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Methionine Requirement of Developing Turkeys From 8–12 Weeks of Age
1414
D . H . LUMIJARVI AND P . VOHRA
McWard, G. W., and H. M. Scott, 1961. Sodium requirements of the young chick fed purified diets. Poultry Sci. 40: 1026-1029. Nott, H., and G. F. Combs, 1969. Sodium requirement of the chick. Poultry Sci. 48: 660-665. Scott, M. L., A. van Tienhoven, E. R. Holm and
R. E. Reynolds, 1960. Studies on the sodium, chlorine and iodine requirements of young pheasants and quail. J. Nutr. 71: 282-288. Vohra, P., 1971. A review of the nutrition of Japanese quail. World's Poultry Sci. J. 27: 26-34.
Methionine Requirement of Developing Turkeys From 8-12 Weeks of Age MARIO G. MURILLO AND L E O S. JENSEN
Department of Poultry Science, University of Georgia, Athens, Georgia 30602 (Received for publication November 28. 1975)
POULTRY SCIENCE 55: 1414-1418, 1976
INTRODUCTION
M
UCH work has been done to estimate the amino acid requirements of turkey poults during the first few weeks of life, but considerably less information is available on the requirements after eight weeks of age. In most practical diets, methionine will be the most critical amino acid during the early stages of the developing period, while lysine will become critical during the latter part of the developing period. The National Research Council (1971) suggests a requirement of 0.4% methionine and 0.7% methionine + cystine (M + C) for developing turkeys from 8-12 weeks of age in a ration containing 2930 kcal. of metabolizable energy (M.E.)/kg. Thus the suggested requirement is 1.37 g. methionine and 2.39 g. of M + C/mcal. of M.E. Experimental data to support the suggested requirements, however, are limited. Balloun (1962) suggested a methionine requirement of ap-
proximately 2% of protein for developing turkeys. Waibel (1968) suggested a methionine requirement of 1.25 g. of methionine and2.19g. of M + C/mcal. of M.E., although no experimental data were presented to support these suggestions. In an experiment in which two calorie-protein ratios were used in diets containing from 0-12% added fat, the performance of turkeys from 8-12 weeks was better when the diets contained 1.39 to 1.45 g. methionine/meal. M.E. than when they contained from 1.30 to 1.36g. methionine (Jensen et al, 1970). Potter (1973) recommended a methionine level of 1.33 g./mcal. and a total sulfur containing amino acid level of 2.44 g./mcal. Auckland and Liddle (1972) fed diets with different protein levels but the same energy content to turkeys from 8-12 weeks of age. They obtained the best growth and feed efficiency with the highest level of protein which contained 1.8 g. methionine
Downloaded from http://ps.oxfordjournals.org/ at NERL on May 22, 2015
ABSTRACT Two experiments were conducted with Large White male turkeys from 8-12 weeks of age to estimate the methionine requirement for optimum growth rate and feed efficiency. The first experiment was conducted with five pens of 22 turkeys per treatment when the mean minimum temperature was 17.2° C. and the maximum 32.2° C. The second experiment was conducted with four groups of 14 turkeys per pen when the mean minimum temperature was 1.4° C. and the maximum 12.4° C. Initial body weight and rate of gain in the first experiment was lower than that in Experiment 2. Maximum growth and feed efficiency in Experiment 1 were obtained with a methionine level between 1.32 and 1.41 g./mcal. of M.E. and in Experiment 2 between 1.27 and 1.43 g. Adding 0.1% L-cystine to the basal diet in Experiment 2 failed to improve growth or feed efficiency significantly. The estimated requirement for methionine in these experiments agrees with the present estimate of the National Research Council.
METHIONINE REQUIREMENT OF TURKEYS
MATERIALS AND METHODS Two experiments were conducted with Large White male turkeys from 8-12 weeks of age. In the first experiment five pens of 22 birds each were fed each of the experimental diets. The birds were kept in floor pens approximately 1.5 x 6.1 meters in size with wood shavings as litter. The poults were used for a methionine study from 0-4 weeks of age in which they were housed 75 to a pen (12 poults/m. 2 ) in a windowless house. From 4-8 weeks the poults were fed a practical starter diet. At eight weeks they were randomly distributed into 20 pens used in the present study. Both the front and rear of the house had open windows covered with wire screen mesh. The experiment was conducted from May 31 to June 28,1974. Average minimum temperature for Athens, Georgia during the four-week period was 17.2° C. and average maximum temperature was 32.2° C. Composition of the basal diet used in the study is presented in Table 1. Four different levels of methionine added as DL-methionine
TABLE I.—Composition of the basal diet Ingredients % Corn 54.865 37.0 Soybean meal (48.5% protein) Limestone 1.14 Dicalcium phosphate 1.22 Iodized salt 0.40 Vitamin mix1 0.25 0.10 Mineral mix2 Poultry fat 5.00 Potassium sulfate 0.025 (22 mg./kg.) Bacitracin (Zn) Calculated analysis:3 Protein, % 22.9 M.E., kcal./kg. 3217 Methionine, % 0.36 Cystine, % 0.36 Methionine, g./mcal. M.E. 1.13 Methionine + cystine, g./mcal. M.E. 2.24 1 Vitamin premix supplied the following per kg. diet: vitamin A, 88001.U.; vitamin D3, 17601.C.U.; vitamin E, 22.0 I.U.; vitamin B12, 13.2 meg.; riboflavin, 8.8 mg.; niacin, 88 mg.; d-pantothenic acid, 17.6 mg.; choline, 0.38 mg.; menadione, 2.3 mg.; folic acid, 11 mg.; d-biotin, 0.22 mg.; pyridoxine hydrochloride, 4.4 mg.; thiamine, 4.03 mg. 2 Trace mineral mix supplied the following per kg. diet: zinc, 20 p.p.m.; manganese, 60 p.p.m.; copper,2 p.p.m.;iron, 25 p.p.m.;iodine, 1.2p.p.m. 3 The basal diets were analyzed for methionine and cystine content but the values were extremely variable, particularly for cystine. Therefore, values commonly used in the feed industry for the ingredients included in the diet were used to calculate the methionine + cystine content. The values used for soybean meal were 0.72% methionine and 0.73% cystine and for corn 0.18% methionine and 0.16% cystine (Hubbell, 1974). (99%) were compared in Experiment 1. Feed and water were supplied ad libitum and the turkeys were weighed individually at the start and end of the experiment and pen feed consumption was recorded. In Experiment 2, four pens of 14 turkeys each were fed each of the experimental diets from 8-12 weeks of age. The poults were housed in battery brooders from 0-3 weeks of age when they were used for a methionine study. At 3 1 / 2 weeks of age they were moved
Downloaded from http://ps.oxfordjournals.org/ at NERL on May 22, 2015
/meal. M.E. and 3.13 g. M + C. In unpublished results from Washington State University the M + C requirement of torn turkeys from 8-12 weeks of age was approximately 2.4 g./mca!. and the results indicated that methionine need only contribute 50% or less of the total (Jensen, 1973). A study with female turkey indicated that the requirement for this sex was 10% less than that observed for male turkeys. The nutrient requirements of turkeys and other animals are affected by environmental temperature. Most of the experiments with developing turkeys have been conducted in a temperate climate. The purpose of the present study was to investigate the methionine requirement of Large White torn turkeys from 8-12 weeks of age at two different times of the year when average temperature would be markedly different.
1415
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M. G. MURILLO AND L. S. JENSEN
RESULTS In Experiment 1, both growth rate and feed efficiency were improved by adding methio-
nine to the basal diet (Table 2). Maximum rate of gain was obtained with the highest level of added methionine, 0.09% (1.41 g. total methionine/meal, of M.E.), but the difference was not significantly different (P > 0.05) from that obtained with the next lowest level of added methionine (1.32 g./mcal. of M.E.). Feed efficiency, however, was significantly better for the highest level compared to the three lower levels. The results indicate that the M + C requirement was at least 0.81% and that the methionine requirement was 0.45% (1.41 g./mcal. of M.E.). In Experiment 2, gain appeared to be improved by methionine supplementation, but the differences among treatments were not statistically significant (P > 0.05) (Table 3). Feed conversion ratio of birds fed the diet with the highest level of added methionine was significantly different from that of birds fed the basal diet. A judgement based on the combined results of gain and feed efficiency suggests that a level of M + C between
TABLE 2.—Body weight gain and feed conversion of turkeys fed different levels of methionine from 8 to 12 weeks of age (Experiment 7)'-2 Added DL-methionine
Methionine + cystine
(%) 0 0.03 0.06 0.09
0.72 0.75 0.78 0.81
g ./meal. M.E. Meth. Meth. + cystine 1.13 1.22 1.32 1.41
2.24 2.33 2.43 2.52
Gain (g.) 2350a2 2410ab 2460bc 2540c
Feed/ gain 2.54a 2.49a 2.48a 2.37b
'Average value of 22 poults/replication; 5 replication/treatment. ! Means in the same column without a common letter are significantly different (P < 0.05). TABLE 3.—Body weight gain and feed conversion of turkeys fed different levels of methionine and cystine from 8 to 12 weeks (Experiment 2)1-2 Supplement added
Methionine + cystine
(%) None 0.05 D,L Meth. O.IOD.L Meth.
0.15 D.LMeth. O.IOL-Cystine
0.72 0.77 0.82 0.87 0.82
g ,/mcal. M.E. Meth. + cystine Meth. 2.24 1.13 2.39 1.27 1.43 2.55 1.59 2.71 2.55 1.13
Gain (g.) 3039a 3116a 3153a 3204a 3012a
Feed/ gain 2.46b 2.43ab 2.39ab 2.38a 2.43ab
'Average value of 14 poults/replication; 5 replication/treatment. Means in the same column without a common letter are significantly different (P < 0.05).
2
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to a large pen approximately 9 x 6 meters in size and were kept here until eight weeks of age (5.2 poults/m. 2 ). At eight weeks of age the turkeys were randomized into the same 20 pens used in the first study and the turkeys were managed similar to those in Experiment 1. The mean temperature in Athens, Georgia during the experiment (conducted from February 5 to March 5, 1975) was a minimum of 1.4° C. and a maximum of 12.4° C. The same basal diet as that shown in Table 1 was used and four different methionine levels were compared. A fifth treatment involved the addition of 0.1% cystine to the basal diet. The data from both experiments were analyzed by analysis of variance and Duncan's (1955) multiple range test.
METHIONINE REQUIREMENT OF TURKEYS
0.77 and 0.82% was adequate for optimum performance of the turkeys. This was equivalent to between 1.27 and 1.43 g. methionine /meal, of M.E. There was no evidence that adding cystine to the basal diet improved the performance of the birds. Initial weight of the birds averaged approximately 2700 g., which was considerably better than that of birds in Experiment 1. DISCUSSION
The results of the two experiments indicate that the methionine requirement was between 1.32 and 1.41 g./mcal. in Experiment 1, and between 1.27 and 1.43 in Experiment 2. This is in close agreement with the present recommendation of the National Research Council (1971) and with the recommendation of Potter (1973). It also agrees with the level in the
highest protein diets which gave optimum performance in the studies of Jensen et al. (1970). The latter turkeys were 8-12 weeks of age during July and August so were subjected to hot environmental temperatures. The results indicate a requirement higher than that recommended by Waibel (1968) who suggested 1.25 g./mcal. of M.E. In a study conducted by Auckland and Liddle (1972) to estimate the protein requirement of turkeys from 8-12 weeks of age, the diet with the highest level of protein gave the highest performance. The diet was calculated to contain 1.8 g. methionine/meal, of M.E. This value is obviously out of line with the estimate of the methionine requirement in this study as well as those of others and it appears that the growth response obtained by Auckland and Liddle (1972) was due to some amino acid or nutritional factor other than methionine. In Experiment 2, adding 0.1% cystine to the diet did not significantly improve growth rate or feed efficiency. The basal diet contained 0.025% potassium sulfate; therefore, the estimate of the requirement in these studies probably was for methionine per se. REFERENCES Auckland, J. N., and P. C. Liddle, 1972. Protein requirements for early finishing of male and female turkeys. Br. Poultry Sci. 13: 273-278. Balloun, S. L., 1962. Lysine, arginine and methionine balance of diets for turkeys to 24 weeks of age. Poultry Sci. 41:417-424. Duncan, D. B., 1955. Multiple range and multiple F test. Biometrics, 11: 1-42. Hubbell, C. H., 1974. Feedstuffs analysis table for feed ingredients. Feedstuffs, July 1. Jensen, L. S., 1973. Lysine and methionine studies with developing turkeys and laying hens. Proc. Maryland Nutrition Conference for Feed Manufacturers, p. 83. Jensen. L. S., G. W. Schumaier and J. D. Latshaw, 1970. "Extra caloric" effect of dietary fat for developing turkeys as influenced by calorie-protein ratio. Poultry Sci. 49: 1697-1704. National Research Council, 1971. Nutrient requirement of poultry.
Downloaded from http://ps.oxfordjournals.org/ at NERL on May 22, 2015
Even though there was considerable difference in the mean ambient temperature during the two experiments in this study, the estimate of the methionine requirement from 8-12 weeks of age was not too different. Feed conversion ratios for turkeys fed an optimum level of methionine was about the same in the two experiments. Theoretically, one would expect a better feed conversion during warm weather. The weather was extremely hot during the first experiment and the temperature inside the house was probably greater than that outside because of body heat from the birds and heat build-up from the metal roof on the house. Thus, it is possible that the temperature conditions to which the birds were exposed were beyond the range where maximum feed efficiency is obtained and that the turkeys were using energy to cool themselves. The turkeys in Experiment 1 were also more crowded than those in Experiment 2 and were maintained under hot, crowded conditions prior to the start of the experiment, which resulted in a lower starting weight (approximately 600 g.) than expected for the strain of turkey used.
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M. G. MURILLO AND L. S. JENSEN
Potter, L. M., 1973. Using proper ingredients properly for poultry. Proc. Virginia Feed Convention and Nutrition Conference, p. 69-76.
Waibel, P. E., 1968. Amino acids and protein for growing turkeys. Proc. 29th Minnesota Nutrition Conference, p. 149-155.
Ring Structure of Avian Egg Yolk1 C. R. GRAU
Department of Avian Sciences, University of California, Davis, California 95616 (Received for publication November 28, 1975)
POULTRY SCIENCE 55: 1418-1422, 1976
I
T has been recognized for more than a century that deposition of yolk in birds occurs by addition of material to the periphery of the oocyte within a follicle of the ovary (Thomson, 1859). This is a continuous process whereby a single yolk of a laying hen may increase by approximately two grams each day during the rapid phase of growth before ovulation (Gilbert, 1972). The deposited yolk is not homogeneous, although it often appears so. This report shows that yolk varies in staining properties depending on the time of day it is deposited in the follicle. Thus, rings are produced which correspond to daily yolk formation. The rate of yolk deposition was found by Warren and Conrad (1939) to be relatively constant. Riddle (1911), on the other hand, had theorized that the ring structure of yolk,
1. A preliminary report of this work was presented to the 64th Poultry Science Association Meeting, Pullman, Washington August 4, 1975 (Poultry Sci. 54: 1767).
which is visible in cross section of some hard-boiled eggs, could be accounted for by differences in deposition during daytime feeding and nighttime inanition, causing the formation of rings of yellow and white yolk in which the white yolk was presumably similar to the central primordial yolk. However, Conrad and Warren (1939) found that when the ring color was visible it reflected variation in the dietary intake of carotenoids. Feeding a laying hen, or injecting it daily with intravenous doses of a fat-soluble dye revealed the ring structure in a hardcooked yolk (Warren and Conrad, 1939). In domestic birds it has been found, by daily feeding or injection of dye and counting of rings in sections of cooked yolks, that the rapid period of yolk deposition takes 7-11 days for chickens (Gilbert, 1972); 11-15 days for turkeys (Bacon and Cherms, 1968); and 5-7 days for quail (Cotumix coturnix japonica) (Homma et al., 1965; Bacon and Koontz, 1972). Little is known about the time course of yolk deposition in wild birds. Bissonnette
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ABSTRACT Differences in the staining properties of yolk deposited during night and day were used to estimate the time required to deposit yolk within the ovarian follicle. Whole eggs were frozen to -10° C. to alter the lipoproteins, the shell was removed, and contents fixed in 4% formalin for 18 hours at 60-70° C. The yolk was cut in half, and one half was put into 6% potassium dichromate for 18 hours at 60-70° C. Slices revealed alternating light and dark grey-green or brown rings. The center (latebra) was always light. From timed dye-feeding experiments it was found that lighter staining rings were deposited at night. Chicken eggs had 7-11 light rings; coturnix quail 4-6; turkeys 10-12; and cackling geese 12. All eggs from a variety of bird species showed ring structures. Staining formalin-fixed slices with acidified ferrocyanide yielded rings of Prussian blue, a test for forms of iron. Variation in the nutrition of the reproducing female, or the effects of acute contacts with environmental contaminants can be localized in discrete rings of yolks without experimental intervention during yolk deposition.
D . H . LUMIJARVI AND P . VOHRA
McWard, G. W., and H. M. Scott, 1961. Sodium requirements of the young chick fed purified diets. Poultry Sci. 40: 1026-1029. Nott, H., and G. F. Combs, 1969. Sodium requirement of the chick. Poultry Sci. 48: 660-665. Scott, M. L., A. van Tienhoven, E. R. Holm and
R. E. Reynolds, 1960. Studies on the sodium, chlorine and iodine requirements of young pheasants and quail. J. Nutr. 71: 282-288. Vohra, P., 1971. A review of the nutrition of Japanese quail. World's Poultry Sci. J. 27: 26-34.
Methionine Requirement of Developing Turkeys From 8-12 Weeks of Age MARIO G. MURILLO AND L E O S. JENSEN
Department of Poultry Science, University of Georgia, Athens, Georgia 30602 (Received for publication November 28. 1975)
POULTRY SCIENCE 55: 1414-1418, 1976
INTRODUCTION
M
UCH work has been done to estimate the amino acid requirements of turkey poults during the first few weeks of life, but considerably less information is available on the requirements after eight weeks of age. In most practical diets, methionine will be the most critical amino acid during the early stages of the developing period, while lysine will become critical during the latter part of the developing period. The National Research Council (1971) suggests a requirement of 0.4% methionine and 0.7% methionine + cystine (M + C) for developing turkeys from 8-12 weeks of age in a ration containing 2930 kcal. of metabolizable energy (M.E.)/kg. Thus the suggested requirement is 1.37 g. methionine and 2.39 g. of M + C/mcal. of M.E. Experimental data to support the suggested requirements, however, are limited. Balloun (1962) suggested a methionine requirement of ap-
proximately 2% of protein for developing turkeys. Waibel (1968) suggested a methionine requirement of 1.25 g. of methionine and2.19g. of M + C/mcal. of M.E., although no experimental data were presented to support these suggestions. In an experiment in which two calorie-protein ratios were used in diets containing from 0-12% added fat, the performance of turkeys from 8-12 weeks was better when the diets contained 1.39 to 1.45 g. methionine/meal. M.E. than when they contained from 1.30 to 1.36g. methionine (Jensen et al, 1970). Potter (1973) recommended a methionine level of 1.33 g./mcal. and a total sulfur containing amino acid level of 2.44 g./mcal. Auckland and Liddle (1972) fed diets with different protein levels but the same energy content to turkeys from 8-12 weeks of age. They obtained the best growth and feed efficiency with the highest level of protein which contained 1.8 g. methionine
Downloaded from http://ps.oxfordjournals.org/ at NERL on May 22, 2015
ABSTRACT Two experiments were conducted with Large White male turkeys from 8-12 weeks of age to estimate the methionine requirement for optimum growth rate and feed efficiency. The first experiment was conducted with five pens of 22 turkeys per treatment when the mean minimum temperature was 17.2° C. and the maximum 32.2° C. The second experiment was conducted with four groups of 14 turkeys per pen when the mean minimum temperature was 1.4° C. and the maximum 12.4° C. Initial body weight and rate of gain in the first experiment was lower than that in Experiment 2. Maximum growth and feed efficiency in Experiment 1 were obtained with a methionine level between 1.32 and 1.41 g./mcal. of M.E. and in Experiment 2 between 1.27 and 1.43 g. Adding 0.1% L-cystine to the basal diet in Experiment 2 failed to improve growth or feed efficiency significantly. The estimated requirement for methionine in these experiments agrees with the present estimate of the National Research Council.
METHIONINE REQUIREMENT OF TURKEYS
MATERIALS AND METHODS Two experiments were conducted with Large White male turkeys from 8-12 weeks of age. In the first experiment five pens of 22 birds each were fed each of the experimental diets. The birds were kept in floor pens approximately 1.5 x 6.1 meters in size with wood shavings as litter. The poults were used for a methionine study from 0-4 weeks of age in which they were housed 75 to a pen (12 poults/m. 2 ) in a windowless house. From 4-8 weeks the poults were fed a practical starter diet. At eight weeks they were randomly distributed into 20 pens used in the present study. Both the front and rear of the house had open windows covered with wire screen mesh. The experiment was conducted from May 31 to June 28,1974. Average minimum temperature for Athens, Georgia during the four-week period was 17.2° C. and average maximum temperature was 32.2° C. Composition of the basal diet used in the study is presented in Table 1. Four different levels of methionine added as DL-methionine
TABLE I.—Composition of the basal diet Ingredients % Corn 54.865 37.0 Soybean meal (48.5% protein) Limestone 1.14 Dicalcium phosphate 1.22 Iodized salt 0.40 Vitamin mix1 0.25 0.10 Mineral mix2 Poultry fat 5.00 Potassium sulfate 0.025 (22 mg./kg.) Bacitracin (Zn) Calculated analysis:3 Protein, % 22.9 M.E., kcal./kg. 3217 Methionine, % 0.36 Cystine, % 0.36 Methionine, g./mcal. M.E. 1.13 Methionine + cystine, g./mcal. M.E. 2.24 1 Vitamin premix supplied the following per kg. diet: vitamin A, 88001.U.; vitamin D3, 17601.C.U.; vitamin E, 22.0 I.U.; vitamin B12, 13.2 meg.; riboflavin, 8.8 mg.; niacin, 88 mg.; d-pantothenic acid, 17.6 mg.; choline, 0.38 mg.; menadione, 2.3 mg.; folic acid, 11 mg.; d-biotin, 0.22 mg.; pyridoxine hydrochloride, 4.4 mg.; thiamine, 4.03 mg. 2 Trace mineral mix supplied the following per kg. diet: zinc, 20 p.p.m.; manganese, 60 p.p.m.; copper,2 p.p.m.;iron, 25 p.p.m.;iodine, 1.2p.p.m. 3 The basal diets were analyzed for methionine and cystine content but the values were extremely variable, particularly for cystine. Therefore, values commonly used in the feed industry for the ingredients included in the diet were used to calculate the methionine + cystine content. The values used for soybean meal were 0.72% methionine and 0.73% cystine and for corn 0.18% methionine and 0.16% cystine (Hubbell, 1974). (99%) were compared in Experiment 1. Feed and water were supplied ad libitum and the turkeys were weighed individually at the start and end of the experiment and pen feed consumption was recorded. In Experiment 2, four pens of 14 turkeys each were fed each of the experimental diets from 8-12 weeks of age. The poults were housed in battery brooders from 0-3 weeks of age when they were used for a methionine study. At 3 1 / 2 weeks of age they were moved
Downloaded from http://ps.oxfordjournals.org/ at NERL on May 22, 2015
/meal. M.E. and 3.13 g. M + C. In unpublished results from Washington State University the M + C requirement of torn turkeys from 8-12 weeks of age was approximately 2.4 g./mca!. and the results indicated that methionine need only contribute 50% or less of the total (Jensen, 1973). A study with female turkey indicated that the requirement for this sex was 10% less than that observed for male turkeys. The nutrient requirements of turkeys and other animals are affected by environmental temperature. Most of the experiments with developing turkeys have been conducted in a temperate climate. The purpose of the present study was to investigate the methionine requirement of Large White torn turkeys from 8-12 weeks of age at two different times of the year when average temperature would be markedly different.
1415
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M. G. MURILLO AND L. S. JENSEN
RESULTS In Experiment 1, both growth rate and feed efficiency were improved by adding methio-
nine to the basal diet (Table 2). Maximum rate of gain was obtained with the highest level of added methionine, 0.09% (1.41 g. total methionine/meal, of M.E.), but the difference was not significantly different (P > 0.05) from that obtained with the next lowest level of added methionine (1.32 g./mcal. of M.E.). Feed efficiency, however, was significantly better for the highest level compared to the three lower levels. The results indicate that the M + C requirement was at least 0.81% and that the methionine requirement was 0.45% (1.41 g./mcal. of M.E.). In Experiment 2, gain appeared to be improved by methionine supplementation, but the differences among treatments were not statistically significant (P > 0.05) (Table 3). Feed conversion ratio of birds fed the diet with the highest level of added methionine was significantly different from that of birds fed the basal diet. A judgement based on the combined results of gain and feed efficiency suggests that a level of M + C between
TABLE 2.—Body weight gain and feed conversion of turkeys fed different levels of methionine from 8 to 12 weeks of age (Experiment 7)'-2 Added DL-methionine
Methionine + cystine
(%) 0 0.03 0.06 0.09
0.72 0.75 0.78 0.81
g ./meal. M.E. Meth. Meth. + cystine 1.13 1.22 1.32 1.41
2.24 2.33 2.43 2.52
Gain (g.) 2350a2 2410ab 2460bc 2540c
Feed/ gain 2.54a 2.49a 2.48a 2.37b
'Average value of 22 poults/replication; 5 replication/treatment. ! Means in the same column without a common letter are significantly different (P < 0.05). TABLE 3.—Body weight gain and feed conversion of turkeys fed different levels of methionine and cystine from 8 to 12 weeks (Experiment 2)1-2 Supplement added
Methionine + cystine
(%) None 0.05 D,L Meth. O.IOD.L Meth.
0.15 D.LMeth. O.IOL-Cystine
0.72 0.77 0.82 0.87 0.82
g ,/mcal. M.E. Meth. + cystine Meth. 2.24 1.13 2.39 1.27 1.43 2.55 1.59 2.71 2.55 1.13
Gain (g.) 3039a 3116a 3153a 3204a 3012a
Feed/ gain 2.46b 2.43ab 2.39ab 2.38a 2.43ab
'Average value of 14 poults/replication; 5 replication/treatment. Means in the same column without a common letter are significantly different (P < 0.05).
2
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to a large pen approximately 9 x 6 meters in size and were kept here until eight weeks of age (5.2 poults/m. 2 ). At eight weeks of age the turkeys were randomized into the same 20 pens used in the first study and the turkeys were managed similar to those in Experiment 1. The mean temperature in Athens, Georgia during the experiment (conducted from February 5 to March 5, 1975) was a minimum of 1.4° C. and a maximum of 12.4° C. The same basal diet as that shown in Table 1 was used and four different methionine levels were compared. A fifth treatment involved the addition of 0.1% cystine to the basal diet. The data from both experiments were analyzed by analysis of variance and Duncan's (1955) multiple range test.
METHIONINE REQUIREMENT OF TURKEYS
0.77 and 0.82% was adequate for optimum performance of the turkeys. This was equivalent to between 1.27 and 1.43 g. methionine /meal, of M.E. There was no evidence that adding cystine to the basal diet improved the performance of the birds. Initial weight of the birds averaged approximately 2700 g., which was considerably better than that of birds in Experiment 1. DISCUSSION
The results of the two experiments indicate that the methionine requirement was between 1.32 and 1.41 g./mcal. in Experiment 1, and between 1.27 and 1.43 in Experiment 2. This is in close agreement with the present recommendation of the National Research Council (1971) and with the recommendation of Potter (1973). It also agrees with the level in the
highest protein diets which gave optimum performance in the studies of Jensen et al. (1970). The latter turkeys were 8-12 weeks of age during July and August so were subjected to hot environmental temperatures. The results indicate a requirement higher than that recommended by Waibel (1968) who suggested 1.25 g./mcal. of M.E. In a study conducted by Auckland and Liddle (1972) to estimate the protein requirement of turkeys from 8-12 weeks of age, the diet with the highest level of protein gave the highest performance. The diet was calculated to contain 1.8 g. methionine/meal, of M.E. This value is obviously out of line with the estimate of the methionine requirement in this study as well as those of others and it appears that the growth response obtained by Auckland and Liddle (1972) was due to some amino acid or nutritional factor other than methionine. In Experiment 2, adding 0.1% cystine to the diet did not significantly improve growth rate or feed efficiency. The basal diet contained 0.025% potassium sulfate; therefore, the estimate of the requirement in these studies probably was for methionine per se. REFERENCES Auckland, J. N., and P. C. Liddle, 1972. Protein requirements for early finishing of male and female turkeys. Br. Poultry Sci. 13: 273-278. Balloun, S. L., 1962. Lysine, arginine and methionine balance of diets for turkeys to 24 weeks of age. Poultry Sci. 41:417-424. Duncan, D. B., 1955. Multiple range and multiple F test. Biometrics, 11: 1-42. Hubbell, C. H., 1974. Feedstuffs analysis table for feed ingredients. Feedstuffs, July 1. Jensen, L. S., 1973. Lysine and methionine studies with developing turkeys and laying hens. Proc. Maryland Nutrition Conference for Feed Manufacturers, p. 83. Jensen. L. S., G. W. Schumaier and J. D. Latshaw, 1970. "Extra caloric" effect of dietary fat for developing turkeys as influenced by calorie-protein ratio. Poultry Sci. 49: 1697-1704. National Research Council, 1971. Nutrient requirement of poultry.
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Even though there was considerable difference in the mean ambient temperature during the two experiments in this study, the estimate of the methionine requirement from 8-12 weeks of age was not too different. Feed conversion ratios for turkeys fed an optimum level of methionine was about the same in the two experiments. Theoretically, one would expect a better feed conversion during warm weather. The weather was extremely hot during the first experiment and the temperature inside the house was probably greater than that outside because of body heat from the birds and heat build-up from the metal roof on the house. Thus, it is possible that the temperature conditions to which the birds were exposed were beyond the range where maximum feed efficiency is obtained and that the turkeys were using energy to cool themselves. The turkeys in Experiment 1 were also more crowded than those in Experiment 2 and were maintained under hot, crowded conditions prior to the start of the experiment, which resulted in a lower starting weight (approximately 600 g.) than expected for the strain of turkey used.
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M. G. MURILLO AND L. S. JENSEN
Potter, L. M., 1973. Using proper ingredients properly for poultry. Proc. Virginia Feed Convention and Nutrition Conference, p. 69-76.
Waibel, P. E., 1968. Amino acids and protein for growing turkeys. Proc. 29th Minnesota Nutrition Conference, p. 149-155.
Ring Structure of Avian Egg Yolk1 C. R. GRAU
Department of Avian Sciences, University of California, Davis, California 95616 (Received for publication November 28, 1975)
POULTRY SCIENCE 55: 1418-1422, 1976
I
T has been recognized for more than a century that deposition of yolk in birds occurs by addition of material to the periphery of the oocyte within a follicle of the ovary (Thomson, 1859). This is a continuous process whereby a single yolk of a laying hen may increase by approximately two grams each day during the rapid phase of growth before ovulation (Gilbert, 1972). The deposited yolk is not homogeneous, although it often appears so. This report shows that yolk varies in staining properties depending on the time of day it is deposited in the follicle. Thus, rings are produced which correspond to daily yolk formation. The rate of yolk deposition was found by Warren and Conrad (1939) to be relatively constant. Riddle (1911), on the other hand, had theorized that the ring structure of yolk,
1. A preliminary report of this work was presented to the 64th Poultry Science Association Meeting, Pullman, Washington August 4, 1975 (Poultry Sci. 54: 1767).
which is visible in cross section of some hard-boiled eggs, could be accounted for by differences in deposition during daytime feeding and nighttime inanition, causing the formation of rings of yellow and white yolk in which the white yolk was presumably similar to the central primordial yolk. However, Conrad and Warren (1939) found that when the ring color was visible it reflected variation in the dietary intake of carotenoids. Feeding a laying hen, or injecting it daily with intravenous doses of a fat-soluble dye revealed the ring structure in a hardcooked yolk (Warren and Conrad, 1939). In domestic birds it has been found, by daily feeding or injection of dye and counting of rings in sections of cooked yolks, that the rapid period of yolk deposition takes 7-11 days for chickens (Gilbert, 1972); 11-15 days for turkeys (Bacon and Cherms, 1968); and 5-7 days for quail (Cotumix coturnix japonica) (Homma et al., 1965; Bacon and Koontz, 1972). Little is known about the time course of yolk deposition in wild birds. Bissonnette
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ABSTRACT Differences in the staining properties of yolk deposited during night and day were used to estimate the time required to deposit yolk within the ovarian follicle. Whole eggs were frozen to -10° C. to alter the lipoproteins, the shell was removed, and contents fixed in 4% formalin for 18 hours at 60-70° C. The yolk was cut in half, and one half was put into 6% potassium dichromate for 18 hours at 60-70° C. Slices revealed alternating light and dark grey-green or brown rings. The center (latebra) was always light. From timed dye-feeding experiments it was found that lighter staining rings were deposited at night. Chicken eggs had 7-11 light rings; coturnix quail 4-6; turkeys 10-12; and cackling geese 12. All eggs from a variety of bird species showed ring structures. Staining formalin-fixed slices with acidified ferrocyanide yielded rings of Prussian blue, a test for forms of iron. Variation in the nutrition of the reproducing female, or the effects of acute contacts with environmental contaminants can be localized in discrete rings of yolks without experimental intervention during yolk deposition.