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Effect of Alfalfa Meal, Corn Gluten Meal and Other Dietary Components on Egg Yolk Color1
Effect of Alfalfa Meal, Corn Gluten Meal and Other Dietary Components on Egg Yolk Color1 T. W. SULLIVAN AND K. A. HOLLEMAN2 Department of Poultry Husbandry, University of Nebraska, Lincoln 3 (Received for publication February 12, 1962)
HE COLOR of egg yolks or their degree of pigmentation has a definite effect on visual estimates of quality. There is considerable variation in consumer preference for egg yolk color (Jasper and Cray, 1953; Slocum and Swanson, 1954). For the graded shell egg market, producers and marketing firms favor eggs with light to medium yellow yolks. Because of the demand for egg yolk as a food coloring ingredient, the egg breaking industry prefers much darker yolks. Egg yolk color continues to be measured and expressed following a method developed for the National Egg Products Association (N.E.P.A.) by Kahlenberg (1949). The breaking industry prefers egg yolks that are at least N.E.P.A. number 3 or darker. Frozen or liquid yolks with a N.E.P.A. number of 4 to 5 generally sell for a premium of 2 to 7 cents more per pound than do lighter colored yolks. The xanthophylls (class term for hydroxy carotenoids e.g., zeaxanthin and lutein) are deposited to a much greater extent in the egg yolk as compared to cryptoxanthin and carotenes (Gillam and Heilbron, 1935; Peterson et al., 1939). Therefore, yolk color is due mainly to the presence of xanthophylls. This study was conducted 1) to determine the dietary levels of dehydrated alfalfa meal, corn gluten meal and purified 1 Published with the approval of the Director as Paper No. 1197, Journal Series, Nebraska Agricultural Experiment Station. 2 Present address: Nebraska Turkey Growers Association, Gibbon, Nebraska.
xanthophyll needed to produce dark egg yolks and 2) to determine the effect of yellow corn, milo and animal fat on egg yolk color. EXPERIMENTAL Three short-term experiments were conducted with S. C. White Leghorn hens maintained in individual laying cages. The first experiment was of 6 weeks duration, however, the subsequent experiments were limited to only 4 weeks. It was observed in the initial experiment that 2 to 4 weeks was sufficient time to measure the effect of diet on yolk color. Five birds were assigned to each experimental group which received a separate diet. Water was supplied by automatic drip-type nozzles; each bird was fed ad libitum in a separate feed box. The composition of the basal diet is presented in Table 1. Whenever possible, dietary alterations and substitutions were made on an isocaloric and isonitrogenous basis. Since these experiments were designed primarily to study the effect of diet on egg yolk color, the egg production and feed efficiency data are not reported herein. Egg yolk color was determined at weekly intervals on 3 or 4 individual eggs from each group, with one exception. In the second experiment, daily yolk color determinations were run on the eggs produced by two experimental groups. Both the beta-carotene (A.O.A.C, 1958) and the N.E.P.A. methods for yolk color were utilized. The pigment in a 2.5 gram sample of fresh egg yolk was extracted with 100 ml. of acetone. The optical density of an aliquot from the
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T
EGG YOLK COLOR AND DIETARY COMPONENTS TABLE 1.—Composition of basal diet Ingredients
Per 1000 lbs.
Total
1,000.2 Calculated average composition
Protein, percent Productive energy, Cal./lb. Calcium, percent Phosphorus, percent Inorganic P, percent
15.62 882 2.25 . 76 .51
* Ten pounds of premix furnishes the following: 2,000,000 U.S.P. units stabilized vitamin A, 400,000 I.C. units vitamin D3, 5,0001, units vitamin E, 2,000 mg. riboflavin, 4,000 mg. calcium pantothenate and 4 mg. vitamin Bi2.
acetone extract was measured at 445 mf*. with a Bausch and Lomb Spectronic-20 colorimeter. Optical density values were applied to standard curves for beta-carotene and potassium dichromate solutions, respectively, to obtain the beta-carotene equivalents per gram of fresh yolk and the N.E.P.A. numbers. The yolk color data obtained at the end of the second, third and fourth weeks of each experiment were subjected to analysis of variance (Snedecor, 1956). In every instance, the different periods or weeks had no significant effect on yolk color. Since the effect of each dietary treatment on yolk color was consistent after the 10th day of every test, all yolk color values reported herein are the average of data obtained at the second, third and fourth weeks. Duncan's (1953) multiple range test was used to compare treatment means when significant differences were detected by the analysis of variance. All interpretations of data
are based on the 1 percent level of probability. RESULTS AND DISCUSSION Preliminary data from experiments 1 and 2 of this study have been previously reported (Holleman and Sullivan, 1959). Experiment 1. Yolk color data obtained in the first experiment are presented in Table 2. When the basal diet containing 60 percent of yellow corn and 3 percent of dehydrated alfalfa meal (17 percent protein) was fed, the beta-carotene equivalent was 44.8 per gram of fresh yolk; the N.E.P.A. number was 3.2. The addition of 10 milligrams (mg.) of purified xanthophyll per pound to this diet did not significantly increase yolk color. When the diet contained 10 percent of good quality dehydrated alfalfa meal, yolk color values were significantly greater; the beta-carotene equivalent was 86.8 and the N.E.P.A. number was 6.2. Yolk color values were drastically reduced when milo completely replaced yellow corn in the bird's diet. The TABLE 2.—Effect of dehydrated alfalfa meal, corn gluten meal, purified xanthophyll and other dietary components on egg yolk color
Diet
1. 2. 3. 4. 5. 1. 2. 3. 4. S. 6. 7. 8. 9. 10. 11.
Experiment 1 Basal ration Diet 1 + 10 mg. xanthophyll/lb. Diet 1 + 1 0 % dehy. alfalfa meal* Milo a n d soybean oil meal Diet 4 + 3 0 mg. xanthophyll/lb. Experiment 2 Basal ration Diet 1 + 4 % animal fat Diet 1 + 4 0 mg. xanthophyll/lb. Diet 1 + 4 % animal f a t + 4 0 mg. xanthophyll/lb. Diet 1 + 10% dehy. alfalfa meal 2 Diet 1 + 1 5 % dehy. alfalfa meal Diet 1 + 1 0 % corn gluten meal Diet 1 + 1 5 % corn gluten meal Diet 1 + 1 2 % dehy. alfalfa meal + 1 2 % corn gluten meal Milo and soybean meal Diet 1 0 + 4 0 mg. xanthophyll/lb.
Beta-caro1 equiva- N . E. P . A. lents per number gram fresh yolk
1tene
4 4 . 8 bb 51.2 86.8°a 7.2 15.8"
3 . 2 bb 3.6 6.2°a 0.5 1.1"
3 6 . 4 bb ° 37.1 ° 42.1°
2.6ob 2.6b0 2.9°
43.0° 6 4 . 5 ed 81.9 67.7d 94.0 £
3.0° 4 . 6 ed 5.8 4.8d 6.7 f
110.7*5 7.9a 25.lb
7.8s 0.6?b 1.8
1 Each value is the average of 12 and 9 individual yolk color determinations in experiments 1 and 2, respectively. Within the same experiment, values having the same letter are not significantly different from each other at the 1% level of probability. 2 In both experiments the supplemental dehy. alfalfa meal was a product containing 20 percent of protein.
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
lbs. 600 130 110 40 30 25 15 35 5 0.2 10
Ground yellow corn Wheat standard middlings Soybean oil meal (44% protein) Meat and bone scrap (50% protein) Dehy. alfalfa meal (17% protein) Dried whole whey Steamed bone meal Ground limestone Iodized salt Manganese sulfate Vitamin premix*
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T. W. SULLIVAN AND K. A. HOLLEMAN
0. D. of Acetone Extract at ljll5 mu.
(fresh yolk)
\ 2
k
6
,'\
"' V 8
Diet 10, milo
10
.-.
12
lit
16
18
20
DASfS
FIG. 1. Daily effect on egg yolk color of diets high and low in pigmenters (Exp. 2).
addition of purified xanthophyll (30 mg./ lb.) to the milo diet did not significantly increase yolk color. Experiment 2. This experiment was conducted to determine the effect of supplemental xanthophyll, dehydrated alfalfa meal, corn gluten meal and fat on egg yolk color. The data are presented in Table 2. Yolk color values obtained with the basal diet were a 36.4 beta-carotene equivalent and a 2.6 N.E.P.A. number. The addition of 4 percent of animal fat to this diet had no effect on yolk color or the utilization of supplemental xanthophyll. Addition of 40 mg. of purified xanthophyll per pound of diet did not significantly increase yolk color. When 10 percent of either dehydrated alfalfa meal or corn gluten meal was present in the diet, the beta-carotene equivalent and N.E.P.A. number were significantly increased. Dietary levels of 15 percent of these products further increased yolk color. The response to corn gluten meal was greater than to dehydrated alfalfa meal. This difference was statistically significant when IS percent of each was fed. Yolk color values obtained with a diet containing 12 percent of each of these
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
Diet 9, yellow corn 12$ deny, alfalfa meal 12$ corn gluten meal
products were significantly greater than the values obtained with any other diet. When milo completely replaced yellow com, yolk color was again drastically reduced. The addition of purified xanthophyll (40 mg./ lb.) to the milo diet significantly increased yolk color. The daily effect on egg yolk color of diets high and low in pigmenters is illustrated in Figure 1. Yolk color values for eggs produced by the groups receiving diets 9 and 10 in experiment 2 were used for these response curves. Two eggs from each group, but not necessarily from the same individual birds, were measured daily for 20 days. It appeared that the full effect of diet on egg yolk color was expressed in 10 days. Several factors will apparently cause variations in yolk color intensity among birds fed the same diet (Romanoff and Romanoff, 1949). Such factors include age and strain of bird, rate of egg production, egg size and the clutch position of each egg. That variations in egg yolk color were more pronounced when the diet contained a high level of pigmenters (diet 9) is illustrated in Figure 1. Calculations based on data from experiment 2 and xanthophyll values reported by Hastings (1961) suggest that 10 to 12 mg. of "available" xanthophyll per pound of diet is required to produce egg yolks with a 4 to S N.E.P.A. number, or with 50 to 75 beta-carotene equivalents per gram. Expressed in grams per ton, this level would be 20 to 24 grams of "available" xanthophyll or about 50 grams of total xanthophylls. For reasons which are as yet unexplained, the xanthophylls in dehydrated alfalfa meal appear to be less available than those in yellow corn and corn gluten meal. Experiment 3. Data obtained in this experiment are presented in Table 3. This test was conducted primarily to determine the levels of dehydrated alfalfa meal necessary in a milo diet to produce the egg yolk
EGG YOLK COLOR AND DIETARY COMPONENTS TABLE 3.—Egg yolk color as influenced by milo rations containing graded levels of dehydrated alfalfa meal Level of dehydrated alfalfa meal 1
Beta-carotene 2 equivalents per gram fresh yolk
N.E.P.A. 2 number
% of diet 3 6 9 12 15
12.8" 22.4 b 31.6" 45.6 d 58.8«
0.9» 1.5" 2.2C 3.2 d 4.2 e
A product containing 17 percent of protein. Each value is the average of 9 individual yolk determinations. Values having the same letter are not significantly different from each other at the 1 % level of probability.
color generally acceptable for table consumption (N.E.P.A. 1.5—3.0) and most desirable for breaking stock (N.E.P.A. 4-5). An alfalfa meal containing 17 percent protein was utilized. About 6 to 10 percent of this product was needed in the milo diet to produce egg yolks acceptable for table consumption. Likewise, at least 15 percent was required to produce yolks desirable for breaking stock.
diet was required to produce egg yolks with a 4 to 5 N.E.P.A. number of with 50 to 75 beta-carotene equivalents per gram. 3. When milo completely replaced yellow corn in the hen's diet, 6 to 10 percent of dehydrated alfalfa meal was needed to produce egg yolks generally acceptable for table consumption. Likewise, at least 15 percent of alfalfa meal was needed to produce the most desirable yolks for breaking stock. 4. The addition of 4 percent of animal fat to a yellow corn-soybean oil meal diet did not influence egg yolk color. 5. Yolk color was increased when purified xanthophyll (10 to 40 mg./lb.) was added to the hen's diet. However, in 3 out of 4 instances these differences were not statistically significant. 6. The full effect of diet on yolk color was expressed in 10 days. ACKNOWLEDGMENT
SUMMARY
In a study concerning the effect of dehydrated alfalfa meal, corn gluten meal and other dietary components on egg yolk color, three short-term (4 to 6 weeks) experiments were conducted. Data pertaining to egg yolk color (beta-carotene equivalents per gram of fresh yolk and N.E.P.A. numbers) were collected. These data suggest or indicate the following: 1. To produce the egg yolk color most desired by the breaking industry (N.E.P.A. 4 to 5), 10 to 12 percent of good quality dehydrated alfalfa meal or about 10 percent of good quality corn gluten meal was needed in diets containing yellow corn. 2. Calculations based on data from this study indicated that 10 to 12 mg. of "available" xanthophyll per pound of
The authors are grateful to Bowman Feed Products, Inc., Holland, Michigan and to Dawe's Laboratories, Inc., Chicago, Illinois for supplying the purified xanthophyll used in this study. REFERENCES Association of Official Agricultural Chemists, 1958. Method for measuring natural color in egg products. Official and Tentative Methods of Analysis, 4 1 : 42. Duncan, D. B., 1953. Significant tests for differences between ranked treatments in analysis of variance. Technical Report No. 3, Dept. of Statistics, Virginia Agr. Expt. Sta., Blacksburg, Va. Gillam, A. D., and I. M. Heilbron, 1935. Vitamin A-active substances in egg yolk. Biochem. J. 29: 1064-1067. Hastings, W. H., 1961. Research on the use of pigmented. Feedstuffs, 33 : No. 46,30-35. Holleman, K. A., and T. W. Sullivan, 1959. Egg yolk color as influenced by xanthophyll and
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
1
2
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T. W. SULLIVAN AND K. A. HOLLEMAN
feedstuffs containing related pigments. Poultry Sci. 38: 1214. Jasper, A. W., and R. E. Cray, 1953. Consumer preferences, practices and demands in purchasing eggs and poultry in Columbus, Ohio. Research Bull. 736, Ohio Agri. Expt. Sta., Wooster, Ohio. Kahlenberg, O. J., 1949. A quick and reliable gauge of yolk color. Food Ind. 21: 467-470. Peterson, W. J., J. S. Hughes and L. F. Payne, 1939. Avian carotenoids. Kansas State Agr. Bull. No.
46.
Romanoff, A. L., and A. J. Romanoff, 1949. The Avian Egg. John Wiley and Sons, Inc., New York, New York. Slocum, W. L., and H. S. Swanson, 1954. Egg consumption habits, purchasing patterns and preferences of Seattle consumers. Bull. 556, Wash. Agri. Expt. Sta., Pullman, Washington. Snedecor, G. W., 1956. Statistical Methods. 5th ed. The Iowa State College Press, Ames, Iowa.
J. KAN, B. N. MCPHERSON AND N. R. GYLES Department of Animal Industry and Veterinary Science, University of Arkansas, Fayetteville,
Arkansas
(Received for publication February 12, 1962)
W
ARMING of hatching eggs prior to the regular incubation period resulted in improvement in the hatchability of chicken and turkey eggs (Kosin, 1956; Becker and Bearse, 1958). Milby and Sherwood (1960) showed that preincubation warming only increased hatchability of turkey eggs produced from hens whose hatchabilities were below the average of the population (Milby and Sherwood, 1960). The usual warming procedure is to subject eggs to a period of five hours at 99.5°F. the day after they are laid, after which time the eggs are returned to the egg holding room for the remainder of the storage period. The question arises as to whether greater benefit could be obtained if warming is applied, instead of on the day after lay, somewhat near the middle of the storage period. Or, the five-hour warming might be given in the form of two or more doses with approximately equal intervals between applications. In January 1960, half of the eggs shipped to the Regional Poultry Genetics Laboratory at Athens, Georgia were warmed for five hours in a Jamesway 252 incubator at 1 Published with the approval of the Director of the Arkansas Agricultural Experiment Station.
99.5°F. prior to shipment. The other half served as the untreated control. The age of the eggs ranged from 8 to 19 days at the time of setting. Hatchability of the treated eggs was 82.7% as compared with 74.6% of the control, a difference significant at the 5% level of probability. There was some indication that the age at which the eggs were treated might be of importance. MATERIALS AND METHODS
This report covers a study of warming procedures employing three lines of the University of Arkansas White Wyandottes. The three lines are designated as High (selected for large 8-week body weight), Low (selected for small 8-week body weight), and High-Low (selected for large 8-week and small 20-week body weights). Eggs produced daily during the first week, after having been divided into the various treatments, were held for three weeks (2228 days old). Similarly, eggs produced during the second week were held for two more weeks (15-21 days old) and those of the third week for one week (8-14 days old). Finally eggs produced during the fourth week were set at the end of the fourth week (1-7 days old). Table 1 shows pre-incubation warming procedures which
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Pre-Incubation Warming of Chicken Eggs 1
HE COLOR of egg yolks or their degree of pigmentation has a definite effect on visual estimates of quality. There is considerable variation in consumer preference for egg yolk color (Jasper and Cray, 1953; Slocum and Swanson, 1954). For the graded shell egg market, producers and marketing firms favor eggs with light to medium yellow yolks. Because of the demand for egg yolk as a food coloring ingredient, the egg breaking industry prefers much darker yolks. Egg yolk color continues to be measured and expressed following a method developed for the National Egg Products Association (N.E.P.A.) by Kahlenberg (1949). The breaking industry prefers egg yolks that are at least N.E.P.A. number 3 or darker. Frozen or liquid yolks with a N.E.P.A. number of 4 to 5 generally sell for a premium of 2 to 7 cents more per pound than do lighter colored yolks. The xanthophylls (class term for hydroxy carotenoids e.g., zeaxanthin and lutein) are deposited to a much greater extent in the egg yolk as compared to cryptoxanthin and carotenes (Gillam and Heilbron, 1935; Peterson et al., 1939). Therefore, yolk color is due mainly to the presence of xanthophylls. This study was conducted 1) to determine the dietary levels of dehydrated alfalfa meal, corn gluten meal and purified 1 Published with the approval of the Director as Paper No. 1197, Journal Series, Nebraska Agricultural Experiment Station. 2 Present address: Nebraska Turkey Growers Association, Gibbon, Nebraska.
xanthophyll needed to produce dark egg yolks and 2) to determine the effect of yellow corn, milo and animal fat on egg yolk color. EXPERIMENTAL Three short-term experiments were conducted with S. C. White Leghorn hens maintained in individual laying cages. The first experiment was of 6 weeks duration, however, the subsequent experiments were limited to only 4 weeks. It was observed in the initial experiment that 2 to 4 weeks was sufficient time to measure the effect of diet on yolk color. Five birds were assigned to each experimental group which received a separate diet. Water was supplied by automatic drip-type nozzles; each bird was fed ad libitum in a separate feed box. The composition of the basal diet is presented in Table 1. Whenever possible, dietary alterations and substitutions were made on an isocaloric and isonitrogenous basis. Since these experiments were designed primarily to study the effect of diet on egg yolk color, the egg production and feed efficiency data are not reported herein. Egg yolk color was determined at weekly intervals on 3 or 4 individual eggs from each group, with one exception. In the second experiment, daily yolk color determinations were run on the eggs produced by two experimental groups. Both the beta-carotene (A.O.A.C, 1958) and the N.E.P.A. methods for yolk color were utilized. The pigment in a 2.5 gram sample of fresh egg yolk was extracted with 100 ml. of acetone. The optical density of an aliquot from the
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T
EGG YOLK COLOR AND DIETARY COMPONENTS TABLE 1.—Composition of basal diet Ingredients
Per 1000 lbs.
Total
1,000.2 Calculated average composition
Protein, percent Productive energy, Cal./lb. Calcium, percent Phosphorus, percent Inorganic P, percent
15.62 882 2.25 . 76 .51
* Ten pounds of premix furnishes the following: 2,000,000 U.S.P. units stabilized vitamin A, 400,000 I.C. units vitamin D3, 5,0001, units vitamin E, 2,000 mg. riboflavin, 4,000 mg. calcium pantothenate and 4 mg. vitamin Bi2.
acetone extract was measured at 445 mf*. with a Bausch and Lomb Spectronic-20 colorimeter. Optical density values were applied to standard curves for beta-carotene and potassium dichromate solutions, respectively, to obtain the beta-carotene equivalents per gram of fresh yolk and the N.E.P.A. numbers. The yolk color data obtained at the end of the second, third and fourth weeks of each experiment were subjected to analysis of variance (Snedecor, 1956). In every instance, the different periods or weeks had no significant effect on yolk color. Since the effect of each dietary treatment on yolk color was consistent after the 10th day of every test, all yolk color values reported herein are the average of data obtained at the second, third and fourth weeks. Duncan's (1953) multiple range test was used to compare treatment means when significant differences were detected by the analysis of variance. All interpretations of data
are based on the 1 percent level of probability. RESULTS AND DISCUSSION Preliminary data from experiments 1 and 2 of this study have been previously reported (Holleman and Sullivan, 1959). Experiment 1. Yolk color data obtained in the first experiment are presented in Table 2. When the basal diet containing 60 percent of yellow corn and 3 percent of dehydrated alfalfa meal (17 percent protein) was fed, the beta-carotene equivalent was 44.8 per gram of fresh yolk; the N.E.P.A. number was 3.2. The addition of 10 milligrams (mg.) of purified xanthophyll per pound to this diet did not significantly increase yolk color. When the diet contained 10 percent of good quality dehydrated alfalfa meal, yolk color values were significantly greater; the beta-carotene equivalent was 86.8 and the N.E.P.A. number was 6.2. Yolk color values were drastically reduced when milo completely replaced yellow corn in the bird's diet. The TABLE 2.—Effect of dehydrated alfalfa meal, corn gluten meal, purified xanthophyll and other dietary components on egg yolk color
Diet
1. 2. 3. 4. 5. 1. 2. 3. 4. S. 6. 7. 8. 9. 10. 11.
Experiment 1 Basal ration Diet 1 + 10 mg. xanthophyll/lb. Diet 1 + 1 0 % dehy. alfalfa meal* Milo a n d soybean oil meal Diet 4 + 3 0 mg. xanthophyll/lb. Experiment 2 Basal ration Diet 1 + 4 % animal fat Diet 1 + 4 0 mg. xanthophyll/lb. Diet 1 + 4 % animal f a t + 4 0 mg. xanthophyll/lb. Diet 1 + 10% dehy. alfalfa meal 2 Diet 1 + 1 5 % dehy. alfalfa meal Diet 1 + 1 0 % corn gluten meal Diet 1 + 1 5 % corn gluten meal Diet 1 + 1 2 % dehy. alfalfa meal + 1 2 % corn gluten meal Milo and soybean meal Diet 1 0 + 4 0 mg. xanthophyll/lb.
Beta-caro1 equiva- N . E. P . A. lents per number gram fresh yolk
1tene
4 4 . 8 bb 51.2 86.8°a 7.2 15.8"
3 . 2 bb 3.6 6.2°a 0.5 1.1"
3 6 . 4 bb ° 37.1 ° 42.1°
2.6ob 2.6b0 2.9°
43.0° 6 4 . 5 ed 81.9 67.7d 94.0 £
3.0° 4 . 6 ed 5.8 4.8d 6.7 f
110.7*5 7.9a 25.lb
7.8s 0.6?b 1.8
1 Each value is the average of 12 and 9 individual yolk color determinations in experiments 1 and 2, respectively. Within the same experiment, values having the same letter are not significantly different from each other at the 1% level of probability. 2 In both experiments the supplemental dehy. alfalfa meal was a product containing 20 percent of protein.
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
lbs. 600 130 110 40 30 25 15 35 5 0.2 10
Ground yellow corn Wheat standard middlings Soybean oil meal (44% protein) Meat and bone scrap (50% protein) Dehy. alfalfa meal (17% protein) Dried whole whey Steamed bone meal Ground limestone Iodized salt Manganese sulfate Vitamin premix*
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T. W. SULLIVAN AND K. A. HOLLEMAN
0. D. of Acetone Extract at ljll5 mu.
(fresh yolk)
\ 2
k
6
,'\
"' V 8
Diet 10, milo
10
.-.
12
lit
16
18
20
DASfS
FIG. 1. Daily effect on egg yolk color of diets high and low in pigmenters (Exp. 2).
addition of purified xanthophyll (30 mg./ lb.) to the milo diet did not significantly increase yolk color. Experiment 2. This experiment was conducted to determine the effect of supplemental xanthophyll, dehydrated alfalfa meal, corn gluten meal and fat on egg yolk color. The data are presented in Table 2. Yolk color values obtained with the basal diet were a 36.4 beta-carotene equivalent and a 2.6 N.E.P.A. number. The addition of 4 percent of animal fat to this diet had no effect on yolk color or the utilization of supplemental xanthophyll. Addition of 40 mg. of purified xanthophyll per pound of diet did not significantly increase yolk color. When 10 percent of either dehydrated alfalfa meal or corn gluten meal was present in the diet, the beta-carotene equivalent and N.E.P.A. number were significantly increased. Dietary levels of 15 percent of these products further increased yolk color. The response to corn gluten meal was greater than to dehydrated alfalfa meal. This difference was statistically significant when IS percent of each was fed. Yolk color values obtained with a diet containing 12 percent of each of these
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
Diet 9, yellow corn 12$ deny, alfalfa meal 12$ corn gluten meal
products were significantly greater than the values obtained with any other diet. When milo completely replaced yellow com, yolk color was again drastically reduced. The addition of purified xanthophyll (40 mg./ lb.) to the milo diet significantly increased yolk color. The daily effect on egg yolk color of diets high and low in pigmenters is illustrated in Figure 1. Yolk color values for eggs produced by the groups receiving diets 9 and 10 in experiment 2 were used for these response curves. Two eggs from each group, but not necessarily from the same individual birds, were measured daily for 20 days. It appeared that the full effect of diet on egg yolk color was expressed in 10 days. Several factors will apparently cause variations in yolk color intensity among birds fed the same diet (Romanoff and Romanoff, 1949). Such factors include age and strain of bird, rate of egg production, egg size and the clutch position of each egg. That variations in egg yolk color were more pronounced when the diet contained a high level of pigmenters (diet 9) is illustrated in Figure 1. Calculations based on data from experiment 2 and xanthophyll values reported by Hastings (1961) suggest that 10 to 12 mg. of "available" xanthophyll per pound of diet is required to produce egg yolks with a 4 to S N.E.P.A. number, or with 50 to 75 beta-carotene equivalents per gram. Expressed in grams per ton, this level would be 20 to 24 grams of "available" xanthophyll or about 50 grams of total xanthophylls. For reasons which are as yet unexplained, the xanthophylls in dehydrated alfalfa meal appear to be less available than those in yellow corn and corn gluten meal. Experiment 3. Data obtained in this experiment are presented in Table 3. This test was conducted primarily to determine the levels of dehydrated alfalfa meal necessary in a milo diet to produce the egg yolk
EGG YOLK COLOR AND DIETARY COMPONENTS TABLE 3.—Egg yolk color as influenced by milo rations containing graded levels of dehydrated alfalfa meal Level of dehydrated alfalfa meal 1
Beta-carotene 2 equivalents per gram fresh yolk
N.E.P.A. 2 number
% of diet 3 6 9 12 15
12.8" 22.4 b 31.6" 45.6 d 58.8«
0.9» 1.5" 2.2C 3.2 d 4.2 e
A product containing 17 percent of protein. Each value is the average of 9 individual yolk determinations. Values having the same letter are not significantly different from each other at the 1 % level of probability.
color generally acceptable for table consumption (N.E.P.A. 1.5—3.0) and most desirable for breaking stock (N.E.P.A. 4-5). An alfalfa meal containing 17 percent protein was utilized. About 6 to 10 percent of this product was needed in the milo diet to produce egg yolks acceptable for table consumption. Likewise, at least 15 percent was required to produce yolks desirable for breaking stock.
diet was required to produce egg yolks with a 4 to 5 N.E.P.A. number of with 50 to 75 beta-carotene equivalents per gram. 3. When milo completely replaced yellow corn in the hen's diet, 6 to 10 percent of dehydrated alfalfa meal was needed to produce egg yolks generally acceptable for table consumption. Likewise, at least 15 percent of alfalfa meal was needed to produce the most desirable yolks for breaking stock. 4. The addition of 4 percent of animal fat to a yellow corn-soybean oil meal diet did not influence egg yolk color. 5. Yolk color was increased when purified xanthophyll (10 to 40 mg./lb.) was added to the hen's diet. However, in 3 out of 4 instances these differences were not statistically significant. 6. The full effect of diet on yolk color was expressed in 10 days. ACKNOWLEDGMENT
SUMMARY
In a study concerning the effect of dehydrated alfalfa meal, corn gluten meal and other dietary components on egg yolk color, three short-term (4 to 6 weeks) experiments were conducted. Data pertaining to egg yolk color (beta-carotene equivalents per gram of fresh yolk and N.E.P.A. numbers) were collected. These data suggest or indicate the following: 1. To produce the egg yolk color most desired by the breaking industry (N.E.P.A. 4 to 5), 10 to 12 percent of good quality dehydrated alfalfa meal or about 10 percent of good quality corn gluten meal was needed in diets containing yellow corn. 2. Calculations based on data from this study indicated that 10 to 12 mg. of "available" xanthophyll per pound of
The authors are grateful to Bowman Feed Products, Inc., Holland, Michigan and to Dawe's Laboratories, Inc., Chicago, Illinois for supplying the purified xanthophyll used in this study. REFERENCES Association of Official Agricultural Chemists, 1958. Method for measuring natural color in egg products. Official and Tentative Methods of Analysis, 4 1 : 42. Duncan, D. B., 1953. Significant tests for differences between ranked treatments in analysis of variance. Technical Report No. 3, Dept. of Statistics, Virginia Agr. Expt. Sta., Blacksburg, Va. Gillam, A. D., and I. M. Heilbron, 1935. Vitamin A-active substances in egg yolk. Biochem. J. 29: 1064-1067. Hastings, W. H., 1961. Research on the use of pigmented. Feedstuffs, 33 : No. 46,30-35. Holleman, K. A., and T. W. Sullivan, 1959. Egg yolk color as influenced by xanthophyll and
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feedstuffs containing related pigments. Poultry Sci. 38: 1214. Jasper, A. W., and R. E. Cray, 1953. Consumer preferences, practices and demands in purchasing eggs and poultry in Columbus, Ohio. Research Bull. 736, Ohio Agri. Expt. Sta., Wooster, Ohio. Kahlenberg, O. J., 1949. A quick and reliable gauge of yolk color. Food Ind. 21: 467-470. Peterson, W. J., J. S. Hughes and L. F. Payne, 1939. Avian carotenoids. Kansas State Agr. Bull. No.
46.
Romanoff, A. L., and A. J. Romanoff, 1949. The Avian Egg. John Wiley and Sons, Inc., New York, New York. Slocum, W. L., and H. S. Swanson, 1954. Egg consumption habits, purchasing patterns and preferences of Seattle consumers. Bull. 556, Wash. Agri. Expt. Sta., Pullman, Washington. Snedecor, G. W., 1956. Statistical Methods. 5th ed. The Iowa State College Press, Ames, Iowa.
J. KAN, B. N. MCPHERSON AND N. R. GYLES Department of Animal Industry and Veterinary Science, University of Arkansas, Fayetteville,
Arkansas
(Received for publication February 12, 1962)
W
ARMING of hatching eggs prior to the regular incubation period resulted in improvement in the hatchability of chicken and turkey eggs (Kosin, 1956; Becker and Bearse, 1958). Milby and Sherwood (1960) showed that preincubation warming only increased hatchability of turkey eggs produced from hens whose hatchabilities were below the average of the population (Milby and Sherwood, 1960). The usual warming procedure is to subject eggs to a period of five hours at 99.5°F. the day after they are laid, after which time the eggs are returned to the egg holding room for the remainder of the storage period. The question arises as to whether greater benefit could be obtained if warming is applied, instead of on the day after lay, somewhat near the middle of the storage period. Or, the five-hour warming might be given in the form of two or more doses with approximately equal intervals between applications. In January 1960, half of the eggs shipped to the Regional Poultry Genetics Laboratory at Athens, Georgia were warmed for five hours in a Jamesway 252 incubator at 1 Published with the approval of the Director of the Arkansas Agricultural Experiment Station.
99.5°F. prior to shipment. The other half served as the untreated control. The age of the eggs ranged from 8 to 19 days at the time of setting. Hatchability of the treated eggs was 82.7% as compared with 74.6% of the control, a difference significant at the 5% level of probability. There was some indication that the age at which the eggs were treated might be of importance. MATERIALS AND METHODS
This report covers a study of warming procedures employing three lines of the University of Arkansas White Wyandottes. The three lines are designated as High (selected for large 8-week body weight), Low (selected for small 8-week body weight), and High-Low (selected for large 8-week and small 20-week body weights). Eggs produced daily during the first week, after having been divided into the various treatments, were held for three weeks (2228 days old). Similarly, eggs produced during the second week were held for two more weeks (15-21 days old) and those of the third week for one week (8-14 days old). Finally eggs produced during the fourth week were set at the end of the fourth week (1-7 days old). Table 1 shows pre-incubation warming procedures which
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Pre-Incubation Warming of Chicken Eggs 1