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Evaluation of the Cystine Requirement of the Commercial Laying Hen1
01996Applied Poultry Science, I n c
EVALUATION OF THE CYSTINE REQUIREMENT OF THE COMMERCIAL LAYING HEN'
Primary Audience: Nutritionists, Poultrymen, Researchers
[l] suggests that the white-egg commercial DESCRIPTION OF PROBLEM layer requires 580 mg of S M d a y , 300 mg of There are 22 amino acids in body protein, and all are physiologically essential. These amino acids can be divided into two categories: those that poultry cannot synthesize at all or rapidly enough to meet metabolic requirements (essential) and those that can be synthesized from other nonessential amino acids (nonessential). The essential amino acids must be supplied by the diet. The NRC 1 2
which must be furnished by Met. Therefore, it is logical to assume that 280 mg can be furnished from cystine, abbreviated "Cys" [2]. Met can be used for meeting the need for Cys when Met is the first limiting amino acid [3]. The molecular weight of Met is 149 and the molecular weight of Cys is 240, and two molecules of Met are required to produce a molecule of Cys. Therefore, Creek [4] sug-
Florida Agricultural Experiment Station Journal Series No. R-04615 To whom correspondence should be addressed
Downloaded from http://japr.oxfordjournals.org/ at Cal Poly Pomona University Library on March 18, 2015
R. H. HARMS2 and G. B. RUSSELL Department of Dairy and Poultry Sciences, University of Florida, Gainesville, FL 326II-0930 Phone: (904) 392-1931 FAX: (904) 392-3047
CYSTINE REQUIREMENT
140
for casein and gelatin and energy for corn oil were based on NRC [l]. Corn oil and sand varied to obtain the desired energy values. Each experiment operated for 8 wk. The first 2 wk were considered as a depletion period and data from the last 6 wk were used to measure treatment differences. Researchers measured egg weight (EW) and shell weight data each week for the last egg weighed by each hen. These eggs were broken out and the shells with membranes dried and weighed. Feed consumption (FC) was calculated by replicate at bi-weekly intervals, at which time new feed replaced the remaining feed. Egg production (EP) was recorded on an individual hen basis; however, analyses were performed on a replicate basis. Researchers calculated egg mass (EM) by multiplying EP times EW for each replicate. Daily intake of Met was calculated for each replicate. Dividing daily Met intake by daily egg content (EC = [EW - shell weight x %EP]) revealed the Met/g of EC. The data were subjected to ANOVA using the general linear model procedure of SAS [12]. The Waller-Duncan Range Test [ 131 separated the significant treatment effects. EXPERIMENT 1 This experiment attempted to develop a suitable diet for use in studying the Cys needs of the commercial laying hen. Hens received four different diets (Table 1).Casein served as an ingredient because it contains five times as much Met as Cys [l].Also, Diet 2 contained 1.5% gelatin. Each of the diets was supplemented with limiting synthetic amino acids. Diets 1 and 2 contained a high level (0.35%) of supplemental DL-methionine. Diet 3, containing 0.28% Met and 0.16% Cys, was formulated by substituting corn for soybean meal and eliminating the supplemental DL-methionine. Diet 4 was formulated by adding 0.034% Cys to Diet 3.
MATERIALS AND METHODS Hy-Line W36 [ 111hens were used in these experiments. The hens were 29 wk old in Experiments 1and 5. Experiments 2,3, and 4 were conducted at the same time with hens 39 wk old. Elght replicates of five hens, maintained in individual cages in a windowless house and given artiticial light (16 hr light9 hr dark) were used per treatment in all experiments. Temperature, controlled to a minimum of 31.7 to 32.2"C to obtain a constant feed intake, resulted in a feed intake that would permit a response from increased levels of Met or Cys. Varying the amount of corn, soybean meal, casein, or casein and gelatin produced the desired levels of Met and Cys. Levels of amino acids in corn and soybean meal were determined by analysis. Amino acid values
EXPERIMENTS 2 AND 3 The basal diet used in Experiments 2 and 3 (Table 2) was essentially the same as that for Diet 3 in Experiment 1, except that researchers made slight changes because of different corn and soybean meal sources. Therefore, adjustments were made for different amounts of amino acid in these ingredients. In Experiment 2, the basal diet
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gested that 1.25 mg of Met is required to produce 1.0 mg of Cys when Cys is the first limiting dietary amino acid. A corn-soybean Met layer diet using supplemental Met and formulated according to specifications suggested by Harms [5] for the hen consuming 77 g of feed would contain 0.62% Met and 0.38% Cys. We have found in our laboratory that no benefit resulted from Cys supplementation of such diets. The lack of response from the Cys supplementation stems from the hen's requirement for egg formation since the egg contains 0.143% Cys and 0.207% Met [6]. Therefore, a corn-soybean meal diet would not be deficient in Cys because such a diet contains more Cys than Met. As feed intake increases with commercial layers to meet the hens' nutrient requirement, the formulas are developed for greater feed intakes. The amount of supplemental Met decreases and the Cys:Met ratio decreases, resulting in an excess of Cys. The requirement for Cys is based on the amount of Cys in a diet that met the SAA requirement [7, 8, 9, 101. Therefore, the experiments reported herein were conducted to study the Cys requirement of the commercial laying hen. The NRC [l] recommendation of a daily intake of 580 mg SAA is therefore probably too high because 280 mg of this requirement could be furnished from Cys. More than this amount of Cys would be supplied by the feed ingredients.
Research Report HARMS and RUSSELL
141
TABLE 1. Composition of diets (Experiment 1)
0.396
0.295
0.335
0.331
Threonine
0.075
0.073 -
0.086 0.013
0.087 0.015
Valine
-
Supplied per kg of diet: retin 1 acetate, 2,724 mcg dla-tocoiherol! 3.0 m 7 cholecalciferol, 2,640 IU; menadione imethylpyrimidmol bisulfite, g.64mg; choline CI, 600.4 m g n oflavm, 4.9 mg, pantothenic acid, 15.8 mg; niacin, mg; atamin Biz, 0.26 m g ethoxyquin, 150mg; manganese, 60 mg; iron, 60 m g copper, 9.6 mg; iodine, 1.3 mg; zinc, me: selenium. 0.12 mg.
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Arginine
JAPR CYSTINE REQUIREMENT
142
INGREDIENT
EXPERIMENTS 2 AND 3
EXPERIMENT 4 The basal diet for this experiment contained more soybean meal than that used in
the basal diet in Experiments 2 and 3 (Table 2). The increase in soybean meal increased the protein level; the Cys content increased from 0.16 to 0.195%. Hens received six diets with Met levels ranging from 0.28 to 0.33% and Cys levels ranging from 0.19 to 0.226%. The increased levels of Met and Cys came from adding DL-methionine and Cys, The diet with 0.28% Met and 0.19% Cys in Experiment 2 was also considered as a treatment in this experiment.
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containing 0.28% Met was fed with five levels of Cys (0.16, 0.17, 0.18, 0.19, and 0.20%), adding synthetic Cys as needed. In Experiment 3, the basal diet containing 0.16% Cys had six levels of Met, obtained by adding supplemental DL-methionine to produce totals of 0.28, 0.29, 0.30, 0.31, 0.32, and 0.33% Met.
EXPERIMENT4
Research Report 143
HARMS and RUSSELL
I
RESULTS AND DISCUSSION EXPERIMENT 1 Performance proved similar for hens fed diets containing 0.35% Met with and without gelatin (Table 4). However, the diet containing gelatin (Table 1) was selected because it required a lower level of supplemental Arg. EP, EW, EC, and FC declined when the Met and Cys content of the diet decreased to 0.28 and 0.16%, respectively (Table 4). All parameters except EW were restored
Isoleucine
0.088
0.082
Corn oil
6.864
2.854
Protein
13.05
13.39
0.050 1.507
13.93
Methionine
0.280
0.280
0.280
Lysine
0.700
0.700
0.700
Ttyptophan
0.160
0.160
0.160
Cystine
0.160 0540
0.180 0540
0.200
Threonine Arginine
0.930
0.930
0.930
Valine
0.674
0.660
0.704
Isoleucine
0580
0.580
0.580
Met Energy (kcavkg)
3300
3190
0.540
3080
BSupplied per kg of diet: retin I acetate, 2,724mcg dl-a-tocopherol, 3.0 m cholecalciferol, 2,640IU; menadione dimethylpyrimidinol bisulfite, %64 m g choline CI,600.4 mg; nboflavin, 4.9Pmg; pantothenic acid, 15.8 mg;niacin, 47.5 m ;vitamin Biz, 0.26 mg, ethoxyquin, 150 mg; manganese, 60 mg; iron, 60 mg; copper, 9.6 mg; iodine, 1.3 m g zinc. 2 2 mg: selenium. 0.12 mg.
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EXPERIMENT 5 For this emeriment, hens received three diets containing three different levels of C y s (0.16, 0.18, and 0.20%) and 0.28% Met (Table 3). These levels of Cys were obtained by varying the amounts of corn and soybean meal, allowing for lower amounts of synthetic amino acids as the level of Cys was increased. Each of these diets, together with DL-methionine, created three diets containing 0.30% Met. W o other diets were formulated to contain 0.16 and 0.20% Cys with 0.32% Met.
JAPR CYSTINE REQUIREMENT
144
TABLE 4. Hen performance when fed diets with varying levels of methionine and cystine (Experiment 1)
when the Cys content of the diet increased to 0.20%. The daily intake of Met and Cys was 286 and 147 mg when the diet contained gelatin, 0.35% Met, and 0.18% C y s (Table 5). The intake of Met and C y s was reduced to 207 and 118 mg, when the hens received the diet with 0.28%Met and 0.16% Cys.When the Cys was increased to 0.20%, the Met and Cys intake increased to 255 and 182 mg. When the diet contained 0.28% Met and 0.16% Cys, a g of EC was produced on 3.28 mg of Cys and 6.24 mg of Met. The intake of 6.24 mg Met per g of egg content is higher than the hen’s requirement recently found in our laboratory [14]. Therefore, Cys was the ftrst limiting amino acid. This finding indicates that this diet would be suitable for evaluating the Cys needs of the commercial laying hen. EXPERIMENT 2 EP and EC increased as the Cys content of the diet increased (Table 6). However, there was no increase when the level of C y s increased from 0.16 to 0.17%. The lack of increase in EP resulted from hens consuming more feed when the diet contained 0.16%Cys than when the diet contained 0.17%.
TREATMENT
METHIONINE INTAKE!
EW was not significantly affected by the Cys content of the diet (Table 6). Likewise,
EC was equal when the diet contained 0.16 and 0.17% Cys. Hens receiving these diets had a daily intake of 143 mg C y s (Table 7), resulting in 3.63 mg Cys intake per g of EC. Hens receiving the diet containing 0.17% Cys had a daily intake of 236 mg Met as compared to 251 mg for hens receiving the diet containing 0.16% Cys. These data indicate that C y s was the first limiting amino acid in these two diets because the hens produced essentially the same daily EC and because the same amount of Cys was required to produce a g of EC. As the level of Cys increased from 0.17 to 0.20%, the daily intake of Cys increased (Table 7) from 143 to 176 w e d d a y . However, the daily intake of Met did not increase. EC increased significantly, indicating that Cys was the ftrst limiting amino acid in this diet. The Cys required to produce a g of EC increased at the higher levels of Cys. Approximately 6 mg of Met was required to produce 1 g of EC. This finding agrees with the previous finding in our laboratory. Weight gain or loss was non-significantly increased when dietary C y s increased (Table 6).
CYSIlNEINTAKE
SAA INTAKE!
302
mg/gEC 6.88
mg/Hen/Day
0.35% Met, 0.18% Cys
155
mg/gEC 3.24
457
10.42
0.35% Met, 0.18% Cys
286
650
147
3.06
434
9.85
0.28% Met, 0.16% Cys
207
6.24
118
3.28
324
9.80
0.28% Met, 0.20% Cys
255
5.85
182
4.18
436
10.03
5
0.08
3
0.05
7
0.14
mg/Hen/Day
SEM
mg/Hen/Day
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a%eans in a column with no common superscript differ significantly (PS.05).
Research Report 145
HARMS and RUSSELL TABLE 6. Hen performance when fed diets with varying levels of methionine and cystine (Experiment 2)
a-c
Means within a column with no common superscript differ significantly (PS.05).
TABLE 7. Methionine, cystine, and SAA intake when hens were fed diets with varying levels of methionine and cvstine ExDeriment 2)
EXPERIMENT 3 EP and EW were lower when hens received the diet containing 0.29% Met than when the hens received the diet containing 0.28% Met (Table 8). This lower EP and EW was a result of the hens consuming less feed when the diet contained 0.29% Met (Table 8). The hens receiving the diet with 0.29% Met had a lower daily intake of Met and Cys. Cys was the first limiting amino acid with a g of EC produced with an intake of 3.44 mg. The intake
of Met was 6.22 mg or greater for each g of EC, a fact which resulted in Cys being the first limiting amino acid. EP increasedwith each increase of dietary Met from 0.29 to 0.33% (Table 8). Egg weight increased when the dietary Met content was increased from 0.29 to 0.30%. Egg content increased as the dietary Met increased from 0.28 to 0.32%. Feed consumption increased at the higher levels of dietary Met (0.31 to 0.33%).
TABLE 8. Hen performance when fed diets with varying levels of methionine and cystine (Experiment 3)
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SEM
CYSTINE REQUIREMENT
146
requirement for Cys and that Met is not efficient in the conversion to Cys. EXPERIMENT 4 Increasing the Met and Cys resulted in an increase in EF', but did not increase EW (Table 10). Maximum EP and EC were produced when the diet contained 0.30%Met and 0.20% Cys. Hens receiving this diet had a daily intake 298.5 mg of Met and 199.0 mg of Cys (Table l l ) , resulting in an intake of 6.63 mg Met and 4.42 mg of Cys for 1 g of EC. These results indicate that the hens had a greater intake of both Met and Cys than was required in this experiment. This contradiction may be partially attributed to a higher feed intake in this experiment. Hens receiving a diet with 0.33% Met and 0.16% Cys produced 42.8 g of EC (Table 8). In Experiment 4 (Table 10) the hens receiving the diet with 0.33% but only contained 0.226% Cys produced 45.5 g of EC. The difference of 2.7 g EC between these two diets was a result
TABLE 9. Methionine, cystine, and SAA intake when hens were fed diets with varying levels of methionine and cystine (Experiment 3)
TREATMENT 0.28% Met, 0.16% Cys 0.29% Met, 0.16% Cys 0.30% Met, 0.16% Cys 0.31% Met, 0.16% Cys 0.32% Met, 0.16% Cys 0.33% Met, 0.16% Cys SEM
TREATMENT
EGG
EGG
PRODUCTION WEIGHT
EGG MASS
EGG FEED WEIGHT C O W N T CONSUMFTION GAIN
g
0.28% Met, 0.19% Cys
70 79.9=
g s7.4a
wemay 45.7
41.8b
g/Hen/Day 91.Ob'
0.29% Met, 0.195% Cys
81.3k
56.6a
46.0'
41.9b
89.6'
0.30% Met, 0.200% Cys
85.4a
57.9a
49.4ab
45.0a
99sa
0.31% Met, 0.205% Cys
84.2ab
57.1a
48.0b
43.8a
92.7b
lob
0.32% Met, 0.214% Cys
84.2ab
s7.9a
48.8ab
44Sa
91.8b
41ab
0.33% Met, 0.226% Cys
%Sa
S7.8a
50.0a
45Sa
95.0ab
7sa
1.3
0.5
0.7
0.6
1.6
18
SEM
-1Zb
ljab 41ab
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The daily Met intake increased from 239.8 to 301.6 mghedday as the Met level increased (Table 9). This increase resulted in an increase from 6.22 to 7.05 mg Met required to produce 1 g of egg content. The Cys/g of EC, essentially the same for all diets ranging from 3.39 to 3.68 mg, indicate that Cys was the first limiting amino acid in these diets and was the factor determining the amount of EC produced. The daily Cys intake ranged from 132.3 to 146.7 mg, or an increase of 14.4 mg. An average of 3.48 mg of Cys was required to produce 1 g of EC. Therefore, the increase of Cys should have resulted in an increase of 4.14 g (14.4 i 3.48) of EC. However, there was an increase of 4.4 g of egg content (42.9 - 38.5). These calculations indicate that Cys was limiting the amount of EC produced. The daily intake of Met increased 61.8 mg (239.8 to 301.6) with more than 6 mg Met/g of EC. The increase of 61.8 mg of Met should have increased EC by 10 g. This finding indicated that the laying hen has a
Research Report 147
HARMS and RUSSELL
TABLE 11. Methionine, cystine, and SAA intake when hens were fed diets with varying levels of methionine and cystine (Experiment 4)
EXPERIMENT 5 Increasing the Cys when the diet contained 0.28% Met resulted in a linear increase of EP, EW, and EC (Table 12).Also, increasing the Met content of the diet from 0.28 to 0.30% when it contained 0.16% Cys resulted in increased EP, EW, and EC. The hens consumed 6.07 mg of Met per g of EC when the diet contained 0.28% Met and 0.20% Cys or 0.30% Met and 0.20% Cys (Table 13). This proportion is slightly high for the Met required per g of EC, but indicated
that the hen was using most of the Met in the diet for EI? The daily intake of Met was increased 31 mg (205 to 236, Table 13) when the Met was increased from 0.28 to 0.30% with 0.20% Cys. As Table 11 shows, the daily EC content increased 4.8 g (34.0 to 38.8) with this Met increase, resulting in 6.45 mg Met required per g increase of EC (31 + 4.8). This finding would indicate that Cys was not limiting since 4.34 and 4.05 mg Cys were consumed per g of EC when the diets contained 0.28 and 0.30% Met, respectively. When the diet contained 0.32% Met and 0.16% Cys, only 3.43 mg of Cys was consumed/g of EC, a result which agrees with results in Experiment 3 when the intake of Cys was limiting (Table 9). Also, it approximates the Cys intake of 3.61 and 3.63 mg of EC in Experiment 2 (Table 7) when the diets contained 0.16 and 0.17% Cys. Table 12 indicates that increasingthe Met from 0.28 to 0.30% resulted in increasing EC
TABLE 12. Hen performance when fed diets with varying levels of methionine and cystine (Experiment 5)
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of the increased Cys intake. Increasingthe Met from 0.29 to 0.31% in Experiment 3 increased production, but further increases did not increase EC equal to the highest produced in this experiment (Experiment 4). The lack of increase indicated that Cys was limiting EC in Experiment 3. Weight gain increased as the level of Met and Cys increased in the diet (Table 10).
JAPR CYSTINE REQUIREMENT
148
7.3 g (22.5 to 29.8) when the diet contained 0.16% Cys. The hens also consumed 38 mg (166 to 204) more of Met, resulting in only 5.21 dg (38 t 7.3) of Met being required to produce a g of EC. The lower Met requirement per g of EC at the lower Met intake agrees with the fmdings of Harms et al. [8].Cys was in excess when the diet contained 0.28% Met and 0.16% Cys, and 4.22 mg Cys was consumed per g of EC (Table 13). Only
3.64 mg Cys was required per g EC when the diet contained 0.30% Met and 0.16% Cys. The finding that the commercial laying hen required only 3.5 mg of Cys per g EC and 175 w e d d a y is considerablylower than the amount suggested by NRC [l]. It is also considerably less than that used in practical layer diets. The findings indicate that formulating for TSAA is not necessary since the ratio of Met to Cys was less than 2:l.
0.32% Met, 0.20% % SEM
268
6.65
167
4.15
436
9.91
6
0.12
5
0.08
9
0.22
CONCLUSIONS AND APPLICATIONS 1. The data from these experiments indicate that the commercial layer requires about
3.5 mg Cys/g EC. 2. The daily requirement would be 175 mg when hens produce 50 g EC. 3. The requirement for Cys is less than what has been previously recommended by NRC [11, and considerablyless than what commercial diets include. 4. A corn-soybeanmeal diet would always furnish more Cys than required by the commercial laying hen; therefore, it is not necessary to formulate for a S A A requirement. *
1. National Research Council, 1994. Nutrient ReVrements of Poultry. 9th Rev. Edition. Natl. Acad. %., ashington, DC.
6. Colterill, OJ., W.W. Marion,andEC. Naber, 1977. A nutrient re-evaluation of shell eggs. Poultry Sci. 561927-1934.
2. "Cy9 is the approved abbreviation for cysteine, but since there is no abbreviation for cystine, this manuscript will use the abbreviation "Cys" for cystine.
7. Novacek, EJ. and C.W. Carlson, 1969. Low protein cage-layer diets and amino acids. Poultry Sci. 4814% 1497.
3. Baker, D.H., 1976. Nutritional and metabolic interrelationshi among sulfur com undsin avian nutrition. Fed. Proc.gd. Am. Soc. Ekp. El.35:1917-1922.
8. Harms, RH.and B.L Damron, 1969. Protein and sulfur amino acid requirement of the laying hen as influenced by dietary formulation. Poultry Sci. 48:144-149.
4. Creek, RD., 1968. Non equivalence in mass in the conversion of phenylalanine to tyrosine and methionine to cystine. Poultry %. 4 7 1 S 1 3 8 6 .
9. Reid, B.L and C.W. Weber, 1973. Dietary protein and sulfur amino acid levels for laying hens during heat stress. Poultry S i . 521335-1343.
5. Harms, RH., 1981.Specifications for feeding commercial layers based on feed intakes. Feedstuffs 53(47):10,40-41.
10. Shutte, J.B. and El.Van Weerden, 1978. Requirements of the hen for sulfur containing amino acids. Br. Poultry Sci. 19573-578.
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TABLE 13. Methionine, cystine, and SAA intake when hens were fed diets with varying levels of methionine and cvstine IExDeriment 5 )
Research Report HARMS and RUSSELL 11. Hy-Line International, Dallas Center, IA 50063. 12. SAS Instituk, 1990. S A S User's Guide: Statistics. 1990 Edition. SAS Institute, Inc., Cary, NC. 13. Waller, Rk and D.B. Duncan, 1969. A bayes rule problem. J. Am. for the m e t r i c multiple StatisticalAssn. 64:1484-1499.
149
I
14. Harms, R H . and G.B. Russell, 1996. A reevaluation of the methionine requirement of the commercial layer. J. h i m . R-. (mpress).
ACKNOWLEDGEMENTS Financial support from Novus International, Inc., St. Charles, MO and Hy-Line International, Dallas Center, IA is gratefullyacknowledged.
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EVALUATION OF THE CYSTINE REQUIREMENT OF THE COMMERCIAL LAYING HEN'
Primary Audience: Nutritionists, Poultrymen, Researchers
[l] suggests that the white-egg commercial DESCRIPTION OF PROBLEM layer requires 580 mg of S M d a y , 300 mg of There are 22 amino acids in body protein, and all are physiologically essential. These amino acids can be divided into two categories: those that poultry cannot synthesize at all or rapidly enough to meet metabolic requirements (essential) and those that can be synthesized from other nonessential amino acids (nonessential). The essential amino acids must be supplied by the diet. The NRC 1 2
which must be furnished by Met. Therefore, it is logical to assume that 280 mg can be furnished from cystine, abbreviated "Cys" [2]. Met can be used for meeting the need for Cys when Met is the first limiting amino acid [3]. The molecular weight of Met is 149 and the molecular weight of Cys is 240, and two molecules of Met are required to produce a molecule of Cys. Therefore, Creek [4] sug-
Florida Agricultural Experiment Station Journal Series No. R-04615 To whom correspondence should be addressed
Downloaded from http://japr.oxfordjournals.org/ at Cal Poly Pomona University Library on March 18, 2015
R. H. HARMS2 and G. B. RUSSELL Department of Dairy and Poultry Sciences, University of Florida, Gainesville, FL 326II-0930 Phone: (904) 392-1931 FAX: (904) 392-3047
CYSTINE REQUIREMENT
140
for casein and gelatin and energy for corn oil were based on NRC [l]. Corn oil and sand varied to obtain the desired energy values. Each experiment operated for 8 wk. The first 2 wk were considered as a depletion period and data from the last 6 wk were used to measure treatment differences. Researchers measured egg weight (EW) and shell weight data each week for the last egg weighed by each hen. These eggs were broken out and the shells with membranes dried and weighed. Feed consumption (FC) was calculated by replicate at bi-weekly intervals, at which time new feed replaced the remaining feed. Egg production (EP) was recorded on an individual hen basis; however, analyses were performed on a replicate basis. Researchers calculated egg mass (EM) by multiplying EP times EW for each replicate. Daily intake of Met was calculated for each replicate. Dividing daily Met intake by daily egg content (EC = [EW - shell weight x %EP]) revealed the Met/g of EC. The data were subjected to ANOVA using the general linear model procedure of SAS [12]. The Waller-Duncan Range Test [ 131 separated the significant treatment effects. EXPERIMENT 1 This experiment attempted to develop a suitable diet for use in studying the Cys needs of the commercial laying hen. Hens received four different diets (Table 1).Casein served as an ingredient because it contains five times as much Met as Cys [l].Also, Diet 2 contained 1.5% gelatin. Each of the diets was supplemented with limiting synthetic amino acids. Diets 1 and 2 contained a high level (0.35%) of supplemental DL-methionine. Diet 3, containing 0.28% Met and 0.16% Cys, was formulated by substituting corn for soybean meal and eliminating the supplemental DL-methionine. Diet 4 was formulated by adding 0.034% Cys to Diet 3.
MATERIALS AND METHODS Hy-Line W36 [ 111hens were used in these experiments. The hens were 29 wk old in Experiments 1and 5. Experiments 2,3, and 4 were conducted at the same time with hens 39 wk old. Elght replicates of five hens, maintained in individual cages in a windowless house and given artiticial light (16 hr light9 hr dark) were used per treatment in all experiments. Temperature, controlled to a minimum of 31.7 to 32.2"C to obtain a constant feed intake, resulted in a feed intake that would permit a response from increased levels of Met or Cys. Varying the amount of corn, soybean meal, casein, or casein and gelatin produced the desired levels of Met and Cys. Levels of amino acids in corn and soybean meal were determined by analysis. Amino acid values
EXPERIMENTS 2 AND 3 The basal diet used in Experiments 2 and 3 (Table 2) was essentially the same as that for Diet 3 in Experiment 1, except that researchers made slight changes because of different corn and soybean meal sources. Therefore, adjustments were made for different amounts of amino acid in these ingredients. In Experiment 2, the basal diet
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gested that 1.25 mg of Met is required to produce 1.0 mg of Cys when Cys is the first limiting dietary amino acid. A corn-soybean Met layer diet using supplemental Met and formulated according to specifications suggested by Harms [5] for the hen consuming 77 g of feed would contain 0.62% Met and 0.38% Cys. We have found in our laboratory that no benefit resulted from Cys supplementation of such diets. The lack of response from the Cys supplementation stems from the hen's requirement for egg formation since the egg contains 0.143% Cys and 0.207% Met [6]. Therefore, a corn-soybean meal diet would not be deficient in Cys because such a diet contains more Cys than Met. As feed intake increases with commercial layers to meet the hens' nutrient requirement, the formulas are developed for greater feed intakes. The amount of supplemental Met decreases and the Cys:Met ratio decreases, resulting in an excess of Cys. The requirement for Cys is based on the amount of Cys in a diet that met the SAA requirement [7, 8, 9, 101. Therefore, the experiments reported herein were conducted to study the Cys requirement of the commercial laying hen. The NRC [l] recommendation of a daily intake of 580 mg SAA is therefore probably too high because 280 mg of this requirement could be furnished from Cys. More than this amount of Cys would be supplied by the feed ingredients.
Research Report HARMS and RUSSELL
141
TABLE 1. Composition of diets (Experiment 1)
0.396
0.295
0.335
0.331
Threonine
0.075
0.073 -
0.086 0.013
0.087 0.015
Valine
-
Supplied per kg of diet: retin 1 acetate, 2,724 mcg dla-tocoiherol! 3.0 m 7 cholecalciferol, 2,640 IU; menadione imethylpyrimidmol bisulfite, g.64mg; choline CI, 600.4 m g n oflavm, 4.9 mg, pantothenic acid, 15.8 mg; niacin, mg; atamin Biz, 0.26 m g ethoxyquin, 150mg; manganese, 60 mg; iron, 60 m g copper, 9.6 mg; iodine, 1.3 mg; zinc, me: selenium. 0.12 mg.
Downloaded from http://japr.oxfordjournals.org/ at Cal Poly Pomona University Library on March 18, 2015
Arginine
JAPR CYSTINE REQUIREMENT
142
INGREDIENT
EXPERIMENTS 2 AND 3
EXPERIMENT 4 The basal diet for this experiment contained more soybean meal than that used in
the basal diet in Experiments 2 and 3 (Table 2). The increase in soybean meal increased the protein level; the Cys content increased from 0.16 to 0.195%. Hens received six diets with Met levels ranging from 0.28 to 0.33% and Cys levels ranging from 0.19 to 0.226%. The increased levels of Met and Cys came from adding DL-methionine and Cys, The diet with 0.28% Met and 0.19% Cys in Experiment 2 was also considered as a treatment in this experiment.
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containing 0.28% Met was fed with five levels of Cys (0.16, 0.17, 0.18, 0.19, and 0.20%), adding synthetic Cys as needed. In Experiment 3, the basal diet containing 0.16% Cys had six levels of Met, obtained by adding supplemental DL-methionine to produce totals of 0.28, 0.29, 0.30, 0.31, 0.32, and 0.33% Met.
EXPERIMENT4
Research Report 143
HARMS and RUSSELL
I
RESULTS AND DISCUSSION EXPERIMENT 1 Performance proved similar for hens fed diets containing 0.35% Met with and without gelatin (Table 4). However, the diet containing gelatin (Table 1) was selected because it required a lower level of supplemental Arg. EP, EW, EC, and FC declined when the Met and Cys content of the diet decreased to 0.28 and 0.16%, respectively (Table 4). All parameters except EW were restored
Isoleucine
0.088
0.082
Corn oil
6.864
2.854
Protein
13.05
13.39
0.050 1.507
13.93
Methionine
0.280
0.280
0.280
Lysine
0.700
0.700
0.700
Ttyptophan
0.160
0.160
0.160
Cystine
0.160 0540
0.180 0540
0.200
Threonine Arginine
0.930
0.930
0.930
Valine
0.674
0.660
0.704
Isoleucine
0580
0.580
0.580
Met Energy (kcavkg)
3300
3190
0.540
3080
BSupplied per kg of diet: retin I acetate, 2,724mcg dl-a-tocopherol, 3.0 m cholecalciferol, 2,640IU; menadione dimethylpyrimidinol bisulfite, %64 m g choline CI,600.4 mg; nboflavin, 4.9Pmg; pantothenic acid, 15.8 mg;niacin, 47.5 m ;vitamin Biz, 0.26 mg, ethoxyquin, 150 mg; manganese, 60 mg; iron, 60 mg; copper, 9.6 mg; iodine, 1.3 m g zinc. 2 2 mg: selenium. 0.12 mg.
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EXPERIMENT 5 For this emeriment, hens received three diets containing three different levels of C y s (0.16, 0.18, and 0.20%) and 0.28% Met (Table 3). These levels of Cys were obtained by varying the amounts of corn and soybean meal, allowing for lower amounts of synthetic amino acids as the level of Cys was increased. Each of these diets, together with DL-methionine, created three diets containing 0.30% Met. W o other diets were formulated to contain 0.16 and 0.20% Cys with 0.32% Met.
JAPR CYSTINE REQUIREMENT
144
TABLE 4. Hen performance when fed diets with varying levels of methionine and cystine (Experiment 1)
when the Cys content of the diet increased to 0.20%. The daily intake of Met and Cys was 286 and 147 mg when the diet contained gelatin, 0.35% Met, and 0.18% C y s (Table 5). The intake of Met and C y s was reduced to 207 and 118 mg, when the hens received the diet with 0.28%Met and 0.16% Cys.When the Cys was increased to 0.20%, the Met and Cys intake increased to 255 and 182 mg. When the diet contained 0.28% Met and 0.16% Cys, a g of EC was produced on 3.28 mg of Cys and 6.24 mg of Met. The intake of 6.24 mg Met per g of egg content is higher than the hen’s requirement recently found in our laboratory [14]. Therefore, Cys was the ftrst limiting amino acid. This finding indicates that this diet would be suitable for evaluating the Cys needs of the commercial laying hen. EXPERIMENT 2 EP and EC increased as the Cys content of the diet increased (Table 6). However, there was no increase when the level of C y s increased from 0.16 to 0.17%. The lack of increase in EP resulted from hens consuming more feed when the diet contained 0.16%Cys than when the diet contained 0.17%.
TREATMENT
METHIONINE INTAKE!
EW was not significantly affected by the Cys content of the diet (Table 6). Likewise,
EC was equal when the diet contained 0.16 and 0.17% Cys. Hens receiving these diets had a daily intake of 143 mg C y s (Table 7), resulting in 3.63 mg Cys intake per g of EC. Hens receiving the diet containing 0.17% Cys had a daily intake of 236 mg Met as compared to 251 mg for hens receiving the diet containing 0.16% Cys. These data indicate that C y s was the first limiting amino acid in these two diets because the hens produced essentially the same daily EC and because the same amount of Cys was required to produce a g of EC. As the level of Cys increased from 0.17 to 0.20%, the daily intake of Cys increased (Table 7) from 143 to 176 w e d d a y . However, the daily intake of Met did not increase. EC increased significantly, indicating that Cys was the ftrst limiting amino acid in this diet. The Cys required to produce a g of EC increased at the higher levels of Cys. Approximately 6 mg of Met was required to produce 1 g of EC. This finding agrees with the previous finding in our laboratory. Weight gain or loss was non-significantly increased when dietary C y s increased (Table 6).
CYSIlNEINTAKE
SAA INTAKE!
302
mg/gEC 6.88
mg/Hen/Day
0.35% Met, 0.18% Cys
155
mg/gEC 3.24
457
10.42
0.35% Met, 0.18% Cys
286
650
147
3.06
434
9.85
0.28% Met, 0.16% Cys
207
6.24
118
3.28
324
9.80
0.28% Met, 0.20% Cys
255
5.85
182
4.18
436
10.03
5
0.08
3
0.05
7
0.14
mg/Hen/Day
SEM
mg/Hen/Day
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a%eans in a column with no common superscript differ significantly (PS.05).
Research Report 145
HARMS and RUSSELL TABLE 6. Hen performance when fed diets with varying levels of methionine and cystine (Experiment 2)
a-c
Means within a column with no common superscript differ significantly (PS.05).
TABLE 7. Methionine, cystine, and SAA intake when hens were fed diets with varying levels of methionine and cvstine ExDeriment 2)
EXPERIMENT 3 EP and EW were lower when hens received the diet containing 0.29% Met than when the hens received the diet containing 0.28% Met (Table 8). This lower EP and EW was a result of the hens consuming less feed when the diet contained 0.29% Met (Table 8). The hens receiving the diet with 0.29% Met had a lower daily intake of Met and Cys. Cys was the first limiting amino acid with a g of EC produced with an intake of 3.44 mg. The intake
of Met was 6.22 mg or greater for each g of EC, a fact which resulted in Cys being the first limiting amino acid. EP increasedwith each increase of dietary Met from 0.29 to 0.33% (Table 8). Egg weight increased when the dietary Met content was increased from 0.29 to 0.30%. Egg content increased as the dietary Met increased from 0.28 to 0.32%. Feed consumption increased at the higher levels of dietary Met (0.31 to 0.33%).
TABLE 8. Hen performance when fed diets with varying levels of methionine and cystine (Experiment 3)
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SEM
CYSTINE REQUIREMENT
146
requirement for Cys and that Met is not efficient in the conversion to Cys. EXPERIMENT 4 Increasing the Met and Cys resulted in an increase in EF', but did not increase EW (Table 10). Maximum EP and EC were produced when the diet contained 0.30%Met and 0.20% Cys. Hens receiving this diet had a daily intake 298.5 mg of Met and 199.0 mg of Cys (Table l l ) , resulting in an intake of 6.63 mg Met and 4.42 mg of Cys for 1 g of EC. These results indicate that the hens had a greater intake of both Met and Cys than was required in this experiment. This contradiction may be partially attributed to a higher feed intake in this experiment. Hens receiving a diet with 0.33% Met and 0.16% Cys produced 42.8 g of EC (Table 8). In Experiment 4 (Table 10) the hens receiving the diet with 0.33% but only contained 0.226% Cys produced 45.5 g of EC. The difference of 2.7 g EC between these two diets was a result
TABLE 9. Methionine, cystine, and SAA intake when hens were fed diets with varying levels of methionine and cystine (Experiment 3)
TREATMENT 0.28% Met, 0.16% Cys 0.29% Met, 0.16% Cys 0.30% Met, 0.16% Cys 0.31% Met, 0.16% Cys 0.32% Met, 0.16% Cys 0.33% Met, 0.16% Cys SEM
TREATMENT
EGG
EGG
PRODUCTION WEIGHT
EGG MASS
EGG FEED WEIGHT C O W N T CONSUMFTION GAIN
g
0.28% Met, 0.19% Cys
70 79.9=
g s7.4a
wemay 45.7
41.8b
g/Hen/Day 91.Ob'
0.29% Met, 0.195% Cys
81.3k
56.6a
46.0'
41.9b
89.6'
0.30% Met, 0.200% Cys
85.4a
57.9a
49.4ab
45.0a
99sa
0.31% Met, 0.205% Cys
84.2ab
57.1a
48.0b
43.8a
92.7b
lob
0.32% Met, 0.214% Cys
84.2ab
s7.9a
48.8ab
44Sa
91.8b
41ab
0.33% Met, 0.226% Cys
%Sa
S7.8a
50.0a
45Sa
95.0ab
7sa
1.3
0.5
0.7
0.6
1.6
18
SEM
-1Zb
ljab 41ab
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The daily Met intake increased from 239.8 to 301.6 mghedday as the Met level increased (Table 9). This increase resulted in an increase from 6.22 to 7.05 mg Met required to produce 1 g of egg content. The Cys/g of EC, essentially the same for all diets ranging from 3.39 to 3.68 mg, indicate that Cys was the first limiting amino acid in these diets and was the factor determining the amount of EC produced. The daily Cys intake ranged from 132.3 to 146.7 mg, or an increase of 14.4 mg. An average of 3.48 mg of Cys was required to produce 1 g of EC. Therefore, the increase of Cys should have resulted in an increase of 4.14 g (14.4 i 3.48) of EC. However, there was an increase of 4.4 g of egg content (42.9 - 38.5). These calculations indicate that Cys was limiting the amount of EC produced. The daily intake of Met increased 61.8 mg (239.8 to 301.6) with more than 6 mg Met/g of EC. The increase of 61.8 mg of Met should have increased EC by 10 g. This finding indicated that the laying hen has a
Research Report 147
HARMS and RUSSELL
TABLE 11. Methionine, cystine, and SAA intake when hens were fed diets with varying levels of methionine and cystine (Experiment 4)
EXPERIMENT 5 Increasing the Cys when the diet contained 0.28% Met resulted in a linear increase of EP, EW, and EC (Table 12).Also, increasing the Met content of the diet from 0.28 to 0.30% when it contained 0.16% Cys resulted in increased EP, EW, and EC. The hens consumed 6.07 mg of Met per g of EC when the diet contained 0.28% Met and 0.20% Cys or 0.30% Met and 0.20% Cys (Table 13). This proportion is slightly high for the Met required per g of EC, but indicated
that the hen was using most of the Met in the diet for EI? The daily intake of Met was increased 31 mg (205 to 236, Table 13) when the Met was increased from 0.28 to 0.30% with 0.20% Cys. As Table 11 shows, the daily EC content increased 4.8 g (34.0 to 38.8) with this Met increase, resulting in 6.45 mg Met required per g increase of EC (31 + 4.8). This finding would indicate that Cys was not limiting since 4.34 and 4.05 mg Cys were consumed per g of EC when the diets contained 0.28 and 0.30% Met, respectively. When the diet contained 0.32% Met and 0.16% Cys, only 3.43 mg of Cys was consumed/g of EC, a result which agrees with results in Experiment 3 when the intake of Cys was limiting (Table 9). Also, it approximates the Cys intake of 3.61 and 3.63 mg of EC in Experiment 2 (Table 7) when the diets contained 0.16 and 0.17% Cys. Table 12 indicates that increasingthe Met from 0.28 to 0.30% resulted in increasing EC
TABLE 12. Hen performance when fed diets with varying levels of methionine and cystine (Experiment 5)
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of the increased Cys intake. Increasingthe Met from 0.29 to 0.31% in Experiment 3 increased production, but further increases did not increase EC equal to the highest produced in this experiment (Experiment 4). The lack of increase indicated that Cys was limiting EC in Experiment 3. Weight gain increased as the level of Met and Cys increased in the diet (Table 10).
JAPR CYSTINE REQUIREMENT
148
7.3 g (22.5 to 29.8) when the diet contained 0.16% Cys. The hens also consumed 38 mg (166 to 204) more of Met, resulting in only 5.21 dg (38 t 7.3) of Met being required to produce a g of EC. The lower Met requirement per g of EC at the lower Met intake agrees with the fmdings of Harms et al. [8].Cys was in excess when the diet contained 0.28% Met and 0.16% Cys, and 4.22 mg Cys was consumed per g of EC (Table 13). Only
3.64 mg Cys was required per g EC when the diet contained 0.30% Met and 0.16% Cys. The finding that the commercial laying hen required only 3.5 mg of Cys per g EC and 175 w e d d a y is considerablylower than the amount suggested by NRC [l]. It is also considerably less than that used in practical layer diets. The findings indicate that formulating for TSAA is not necessary since the ratio of Met to Cys was less than 2:l.
0.32% Met, 0.20% % SEM
268
6.65
167
4.15
436
9.91
6
0.12
5
0.08
9
0.22
CONCLUSIONS AND APPLICATIONS 1. The data from these experiments indicate that the commercial layer requires about
3.5 mg Cys/g EC. 2. The daily requirement would be 175 mg when hens produce 50 g EC. 3. The requirement for Cys is less than what has been previously recommended by NRC [11, and considerablyless than what commercial diets include. 4. A corn-soybeanmeal diet would always furnish more Cys than required by the commercial laying hen; therefore, it is not necessary to formulate for a S A A requirement. *
1. National Research Council, 1994. Nutrient ReVrements of Poultry. 9th Rev. Edition. Natl. Acad. %., ashington, DC.
6. Colterill, OJ., W.W. Marion,andEC. Naber, 1977. A nutrient re-evaluation of shell eggs. Poultry Sci. 561927-1934.
2. "Cy9 is the approved abbreviation for cysteine, but since there is no abbreviation for cystine, this manuscript will use the abbreviation "Cys" for cystine.
7. Novacek, EJ. and C.W. Carlson, 1969. Low protein cage-layer diets and amino acids. Poultry Sci. 4814% 1497.
3. Baker, D.H., 1976. Nutritional and metabolic interrelationshi among sulfur com undsin avian nutrition. Fed. Proc.gd. Am. Soc. Ekp. El.35:1917-1922.
8. Harms, RH.and B.L Damron, 1969. Protein and sulfur amino acid requirement of the laying hen as influenced by dietary formulation. Poultry Sci. 48:144-149.
4. Creek, RD., 1968. Non equivalence in mass in the conversion of phenylalanine to tyrosine and methionine to cystine. Poultry %. 4 7 1 S 1 3 8 6 .
9. Reid, B.L and C.W. Weber, 1973. Dietary protein and sulfur amino acid levels for laying hens during heat stress. Poultry S i . 521335-1343.
5. Harms, RH., 1981.Specifications for feeding commercial layers based on feed intakes. Feedstuffs 53(47):10,40-41.
10. Shutte, J.B. and El.Van Weerden, 1978. Requirements of the hen for sulfur containing amino acids. Br. Poultry Sci. 19573-578.
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TABLE 13. Methionine, cystine, and SAA intake when hens were fed diets with varying levels of methionine and cvstine IExDeriment 5 )
Research Report HARMS and RUSSELL 11. Hy-Line International, Dallas Center, IA 50063. 12. SAS Instituk, 1990. S A S User's Guide: Statistics. 1990 Edition. SAS Institute, Inc., Cary, NC. 13. Waller, Rk and D.B. Duncan, 1969. A bayes rule problem. J. Am. for the m e t r i c multiple StatisticalAssn. 64:1484-1499.
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14. Harms, R H . and G.B. Russell, 1996. A reevaluation of the methionine requirement of the commercial layer. J. h i m . R-. (mpress).
ACKNOWLEDGEMENTS Financial support from Novus International, Inc., St. Charles, MO and Hy-Line International, Dallas Center, IA is gratefullyacknowledged.
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