Studies with Corn-Soya Laying Diets

Studies with Corn-Soya Laying Diets 2. OPTIMUM COMBINATIONS OF CORN AND SOYBEAN PROTEIN D. J. BRAY Department of Animal Science, University of Illinois, Urbana, Illinois (Received for publication March 10, 1960)

age when placed on test in Experiments 1, 2 and 3, respectively. Egg production was recorded daily. Feed consumption, egg production and body weight data were summarized weekly in Experiment 2, while in Experiment 3 these data were summarized at the end of the first week, by 2-week intervals thereafter and for the terminal week of the experiment. Percent egg production was calculated on a hen-day basis, feed consumption as grams per bird per day and body weight as a percent of the weight when the birds were placed on test. The basal diet, Table 1, was considered to contain levels of minerals, vitamins, and essential fatty acids to adequately supplement all combinations of the three variable ingredients fed. Therefore, the effects of varying the proportions of carbohydrate, corn and soybean oil meal were interpreted solely in terms of the protein and amino acid adequacy of the diet. The amino acid TABLE 1.—Basal diet, Experiments 1, 2 and 3

EXPERIMENTAL

White Leghorn pullets confined to individual cages were used in all experiments. The birds were 182, 205 and 203 days of

Ingredient

Percent

Variable1 Corn oil Ground limestone Dicalcium phosphate (feed grade) Iodized salt Manganese sulfate 70% Zinc carbonate Choline chloride Vitamins 1.9 gm./kg. 2 a tocopherol acetate 20 mg./kg. Procaine penicillin 11 mg./kg.

90.800 1.000 3.965 3.500 .500 .025 .010 .200

+ + + 100.000

1 Corn, soybean oil meal, glucose (Experiments 1 and 2) and starch (Experiment 3). 2 Scott etal. (1957) less inositol.

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ORN and soybean oil meal are the major sources of amino acids in high energy laying diets. When the protein level of such diets is altered, the amino acid pattern is altered simultaneously due to the shift in the relative amounts of protein originating from corn and soybean oil meal. For this reason data regarding the optimum combination of corn and soybean protein would be pertinent to the interpretation of experiments concerned with levels of protein. Almquist and Grau (1944) fed graded combinations of soybean and sesame protein to chicks in isonitrogenous diets and found that a sesame-soybean protein ration of 7:13 maximized growth. Following a preliminary experiment, this technique was used in two experiments reported herein in which graded combinations of corn and soybean protein were fed to laying pullets in isonitrogenous diets at suboptimal protein levels. The combination which maximized performance was considered to have provided the best possible pattern of amino acids for laying pullets from these sources. In view of the amino acid adequacy of corn-soya laying diets calculated to contain 11 percent protein reported by Thornton et al. (1957), either 9 or 10 percent protein assay diets were used to insure sensitivity to graded combinations of corn and soybean protein.

C

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D. J. BRAY

TABLE 2.—Time series data of egg production, Experiment 1 Protein % of diet % from soybean oil meal

10 58

10 22

Percent Egg Pre ductii 73 81 77 78 76 85 73 71 85 65 69 90 62 65 89 41 57 85 42 56 84 30 48 — 37 35 —. 35 42 — 29 45 — 30 43 — 26 44 —

content of experimental diets was calculated using the values of Block and Weiss (1956). Experiment 1 was initiated May 28, 1958. A 16 percent protein diet in which soybean oil meal provided 58 percent of the protein was fed for 7 weeks after which this treatment was terminated by design in keeping with another phase of the experiment not reported herein. Two 10 percent protein diets were formulated, one by proportionate decreases in corn and soybean oil meal, the other by increasing corn at the expense of soybean oil meal. Thus, the amino acid pattern of the former was identical to that of the 16 percent protein diet in that soybean oil meal provided 58 percent of the protein, whereas it provided only 22 percent of the protein in the latter. The 10 percent protein diets were fed for 13 weeks. Each of the three diets were fed to four 5-bird groups. Experiment 2 was started September 19, 1958, with pullets in 76 percent production. A 16 percent protein control diet and five diets containing 10 percent protein in which soybean oil meal contributed 100, 81, 61, 42 and 22 percent of the protein were each fed to four replicate groups of 5 birds each for a 12-week period. Experiment 3 was initiated October 28,

RESULTS AND DISCUSSION While neither of the 10 percent protein diets was capable of sustaining a high rate of egg production over a 7-week period in Experiment 1, the greater inadequacy of the 10 percent protein diet in which soybean oil meal provided only 22 percent of the protein became increasingly evident during the 13-week period, Table 2. Statistical analysis of 5-bird-group data indicated a significant difference (P <.06) between the two 10 percent diets in total eggs produced during the 13-week period. Thus, it appeared that a 10 percent protein diet in which soybean oil meal contributed 58 percent of the protein was superior to a 10 percent protein diet in which it provided only 22 percent of the protein. This observation suggested the feeding of graded proportions of corn and soybean protein as a means of detecting an optimum combination of these two proteins. None of the 10 percent protein diets in experiment 2 was adequate to maximize egg production, feed consumption, or body weight, Table 3. However, analysis of variance of 5-bird-group data indicated a highly significant difference (P <.01) among the 10 percent protein diets in total eggs laid over the 12-week period. When the data were subjected to regression analysis, egg production was maximized when a calculated 55.5 ± 2.8 percent of the protein originated from soybean oil meal. Although analysis of variance of the 12-week body

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Week 1 2 3 4 5 6 7 8 9 10 11 12 13

16 58

1959, with pullets in 81 percent production. Nine percent protein diets in which 68, 62, 56, 50, 44, 38 and 32 percent of the protein originated from soybean oil meal were fed for 12 weeks to groups of 17 pullets each. All birds were individually fed. Blended samples of corn and soybean oil meal containing 8.25 and 51.0 percent protein (N X 6.25), respectively, were used to formulate all diets in Experiment 3.

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CORN-SOYA DIETS TABLE 3.—Time series data of egg production, feed consumption and body weight, Experiment 2 Protein % of diet % from soybean oil meal Week 1 2 3 4 5 6 7 8 9 10 11 12

16

10

10

10

10

10

16

10

10

10

10

10

16

10

10

10

10

10

61

100

81

61

42

22

61 100

81

61

42

22

61 100

81

61

42

22

Percent egg production 72 71 74 69 60 70 82 71 38 67 71 69 39 49 62 67 54 55 65 71 41 43 59 67 40 46 60 65 25 44 53 49 26 44 44 46 27 37 51 54 24 41 45 50 19 29 42 42

70 72 67 54 47 46 40 37 31 30 31 24

Feed consumption 125 126 138 143 122 120 123 122 123 115 119 118 122 107 123 115 106 107 119 115 105 107 111 114 101 102 108 110 93 101 109 110 92 108 111 107 84 103 101 103 87 102 102 104 96 105 105 111

137 126 121 113 109 99 97 93 91 88 78 87

69 73 79 78 81 82 78 76 71 73 74 71

141 130 125 126 127 127 125 131 128 121 122 128

Relative body weight 100 101 103 105 100 101 102 106 101 100 101 105 104 99 104 105 102 99 104 105 103 99 104 105 102 98 104 105 102 99 104 106 102 98 107 106 100 98 105 105 100 98 105 105 100 98 104 105

103 104 104 104 105 105 106 105 105 103 101 101

percent of the protein in a low protein cornsoya laying diet originated from soybean oil meal, the minimum deficiency of any single amino acid was realized. Supposedly, whenever soybean oil meal was the major protein source one or more amino acids became limiting which differed from the deficiency encountered when corn was the major source of protein. When the amino acid patterns of various combinations of corn and soybean protein were compared to the amino acid standard suggested by Johnson and Fisher (1958), Table 5, the calculated minimum deficiency of any one amino acid occurred when approximately 40 percent of the protein originated from soybean oil meal. When less than 40 percent of the protein came from soybean oil meal, by calculation tryptophan was the first limiting amino acid. When soybean oil meal was the major protein source, methionine and cystine calculated to be most limiting.

TABLE 4.—Time series data of egg production, feed consumption, and body weight, Protein % of diet 9 9 9 9 9 9 9 % from soybean oil meal 68 62 56 50 44 38 32 Week 1 3 5 7 9 11 12

83 80 73 59 48 46 51

Percent egg production 81 84 83 83 82 77 80 81 83 81 76 80 72 82 77 80 74 72 57 70 71 67 64 51 56 67 65 55 52 44 51 58 59 57 60 45 43 65 59 63 51 50

9

9

9

9

9

9

9

9

9

9

9

9

9

9

68

62

56

50

44

38

32

68

62

56

50

44

38

32

Feed consumptioni 135 135 139 148 138 143 118 116 119 121 118 120 106 111 115 114 111 102 103 107 111 112 110 96 94 109 107 108 103 93 99 103 107 113 102 94 93 95 102 100 97 89

102 101 99 99 101 101 100

123 109 101 95 93 94 90

Relative body weight 103 105 104 105 104 104 102 103 103 105 103 101 99 102 101 103 100 97 102 100 101 102 99 97 99 102 99 96 100 101 100 101 100 102 96 97 101 100 100 97 95 94

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weight data revealed no effect of significance attributable to diet, inspection of the data indicated that the same 10 percent protein diets which maximized egg production also tended to maximize body weight. As anticipated, feed consumption reflected the combined trends in egg production and body weight. Regression analysis of experiment 3 data indicated that egg production was maximized when a calculated 50.5 ± 1.3 percent of the protein originated from soybean oil meal. Body weight data suggested that when corn was the major protein source the birds were less able to sustain their body weight than when soybean oil meal was the major source, Table 4. However, this tendency was not apparent in Experiment 2. As in Experiment 2, feed consumption patterns reflected trends in egg production and body weight. Apparently when approximately 50 to 55

107 109 109 110 112 114 114 116 118 119 119 119

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D. J. BRAY TABLE 5.—Calculated amino acid adequacy of 9 percent protein corn-soya laying diets containing graded combinations of corn and soybean protein

Amino acid1

Standard 2

Percent of protein. from soybean
.40 .12 .50 .50 .54

50

40

30

20

Adequiicy expressed as a % of standard

% of diet Methionine and cystine Tryptophan Lysine Isoleucine Valine

60

70

57* 83 105 98 87

62* 75 91 91 87

59* 79 98 95 87

64* 71 84 88 88

67* 68 77 85 88

69 64* 70 82 88

72 60* 63 78 88

1

All other amino acids calculate to be 100 percent or more adequate at all corn-soybean combinations. Johnson and Fisher (1958). * First limiting amino acid.

2

diet overestimated the requirement on a diet containing .12 percent tryptophan. This observation may reflect a reduction in the methionine content of eggs from birds fed low protein diets, Csonka et al. (1947), or it may indicate an instance in which the egg protein ratio technique proposed by Johnson and Fisher (1958) is subject to question. Corn-soya diets in which soybean oil meal contributes 55 percent of the protein contain approximately the 15 percent level of protein recommended by the National Research Council (1954). The exact protein level is influenced considerably by the protein content of the ingredients. For example, a corn-soya diet containing 90 percent of 8 percent protein corn and 50 percent protein soybean oil meal would contain 13.4 precent protein if formulated for TABLE 6.—Egg production from supplemented and unsupplemented 10 percent protein diets Supplement1 None .16% DL-tryptophan •43% 95% L-lysine HC1 .25% DL-methionine 1

Percent egg production 0-12 weeks 42.7 + 5.1 62.9 + 2.2** 57.9±4.7* 54.8 + 5.9

Fifteen birds per diet. * Significantly different from unsupplemented diet (P<.05). ** Significantly different from unsupplemented diet (P<.01).

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In an experiment conducted in the Illinois laboratory, Bray (1959), a 10 percent protein corn-soya diet to which soybean oil meal contributed approximately 20 percent of the protein was supplemented with either tryptophan, lysine or sulfur amino acids (methionine) in quantities sufficient to simulate the levels of these amino acids in a 10 percent protein whole egg protein diet. Analysis of egg production data summarized in Table 6 indicated significant responses to tryptophan and lysine. The magnitude of response from these three amino acids was in accord with their calculated relative deficiencies in a corn-soya diet to which soybean oil meal contributed 20 percent of the protein, Table 5. These observations lend support to the egg protein ratio technique suggested by Johnson and Fisher (1958) for establishing the amino acid requirements of laying pullets. However, the discrepancy between the calculated (Table 5) and determined optimum combinations of corn and soybean protein remains to be resolved. Assuming (1) that either tryptophan or the sulfur amino acids were the first limiting nutrients at near optimal combinations of corn and soybean protein and (2) that the calculated amino acid values were appropriate for our ingredients, it appeared that a sulfur amino acid level of .40 percent of the

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CORN-SOYA DIETS

SUMMARY When the protein level of a 16 percent corn-soya laying ration in which soybean oil meal contributed 58 percent of the protein was lowered to 10 percent by either (1) maintaining soybean oil meal

as a source of 58 percent of the protein or (2) by permitting soybean oil meal to contribute only 22 percent of the protein, it was demonstrated that neither 10 percent protein diet was capable of sustaining a high rate of egg production. However, over a 13-week assay period the diet in which soybean oil meal contributed 58 percent of the protein proved to be the better of the two 10 percent protein diets in terms of egg production. When graded combinations of corn and soybean protein were fed at the 10 percent and 9 percent protein levels regression analysis indicated that egg production was maximized when 55.5 ± 2.8 and 50.5 ± 1.3 percent of the protein originated from soybean oil meal, respectively. ACKNOWLEDGMENT

Generous quantities of tryptophan, lysine and methionine were made available by Dow Chemical Company, Midland, Michigan; Merck Sharp and Dohme, Railway, New Jersey; and U. S. Industrial Chemicals Company, New York, New York, respectively. REFERENCES Almquist, H. J., and C. R. Grau, 1944. Mutual supplementary effect of the proteins of soybean and sesame meals. Poultry Sci. 23: 341-343. Block, R. J., and K. W. Weiss, 1956. Amino Acid Handbook. Charles C Thomas, Springfield, Illinois. Bray, D. J., 1959. Unpublished data. University of Illinois. Bray, D. J., and J. D. Garlich, 1960. Studies with corn-soya laying diets. 1. Amino acid supplementation of low protein diets. Poultry Sci. 39: (in press). Csonka, F. A., C. A. Denton and S. J. Ringel, 1947. The methionine and cystine content of hen's eggs. J. Biol. Chem. 169: 259-265. Fox, S. W., and G. F. Sprague, 1946. Characterization of corn proteins. Iowa Corn Research Institute. Eleventh Ann. Report, p. 58. Johnson, D., Jr., and H. Fisher, 1958. The amino acid requirement of laying hens. 3. Minimal requirement levels of essential amino acids; tech-

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soybean oil meal to provide 55 percent of the protein. If 10 percent protein corn and 44 percent soybean oil meal were used, the diet would contain 15.6 percent protein. Expressed in another way, if the corn and soybean oil meal samples cited in the former example were used to formulate a 15 percent protein diet, 62 percent of the protein would originate from soybean oil meal; in the latter instance only 52 percent of the protein would originate from soybean oil meal. These variations plus the variations in lysine and tryptophan content of corn protein as influenced by the protein content of corn, Fox and Sprague (1946), indicate that the application of the optimum combination of corn and soybean protein concept to practical formulation would be somewhat involved. Despite a shift from optimum combinations of corn and soybean protein, Thornton et al. (1957) were able to formulate corn-soya diets to which bone meal and alfalfa meal also contributed amino acids, that sustained satisfactory egg production at a calculated 11-percent protein level. Unfortunately, the protein level and amino acid patterns were such that responses from amino acid supplementation to their 11 percent protein diet in terms of egg production and body weight could not be detected. Unpublished data previously cited herein, Bray (1959), indicated that tryptophan would have been the first limiting amino acid if Thornton et al. (1957) had fed still lower levels of protein. Corn-soya diets containing 9 percent protein have also been shown to respond to amino acid supplementation by Bray and Garlich (1960).

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D. J. BRAY

niques and development of diet. Brit. J. Nutr. 12: 276-28S. National Research Council, 1954. Nutrient requirements of poultry. Publication 301. Scott, H. M., M. W. Moeller and S. W. Hinners,

1957. Studies with purified diets. 2. Protein requirements. Poultry Sci. 36: 1000-1002. Thornton, P. A., L. G. Blaylock and R. E. Moreng, 1957. Protein level as a factor in egg production. Poultry Sci. 36: 552-557.

Performance of Pullets Debeaked at Various Times During the Laying Year

(Received for publication March 10, 1960)

T

HE experimental evidence indicates that chicks or growing pullets debeaked prior to the onset of sexual maturity retain their full potential to lay, Morgan (1957). However, a critical examination of the effects of debeaking laying birds has not come to the authors' attention. In the studies reported herein, springhatched pullets were debeaked during the following fall, winter and spring and the effects measured by trends in egg production and body weight as compared to control populations. EXPERIMENTAL

White Leghorn pullets hatched March 12, 1958, were used in experiments 1 and 2. New Hampshire pullets hatched January 9 and White Rock and Rhode Island Red pullets hatched February 26 were used in the second experiment. The pullets were floor brooded, range reared, and housed at maturity in groups of 25 and 24 pullets each in experiments 1 and 2, respectively. Combined floor and dropping pit space was approximately 3^ square feet per bird. Water, oyster shells and an all-mash laying ration containing 18 percent protein were provided ad libitum. All-night lights were provided using one 40-watt bulb per pen. This provided a minimum of 3 foot candles of

light at floor level over the roosting and feeding areas at all times. Supplemental heat was provided by circulating hot water through pipes imbedded in the concrete floor only when necessary to prevent exposed water piping in the laying quarters from freezing. One-half of the upper beak, as measured by marking a point precisely equidistant between the anterior tip of the upper beak and the anterior margin of the external nares, was severed and cauterized with an electric debeaker. Four millimeters of the lower beak, measured from the anterior tip, were also removed. In experiment 2, three pens of New Hampshire and two pens each of White Leghorn, White Rock and Rhode Island Red pullets were randomly identified in each pen with wing badges numbered in series from 1-24 when housed. Each pen was divided by wing badge number into four populations, groups A, B, C and D of six pullets each. Group A served as a nondebeaked control within each pen. Group B was debeaked October 9. Groups C and D were debeaked January 15 and May 7, 1959, respectively. Thus debeaked and nondebeaked individuals were intermingled within each pen. Individual egg production was recorded weekly on the basis of three

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D. J. BRAY, S. F. RIDLEN AND J. A. GESELL Department of Animal Science, University of Illinois, Urbana, Illinois