Response of Two Breeds of Chickens to Graded Levels of Dietary Phosphorus

Response of Two Breeds of Chickens to Graded Levels of Dietary Phosphorus E. E.

GARDINER

Research Station, Canada Department of Agriculture, Lethbridge, Alberta (Received for publication November 8, 1968)

B

battery type. The experiment was conducted three times. Dicalcium phosphate supplied the added phosphorus and limestone was used to maintain a dietary calcium level of 1.0 percent (Table 1). One-day old chickens were placed on treatment with feed and water supplied ad libitum. The chicks were individually weighed at 4 weeks of age. Mortality was recorded daily. Feed-to-gain ratios were calculated on a chick-day basis. T h e experiments were terminated when chickens were 4 weeks old. Where possible five blood samples were

The purpose of the present experiments was to study the effects of low levels of dietary phosphorus on growth, feed efficiency, bone-ash, mortality, and plasma inorganic phosphorus of two breeds of chickens of both sexes.

TABLE 1.—Composition and chemical analyses of basal diets

PROCEDURE

Two breeds of chickens were studied in a 3 X 2 X 2 X 2 factorial experiment involving three levels of added dietary phosphorus (0.0, 0.1, and 0.2 percent added to a basal diet), two breeds (commercial broiler crossbreds and Single Comb White Leghorns), two sexes, and two battery types. Type-A batteries had five tiers with an individual heating unit for each tier of 50-chick capacity. Type-B batteries had six tiers with one heating unit servicing four pens of 12-chick capacity on each tier. There were two replicates of 10 chicks each for each treatment in each

Diet No. Ingredients

1

2

3

%

%

%

Ground yellow corn 29.20 Ground wheat 30.00 Soybean meal (44% protein) 34.00 Alfalfa leaf meal 3.00 Iodized salt 0.50 Manganese sulfate 0.05 1 Vitamin premix 1.00 Limestone 2.25 Dicalcium phosphate 0.00

29.15 30.00 34.00 3.00 0.50 0.05 1.00 1.75 0.55

29.10 30.00 34.00 3.00 0.50 0.05 1.00 1.25 1.10

Composition by chemical analyses2 Calcium 1.03 Phosphorus 0.44 Protein 21.01

0.99 0.55 20.86

1.01 0.64 20.94

1 Supplied in amounts per 100 grams of diet: vitamin A, 1000 I.U., vitamin D3, 150 I.C.U.; vitamin E acetate, 0.56 I.U.; choline chloride, 150 mg.; niacin, 3.17 mg.; D-calcium pantothenate, 1.41 mg.; riboflavin, 0.71 mg.; menadione sodium bisulfite, 0.07 mg.; procaine penicillin, 0.44 mg.; vitamin Bio, 0.66 mg.; and DL-methionine, 150 mg. 2 Average of nine separate analyses for each factor.

986

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R E E D S of chickens may differ in utilization and metabolism of various nutrients (Nesheim and H u t t , 1962; Thornton and Whittet, 1962; Daghir and Balloun, 1963; Donovan, 1965; Yoshida el al., 1966). This may be the reason for a wide variation (Peeler, 1963) in the recommendations in the dietary phosphorus requirements. Although Lillie el al. (1964) concluded t h a t phosphorus requirement did not differ between strains of chickens, they used relatively high levels of phosphorus and strains with similar growth rates which might have prevented differences in response to certain criteria from being exhibited.

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B R E E D R E S P O N S E TO P H O S P H O R U S

TABLE 2.—Weighted average body weight (gm.) of chicks fed varied levels of dietary phosphorus by sex, battery type, and time1 Battery type A2 D1HM 4 D2HM D3HM

Tl' 232 405 494

T2 226 356 562

T3 227 360 538

DILM 5 D2LM D3LM

Tl 217 270 293

T2 211 243 265

T3 193 238 299

D1HF D2HF D3HF

194 410 464

248 369 532

246 348 499

DILF D2LF D3LF

204 240 273

215 229 274

212 236 263

Battery type B 302 449 485

252 418 573

265 408 536

DILM D2LM D3LM

237 272 298

222 265 292

205 266 302

D1HF D2HF D3HF

337 442 486

280 420 514

246 420 486

DILF D2LF D3LF

233 264 274

203 240 255

207 258 273

1

For means of main effects see Table 7. For significant mean squares see Table 8. A=Five tier batteries with one pen and an individual heating unit for each tier of 50-chick capacity. B = Six tier batteries, 4 pens each of 12-chick capacity per tier, with one heating unit servicing each tier. 3 T l , T2, and T3 are the three times the experimental design was repeated. 4 For example, D1HM means diet 1, meat-type males. ' For example, DILM means diet 1, S.C.W.L. males. 2

taken by cardiac puncture from each treatment disregarding replicate. Heparin was used as an anticoagulant. Blood plasma inorganic phosphorus was determined by the method of Fiske and Subbarow (1925). Where possible, five femurs from each treatment were taken disregarding replicate (Gardiner, 1962) and their ash content was determined. Bone-ash was calculated on a dry, fat-free basis. Chick weights, plasma inorganic phosphorus, percent bone-ash, percent livability, and feed-to-gain ratios were analyzed by analysis of variance. Unweighted group means were used instead of totals because the number of observations varied between groups. Missing values of replicate means were calculated for feed efficiency and body weight in one group where mortality was 100 percent, realizing t h a t it makes the biological response of this replicate appear to be better t h a n the chicks were able to demonstrate. Percent livability figures were transformed to

arc sin for statistical analyses (Snedecor, 1956). Error mean squares were calculated by the method of Cox (1954). RESULTS

Body weight. Means of 4-week b o d y weights for the three times t h a t the experiment was repeated were similar (Tables 2 and 7). Both the P level ( P < 0 . 0 1 ) and the breed of chicken affected the 4-week body weight. Broiler crossbreds gained more than the Leghorns (P <0.01) and the difference widened as the level of dietary P increased. Sex had no effect on 4-week body weight. Birds in battery B gained faster than those in b a t t e r y A ( P < 0 . 0 5 ) . Low-phosphorus diets depressed the body weights of the broiler-type chickens more than t h a t of the Leghorns ( P < 0 . 0 1 ) . T h e y also depressed the 4-week weights of males more than those of the females ( P < 0 . 0 5 ) (Tables 7 and 8). Percent

bone-ash.

Bone-ash

percentages

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D1HM D2HM D3HM

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E. E.

GARDINER

TABLE 3.—Percent bone-ash of femurs from chicks fed varied levels oj dietary phosphorus by sex, battery type, and time1 Battery type A2 Tl3

T2

T3

DIHM 4 D2HM D3HM

25.0 26.3 37.1

32.0 33.1 36.5

28.2 29.6 37.7

DIHF D2HF D3HF

24.9 26.6 38.5

27.3 28.1 40.0

24.2 28.7 41.1

Tl

T2

T3

D1LM5 D2LM D3LM

30.0 40.8 41.4

30.1 40.9 41.9

31.2 39.6 44.0

DILF D2LF D3LF

31.8 43.0 43.7

32.9 34.5 45.4

33.0 40.9 44.2

DIHM D2HM D3HM

29.7 31.0 39.7

29.1 33.0 41.2

26.4 30.8 38.8

D1LM D2LM D3LM

38.2 42.7 43.6

32.3 39.6 42.8

36.8 39.8 42.5

DIHF D2HF D3HF

30.0 31.9 40.9

26.9 32.2 37.9

28.3 32.9 41.5

DILF D2LF D3LF

40.3 41.6 46.7

35.8 40.3 43.5

35.5 41.0 44.1

1,2,3.4,5 See Table 2, footnotes 1, 2, 3, 4, and 5.

were influenced b y the same main effects as was body weight, namely P level, breed, and b a t t e r y type (Tables 3 and 7). T h e percent bone-ash increased with each increase in dietary phosphorus and was higher for the Leghorns than for the broiler chickens. Percent bone-ash of chickens reared in b a t t e r y type A was significantly lower t h a n t h a t of chickens reared in b a t t e r y t y p e B. The percent bone-ash of the broilertype chickens was decreased more in the low-phosphorus diets t h a n was the percent bone-ash of the Leghorns. Percent bone-ash did not respond in the same way within breeds or within each b a t t e r y type each time the experiment was conducted (Table 8). Plasma inorganic phosphorus. P level, breed, and b a t t e r y type affected plasma inorganic phosphorus (Tables 4 and 7). T h e level of plasma inorganic phosphorus increased with each increase in dietary phosphorus but was lower for the broilertype chickens t h a n for the Leghorns. I t also was lower in the blood from chickens

reared in type-A batteries than from chickens reared in type-B batteries. T h e plasma inorganic phosphorus levels were lower ( P < 0 . 0 5 ) for the broiler-type chickens t h a n for the Leghorns. T h a t these levels responded differently with b a t t e r y and breed in time is evidenced b y the significant b a t t e r y X time and breed X t i m e interactions obtained (Table 8). Percent livability. P level and breed each significantly affected percent livability, which decreased as dietary phosphorus level decreased and was lower in the broiler-type chickens than in the Leghorn breed (Tables 5 and 7). B a t t e r y t y p e significantly affected livability ( P < 0 . 0 5 ) and so did a significant P level X breed interaction. Livability was high ( 8 0 100%) for the Leghorns on the low phosphorus diet b u t low (20-50%) for the broiler-type chickens. I n b o t h sexes, livability of broiler-type chickens was higher in battery type B than in b a t t e r y type A (Table 5). T h e livability of the Leghorns was high in both b a t t e r y types and was near or a t

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Battery type B

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B R E E D R E S P O N S E TO P H O S P H O R U S TABLE 4.-

-Plasma inorganic phosphorus level of blood from chicks fed varied levels of dietary phosphorus by sex, battery type, and time1 Battery type A2

TV 4

T2

T3 6

Tl

T2

T3

DIHM D2HM D3HM

2.39 2.66 3.37

2.57 3.14 4.59

1.96 2.96 3.99

DILM D2LM D3LM

2.30 4.50 7.08

1.99 4.45 6.78

2.01 3.17 6.61

DIHF D2HF D3HF

2.12 2.93 5.00

2.14 2.52 5.96

1.68 2.26 5.62

DILF D2LF D3LF

2.91 5.19 7.23

2.87 5.26 7.32

2.24 3.40 6.37

DIHM D2HM D3HM

2.08 2.22 5.92

2.52 2.99 6.23

3.31 3.57 6.06

DILM D2LM D3LM

3.35 5.80 6.90

2.84 4.59 6.11

3.22 5.07 6.78

DIHF D2HF D3HF

1.94 2.26 5.46

2.20 3.04 5.64

2.27 2.68 5.64

DILF D2LF D3LF

4.07 5.32 6.70

2.17 4.96 7.27

3.78 4.67 6.79

'•4'5 See Table 2, footnotes 1, 2, 3, 4, and 5.

100%. Although the difference in livability due to sex was not significant, the percent livability was consistently higher for the females than for the males. Mortality was not the same each time the experim e n t was conducted (Tables 7 and 8). Feed-to-gain ratios and feed consumption. Feed-to-gain ratios decreased with each inTABLE 5.-—Percent

crease in dietary phosphorus and changed more with increases in dietary phosphorus in the broiler-type chickens than in the Leghorns. In every case feed consumption per chicken per day increased with each increase in dietary phosphorus (Table 6) regardless of breed or sex. Feed consumption, especially of the two low-P diets, was

livability of chicks fed varied levels of dietary phosphorus by sex, battery type, and time1 Battery type A2 Tl3

4

T2

T3 5

Tl

T2

T3

DIHM D2HM D3HM

50 90 100

20 60 95

20 80 100

DILM D2LM D3LM

95 100 100

100 100 95

80 100 100

DIHF D2HF D3HF

40 90 95

25 85 90

25 80 95

DILF D2LF D3LF

100 100 90

100 100 100

100 100 95

Battery type: B DIHM D2HM D3HM

75 90 100

70 90 95

75 90 90

DILM D2LM D3LM

100 100 100

100 100 100

95 100 95

DIHF D2HF D3HF

80 95 100

80 90 90

55 100 100

DILF D2LF D3LF

100 100 100

100 100 100

95 100 100

»'4'6 See Table 2, footnotes 1, 2. 3, 4, and 5.

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Battery type B

990

E. E. GARDINER

TABLE 6.—Feed consumed per chick per day (gm.) by breed, sex, battery type, and diet {weighed averages of replicate and time) Battery type 1 B

12.0 22.0 31.3

16.4 25.7 31.6

DIHF D2HF D3HF

12.1 22.4 29.4

16.7 25.9 29.4

DILM D2LM D3LM

14.8 17.9 19.5

16.5 19.1 20.3

DILF D2LF D3LF

15.5 17.2 18.4

16.0 18.8 19.4

D1HM D2HM D3HM

1 2

See footnote 2, Table 2. See footnote 4, Table 2.

higher in the type-B batteries than in the Type-A batteries. The Leghorns consumed more per chick per day of the lowest P diet in the type-A battery than did the broiler-type chickens but both lines in type-B batteries consumed approximately the same amount of this diet. Time and replicates. Differences in main effects were repeatable in time (Tables 7 and 8). Time was involved in significant first-order interactions. It would appear that percent bone-ash and plasma inorganic phosphorus were more subject to the influence of time than were bodyweight or feed-gain ratios. DISCUSSION

Body weight and feed consumption. The differences in body weight due to P level for the broiler-type chickens were similar to those obtained earlier (Gardiner, 1962). One would also expect a difference in body weight between the two breeds used but it is difficult to explain the significant effect of battery type. However, one could speculate that the broiler-type chickens,

It should be noted that the chicks were approximately the same size at day-old. Level of dietary phosphorus affected the voluntary feed intake of the broiler-type chicken to a greater extent than that of the Leghorns (Table 6). That there was no physical barrier to obtaining feed is evidenced by the fact that the males and females in battery type A consumed approximately the same amount of the high phosphorus diet as those in battery type B (Table 6). Another factor which could

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A 2

having an inherently lower feed-gain ratio, became rachitic and had more difficulty in getting to the feed in the larger pens (type-A batteries) than they did in the smaller pens (type-B batteries). The source of heat was closer to the feed supply in the smaller pens than it was in the larger pens. The significant P level X breed interaction is not in agreement with Lillie et al. (1964), either because the levels of phosphorus used in the present experiments were lower than those they used or the strains they used were more similar in growth rate, feed efficiency, or all three. This interaction also points out that the fast-growing chickens were not able to tolerate a low-phosphorus diet so well as the slow-growing breed. This may be due to the fact that the slow-growing breed inherently consume more feed per unit gain than do the broiler-type chickens and would therefore be consuming more phosphorus per unit weight on any given dietary phosphorus level. They would therefore not be as phosphorus deficient on the low phosphorus diets as were the broilertype chickens. Support for this is provided by the higher feed consumption, higher percent bone-ash, higher plasma inorganic phosphorus levels, lower mortality, and lower decreases in growth rate for the Leghorns as compared to the broiler type chickens being fed diet 1.

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B R E E D R E S P O N S E TO P H O S P H O R U S

TABLE 7.—Means of 4-week body weights {gm.), feed efficiency, percent bone-ash, plasma inorganic phosphorus (mg. % ) , and percent livability by main effects

Main effects

Body weight (gm.)

Feed/gain

Percent bone-ash

Plasma inorganic P (mg. %)

Livability

Tl T2 T3

324 321 314

2.34 2.51 2.33

36.0 35.7 35.9

4.15 4.06 4.05

91.5 86.9 86.3

Battery 2

A B

309 330

2.56 2.23

34.8 36.9

3,77 4.40

83.3 93.1

P level3

Dl D2 D3

236 326 397

2.91 2.22 2.05

30.9 35.5 41.3

2.65 3.55 6.06

74.2 93.3 97.1

Sex4

M F

325 314

2.36 2.42

35.6 36.1

4.00 4,17

87.5 88.9

Breed6

B L

391 248

2.38 2.40

32.4 39.3

3.50 4.67

77.9 98.5

Replicate 6

1 2

320 319

2.43 2.35

320

2.39

Overall 1 2 3 4 6 6

88.2 88.2 35.9

4.09

88.2

See Table 2, footnote 3. See Table 2, footnote 2. D l , D2, and D3 are diets 1, 2, and 3, respectively, in Table 1. M = male, F=female. B = broiler-type, L = Single Comb White Leghorns. Replicate 1 and 2 represent the two replicates of 10 chicks each in each battery type.

TABLE 8.—Significant mean squares from analyses of variances of 4-week body weight, feed efficiency, percent bone-ash, plasma inorganic phosphorus (mg.%), and percent livability Mean squares 1 Source of variance

D.F. 2

Body weight

Feed/gain

Battery P level Breed

1 2 1

15,960* 314,456** 731,880**

9.91*

78.23* 660.08** 862.30**

7.07* 74.90** 24.85**

1,881* 5,049* 15,918**

P level X breed P level X sex P level X battery B reed X battery Breed X time BatteryX time

2 2 2 1 2 2

107,804** 2,650*

5.24*

42.81**

4.75**

3,909**

Battery X diet X breed TimeXP levelXbreed TimeXP level X battery

2 4 4

1,526* 2,635** 1,770**

1

Bone-ash

16.81* 15.40*

Plasma inorganic P

Livability

2.49** 2.58**

2.90** 0.31*

The error terms used to test the mean squares were calculated by the method of Cox (1954). Degrees of freedom. * Statistical significance (P<0.05). ** Statistical significance (P<0.01). 2

583** 989** 386**

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Time 1

992

E. E.

GARDINER

Percent bone-ash and plasma inorganic phosphorus. T h e effects of dietary phosphorus on percent bone-ash and plasma inorganic phosphorus agree with previously reported results (Gardiner, 1962). T h e fact t h a t percent bone-ash and plasma inorganic phosphorus were lower in b a t t e r y type-A than in b a t t e r y type-B probably reflects the differences in feed intake b y chickens in the two b a t t e r y types. Interactions of P level X breed with plasma inorganic phosphorus and with percent bone-ash have not been previously reported. The significant interactions obtained in the present experiment point out the importance of using the

same breed of chickens when using boneash as a criterion of phosphorus status. T h a t bone-ash and plasma inorganic phosphorus are less reproducible in time than body weight is supported by the significant breed X time and b a t t e r y X time interactions for these factors. Livability. T h e significant effects of P level and breed on livability indicate t h a t the low phosphorus diet was not adequate to support life and t h a t it was less adequate for the broiler-type chickens than for the Leghorns. This is also supported by the significant P level X breed interactions. As mentioned earlier, the volu n t a r y food intake of the broiler-type chickens was affected more b y the low phosphorus diets t h a n was the food intake of the Leghorns. T h e difference in feed intake b y the broiler-type chickens m a y have been due to their becoming severely rachitic faster than the Leghorns, thus having more difficulty in getting to the feed. Leghorns inherently consume more feed per unit gain t h a n do broiler-type chickens. T h e significant interaction of P level and breed with b a t t e r y type m a y also be explained by the reduced intake by chickens in b a t t e r y type-A. I t is not known why feed intake by chickens on the lowphosphorus diets was reduced in type-A batteries but the reduction may have been due to the more severely rachitic heavytype chickens having more difficulty in getting to the feed in type-A than type-B batteries. These experiments demonstrate t h a t the Leghorn chickens were better able than the broiler-type chickens to tolerate a low-phosphorus diet. This m a y be imp o r t a n t in raising replacement chickens for laying purposes where optimal growth is not essential.

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enter into the P level X breed interaction is ability to utilize phytic acid phosphorus. Gillis et al. (1957) have reported t h a t species influences phytic acid phosphorus utilization b y poultry, chickens being more efficient t h a n poults. If the Leghorn chickens had been better able to utilize phytic acid phosphorus than the broilertype chickens, the differences obtained could have been explained more easily. However, there is no experimental evidence to support a breed difference in the ability to utilize phytic acid phosphorus. There is disagreement in the literature as to the effect of the ratio of calcium to inorganic phosphorus on aphosphorosis. Waldroup et al. (1963) state t h a t widening the Ca: P ratio at a suboptimal level of phosphorus resulted in lowered body weight or percent bone-ash; whereas, Lillie et al. (1964) indicate t h a t increasing the dietary calcium level from 0.9 to 1.2 percent did not show any significant effects at any of the dietary phosphorus levels. Even though the C a : P ratio did vary among the diets used in these experiments, the comparison of the breeds to these different diets is still valid.

BREED RESPONSE TO PHOSPHORUS SUMMARY

993

REFERENCES

A 3 X 2 X 2 X 2 factorial design was repeated three times. The variables were level of dietary phosphorus (0.0, 0.1, and 0.2 percent added dietary phosphorus), two breeds (broiler crossbreds, and Single Comb White Leghorns) two sexes, and two battery types. There were two replicates of 10 chickens each for each treatment in each battery type. Criteria observed included body weight (4-week), feed consumption, percent boneash, plasma inorganic phosphorus, and percent livability. P level, breed, and battery type had a significant effect on body weight, percent bone-ash, plasma inorganic phosphorus levels, and percent livability. A significant P level X breed interaction for all the five criteria indicated that the breeds responded differently to suboptimal levels of dietary phosphorus. Battery type was involved with P level and breed with two significant interactions with livability. Voluntary food intake by chickens on Iowa State College Press, Ames, Iowa. the low-phosphorus diets was lower in the crossbreds than in the Leghorns and Thornton, P. A., and W. A. Whittet, 1962. The influence of dietary energy level, energy source, lower in type-A batteries than in type-B bread, and sex on vitamin A requirement in the batteries. chicks. Poultry Sci. 41: 32-36. ACKNOWLEDGEMENTS

The author acknowledges the contributions to this study of G. L. Norman and staff for care and management of chickens, D. Smid for chemical analyses, and A. H. Woolliscroft for statistical analyses.

Waldroup, P. W., C. B. Ammerman and R. H. Harms, 1963. The relationship of phosphorus, calcium, and vitamin D3 in the diet of broilertype chicks. Poultry Sci. 42: 982-989. Yoshida, M., H. Hoshii and H. Morimoto, 1966. Studies on the vitamin requirements of poultry. 8. Genetic differences in the requirements for niacin and riboflavin of meat-type and egg-type chicks. Poultry Sci. 45: 736-744.

NEWS AND NOTES {continued from page 960) National Distillers Products Co.; Mrs. B. Hurst, J. B. Bean Distilling Co.; J. W. Spanyer, BrownForman Distillers Corporation; J. Svihovec, Barton

Distilling Co.; and J. M. Van Lanen, Hiram Walker & Sons, Inc.

{continued on page 1026)

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Cox, C. E., 1954. Handbook on Statistical Methods, Canada Department of Agriculture, Statistical Research and Service Unit. Revised Dec. 1954. Daghir, N. J., and S. L. Balloun, 1963. Evaluation of the effect of breed on vitamin B6 requirements of chicks. J. Nutr. 79: 279-288. Donovan, G. A., 1965. Vitamin A requirements of growing birds. 1. Influence of breeds. Poultry Sci. 44: 1292-1298. Fiske, C. H., and Y. Subbarow, 1925. Determination of inorganic phosphorus and acid soluble phosphorus in blood. J. Biol. Chem. 66: 375-399. Gardiner, E. E., 1962. The relationship between dietary phosphorus level and the level of plasma inorganic phosphorus of chicks. Poultry Sci. 41: 1156-1163. Giffis, M. B., K. W. Keane and R. A. Collins, 1957. Comparative metabolism of phytate and inorganic P32 by chicks and poults. J. Nutr. 62: 13-26. Lillie, R. J., P. F. Twining and C. A. Denton, 1964. Calcium and phosphorus requirements of broilers as influenced by energy, sex, and strain. Poultry Sci. 43: 1126-1131. Nesheim, M. C , and F. B. Hutt, 1962. Genetic differences among White Leghorn chicks in requirements for arginine. Science, 137: 691-692. Peeler, H. T., 1963. The calcium and phosphorus requirements of poultry. Proc. Maryland Nutrition Conference for Feed Manuf. 19-28. Snedecor, G. W., 1956. Statistical Methods. The