- Email: [email protected]
Urea and Diammonium Citrate for Laying Hens1
Urea and Diammonium Citrate for Laying Hens 1 R. KAZEMI AND S. L. BALLOUN
Iowa State University, Ames, Iowa 50010 (Received for publication March 25, 1972)
ABSTRACT In two experiments, urea, diammonium citrate (DAC), and soybean meal were added at 2 or 4% protein equivalent to a basal 10.14% protein ration. In the first experiment, crystalline amino acids were added to equal the levels supplied by a 14.14% protein corn-soybean meal ration or the National Research Council (1966) recommended levels, whichever were higher. No attempt was made to equalize amino acids in the second experiment. Egg weight, egg production, feed consumption, and feed consumption per kilogram of eggs were significantly better when the basal diet was supplemented by additional soybean meal than when urea or DAC were added. Urea and DAC were both equally inferior to soybean meal. Addition of 4% protein from soybean meal did not result in significant improvements compared with 2% protein supplementation from the same source. Serum total nitrogen and protein nitrogen concentrations paralleled the pattern of production data and were greater in serum of hens fed soybean meal diets. Serum uric acid was not significantly affected by diets. Haugh unit and shell thickness were not affected by urea- and DAC-supplementation. POULTRY SCIENCE 52:
INTRODUCTION
44-50,
1973
3 % protein equivalent to a 12.75% protein diet. Egg production and egg size were significantly improved by the addition of the NPN source. Moran et al. (1967), however, showed no improvement in egg production or weight gain by supplementing a 16% protein ration with DAC at 1.60, 3.12, and 4.72% protein equivalent. Akintunde et al. (1968) reported that supplementation of 2 or 4% DAC or diammonium phosphate (DAP) to a 12% protein basal diet did not lead to an increased production rate. These results, together with the results obtained for egg weight and feed efficiency, led them to conclude that laying hens are unable to utilize these sources of NPN for egg production. Bornstein and Lipstein (1968) indicated that laying hens are unable to utilize DAP and DAC during the period of peak production accompanied by an increase in egg and body weights, but that DAP might replace the non-essential amino acid required by the adult hen for body maintenance. The studies reported in this paper were conducted to determine if growing pullets and laying hens fed a low protein (10.14%) basal ration could benefit from urea and
A
LTHOUGH the use of urea in rumi* nant feeding has been studied and practiced for many years, the value of nonprotein nitrogen (NPN) as a partial substitute for protein in poultry rations remains controversial. Van der Meulen (1943) reported that urea supplementation to the rations of laying hens had no protein-sparing or substituting effect. Young et al. (1965) indicated that there was some improvement in egg production with hens fed diammonium citrate (DAC) or glutamic acid. When DAC or glutamic acid were added at 3 % protein equivalent (N X 6.25) to a 13% protein diet of corn, soybean meal, fish meal, minerals and vitamins, the supplementation improved production up to that obtained with hens fed the 16% protein diet. With a corn-soybean meal diet, only DAC improved egg production. More evidence of the beneficial effects of DAC on egg production was presented by Chavez et al. (1966) who fed DAC to add 'Journal Paper No. J-7203 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa. Project No. 1721. 44
45
UREA AND DIAMMONIUM CITRATE FOR LAYERS
DAC (at 2 or 4% protein equivalent) supplementation compared with hens fed the basal diet with 2 or 4% protein equivalent added from soybean meal in the presence or absence of added critical amino acids. EXPERIMENTAL In the first experiment, chicks were fed a pre-experimental 20% protein corn-soybean meal diet for the first 8 weeks (Table 1). Experimental diets for the growing period (8-22 weeks) were formulated low in protein (10.14%). Diammonium citrate, urea, or soybean meal were added at 2 or 4% protein equivalents (N X 6.25), replacing cellulose on an equal weight basis. Crystalline amino acids were added to the rations to equal the levels supplied by a 14.14% protein corn-soybean meal ration or the 1966 N.R.C. recommended levels, whichever were higher (Table 2). Thus, all the rations had the same level of the critical amino acids lysine, methionine, cystine,
arginine, tryptophan, and glycine. Soy oil was added to the diets to increase the energy to 2880 Kcal. M.E./Kg. and to make the rations isocaloric. Beginning when pullets reached 50% production, the laying diets were fed (Table 1). As in grower diets, DAC, urea, and soybean meal were supplemented at 2 or 4% protein equivalents. The technique for amino acid supplementation was the same as during the growing period with the exception that 1966 N.R.C. recommended levels for laying hens were used as a standard (Table 3). In the second experiment, pullets were fed a 15% protein pre-experimental ration from 16 to 22 weeks and then where fed the experimental diets. The laying rations were formulated as before (Table 1), with one major difference; no crystalline amino acids were added to the rations. DAC, urea, and soybean meal were added at 2 or 4% protein equivalents as before. The ra-
TABLE 1.—Composition of diets during starting, growing and laying periods
Ingredients Corn, ground yellow Soybean meal (49% protein) Soy oil Alfalfa meal (18% protein) Dicalcium phosphate Limestone Salt mixture Vitamin mixture Methionine hydroxy analogue Amino acid mixture Urea Diammonium citrate Added soybean meal Cellulose
Chickens (1-8 weeks)
Chickens (8-22 weeks)
Laying hens (22-38 weeks)
(%)
(%)
(%)
60.00 31.00 2.00 3.00 1.50 1.40 0.S0 1 0.50 2 0.10
70.00 8.00 Variable
70.00 8.00 Variable
— — — — —
—
1.50 2.00 0.50 1 0.50 2
—
Variable4 Variable Variable Variable Variable
—
2.50 6.00 0.50 1 0.50 3
—
Variable6 Variable Variable Variable Variable
1 Supplies the following minerals per kg. of diet—NaCl 4.5 g.; Mn 88 mg.; Zn 19 mg.; Fe 14 mg.; Cu 2.2 mg.; I2 1.2 mg.; Co 0.14 mg. 2 Supplies the following vitamins per kg. of diet—A 7500 I.U.; D 3 1000 I.C.U.; E 10 I.U.; menadione sodium bisulfite 1 mg.; Bi 2.9 mg.; B2 2.9 mg.; B 6 3 mg.; Bi2 10 meg.; pantothenic acid 10 mg.; choline 450 mg.; niacin 25 mg. 3 Supplies the following vitamins per kg. of diet—A 8000 I.U.; D 3 1500 I.C.U.; B 2 5 mg.; B« 5 meg.; pantothenic acid 5 mg.; niacin 15 mg.; choline 325 mg. 4 Amino acid mixture added at 0.5%, 1.06%, and 1.63% to 8.25% added soybean meal ration, 4.12% added soybean meal ration, and N P N rations, respectively (Table 2). 6 Amino acid mixture added at 0.44, 1.00, and 1.57% to 8.25% soybean meal ration, 4.12% soybean meal ration, and N P N rations, respectively (Table 3).
46
R.
KAZEMI AND S. L. BALLOUN
TABLE 2.—Calculated and supplemented (% of diet) levels of critical amino acids to grower diets—Experiment 1
Lysine Methionine Cystine Arginine Tryptophan Glycine
N.R.C. 1 1966 Req.
Basal-f8.25% S.B.M.
Cryst. 2 A. A. added
Basal-f4.12% S.B.M.
Cryst. A. A. added
Basal' N+ PN
Cryst. A. A. added
0.82 0.30 0.26 0.90 0.15 0.75
0.68 0.25 0.23 0.93 0.19 0.61
0.14 0.05 0.03
0.56 0.23 0.20 0.79 0.16 0.51
0.26 0.07 0.06 0.14 0.03 0.24
0.44 0.20 0.17 0.65 0.13 0.41
0.38 0.10 0.09 0.28 0.06 0.34
Total
— —
0.14 0.5
1.06
1.63
1
National Research Council requirement, assuming that amino acid requirements for the growing pullet are2in the same proportion to protein as in the starting diet. Crystalline amino acids added in first experiment only. 3 NPN sources were diammonium citrate and urea.
tions were isonitrogenous at 12.14 or 14.14% crude protein and isocaloric at 2880 Kcal. M.E./Kg. In the first experiment, ISO day-old female chicks (Welp-line) were distributed in battery brooders with controlled temperature and free access to feed and water. One hundred and twenty of the pullets were randomized in four-deck growing batteries, with the remaining 30 reserved as "spares." For each of the six treatments, there were five replicates with 4 pullets per replicate, making 20 birds per experimental treatment. Pullets were weighed individually each month, and feed consumption was recorded. Dead birds were replaced by
spares of approximate weight fed the same ration. In the second experiment, pullets (Welp-line) were obtained at 16 weeks of age. They had been fed commercial starter and grower rations. Experiments were carried out in a windowless cage house with thermostatically controlled ventilating fans and 14 hours of light per 24-hour period. Hens were individually caged, and four adjacent 25.4 X 40.6 cm. cages with a common feeder constituted an experimental unit. All birds were weighed individually every 28 days, and feed consumption of each unit was recorded. Eggs were collected daily, and, for the egg weight estimates, all eggs laid on three con-
TABLE 3.—Calculated and supplemented (% of diet) levels of critical amino acids to the laying diets—Experiment 1
Lysine Methionine Cystine Arginine Tryptophan Glycine Total
N.R.C. 1 1966 Req.
Basal-r8.25% S.B.M.
0.50 0.28 0.25 0.80 0.15 ?
0.68 0.25 0.23 0.93 0.19 0.61
Cryst. A. A. added
Basal-)4.12% S.B.M.
Cryst. A. A. added
Basal2 NPN
+
Cryst. A. A. added
—
0.56 0.23 0.20 0.79 0.16 0.51
0.12 0.05 0.05 0.14 0.03 0.49
0.44 0.20 0.17 0.65 0.13 0.41
0.24 0.08 0.08 0.28 0.06 0.59
0.03 0.02
— —.
0.39 0.44
1.00
1.57
1 National Research Council requirements. Glycine requirement assumed the same as for young chicks (1%). 2 NPN sources were diammonium citrate and urea.
47
UREA AND DIAMMONIUM CITRATE FOR LAYERS
secutive days within each 28-day period were weighed individually. Data were collected for four 28-day periods. Blood was collected at 30 and 38 weeks in the first experiment and at the beginning and end of the second experiment. Blood samples were drawn from one bird of each replicate by heart puncture. Total serum nitrogen and serum NPN were determined by standard micro-Kjeldahl method. For NPN, 1 volume of serum was mixed with 9 volumes of 10% trichloroacetic acid and left for 10 minutes at room temperature before centrifuging at 5000 r.p.m. for 10 minutes. Serum uric acid was determined by the method described in Sigma Chemical Company (1968). In the second experiment, samples of eggs were collected at the beginning and end of the experiment, and Haugh unit and shell thickness were determined. Statistical analysis of the data was by the method of analysis of variance. Orthogonal comparisons were made among treatments, and all statements of significance are based on the 0.01 level of probability unless otherwise stated. RESULTS AND DISCUSSION
Data on weight gain, feed consumption, and feed efficiency of pullets during the growing periods are presented in Table 4. Pullets fed soybean meal diets grew significantly (P < 0.05) faster than did NPNfed birds. There was no significant difference, however, between the DAC- and urea-fed pullets. Weight gains were less (but not significantly) when levels of DAC and urea were increased to 4 % protein equivalent. Efficiency of feed utilization was better for pullets fed soybean meal diets; the difference, however, was not statistically significant. Pullets fed soybeanmeal rations reached 50% production less than a week earlier than DAC- and ureafed birds. Waldroup and Harms (1962) re-
ported that low dietary protein levels during the growing period delayed sexual maturity of egg-production-type pullets. Hens fed the basal corn-soybean meal diet with added soybean meal produced significantly more and larger eggs than did urea- and DAC-supplemented hens (Table 5). DAC and urea diets were equally inferior to soybean meal diets. Eggs, although surprisingly small in both experiments, averaged 5 g. heavier in the first experiment when critical amino acids were supplemented. It seems that the quality and the quantity of the protein in the basal ration determine the extent to which hens respond to NPN supplementation. Young et al. (1965) and Chavez et al. (1966) hypothesized the presence of an "unidentified factor," beneficial in nonessential amino acid synthesis, in fish meal. Because of the simplicity of the basal ration in these studies, the presence of an unidentified factor was not anticipated. Small egg size might be partly because of the low protein in the basal ration, although Smith and Lewis (1964) reported that 12.5% protein was adequate for egg production. Blair et al. (1970) noted that the number of eggs laid was not significantly affected when protein level was increased from 14 to 16%, but that birds fed the higher protein ration laid significantly TABLE 4.—Weight gain, feed consumption, and feed efficiency of growing pullets—• Experiment 1
Dietary treatments 1 Basal 2% 4% 2% 4% 2% 4%
4DAC DAC Urea Urea S.B.M. S.B.M.
Weight gain /bird (8-22 weeks) (g.)
Feed consumed/bird (8-22 weeks) (g.)
Feed/gain
566 ±262 553 599 555 601 643
4300 ±201 4222 4448 4415 4323 4411
7.60 7.64 7.43 7.95 7.20 6.86
1 Diammonium citrate (DAC) and urea were added to provide the amounts of nitrogen in crude protein indicated as % of the diet. Sufficient soybean meal (S.B.M.) was added to provide 2 or 4% additional crude protein to the basal diet. * All values represent means ± their standard errors.
48
O04-)
VO
eal
Shell ;hickne (mm.)
R. KAZEMI AND S. L. BALLOUN
O
S
00 00 0 0 a 0 00 CM CM CM CM CM CM
CM
B* w
CM
+1
O O O O O O
+1
3
tn
O in
•<# \0 * 0 rr> ID 00 00 0 0 0 0 0 0
'G
•& 00
$3 •4->
£*
t^. CO CM
O
d
C/l
bO
+|
5 *o
CM CO CO f 3 CM CN
6s 10
• * t ~ ~ - i - H O ' * o\ >o PO vo r o >o O O C O O N N ^ 1
bo •4-t
O
-3 0
^
• bb
d
SP-a
5
-a V
4J C3 O
O
d
3
+1
X
O O O O O O
r - n ^ c s r o N N CN CN CN y-t © \ 0 0
'5a3
f O r O f O f O M C S
0 M
a,
CM
>> cd G 4)
s-* . •
a; 3
CO
d X
HI
+1
0
in ^ 0 C N t o i n 0 0 Ir— * > • t~- 0 0 0 0 CN
W
a 60 O
+1
d
1-1 CN CN * 0 T H CN
W
'3.» H5"S
3 S lO CO
d
+1 T3.S
%)
oduction
CM
M S_> PH
two bO
\0
~* d
O
(H
O
t-H
a a 0
O
+1
K
(-1 W
Tigs d •s, bo
w
u.-S 3
+1^ O CO CN t ~ -
O
' • D C 53 "3 rt IT)
^* ^ ^ ^ ^ ^
l O f o ' o ^ N ' O
"53 ^-^
&3 bO 60
0) O T J Hi • " * Hi
C\ O*
CM
BfeSE "S^'53 fi
HI
O
S
+1
Bw
.—• 0 a 0 \ 0 0 ; o g H r t • ^ t 1 0 ^ •<# 1 0 1 0
S H C •HJ
S
3 ^ 3
iry lents
•s| S|
rt
- c3 C M0 +? )3 T-I
S
HI
IO 11
< « ! g gPQPQ _|_Q O
3 3 C/j CO
g CM • * CM • * CM • *
M
«^^ CO
larger eggs. In the trials reported here, the addition of the greater amount of soybean meal protein (4% vs. 2%) to a 10.14% protein ration resulted in better egg production. However, when amino acid levels in the diet with 2% added soybean meal protein (diet total protein 12.14%) were equalized to those of the 4% added soybean meal ration (total protein 14.14%), egg production rate also was equalized. This indicates that the hens were suffering more from an amino acid deficiency when fed the 12.14% protein ration, rather than from nitrogen deficiency. Two parameters of egg quality (Haugh unit and shell thickness) were unaffected by the different dietary treatments (Table 5). Hunt (1964) noted a lack of influence of other ammonium compounds (sulphate, carbonate, and acetate) on Haugh units. Period, however, significantly affected both shell thickness and Haugh unit. Hens laid eggs with significantly thinner shells and greater Haugh unit values at the commencement of lay. This may have been because of the pre-experimental rations, which were lower in calcium and higher in protein concentration. Data on serum components are shown in Table 6. Total serum nitrogen was significantly affected by dietary treatments. Birds fed soybean meal rations had significantly more total serum nitrogen than did those fed diets supplemented with NPN, regardless of amino acid supplementation. This correlates well with growth and egg production data; soybean meal-fed birds grew faster and laid more eggs, whereas ureaand DAC-fed birds grew slowly and laid fewer eggs. Serum NPN was unaffected in the first experiment, remaining relatively constant at 28 mg. per 100 ml. However, in the second experiment, in which amino acids were not supplemented, serum NPN of hens fed soybean meal was significantly (P < 0.05)
49
UREA AND DIAMMONIUM CITRATE FOR LAYERS TABLE 6.—Serum total nitrogen, NPN, protein nitrogen and uric acid—Experiments 1 and 2 Nitrogen components in serum (mg./lOO ml.) Dietary treatments 1
Nitrogen Exp. 1
Basal+ 2% 4% 2% 4% 2% 4%
DAC DAC urea urea S.B.M. S.B.M.
Exp. 2
717 + 173 559 + 24 758 660 780 601 753 633 773 657 835 694
Protein N 2
NPN Exp. 1
Exp. 2
28 + 2 28 29 29 33 28
22 + 1 24 22 23 25 24
Exp. 1
Exp. 2
689 + 18 538 + 24 730 636 751 579 724 610 740 632 807 670
Uric acid Exp. 1
Exp. 2
8.2 9.8 8.6 8.8 9.8 8.5
7.8 + 0.4 8.3 8.6 8.5 9.0 8.7
1 Diammonium citrate (DAC) and urea were added to provide the amounts of nitrogen in crude protein indicated as % of the diet. Sufficient soybean meal (S.B.M.) was added to provide 2 or 4 % additional crude protein to the basal diet. 2 Protein N calculated as the difference between total nitrogen and non-protein nitrogen (NPN). 8 All values represent means+their standard errors.
higher than in the other groups. Protein nitrogen (the difference between total nitrogen and NPN) showed the same trend as total serum nitrogen in both experiments; that is, significantly higher for hens fed soybean meal diets compared with those fed diets supplemented with NPN. No differences in serum components were observed between the urea- and DAC-fed hens. This correlates well with production data (egg weight, egg production, and feed consumption). In contrast to the first experiment, supplementation with 4% crude protein from soybean meal, DAC, or urea in the second experiment resulted in significant increases of total serum nitrogen and protein, although this was not reflected in improvements in production traits. Serum protein and NPN, expressed as percentage of total nitrogen, were not significantly different, and the ratio remained the same, even though absolute values changed. Since uric acid is the main excretory product of avian nitrogen metabolism, blood levels might be expected to reflect differences in diet and nutritional state, as observed by Oppenheimer and Kunkel (1943). Higher uric acid values were expected for NPN-fed hens as compared with hens fed soybean meal diets, indicating sur-
plus nitrogen resulting from depressed synthesis of tissue protein or egg protein. Levels of serum uric acid, however, were not affected by diet differences, probably because of many contributing factors. Bell (1957) indicated that sex, age, the nutritional state and egg production affect the level of serum uric acid. Concentrations of total serum nitrogen, NPN, and protein nitrogen were greater when rations were supplemented with amino acids. This agrees with the greater egg production, egg weight, and feed consumption. REFERENCES Akintunde, F. O., R. H. Davis and A. H. Sykes, 1968. The performance of laying hens on diets supplemented with non-protein nitrogen. Proc. Nutr. Soc. 27 :S2A. Bell, D. J., 1957. Tissue components of the domestic fowl. 2. Blood urea. Biochem. J. 67: 33-36. Blair, R., W. Bolton and R. M. Jones, 1970. Egg production of light and medium hybrids given diets varying in protein level during the rearing and laying stages. Br. Poultry Sci. 1 1 : 249-2S8. Bornstein, S., and B. Lipstein, 1968. A note on non-protein nitrogen supplementation of a lowprotein layer's diet. Proc. 3rd European Poultry Congress, Jerusalem. 373-375. Chavez, R., J. M. Thomas and B. L. Reid, 1966.
so
R. KAZEMI AND S. L. BALLOUN
The utilization of nonprotein nitrogen by laying hens. Poultry Sci. 45: 547-553. Hunt, J. R., 1964. Electrolyte changes in albumen on feeding NH4C1. Poultry Sci. 4 3 : 1331. Moran, E. T., J. D. Summers and W. F. Pepper, 1967. Effect of non-protein nitrogen supplementation of low protein rations on laying hen performance with a note on essential amino acid requirements. Poultry Sci. 46: 1134-1144. National Academy of Sciences—National Research Council, 1966. Nutrient requirements of domestic animals: I. Nutrient requirements of poultry. National Research Council Publication 1345: 23-45. Oppenheimer, E. H., and H. G. Kunkel, 1943. Further observations on the lowering of blood uric acid by uricase injections. Johns Hopkins Hosp. Bull. No. 73: 40-53.
Sigma Chemical Company, 1968. Uric acid in serum, urine, or other fluids. Sigma Technical Bui. 292. Smith, A. J., and D. Lewis, 1964. Protein and energy nutrition of the laying hen. 1. Protein requirements of hybrids of medium size. Br. Poultry Sci. 5: 113-120. Van der Meulen, J. B., 1943. The effect of urea in the feeding of laying hens. Landouwkund Tijdschr. 55: 5-10. Waldroup, P. W., and R. H. Harms, 1962. Effect of grower diets on the performance of egg production type pullets. Florida Agr. Exp. Sta. Tech Bui. 646. Young, R. J., M. Griffith, I. D. Desai and M. L. Scott, 1965. The response of laying hens fed low protein diets to glutamic acid and diammonium citrate. Poultry Sci. 44: 1428.
NEWS AND NOTES (Continued from page 34) try Science, Virginia Polytechnic Institute and State University by Dow Chemical Company and two Virginia poultry firms. The funds are part of some $67,000 in grants awarded by Dow in a joint program with the poultry industry. Daniel A. Sutton, a sophomore from Timberville, received a scholarship of $360 from Long Foods, Inc., New Market. James S. Brown, a sophomore from Hamilton, and C. Shields Jones, Jr., a sophomore from Esmont, each received a $300 scholarship from Rocco Feeds, Inc., Harrisburg. Criteria for the awards include scholastic achievement and financial need. WORLD'S POULTRY SCIENCE JOURNAL Dr. R. George Jaap who has carried on the duties of Editor of the Worlds Poultry Science Journal for 15 years, has resigned. He will continue as Treasurer of the World's Poultry Science Association. Dr. R. F. Gordon of the United Kingdom was appointed Editor to take effect at the end of 1972. He received a D.Sc. degree at the University of Aberdeen, a D.V.Sc. degree at the University of Liverpool, and is a Fellow of the Royal Veterinary College, London. He recently was awarded a C.B.E. He began his career in the Central Veterinary Laboratory, British Ministry of Agriculture, Weybridge, as Senior Research Officer In Charge of the Poultry Diagnostic Department. He left Wey-
bridge in the late 40's to direct the newly established Poultry Research Station at Houghton, set up by the Animal Health Trust. This was later grant aided by the Agriculture Research Council of the U.K. Government, and Dr. Gordon became the first Director of the Houghton Poultry Research Station, a position he currently holds, but from which he retires in the fall of 1973. CARGILL NOTES George L. Jones, Edward E. Reynolds, F. Clayton Tonnemaker and Henrick Van Veen, all of Minneapolis, have been appointed Division VicePresidents, Cargill, Inc. Jones, a native of Minneapolis, is General Manager of the Seed Department. Reynolds was born in Oklahoma, and received degrees at the University of Illinois and Northwestern University. He joined Cargill in 1966 after a number of years with Central Soya Company in Indiana. He is General Manager of the Poultry Products Department, and is a Director of the Poultry and Egg Institute of America, and the National Broiler Council. Tonnemaker, from Ogilvie, Minnesota, graduated in 1950 from the University of Minnesota. He is General Manager of the Salt Department. Van Veen is Manager of Overseas Soybean Processing, overseeing operations in France, Spain, The Netherlands and Brazil. Cargill of Arkansas, Inc. has begun building a
(Continued on page 57)
Iowa State University, Ames, Iowa 50010 (Received for publication March 25, 1972)
ABSTRACT In two experiments, urea, diammonium citrate (DAC), and soybean meal were added at 2 or 4% protein equivalent to a basal 10.14% protein ration. In the first experiment, crystalline amino acids were added to equal the levels supplied by a 14.14% protein corn-soybean meal ration or the National Research Council (1966) recommended levels, whichever were higher. No attempt was made to equalize amino acids in the second experiment. Egg weight, egg production, feed consumption, and feed consumption per kilogram of eggs were significantly better when the basal diet was supplemented by additional soybean meal than when urea or DAC were added. Urea and DAC were both equally inferior to soybean meal. Addition of 4% protein from soybean meal did not result in significant improvements compared with 2% protein supplementation from the same source. Serum total nitrogen and protein nitrogen concentrations paralleled the pattern of production data and were greater in serum of hens fed soybean meal diets. Serum uric acid was not significantly affected by diets. Haugh unit and shell thickness were not affected by urea- and DAC-supplementation. POULTRY SCIENCE 52:
INTRODUCTION
44-50,
1973
3 % protein equivalent to a 12.75% protein diet. Egg production and egg size were significantly improved by the addition of the NPN source. Moran et al. (1967), however, showed no improvement in egg production or weight gain by supplementing a 16% protein ration with DAC at 1.60, 3.12, and 4.72% protein equivalent. Akintunde et al. (1968) reported that supplementation of 2 or 4% DAC or diammonium phosphate (DAP) to a 12% protein basal diet did not lead to an increased production rate. These results, together with the results obtained for egg weight and feed efficiency, led them to conclude that laying hens are unable to utilize these sources of NPN for egg production. Bornstein and Lipstein (1968) indicated that laying hens are unable to utilize DAP and DAC during the period of peak production accompanied by an increase in egg and body weights, but that DAP might replace the non-essential amino acid required by the adult hen for body maintenance. The studies reported in this paper were conducted to determine if growing pullets and laying hens fed a low protein (10.14%) basal ration could benefit from urea and
A
LTHOUGH the use of urea in rumi* nant feeding has been studied and practiced for many years, the value of nonprotein nitrogen (NPN) as a partial substitute for protein in poultry rations remains controversial. Van der Meulen (1943) reported that urea supplementation to the rations of laying hens had no protein-sparing or substituting effect. Young et al. (1965) indicated that there was some improvement in egg production with hens fed diammonium citrate (DAC) or glutamic acid. When DAC or glutamic acid were added at 3 % protein equivalent (N X 6.25) to a 13% protein diet of corn, soybean meal, fish meal, minerals and vitamins, the supplementation improved production up to that obtained with hens fed the 16% protein diet. With a corn-soybean meal diet, only DAC improved egg production. More evidence of the beneficial effects of DAC on egg production was presented by Chavez et al. (1966) who fed DAC to add 'Journal Paper No. J-7203 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa. Project No. 1721. 44
45
UREA AND DIAMMONIUM CITRATE FOR LAYERS
DAC (at 2 or 4% protein equivalent) supplementation compared with hens fed the basal diet with 2 or 4% protein equivalent added from soybean meal in the presence or absence of added critical amino acids. EXPERIMENTAL In the first experiment, chicks were fed a pre-experimental 20% protein corn-soybean meal diet for the first 8 weeks (Table 1). Experimental diets for the growing period (8-22 weeks) were formulated low in protein (10.14%). Diammonium citrate, urea, or soybean meal were added at 2 or 4% protein equivalents (N X 6.25), replacing cellulose on an equal weight basis. Crystalline amino acids were added to the rations to equal the levels supplied by a 14.14% protein corn-soybean meal ration or the 1966 N.R.C. recommended levels, whichever were higher (Table 2). Thus, all the rations had the same level of the critical amino acids lysine, methionine, cystine,
arginine, tryptophan, and glycine. Soy oil was added to the diets to increase the energy to 2880 Kcal. M.E./Kg. and to make the rations isocaloric. Beginning when pullets reached 50% production, the laying diets were fed (Table 1). As in grower diets, DAC, urea, and soybean meal were supplemented at 2 or 4% protein equivalents. The technique for amino acid supplementation was the same as during the growing period with the exception that 1966 N.R.C. recommended levels for laying hens were used as a standard (Table 3). In the second experiment, pullets were fed a 15% protein pre-experimental ration from 16 to 22 weeks and then where fed the experimental diets. The laying rations were formulated as before (Table 1), with one major difference; no crystalline amino acids were added to the rations. DAC, urea, and soybean meal were added at 2 or 4% protein equivalents as before. The ra-
TABLE 1.—Composition of diets during starting, growing and laying periods
Ingredients Corn, ground yellow Soybean meal (49% protein) Soy oil Alfalfa meal (18% protein) Dicalcium phosphate Limestone Salt mixture Vitamin mixture Methionine hydroxy analogue Amino acid mixture Urea Diammonium citrate Added soybean meal Cellulose
Chickens (1-8 weeks)
Chickens (8-22 weeks)
Laying hens (22-38 weeks)
(%)
(%)
(%)
60.00 31.00 2.00 3.00 1.50 1.40 0.S0 1 0.50 2 0.10
70.00 8.00 Variable
70.00 8.00 Variable
— — — — —
—
1.50 2.00 0.50 1 0.50 2
—
Variable4 Variable Variable Variable Variable
—
2.50 6.00 0.50 1 0.50 3
—
Variable6 Variable Variable Variable Variable
1 Supplies the following minerals per kg. of diet—NaCl 4.5 g.; Mn 88 mg.; Zn 19 mg.; Fe 14 mg.; Cu 2.2 mg.; I2 1.2 mg.; Co 0.14 mg. 2 Supplies the following vitamins per kg. of diet—A 7500 I.U.; D 3 1000 I.C.U.; E 10 I.U.; menadione sodium bisulfite 1 mg.; Bi 2.9 mg.; B2 2.9 mg.; B 6 3 mg.; Bi2 10 meg.; pantothenic acid 10 mg.; choline 450 mg.; niacin 25 mg. 3 Supplies the following vitamins per kg. of diet—A 8000 I.U.; D 3 1500 I.C.U.; B 2 5 mg.; B« 5 meg.; pantothenic acid 5 mg.; niacin 15 mg.; choline 325 mg. 4 Amino acid mixture added at 0.5%, 1.06%, and 1.63% to 8.25% added soybean meal ration, 4.12% added soybean meal ration, and N P N rations, respectively (Table 2). 6 Amino acid mixture added at 0.44, 1.00, and 1.57% to 8.25% soybean meal ration, 4.12% soybean meal ration, and N P N rations, respectively (Table 3).
46
R.
KAZEMI AND S. L. BALLOUN
TABLE 2.—Calculated and supplemented (% of diet) levels of critical amino acids to grower diets—Experiment 1
Lysine Methionine Cystine Arginine Tryptophan Glycine
N.R.C. 1 1966 Req.
Basal-f8.25% S.B.M.
Cryst. 2 A. A. added
Basal-f4.12% S.B.M.
Cryst. A. A. added
Basal' N+ PN
Cryst. A. A. added
0.82 0.30 0.26 0.90 0.15 0.75
0.68 0.25 0.23 0.93 0.19 0.61
0.14 0.05 0.03
0.56 0.23 0.20 0.79 0.16 0.51
0.26 0.07 0.06 0.14 0.03 0.24
0.44 0.20 0.17 0.65 0.13 0.41
0.38 0.10 0.09 0.28 0.06 0.34
Total
— —
0.14 0.5
1.06
1.63
1
National Research Council requirement, assuming that amino acid requirements for the growing pullet are2in the same proportion to protein as in the starting diet. Crystalline amino acids added in first experiment only. 3 NPN sources were diammonium citrate and urea.
tions were isonitrogenous at 12.14 or 14.14% crude protein and isocaloric at 2880 Kcal. M.E./Kg. In the first experiment, ISO day-old female chicks (Welp-line) were distributed in battery brooders with controlled temperature and free access to feed and water. One hundred and twenty of the pullets were randomized in four-deck growing batteries, with the remaining 30 reserved as "spares." For each of the six treatments, there were five replicates with 4 pullets per replicate, making 20 birds per experimental treatment. Pullets were weighed individually each month, and feed consumption was recorded. Dead birds were replaced by
spares of approximate weight fed the same ration. In the second experiment, pullets (Welp-line) were obtained at 16 weeks of age. They had been fed commercial starter and grower rations. Experiments were carried out in a windowless cage house with thermostatically controlled ventilating fans and 14 hours of light per 24-hour period. Hens were individually caged, and four adjacent 25.4 X 40.6 cm. cages with a common feeder constituted an experimental unit. All birds were weighed individually every 28 days, and feed consumption of each unit was recorded. Eggs were collected daily, and, for the egg weight estimates, all eggs laid on three con-
TABLE 3.—Calculated and supplemented (% of diet) levels of critical amino acids to the laying diets—Experiment 1
Lysine Methionine Cystine Arginine Tryptophan Glycine Total
N.R.C. 1 1966 Req.
Basal-r8.25% S.B.M.
0.50 0.28 0.25 0.80 0.15 ?
0.68 0.25 0.23 0.93 0.19 0.61
Cryst. A. A. added
Basal-)4.12% S.B.M.
Cryst. A. A. added
Basal2 NPN
+
Cryst. A. A. added
—
0.56 0.23 0.20 0.79 0.16 0.51
0.12 0.05 0.05 0.14 0.03 0.49
0.44 0.20 0.17 0.65 0.13 0.41
0.24 0.08 0.08 0.28 0.06 0.59
0.03 0.02
— —.
0.39 0.44
1.00
1.57
1 National Research Council requirements. Glycine requirement assumed the same as for young chicks (1%). 2 NPN sources were diammonium citrate and urea.
47
UREA AND DIAMMONIUM CITRATE FOR LAYERS
secutive days within each 28-day period were weighed individually. Data were collected for four 28-day periods. Blood was collected at 30 and 38 weeks in the first experiment and at the beginning and end of the second experiment. Blood samples were drawn from one bird of each replicate by heart puncture. Total serum nitrogen and serum NPN were determined by standard micro-Kjeldahl method. For NPN, 1 volume of serum was mixed with 9 volumes of 10% trichloroacetic acid and left for 10 minutes at room temperature before centrifuging at 5000 r.p.m. for 10 minutes. Serum uric acid was determined by the method described in Sigma Chemical Company (1968). In the second experiment, samples of eggs were collected at the beginning and end of the experiment, and Haugh unit and shell thickness were determined. Statistical analysis of the data was by the method of analysis of variance. Orthogonal comparisons were made among treatments, and all statements of significance are based on the 0.01 level of probability unless otherwise stated. RESULTS AND DISCUSSION
Data on weight gain, feed consumption, and feed efficiency of pullets during the growing periods are presented in Table 4. Pullets fed soybean meal diets grew significantly (P < 0.05) faster than did NPNfed birds. There was no significant difference, however, between the DAC- and urea-fed pullets. Weight gains were less (but not significantly) when levels of DAC and urea were increased to 4 % protein equivalent. Efficiency of feed utilization was better for pullets fed soybean meal diets; the difference, however, was not statistically significant. Pullets fed soybeanmeal rations reached 50% production less than a week earlier than DAC- and ureafed birds. Waldroup and Harms (1962) re-
ported that low dietary protein levels during the growing period delayed sexual maturity of egg-production-type pullets. Hens fed the basal corn-soybean meal diet with added soybean meal produced significantly more and larger eggs than did urea- and DAC-supplemented hens (Table 5). DAC and urea diets were equally inferior to soybean meal diets. Eggs, although surprisingly small in both experiments, averaged 5 g. heavier in the first experiment when critical amino acids were supplemented. It seems that the quality and the quantity of the protein in the basal ration determine the extent to which hens respond to NPN supplementation. Young et al. (1965) and Chavez et al. (1966) hypothesized the presence of an "unidentified factor," beneficial in nonessential amino acid synthesis, in fish meal. Because of the simplicity of the basal ration in these studies, the presence of an unidentified factor was not anticipated. Small egg size might be partly because of the low protein in the basal ration, although Smith and Lewis (1964) reported that 12.5% protein was adequate for egg production. Blair et al. (1970) noted that the number of eggs laid was not significantly affected when protein level was increased from 14 to 16%, but that birds fed the higher protein ration laid significantly TABLE 4.—Weight gain, feed consumption, and feed efficiency of growing pullets—• Experiment 1
Dietary treatments 1 Basal 2% 4% 2% 4% 2% 4%
4DAC DAC Urea Urea S.B.M. S.B.M.
Weight gain /bird (8-22 weeks) (g.)
Feed consumed/bird (8-22 weeks) (g.)
Feed/gain
566 ±262 553 599 555 601 643
4300 ±201 4222 4448 4415 4323 4411
7.60 7.64 7.43 7.95 7.20 6.86
1 Diammonium citrate (DAC) and urea were added to provide the amounts of nitrogen in crude protein indicated as % of the diet. Sufficient soybean meal (S.B.M.) was added to provide 2 or 4% additional crude protein to the basal diet. * All values represent means ± their standard errors.
48
O04-)
VO
eal
Shell ;hickne (mm.)
R. KAZEMI AND S. L. BALLOUN
O
S
00 00 0 0 a 0 00 CM CM CM CM CM CM
CM
B* w
CM
+1
O O O O O O
+1
3
tn
O in
•<# \0 * 0 rr> ID 00 00 0 0 0 0 0 0
'G
•& 00
$3 •4->
£*
t^. CO CM
O
d
C/l
bO
+|
5 *o
CM CO CO f 3 CM CN
6s 10
• * t ~ ~ - i - H O ' * o\ >o PO vo r o >o O O C O O N N ^ 1
bo •4-t
O
-3 0
^
• bb
d
SP-a
5
-a V
4J C3 O
O
d
3
+1
X
O O O O O O
r - n ^ c s r o N N CN CN CN y-t © \ 0 0
'5a3
f O r O f O f O M C S
0 M
a,
CM
>> cd G 4)
s-* . •
a; 3
CO
d X
HI
+1
0
in ^ 0 C N t o i n 0 0 Ir— * > • t~- 0 0 0 0 CN
W
a 60 O
+1
d
1-1 CN CN * 0 T H CN
W
'3.» H5"S
3 S lO CO
d
+1 T3.S
%)
oduction
CM
M S_> PH
two bO
\0
~* d
O
(H
O
t-H
a a 0
O
+1
K
(-1 W
Tigs d •s, bo
w
u.-S 3
+1^ O CO CN t ~ -
O
' • D C 53 "3 rt IT)
^* ^ ^ ^ ^ ^
l O f o ' o ^ N ' O
"53 ^-^
&3 bO 60
0) O T J Hi • " * Hi
C\ O*
CM
BfeSE "S^'53 fi
HI
O
+1
Bw
.—• 0 a 0 \ 0 0 ; o g H r t • ^ t 1 0 ^ •<# 1 0 1 0
S H C •HJ
S
3 ^ 3
iry lents
•s| S|
rt
- c3 C M0 +? )3 T-I
S
HI
IO 11
< « ! g gPQPQ _|_Q O
3 3 C/j CO
g CM • * CM • * CM • *
M
«^^ CO
larger eggs. In the trials reported here, the addition of the greater amount of soybean meal protein (4% vs. 2%) to a 10.14% protein ration resulted in better egg production. However, when amino acid levels in the diet with 2% added soybean meal protein (diet total protein 12.14%) were equalized to those of the 4% added soybean meal ration (total protein 14.14%), egg production rate also was equalized. This indicates that the hens were suffering more from an amino acid deficiency when fed the 12.14% protein ration, rather than from nitrogen deficiency. Two parameters of egg quality (Haugh unit and shell thickness) were unaffected by the different dietary treatments (Table 5). Hunt (1964) noted a lack of influence of other ammonium compounds (sulphate, carbonate, and acetate) on Haugh units. Period, however, significantly affected both shell thickness and Haugh unit. Hens laid eggs with significantly thinner shells and greater Haugh unit values at the commencement of lay. This may have been because of the pre-experimental rations, which were lower in calcium and higher in protein concentration. Data on serum components are shown in Table 6. Total serum nitrogen was significantly affected by dietary treatments. Birds fed soybean meal rations had significantly more total serum nitrogen than did those fed diets supplemented with NPN, regardless of amino acid supplementation. This correlates well with growth and egg production data; soybean meal-fed birds grew faster and laid more eggs, whereas ureaand DAC-fed birds grew slowly and laid fewer eggs. Serum NPN was unaffected in the first experiment, remaining relatively constant at 28 mg. per 100 ml. However, in the second experiment, in which amino acids were not supplemented, serum NPN of hens fed soybean meal was significantly (P < 0.05)
49
UREA AND DIAMMONIUM CITRATE FOR LAYERS TABLE 6.—Serum total nitrogen, NPN, protein nitrogen and uric acid—Experiments 1 and 2 Nitrogen components in serum (mg./lOO ml.) Dietary treatments 1
Nitrogen Exp. 1
Basal+ 2% 4% 2% 4% 2% 4%
DAC DAC urea urea S.B.M. S.B.M.
Exp. 2
717 + 173 559 + 24 758 660 780 601 753 633 773 657 835 694
Protein N 2
NPN Exp. 1
Exp. 2
28 + 2 28 29 29 33 28
22 + 1 24 22 23 25 24
Exp. 1
Exp. 2
689 + 18 538 + 24 730 636 751 579 724 610 740 632 807 670
Uric acid Exp. 1
Exp. 2
8.2 9.8 8.6 8.8 9.8 8.5
7.8 + 0.4 8.3 8.6 8.5 9.0 8.7
1 Diammonium citrate (DAC) and urea were added to provide the amounts of nitrogen in crude protein indicated as % of the diet. Sufficient soybean meal (S.B.M.) was added to provide 2 or 4 % additional crude protein to the basal diet. 2 Protein N calculated as the difference between total nitrogen and non-protein nitrogen (NPN). 8 All values represent means+their standard errors.
higher than in the other groups. Protein nitrogen (the difference between total nitrogen and NPN) showed the same trend as total serum nitrogen in both experiments; that is, significantly higher for hens fed soybean meal diets compared with those fed diets supplemented with NPN. No differences in serum components were observed between the urea- and DAC-fed hens. This correlates well with production data (egg weight, egg production, and feed consumption). In contrast to the first experiment, supplementation with 4% crude protein from soybean meal, DAC, or urea in the second experiment resulted in significant increases of total serum nitrogen and protein, although this was not reflected in improvements in production traits. Serum protein and NPN, expressed as percentage of total nitrogen, were not significantly different, and the ratio remained the same, even though absolute values changed. Since uric acid is the main excretory product of avian nitrogen metabolism, blood levels might be expected to reflect differences in diet and nutritional state, as observed by Oppenheimer and Kunkel (1943). Higher uric acid values were expected for NPN-fed hens as compared with hens fed soybean meal diets, indicating sur-
plus nitrogen resulting from depressed synthesis of tissue protein or egg protein. Levels of serum uric acid, however, were not affected by diet differences, probably because of many contributing factors. Bell (1957) indicated that sex, age, the nutritional state and egg production affect the level of serum uric acid. Concentrations of total serum nitrogen, NPN, and protein nitrogen were greater when rations were supplemented with amino acids. This agrees with the greater egg production, egg weight, and feed consumption. REFERENCES Akintunde, F. O., R. H. Davis and A. H. Sykes, 1968. The performance of laying hens on diets supplemented with non-protein nitrogen. Proc. Nutr. Soc. 27 :S2A. Bell, D. J., 1957. Tissue components of the domestic fowl. 2. Blood urea. Biochem. J. 67: 33-36. Blair, R., W. Bolton and R. M. Jones, 1970. Egg production of light and medium hybrids given diets varying in protein level during the rearing and laying stages. Br. Poultry Sci. 1 1 : 249-2S8. Bornstein, S., and B. Lipstein, 1968. A note on non-protein nitrogen supplementation of a lowprotein layer's diet. Proc. 3rd European Poultry Congress, Jerusalem. 373-375. Chavez, R., J. M. Thomas and B. L. Reid, 1966.
so
R. KAZEMI AND S. L. BALLOUN
The utilization of nonprotein nitrogen by laying hens. Poultry Sci. 45: 547-553. Hunt, J. R., 1964. Electrolyte changes in albumen on feeding NH4C1. Poultry Sci. 4 3 : 1331. Moran, E. T., J. D. Summers and W. F. Pepper, 1967. Effect of non-protein nitrogen supplementation of low protein rations on laying hen performance with a note on essential amino acid requirements. Poultry Sci. 46: 1134-1144. National Academy of Sciences—National Research Council, 1966. Nutrient requirements of domestic animals: I. Nutrient requirements of poultry. National Research Council Publication 1345: 23-45. Oppenheimer, E. H., and H. G. Kunkel, 1943. Further observations on the lowering of blood uric acid by uricase injections. Johns Hopkins Hosp. Bull. No. 73: 40-53.
Sigma Chemical Company, 1968. Uric acid in serum, urine, or other fluids. Sigma Technical Bui. 292. Smith, A. J., and D. Lewis, 1964. Protein and energy nutrition of the laying hen. 1. Protein requirements of hybrids of medium size. Br. Poultry Sci. 5: 113-120. Van der Meulen, J. B., 1943. The effect of urea in the feeding of laying hens. Landouwkund Tijdschr. 55: 5-10. Waldroup, P. W., and R. H. Harms, 1962. Effect of grower diets on the performance of egg production type pullets. Florida Agr. Exp. Sta. Tech Bui. 646. Young, R. J., M. Griffith, I. D. Desai and M. L. Scott, 1965. The response of laying hens fed low protein diets to glutamic acid and diammonium citrate. Poultry Sci. 44: 1428.
NEWS AND NOTES (Continued from page 34) try Science, Virginia Polytechnic Institute and State University by Dow Chemical Company and two Virginia poultry firms. The funds are part of some $67,000 in grants awarded by Dow in a joint program with the poultry industry. Daniel A. Sutton, a sophomore from Timberville, received a scholarship of $360 from Long Foods, Inc., New Market. James S. Brown, a sophomore from Hamilton, and C. Shields Jones, Jr., a sophomore from Esmont, each received a $300 scholarship from Rocco Feeds, Inc., Harrisburg. Criteria for the awards include scholastic achievement and financial need. WORLD'S POULTRY SCIENCE JOURNAL Dr. R. George Jaap who has carried on the duties of Editor of the Worlds Poultry Science Journal for 15 years, has resigned. He will continue as Treasurer of the World's Poultry Science Association. Dr. R. F. Gordon of the United Kingdom was appointed Editor to take effect at the end of 1972. He received a D.Sc. degree at the University of Aberdeen, a D.V.Sc. degree at the University of Liverpool, and is a Fellow of the Royal Veterinary College, London. He recently was awarded a C.B.E. He began his career in the Central Veterinary Laboratory, British Ministry of Agriculture, Weybridge, as Senior Research Officer In Charge of the Poultry Diagnostic Department. He left Wey-
bridge in the late 40's to direct the newly established Poultry Research Station at Houghton, set up by the Animal Health Trust. This was later grant aided by the Agriculture Research Council of the U.K. Government, and Dr. Gordon became the first Director of the Houghton Poultry Research Station, a position he currently holds, but from which he retires in the fall of 1973. CARGILL NOTES George L. Jones, Edward E. Reynolds, F. Clayton Tonnemaker and Henrick Van Veen, all of Minneapolis, have been appointed Division VicePresidents, Cargill, Inc. Jones, a native of Minneapolis, is General Manager of the Seed Department. Reynolds was born in Oklahoma, and received degrees at the University of Illinois and Northwestern University. He joined Cargill in 1966 after a number of years with Central Soya Company in Indiana. He is General Manager of the Poultry Products Department, and is a Director of the Poultry and Egg Institute of America, and the National Broiler Council. Tonnemaker, from Ogilvie, Minnesota, graduated in 1950 from the University of Minnesota. He is General Manager of the Salt Department. Van Veen is Manager of Overseas Soybean Processing, overseeing operations in France, Spain, The Netherlands and Brazil. Cargill of Arkansas, Inc. has begun building a
(Continued on page 57)