average weight of bone, ash and P for lots 1 and 7
Lot. no.
Av. wt. of defatted dehydrated bone (gm.)
Av. wt. of ash (gm.)
Av. wt. of P per bone
1.4192 1.1344
0.4883 0.4582
39.19 37.87
(nig-)
RESULTS
The averages of the data secured for two and four week weights, two and four week percent bone ash, four week blood P, total four week feed consumption, and P consumed per 100 grams of gain are presented in Table 3. The averages for the bone data secured separately for lots 1 and 7 are presented in Table 4. The analyses of variance for the data of Table 3 are given in Table 5. Growth. The average final weights of the birds within each basal diet were not significantly different per level P fed, as shown by the statistical analysis (Table 5). As expected, however, the ration effect was highly significant, indicating that the main objective of the experiment, namely producing faster and slower growing birds on rations essentially the same except for energy content, was realized.
TABLE 5.—Analyses of variance of data Growth at 4 wks.
% ash at 2 wks.
% ash at 4 wks.
Source of • D.F.
Mean square '
j-. p ' '
Mean square
Yy -p ' '
Level of P
5
3,439
5
107.741
5
Rations
1
380,6041
1
93.581
1
LXR
5
2,386
5
35.651
5
154
2,788
66
4.02
Within Pen (error)
121
Mean square
P level trend analysis % of ash at 4 wl S.V.
142.08301 Reduction due to slope 67.54101 Linear residual 35.11411 Reduction due to quadr. 3.3502 Quadratic residual
D.F.
M.S.
1
515.5533*
4
48.8028'
1
177.5893f
3
5.874
* Significant at 5 % level, t Significant at 2% level. 1 Significant at 0 . 1 % level. » Significant at 5 % level against Within Pen error. Significant difference (5%) for growth 37.79 gm., S.d. for % ash at 2 wks. 2.14%, S.d. for % ash at 4 wks. 1.48%.
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Feed Consumption. Table 3 shows the remarkable fact that feed consumption was about equal on both basal rations. This was tested statistically by setting up and testing the null hypothesis that the Average Difference between the Average P Consumption per bird per level of P (lot 1-7, 2-8, etc.) was zero. Student's t test confirmed the hypothesis, i.e., the average amount of P consumed per bird per level of P fed was essentially the same for both basal rations. Bone Ash. The significant interaction term, ration X level of P, in the analysis of variance indicates that the type of ration effected the utilization of P for bone calcification. In Figure 1 are plotted the fitted quadratic curves for the data of both rations. In each case the quadratic curves gave the best fit over the raw data or the log percent P data, fitted as straight lines. In the equation describing the dosage-response curves Y equals percent bone ash and X equals 102 percent P in the ration. From the slopes of the curves it would appear that the birds on the high energy ration were much more efficient in their utilization of P. To confirm this, in view of the changing slope, the points of maxi-
752
z(A
H. FISHER, E. P. SINGSEN AND L. D. MATTEESON
40.5
< IU
o
to
3S.S
0
LOW ENERGY
Y • 34.0311 + 0.3502X - 0.0030X*
X
HIGH ENERGY
Y « 9.8626 +• I.3S92X -
34.5lv* 2 0 ~*
^30
A0
J50
0.0I33X*
To
% PHOSPHORUS. FIG. 1. The relationship of tibia bone ash to energy level and P content of the chick ration.
mum response were determined. Equating the first derivative of the quadratic equation Y = a-\-bx-\-cx2 to zero, we obtain the following maxima:
Z'=-
-b 2c
or X'
1.3592
2
-0.0266
10
= 0.51098% P for High Energy and X'
-0.3502
2
0.0060
10
= 0.58367% P for Low Energy It is clear from this comparison that the amount of calcification per increment of P is much greater for birds on the high energy ration. The last column of Table 3, mg. P per 100 gm. of gain, lends further
DISCUSSION Growth. The large difference in final weights between the birds kept on the high and low energy rations differs from the results reported by Hill and Dansky (1951) who found equally good growth over a wide energy range of the ration; energy values in this study were well
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on April 12, 2015
z
support to this conclusion, indicating that the birds on the high energy ration, growing more rapidly, attained greater bone weights with more absolute amount of P deposited. On the basis of the maximum response obtained above, it appears that the absolute requirement for P was actually slightly lower on the high energy ration than on the low energy ration. Blood and Ash P. Table 3 shows that birds in lot 1 and possibly lot 7 had a distinctly lower level of blood P than all other lots, while the P level was nearly constant for the other lots. In order to find out whether the low blood P value for lot 1 might be due to a greater amont of P deposited in the skeleton, or was due to the greater tissue needs for the faster growth, the ash from several birds from lots 1 and 7 was analyzed for its P content. The results shown in Table 4 indicate that the amount of P per bone was nearly the same for both lots and that the lower percent P in the blood of birds from lot 1 cannot be due to its greater utilization in the skeleton; nor is the lower percent ash for lot 1 due to less P than is found in the bones of birds from lot 7, but rather to a greater skeletal growth, accompanying the faster growth of the body as a whole. Table 4 also gives the figures for the average absolute amounts of ash and bone for lots 1 and 7, thus indicating that the difference between the percent ash values of the two lots was due entirely to greater skeletal growth of birds in lot 1.
P UTILIZATION ON HIGH AND LOW ENERGY RATIONS
Calcification. The optimum percent P level for calcification for birds on both high and low energy rations is in the same range of values (0.45-0.60) reported by earlier workers (Singsen, 1948; Ewing, 1951). Since, as was previously stated, many early workers used synthetic diets which did not support maximum growth of their birds, it appears likely that efficiency of P utilization might also have been poor and that, therefore, the margin included in the National Research Council recommendation more than covers the needs for P of birds on the high efficiency rations in use today. It is interesting to note the close agreement of absolute amount of P deposited per bone for lots 1 and 7 and yet observe such differences in their percent ash value. It may be theorized that the extra weight of bone for birds in lot 1 is derived in part from extra organic matter and in part from a probable shift in the phosphate: carbonate ratio; on ashing the carbonate is lost as* carbon dioxide, thus explaining the final weight of ash for lot 1 being essentially the same as for lot 7. SUMMARY
The comparative requirement of P for growth and bone calcification has been studied in chicks fed high and low energy rations. Both diets were fed at levels of P ranging from 0.24 to 0.60 percent, with the Ca:P ratio maintained at approximately 2 : 1 . To vary the energy content, 25 percent of the corn meal in the high energy ration was replaced with 25 percent oat huller feed. The following results were obtained: 1. All birds on the high energy ration, regardless of P level, gained more rapidly than the birds on the low energy ration. 2. No growth response was obtained with increasing levels of P on either the high or low energy ration.
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within their specified range. Two possibilities that might explain this discrepancy are: (1) the particular strain of birds employed by Hill and Dansky was slow growing and thus the higher energy rations could not express themselves, or (2) the ration employed by the Cornell workers was deficient or unbalanced so as to prevent optimum growth. Unpublished work from this station (1951) has shown that on a diet which is slightly unbalanced (even though all nutrients are apparently adequate) similar results are obtained as reported by Hill and Dansky and furthermore under these conditions the total feed intake of the lower energy birds is considerably higher than for the birds fed a high energy ration. I t followed that under these conditions, the lower energy birds were able to grow just as fast as the higher enregy birds due to the considerably greater feed intake of the former. It appears, from the results of the present investigation, that fast growing birds will consume the maximum amount of feed that can be normally taken care of by these birds, and that it is therefore unlikely that birds on a less efficient ration will consume additional feed and thus grow as rapidly as those fed the high energy ration. It should also be pointed out that the final weights reported here for the high energy birds are very close to the maximum obtainable on the best rations, under the best conditions for this strain of birds. This is of great importance in considering that much of the earlier work on the P requirement of chicks was carried out with highly synthetic diets which seldom supported good growth even in the presence of an optimum amount of P. The fact that under the conditions of this experiment no growth response was obtained with P suggests that 0.24 percent is actually sufficient for growth.
753
754
S. J. SLINGER, W. F. PEPPER, A.. M . MORPHET AND E . V. EVANS
REFERENCES A.O.A.C., 1950. Official
Methods of Analysis,
Seventh Edition, pp. 97-98. Ewing, W. R., 1951. Poultry Nutrition, Fourth Edition, page 531. W. Ray Ewing Publisher, South Pasadena, California. Fisher, H., E. P. Singsen and L. D. Matterson, 1951. Unpublished data. Storrs Agr. Expt. Sta., Univ. of Conn., Storrs. Fraps, G. S., 1946. Composition and productive energy of poultry feeds and rations. Texas Agr. Sta. Bull. 678. Gomori, G., 1942. A modification of the colorimetric phosphorus determination for use with the photoelectric colorimeter. J. Lab. Clin. Med. 27: 951. Hill, F. W., and L. M. Dansky, 1951. The influence of diet on body composition of growing chicks. Proc. Cornell Nutrition Conference for Feed Manufacturers, pp. 27-32. Singsen, E. P., 1948. The phosphorus requirement of the chick. Storrs Agr. Exp. Sta. Bull. 260. Singsen, E. P., 1951. High efficiency rations— progress and problems. Frontiers in Nutrition, Supplement No. 24: 2-1. Dawe's Mfg. Co., Chicago, 111.
Effect of Penicillin on the Niacin Requirement of Turkeys and .a Carry-over Effect of Penicillin from Dams to Progeny S. J. SLINGER, W. F. PEPPER, A. M. MORPHET AND E. V. EVANS Departments of Poultry Husbandry and Nutrition, Ontario Agricultural College, Guelph, Canada (Received for publication December 23, 1952)
B
IELY and March (1951) reported that dietary levels of nicotinic acid, folic acid or riboflavin that are suboptimal for maximum growth rate of chicks under normal conditions may be adequate when aureomycin is fed. Coates et al. (1951) found that the presence of penicillin increased the degree of deficiency of nicotinic acid. On the other hand, Nelson and Scott (1952) found that, under their conditions, antibiotics neither spared nor accentuated niacin deficiency in chicks. Similarly, Pepper et al. (1953) observed that, while aureomycin enhanced niacin utilization by chicks for growth promotion and the prevention of perosis, the anti-
biotic did not appear to reduce the dietary requirement for niacin. No reports appear to have been published concerning the influence of antibiotics on the niacin requirement of turkeys. The present experiments were made to investigate the possible need for supplementary niacin in practical Canadian type diets both in the absence and presence of penicillin. The possible carryover influence of penicillin from dams to progeny was also studied. EXPERIMENT 1
Day old Broad Breasted Bronze poults hatched from hens, half of which received
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3. A phosphorus level of 0.51 percent was found from a dosage-response curve to give maximum calcification on the high energy ratio as compared to 0.58 percent P, similarly determined for the low energy ration. 4. Birds fed the high energy ration were much more efficient in their utilization of P for calcification. 5. There is no increase in the absolute requirement for P on a high energy ration as compared to a low energy ration, despite the appproximately 25 percent smaller nutrient intake on the high energy over the low energy ration; this is explained by the much greater efficiency of P utilization.
H. FISHER, 2 E. P. SINGSEN AND L. D. MATTERSON Storrs Agricultural Experiment Station, Poultry Department, University of Connecticut, Storrs, Connecticut (Received for publication October 30, 1952)
E
VER since the development and widespread use of high energy broiler and starter rations, the adequacy of many specific nutrients in those rations has been open to some questioning. On the basis of the greater gain per unit of feed consumed on the high energy rations over the standard type ration in use in 1944-45, a three pound bird consumes approximately three fourths the nutrients consumed by a three pound bird on older type rations. Singsen (1951) believed that today's birds are growing on the margin of safety provided in earlier nutrient recommendations. One of the nutrient recommendations of the National Research Council believed by Singsen (1951) to be critical is for the mineral phosphorus which has been the subject of the present investigation. Two exploratory experiments were conducted to find a low P ration that would support maximum growth and that could be changed in its 1 Supported in part by grants from the Yantic Grain & Products Co., Norwich, Connecticut, and Merck & Co., Inc., Rahway, New Jersey. 2 Present address, Department of Animal Science, University of Illinois, TJrbana, Illinois.
749
energy content without changing other nutrients so as to give the equivalent of both the high energy ration of today as well as the older type low energy ration. The approach used in the experiment to be presented was one of comparing growth and calcification at increasing levels of phosphorus on two rations that were alike except in their energy content and which were thought to represent the 1944-45 standard type ration, as well as the present day high energy type of ration. EXPERIMENTAL
The experimental design is given in Table 1. Three hundred male chicks from the University farm flock of New Hampshire males X Barred Rock females were randomly assigned into twelve lots of twenty-five birds each. The chicks were wingbanded, weighed and then placed in a metal chick starting battery unit, water and feed being supplied ad libitum. The birds were weighed individually at weekly intervals for four weeks; at two weeks seven birds were randomly removed from each lot and sacrificed for bone ash. At four weeks, the end of the experiment,
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on April 12, 2015
The Influence of Feed Efficiency on the Phosphorus Requirement for Growth and Bone Calcification in the Chick1
750
H. FISHER, E. P. SINGSEN AND L. D. MATTERSON TABLE 1.—Experimental design
TABLE 2.—Percentage composition of basal rations
Level of P (%) Basal ration
0.24
0.35
0.40
0.45
Rations 0.50
Ingredients
0.60
Lot number High energy A Low energy B
1
4
5
6
7
10
11
12
B Parts by weight
67.07 11.00 2.00 2.50
42.07 25.00 11.00 .00 .50
2.00 2.00 8.00 1.00 0.50
00 00 8.00 1.00 0.50
0.25 0.0125
0.25 0.0125
Variable
Variable
* Per 100 lbs. of feed: choline chloride (25%) 200 gm., niacin 0.9 gm., calcium pantothenate 50 mg., vitamin B21 (Merck 12.5 mg./lb.) 26 gm., procaine penicillin 0.315 gm. Phosphorus analysis 0.24% for both rations Calcium analysis 0.20% for both rations f The Quaker Oats Co., Chicago, Illinois.
feed. Both basal rations analyzed to contain 0.24 percent P by the method of Gomori (1942), while their calcium contents were 0.20 by the A.O.A.C. method (1950). Each ration was fed at six levels of P, the added P being supplied as Sodium Acid Phosphate, C.P. A Ca:P ratio of 2:1 was maintained on all P levels.
TABLE 3.—The effect of ration and phosphorus level in the diet of chicks on growth, blood phosphorus and bone calcification Level of P
Lot
Basal ration
Av. wts. 2 weeks (gm.)
Av. wts. 4 weeks (gm.)
Av. % ash 2 wks.
Av. % ash 4 wks.
1 7 2 8 3 9 4 10 5 11 6 12
A B A B A B A B A B A B
153.44 127.60 157.68 134,12 150.79 128.28 146.60 134.75 153.29 125.25 150.13 123.50
385.47 307.33 407.33 303.47 407.53 295.47 406.53 341.13 407.27 303.60 387.73 299.07
30.39 37.76 38.02 40.40 39.47 41.71 40.01 42.07 40.63 41.86 42.35 39.73
34.43 40.69 42.40 42.59 42.71 43.44 42.74 44.07 44.77 43.73 43.46 44.47
% 0.24 0.35 0.40 0.45 0.50 0.60
Av. blood Av. total M g . P / P 4 weeks feed cons. 100 gm. (mg.%) 4 wks. (gm.) gain 3.37 4.87 5.19 5.17 5.29 5.16 5.12 5.21 5.42 5.26 5.14 5.05
616.50 637.62 634.85 647.31 655.85 624.02 632.35 691.79 667.62 638.67 654.65 666.90
4.30 5.76 6.19 8.40 7.25 9.63 7.95 10.44 9.08 12.45 11.30 15.75
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five birds from each lot were bled by heart puncture for blood phosphate determination, and then were sacrificed with the remaining birds from each lot for bone ash determination. After percent ash had been determined, several ash samples from lots 1 and 7 were also analyzed for P content. Care was taken not to place lots of corresponding P level (1 and 7, 2 and 8, etc.) on the same tier of the battery so as not to confound P level with position in the battery in the absence of replication. The two basal rations (Table 2) differed in energy content, 25 percent corn meal by weight in ration A being replaced with 25 percent oat huller feed in ration B. The energy values calculated from Fraps' (1946) table show ration A to contain approximately 968 Calories/lb. of feed while ration B calculated to contain approximately 683 Calories/lb. of
White corn meal, debranned, degerminatedf Oat huller feedf Soybean grits (50%) Liver meal Alfalfa Butyl solubles (500 Mg. ribo./gm.) Distillers solubles Casein—crude Wheat germ oil Salt Vitamin A & D oil (300 D—1,500 A) Manganese sulfate Vitamin supplement Calcium carbonate C.P.
A Parts by weight
751
P UTILIZATION ON HIGH AND LOW ENERGY RATIONS TABLE 4.—Average weight of bone, ash and P for lots 1 and 7
Lot. no.
Av. wt. of defatted dehydrated bone (gm.)
Av. wt. of ash (gm.)
Av. wt. of P per bone
1.4192 1.1344
0.4883 0.4582
39.19 37.87
(nig-)
RESULTS
The averages of the data secured for two and four week weights, two and four week percent bone ash, four week blood P, total four week feed consumption, and P consumed per 100 grams of gain are presented in Table 3. The averages for the bone data secured separately for lots 1 and 7 are presented in Table 4. The analyses of variance for the data of Table 3 are given in Table 5. Growth. The average final weights of the birds within each basal diet were not significantly different per level P fed, as shown by the statistical analysis (Table 5). As expected, however, the ration effect was highly significant, indicating that the main objective of the experiment, namely producing faster and slower growing birds on rations essentially the same except for energy content, was realized.
TABLE 5.—Analyses of variance of data Growth at 4 wks.
% ash at 2 wks.
% ash at 4 wks.
Source of • D.F.
Mean square '
j-. p ' '
Mean square
Yy -p ' '
Level of P
5
3,439
5
107.741
5
Rations
1
380,6041
1
93.581
1
LXR
5
2,386
5
35.651
5
154
2,788
66
4.02
Within Pen (error)
121
Mean square
P level trend analysis % of ash at 4 wl S.V.
142.08301 Reduction due to slope 67.54101 Linear residual 35.11411 Reduction due to quadr. 3.3502 Quadratic residual
D.F.
M.S.
1
515.5533*
4
48.8028'
1
177.5893f
3
5.874
* Significant at 5 % level, t Significant at 2% level. 1 Significant at 0 . 1 % level. » Significant at 5 % level against Within Pen error. Significant difference (5%) for growth 37.79 gm., S.d. for % ash at 2 wks. 2.14%, S.d. for % ash at 4 wks. 1.48%.
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Feed Consumption. Table 3 shows the remarkable fact that feed consumption was about equal on both basal rations. This was tested statistically by setting up and testing the null hypothesis that the Average Difference between the Average P Consumption per bird per level of P (lot 1-7, 2-8, etc.) was zero. Student's t test confirmed the hypothesis, i.e., the average amount of P consumed per bird per level of P fed was essentially the same for both basal rations. Bone Ash. The significant interaction term, ration X level of P, in the analysis of variance indicates that the type of ration effected the utilization of P for bone calcification. In Figure 1 are plotted the fitted quadratic curves for the data of both rations. In each case the quadratic curves gave the best fit over the raw data or the log percent P data, fitted as straight lines. In the equation describing the dosage-response curves Y equals percent bone ash and X equals 102 percent P in the ration. From the slopes of the curves it would appear that the birds on the high energy ration were much more efficient in their utilization of P. To confirm this, in view of the changing slope, the points of maxi-
752
z(A
H. FISHER, E. P. SINGSEN AND L. D. MATTEESON
40.5
< IU
o
to
3S.S
0
LOW ENERGY
Y • 34.0311 + 0.3502X - 0.0030X*
X
HIGH ENERGY
Y « 9.8626 +• I.3S92X -
34.5lv* 2 0 ~*
^30
A0
J50
0.0I33X*
To
% PHOSPHORUS. FIG. 1. The relationship of tibia bone ash to energy level and P content of the chick ration.
mum response were determined. Equating the first derivative of the quadratic equation Y = a-\-bx-\-cx2 to zero, we obtain the following maxima:
Z'=-
-b 2c
or X'
1.3592
2
-0.0266
10
= 0.51098% P for High Energy and X'
-0.3502
2
0.0060
10
= 0.58367% P for Low Energy It is clear from this comparison that the amount of calcification per increment of P is much greater for birds on the high energy ration. The last column of Table 3, mg. P per 100 gm. of gain, lends further
DISCUSSION Growth. The large difference in final weights between the birds kept on the high and low energy rations differs from the results reported by Hill and Dansky (1951) who found equally good growth over a wide energy range of the ration; energy values in this study were well
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z
support to this conclusion, indicating that the birds on the high energy ration, growing more rapidly, attained greater bone weights with more absolute amount of P deposited. On the basis of the maximum response obtained above, it appears that the absolute requirement for P was actually slightly lower on the high energy ration than on the low energy ration. Blood and Ash P. Table 3 shows that birds in lot 1 and possibly lot 7 had a distinctly lower level of blood P than all other lots, while the P level was nearly constant for the other lots. In order to find out whether the low blood P value for lot 1 might be due to a greater amont of P deposited in the skeleton, or was due to the greater tissue needs for the faster growth, the ash from several birds from lots 1 and 7 was analyzed for its P content. The results shown in Table 4 indicate that the amount of P per bone was nearly the same for both lots and that the lower percent P in the blood of birds from lot 1 cannot be due to its greater utilization in the skeleton; nor is the lower percent ash for lot 1 due to less P than is found in the bones of birds from lot 7, but rather to a greater skeletal growth, accompanying the faster growth of the body as a whole. Table 4 also gives the figures for the average absolute amounts of ash and bone for lots 1 and 7, thus indicating that the difference between the percent ash values of the two lots was due entirely to greater skeletal growth of birds in lot 1.
P UTILIZATION ON HIGH AND LOW ENERGY RATIONS
Calcification. The optimum percent P level for calcification for birds on both high and low energy rations is in the same range of values (0.45-0.60) reported by earlier workers (Singsen, 1948; Ewing, 1951). Since, as was previously stated, many early workers used synthetic diets which did not support maximum growth of their birds, it appears likely that efficiency of P utilization might also have been poor and that, therefore, the margin included in the National Research Council recommendation more than covers the needs for P of birds on the high efficiency rations in use today. It is interesting to note the close agreement of absolute amount of P deposited per bone for lots 1 and 7 and yet observe such differences in their percent ash value. It may be theorized that the extra weight of bone for birds in lot 1 is derived in part from extra organic matter and in part from a probable shift in the phosphate: carbonate ratio; on ashing the carbonate is lost as* carbon dioxide, thus explaining the final weight of ash for lot 1 being essentially the same as for lot 7. SUMMARY
The comparative requirement of P for growth and bone calcification has been studied in chicks fed high and low energy rations. Both diets were fed at levels of P ranging from 0.24 to 0.60 percent, with the Ca:P ratio maintained at approximately 2 : 1 . To vary the energy content, 25 percent of the corn meal in the high energy ration was replaced with 25 percent oat huller feed. The following results were obtained: 1. All birds on the high energy ration, regardless of P level, gained more rapidly than the birds on the low energy ration. 2. No growth response was obtained with increasing levels of P on either the high or low energy ration.
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within their specified range. Two possibilities that might explain this discrepancy are: (1) the particular strain of birds employed by Hill and Dansky was slow growing and thus the higher energy rations could not express themselves, or (2) the ration employed by the Cornell workers was deficient or unbalanced so as to prevent optimum growth. Unpublished work from this station (1951) has shown that on a diet which is slightly unbalanced (even though all nutrients are apparently adequate) similar results are obtained as reported by Hill and Dansky and furthermore under these conditions the total feed intake of the lower energy birds is considerably higher than for the birds fed a high energy ration. I t followed that under these conditions, the lower energy birds were able to grow just as fast as the higher enregy birds due to the considerably greater feed intake of the former. It appears, from the results of the present investigation, that fast growing birds will consume the maximum amount of feed that can be normally taken care of by these birds, and that it is therefore unlikely that birds on a less efficient ration will consume additional feed and thus grow as rapidly as those fed the high energy ration. It should also be pointed out that the final weights reported here for the high energy birds are very close to the maximum obtainable on the best rations, under the best conditions for this strain of birds. This is of great importance in considering that much of the earlier work on the P requirement of chicks was carried out with highly synthetic diets which seldom supported good growth even in the presence of an optimum amount of P. The fact that under the conditions of this experiment no growth response was obtained with P suggests that 0.24 percent is actually sufficient for growth.
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S. J. SLINGER, W. F. PEPPER, A.. M . MORPHET AND E . V. EVANS
REFERENCES A.O.A.C., 1950. Official
Methods of Analysis,
Seventh Edition, pp. 97-98. Ewing, W. R., 1951. Poultry Nutrition, Fourth Edition, page 531. W. Ray Ewing Publisher, South Pasadena, California. Fisher, H., E. P. Singsen and L. D. Matterson, 1951. Unpublished data. Storrs Agr. Expt. Sta., Univ. of Conn., Storrs. Fraps, G. S., 1946. Composition and productive energy of poultry feeds and rations. Texas Agr. Sta. Bull. 678. Gomori, G., 1942. A modification of the colorimetric phosphorus determination for use with the photoelectric colorimeter. J. Lab. Clin. Med. 27: 951. Hill, F. W., and L. M. Dansky, 1951. The influence of diet on body composition of growing chicks. Proc. Cornell Nutrition Conference for Feed Manufacturers, pp. 27-32. Singsen, E. P., 1948. The phosphorus requirement of the chick. Storrs Agr. Exp. Sta. Bull. 260. Singsen, E. P., 1951. High efficiency rations— progress and problems. Frontiers in Nutrition, Supplement No. 24: 2-1. Dawe's Mfg. Co., Chicago, 111.
Effect of Penicillin on the Niacin Requirement of Turkeys and .a Carry-over Effect of Penicillin from Dams to Progeny S. J. SLINGER, W. F. PEPPER, A. M. MORPHET AND E. V. EVANS Departments of Poultry Husbandry and Nutrition, Ontario Agricultural College, Guelph, Canada (Received for publication December 23, 1952)
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IELY and March (1951) reported that dietary levels of nicotinic acid, folic acid or riboflavin that are suboptimal for maximum growth rate of chicks under normal conditions may be adequate when aureomycin is fed. Coates et al. (1951) found that the presence of penicillin increased the degree of deficiency of nicotinic acid. On the other hand, Nelson and Scott (1952) found that, under their conditions, antibiotics neither spared nor accentuated niacin deficiency in chicks. Similarly, Pepper et al. (1953) observed that, while aureomycin enhanced niacin utilization by chicks for growth promotion and the prevention of perosis, the anti-
biotic did not appear to reduce the dietary requirement for niacin. No reports appear to have been published concerning the influence of antibiotics on the niacin requirement of turkeys. The present experiments were made to investigate the possible need for supplementary niacin in practical Canadian type diets both in the absence and presence of penicillin. The possible carryover influence of penicillin from dams to progeny was also studied. EXPERIMENT 1
Day old Broad Breasted Bronze poults hatched from hens, half of which received
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3. A phosphorus level of 0.51 percent was found from a dosage-response curve to give maximum calcification on the high energy ratio as compared to 0.58 percent P, similarly determined for the low energy ration. 4. Birds fed the high energy ration were much more efficient in their utilization of P for calcification. 5. There is no increase in the absolute requirement for P on a high energy ration as compared to a low energy ration, despite the appproximately 25 percent smaller nutrient intake on the high energy over the low energy ration; this is explained by the much greater efficiency of P utilization.