- Email: [email protected]
Effects of Dietary Protein Level on Performance of Four Commercial Egg Production Stocks
936
A. B. STEPHENSON, Q. B. KINDER AND E. M.
numbers for tables of multiple classification with disproportionate subclass numbers. J. Amer. Stat. Assn. 29: 389-393. Snedecor, G. W., 1956. Statistical Methods. The Iowa State College Press.
FUNK
Warren, D. C , 1953. Practical Poultry Breeding. MacMillan. Water, N. F., 1938. The influence of inbred sires top crossed on White Leghorn fowl. Poultry Sci. 17: 490-497.
JAMES W. DEATON AND J O H N H. QUISENBEREY Texas A&M University, College Station, Texas (Received for publication October 13, 1964)
W
ITH the advent of commercialization in the poultry industry there has been a decrease in the number of breeders of egg production stocks, and in turn, an increase in the number of laying hens produced by one breeder. Since this trend is expected to continue, the genetic influence of one breeder's stock will become more widespread and the assumption is made that each breeder's stock will have a different genetic background. In order to attain the precision that is necessary to maintain progress in a breeding program, the bird sold by the breeder of the future will probably have specific nutritional and environmental requirements. Since protein is one of the more expensive items in a laying ration, considerable work has been done to determine the minimum ended for optimum returns. Several workers, Neywang et al. (1955), Miller et al. (1956), Frank and Waibel (1959), Griminger and Fisher (1959), Thornton et al. (1957) and Thornton and Whittet (1959), have reported satisfactory egg production with protein levels of 13-15%. Other workers, Reid et al. (1951), Quisenberry and Bradley (1962), Milton and Ingram (1957) and Denton and Lillie (1959), have reported optimum performance from protein levels above 15%.
Considerable controversy exists concerning the amount of protein necessary for optimum performance. These differences in results could be due in part to differences in strains of birds used by the various investigators. Thornton and Whittet (I960), using four different strains of egg production stocks and four levels of protein, could find no consistent trends; whereas, Moreng et al. (1963) using three different levels of dietary protein on four commercial strains of egg type chickens found highly significant differences in Haugh unit values within the same season, strain and dietary protein level. An interaction of strain and diet for egg production was also found to exist. Harms and Waldroup (1962) reported a significant strain X protein level interaction as measured by rate of egg production. This present study was conducted to determine if genetic differences in protein requirements existed between four commercial egg production stocks made available to the Texas A&M University Poultry Science Department. EXPERIMENTAL PROCEDURE
Sexed day-old chicks hatched March 7, 1961, representing four nationally-known egg production stocks, were wing banded
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on June 10, 2015
Effects of Dietary Protein Level on Performance of Four Commercial Egg Production Stocks
937
PROTEIN LEVEL AND PRODUCTION T A B L E 1.—Composition of laying Ingredients
rations
Protein Level (%) 17
16
15
14
46.47 20.00
49.50 20.00
52.59 20.00
55.80 20.00
18.63
Grain sorghum Corn Soybean meal (44% protein) Alfalfa meal (20% protein) Distillers dried solubles Oyster shell flour Defluorinated rock phosphate Vitamin mix* Salt Manganese sulfate
15.67
12.65
9.51
3.00 2.00 4.25
3.00 2.00 4.25
3.00 2.00 4.25
3.00 2.00 4.25
2.90 2.50 0.25 i#/ton
2.83 2.50 0.25 i#/ton
2.76 2.50 0.25 i#/ton
2.69 2.50 0.25 i#/ton
% Protein % Fiber Calories (PE./lb.)
17.00 3.58 890
16.00 3.46 907
15.00 3.32 921
14.00 3.19 941
* The vitamin mix contributed the following per ton of feed: dry fish solubles 20 lbs.; delactosed whey product 10 lbs.; antibiotic fermentation solubles 5 lbs.; 25% choline chloride 4 lbs.; stable dry vit. A (10,000 I.U. gm.) 1 lb.; dry Da (3,000 I.C.U. gm.) 1 lb.; 3-nitro-4-hydroxyphenylarsonic acid 45 gms.; B vitamins with antibiotic supplement1 1 lb.; and soybean meal to make 50 lbs. 1 Contained: riboflavin 4 gms.; calcium pantothenate 10 gms.; niacin 25 gms.; vitamin B12 12 mgs.; bacitracin 10 gms.; penicillin 10 gms.
was 16%. Before mixing the ingredients were analyzed for protein and after mixing the protein content was analyzed for each diet by the Texas A&M University Analytical Services Laboratory. If necessary to keep the protein levels constant, the diets were remixed. The diet compositions given in Table 1 are the averages for the entire experimental period. In order to keep the four diets on a practical type basis no attempt was made to keep the amino acid relationship the same by the use of a fillertype ingredient. Records on body weight, egg production, egg weight, feed efficiency and mortality were recorded for twelve 28-day laying periods. These records were recorded in the following manner: Body weight—the initial body weight at the beginning of the experiment and the body weight at the end of each of the twelve 28-day laying periods on an individual basis. Egg production—a daily individual henday egg production records were kept. Egg weight—average egg weight was based on the last seven days of each of
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on June 10, 2015
for identification and then reared in confinement as one group on the Texas A&M University Poultry Farm. The pullets were reared on litter in a conventional type brooder house. They were given 1 square foot of floor space to 8 weeks and 2 square feet thereafter until moved into the laying cages at 22 weeks of age. The pullets were vaccinated for Newcastle, intra-ocularly at one day of age, by the water method at 3 weeks and intra-ocularly at 21 weeks. Two pox vaccinations were given at 8 and 21 weeks respectively and bronchitis at 12 weeks. At 22 weeks of age 80 birds from each stock were randomly selected and placed in individual 10" X 18" laying cages. An additional 112 birds from each stock were randomly selected and placed in 3 ^ X 4 foot colony cages with 14 birds per cage. A highly significant stock X protein level interaction was found for body weight, egg production, egg weight and feed efficiency for the two replicates of 14 birds housed in colony cages. No egg quality data were recorded for birds housed in the colony cages. Data on the birds housed in individual cages only are included in this report. In Table 1 the diet compositions used during the laying period are given. One of the four treatment combinations consisted of a constant 17% protein level and one a constant 14% protein level for the twelve 28-day laying periods. The third treatment consisted of a decreasing protein level (17% decreased to 14%) with a decrease of one percent each two months until the 14% level was reached. Thus, the average protein content for the twelve 2 8-day laying periods was 15%. The fourth treatment consisted of increasing the protein level (14% increased to 17%) with an increase of one percent every two months until the 17% protein level was reached. The average protein content for the twelve 28-day laying periods for this treatment
J . W . DEATON AND J . H . QuiSENBERRY
938
Egg quality measurements which consisted of Haugh units and egg shell thicknesses were recorded for eleven of the twelve 28-day laying periods. This was accomplished by taking all of the eggs laid on the fourteenth day for each of the last eleven 28-day laying periods and recording the Haugh units and shell thickness from this. There were two replicates of ten birds for each of the sixteen treatment combinations. The data were statistically analyzed by a split-plot analysis according to Cochran and Cox (1962). Treatment means 2000
were separated according to Duncan's (1955) multiple range analysis. RESULTS AND DISCUSSION
The birds were carried on this experiment for 336 days beginning August 8, 1961. The Leghorn-type egg production stocks used will be identified as 1, 2, 3 and 4. Stock 1 is an incrossbred and stocks 2, 3 and 4 are strain crosses. A highly significant stock X protein level interaction existed for body weight, egg production, egg weight, feed efficiency, Haugh unit score and egg shell thickness, indicating that genetic differences for protein requirements exist for these four commercial egg production stocks. Graphical illustrations of these interactions are given in Figures 1 through 6. Because the nature and degree of interactions are so much more effectively presented in line charts the authors have included one figure to depict the breed X protein level interaction
_
1900
1800
170C _ *
1600
Stock Stock Stock Stock
1 2 3 4
_ _U 17
_1_
17-
U
14+
Percent Protein FIG. 1. Average body weight of four egg production stocks housed in individual cages as influenced by dietary protein levels.
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on June 10, 2015
the twelve 28-day laying periods for each replicate. Feed efficiency—feed efficiency was calculated at the end of each of the twelve 28-day laying periods and was based on the amount of feed required to produce a dozen two-ounce eggs. Mortality—mortality was recorded as it occurred.
PROTEIN LEVEL AND PRODUCTION
939
78 74 70 66
62 58
54 50 46
42 38 17
17-
14-;-
14
Percent Protein FIG. 2. Hen-day production of four egg production stocks housed in individual cages as influenced by dietary protein levels.
for each of the six traits for which interactions were significant; (1) body weight, (2) percent hen-day egg production, (3)
egg weight, (4) feed per dozen 2-ounce eggs, (5) Haugh unit score and (6) egg shell thickness.
60 r-
59
-
58
57
_L
56 17
17-
14
14+
Percent Protein FIG. 3. Egg weight of four egg production stocks housed in individual cages as influenced by dietary protein levels.
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on June 10, 2015
rt
940
J . W . DEATON AND J . H . QUISENBERRY 7.4 7.0 6.6
_
6.2
_
5.8
Stock 1 5.0
Stock 2 O Stock 3
6H
4.6
K Stock 4
_
4.2 3.8
-L
3.4
17
J_ 17-
J_ 14-t
14 Percent Protein
FIG. 4. Feed required to produce a dozen 2-ounce eggs by four egg production stocks housed in individual cages as influenced by dietary protein levels.
When only protein levels were considered, birds receiving the increasing protein level diet (14% increased to 17%) laid
significantly more eggs with a significantly heavier body and egg weight and with a better feed efficiency than the other three
90
86 84 82 80
ffl
78
_
76
_
-O Stock 3 •X S t o c k 4
74
72 h70 i 17
17-
14
14+
Percent Protein FIG.
S. Egg quality as measured by Haugh units of four egg production stocks housed in individual cages as influenced by dietary protein levels.
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on June 10, 2015
5.4
941
PROTEIN LEVEL AND PRODUCTION .0160
r
.0158
_
.0156 .0154 .0152 .0150
Stock Stock Stock Stock
1 2 3 4
.0148 .0146 .0144 .0142 .0140
_L
17
17-
14
14+
Percent Protein
FIG. 6. Egg quality as measured by shell thickness of four egg production stocks housed in individual cages as influenced by dietary protein levels.
treatment groups (Table 2). No significant differences were noted in mortality or shell thickness, but birds receiving the highest protein level diet (17%) had a significantly lower average Haugh unit score. When a comparison was made between the 17% and 14% protein diets (Table 2) no significant difference existed for egg production, but birds receiving the 17% protein diet had a significantly heavier egg weight with a significantly better feed efficiency. Birds receiving the 14% protein diet had a significantly heavier
body weight and a higher Haugh unit score when compared to the 17% protein diet. Significant stock differences were noted for all factors included in this study except shell thickness (Table 3). SUMMARY
When four commercial egg production stocks were subjected to four different protein levels, a highly significant stock X protein level interaction was found for body weight, egg production, egg weight, feed efficiency, Haugh unit score
TABLE 2.—Comparison of average body weight, hen-day production, egg weight, feed efficiency, mortality, Haugh units and shell thickness as influenced by dietary protein level for birds housed in individual cages Protein Average Hen-day iI e v e li body weight production (gms.) (%) 17 1714 14+
1
1,763 a 1,785 b 1,783 b 1,810 c
63.89 65.29 64.36 68.71
a a a b
Mortality
Average egg weight (gms.)
Feed/doz. 2-oz. eggs (lbs.)
No.
%
58.33 a 57.99 a 57.50 b 58.84 c
4.10 a 4.05 ab 4.24 c 3.94 b
11 9 12 9
14 11 15 11
a a a a
Shell thickness (inches)
Haugh units 75.18 78.60 78.23 77.95
a b b b
.0148 .0147 .0147 .0148
a a a a
1 Values having the same letters are not significantly different from each other at the .05 level of probability.
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on June 10, 2015
— O -X
942
J . W . DEATON AND J . H . QUISENBEERY
TABLE 3.—Comparison of average body weight, hen-day production, egg weight, feed efficiency, mortality, Haugh units and shell thickness as influenced by breeding for birds housed in individual cages Average Strain body weight (gms.) 1,702 a 1,834 c 1,752 b 1,860 d
68.11 69.11 62.43 62.36
a a b b
Average egg weight (gms.)
Feed/doz. 2-oz. eggs (lbs.)
Mortality No.
%
58.27 ab 57.98 a 58.57 b 57.93 a
3.91 a 3.92 a 4.14 b 4.40 c
la 13 b 16 b 11 b
1 16 20 14
Haugh units 74.43 a 79.56 b 76.11 c 80.87 d
Shell thickness (inches) .0147 .0147 .0148 .0148
a a a a
1 Values having the same letters are not significantly different from each other at the .05 level of probability.
and egg shell thickness, demonstrating that genetic differences in protein requirements existed for these four egg production stocks. REFERENCES Cochran, W. G., and G. M. Cox, 1962. Experimental Designs. 2nd ed. John Wiley and Sons, Inc., New York and London. Denton, A. A., and R. J. Lillie, 19S9. Effect of protein restriction in growing and laying diets on the performance of White Leghorn pullets. Poultry Sci. 38: 1198. Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics, 11: 1-42. Frank, F. R., and P. E. Waibel, 1959. Effect of dietary energy and protein level and energy source on White Leghorn pullets in cages. Poultry Sci. 38: 1204-1205. Griminger, P., and H. Fisher, 1959. Amino acid requirements of laying hens. 5. Effect of amino acid balance in low protein diets. Poultry Sci. 38: 1210. Harms, R. H., and P. W. Waldroup, 1962. Strain differences in the protein requirement of laying hens. Poultry Sci. 4 1 : 1985-1987. Heywang, B. W., H. R. Bird and M. G. Vavich, 1955. The level of protein in the diet of laying White Leghorns during hot weather. Poultry Sci. 34: 148-152.
Miller, E. C , M. L. Sunde and C. A. Elvehjem, 1956. Minimum protein requirements of laying pullets at different energy levels. Poultry Sci. 35: 1159. Milton, J. E., and G. R. Ingram, 1957. The protein requirements of laying hens as affected by temperature, age, breed, system of management and rate of lay. Poultry Sci. 36: 11411142. Moreng, R. E., H. L. Enos and W. A. Whittet, 1963. An analysis of strain response to dietary protein level. Poultry Sci. 42: 1293. Quisenberry, J. H., and J. W. Bradley, 1962. Effects of dietary protein and changes in energy levels on the laying house performance of egg production stocks. Poultry Sci. 4 1 : 717-724. Reid, B. L., J. H. Quisenberry and J. R. Couch, 1951. Aureomycin, vitamin BJ2, methionine and level of protein in mature fowl nutrition. Poultry Sci. 30: 935-936. Thornton, P. A., L. G. Blaylock and R. E. Moreng, 1957. Protein level as a factor in egg production. Poultry Sci. 36: 552-557. Thornton, P. A., and W. Whittet, 1959. The adequacy of low protein levels for egg production under various conditions. Poultry Sci. 38: 1255. Thornton, P. A., and W. A. Whittet, 1960. Protein requirement for egg production as influenced by management, genetic background and dietary energy level. Poultry Sci. 39: 916-921.
NEWS AND NOTES OHIO NOTES W. P. Jaffe (Ph.D., Edinburgh) from the University of Bristol, England, was appointed Visiting Professor of Poultry Science for the period January through June, 1965. Dr. Jaffe taught courses in the areas of genetic polymorphisms and physiological genetics as a part of the interde-
partmental (Animal, Dairy and Poultry Science) graduate program in animal breeding programs. Jack L. Turk (Ph.D.), Washington State University) was appointed Post-doctoral Fellow in Poultry Nutrition for the period October, 1964 through September, 1965. His teaching duties consist of a course in Market Egg Production as well
Continued on page 956
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on June 10, 2015
1 2 3 4
1
Hen-day production (%)
A. B. STEPHENSON, Q. B. KINDER AND E. M.
numbers for tables of multiple classification with disproportionate subclass numbers. J. Amer. Stat. Assn. 29: 389-393. Snedecor, G. W., 1956. Statistical Methods. The Iowa State College Press.
FUNK
Warren, D. C , 1953. Practical Poultry Breeding. MacMillan. Water, N. F., 1938. The influence of inbred sires top crossed on White Leghorn fowl. Poultry Sci. 17: 490-497.
JAMES W. DEATON AND J O H N H. QUISENBEREY Texas A&M University, College Station, Texas (Received for publication October 13, 1964)
W
ITH the advent of commercialization in the poultry industry there has been a decrease in the number of breeders of egg production stocks, and in turn, an increase in the number of laying hens produced by one breeder. Since this trend is expected to continue, the genetic influence of one breeder's stock will become more widespread and the assumption is made that each breeder's stock will have a different genetic background. In order to attain the precision that is necessary to maintain progress in a breeding program, the bird sold by the breeder of the future will probably have specific nutritional and environmental requirements. Since protein is one of the more expensive items in a laying ration, considerable work has been done to determine the minimum ended for optimum returns. Several workers, Neywang et al. (1955), Miller et al. (1956), Frank and Waibel (1959), Griminger and Fisher (1959), Thornton et al. (1957) and Thornton and Whittet (1959), have reported satisfactory egg production with protein levels of 13-15%. Other workers, Reid et al. (1951), Quisenberry and Bradley (1962), Milton and Ingram (1957) and Denton and Lillie (1959), have reported optimum performance from protein levels above 15%.
Considerable controversy exists concerning the amount of protein necessary for optimum performance. These differences in results could be due in part to differences in strains of birds used by the various investigators. Thornton and Whittet (I960), using four different strains of egg production stocks and four levels of protein, could find no consistent trends; whereas, Moreng et al. (1963) using three different levels of dietary protein on four commercial strains of egg type chickens found highly significant differences in Haugh unit values within the same season, strain and dietary protein level. An interaction of strain and diet for egg production was also found to exist. Harms and Waldroup (1962) reported a significant strain X protein level interaction as measured by rate of egg production. This present study was conducted to determine if genetic differences in protein requirements existed between four commercial egg production stocks made available to the Texas A&M University Poultry Science Department. EXPERIMENTAL PROCEDURE
Sexed day-old chicks hatched March 7, 1961, representing four nationally-known egg production stocks, were wing banded
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on June 10, 2015
Effects of Dietary Protein Level on Performance of Four Commercial Egg Production Stocks
937
PROTEIN LEVEL AND PRODUCTION T A B L E 1.—Composition of laying Ingredients
rations
Protein Level (%) 17
16
15
14
46.47 20.00
49.50 20.00
52.59 20.00
55.80 20.00
18.63
Grain sorghum Corn Soybean meal (44% protein) Alfalfa meal (20% protein) Distillers dried solubles Oyster shell flour Defluorinated rock phosphate Vitamin mix* Salt Manganese sulfate
15.67
12.65
9.51
3.00 2.00 4.25
3.00 2.00 4.25
3.00 2.00 4.25
3.00 2.00 4.25
2.90 2.50 0.25 i#/ton
2.83 2.50 0.25 i#/ton
2.76 2.50 0.25 i#/ton
2.69 2.50 0.25 i#/ton
% Protein % Fiber Calories (PE./lb.)
17.00 3.58 890
16.00 3.46 907
15.00 3.32 921
14.00 3.19 941
* The vitamin mix contributed the following per ton of feed: dry fish solubles 20 lbs.; delactosed whey product 10 lbs.; antibiotic fermentation solubles 5 lbs.; 25% choline chloride 4 lbs.; stable dry vit. A (10,000 I.U. gm.) 1 lb.; dry Da (3,000 I.C.U. gm.) 1 lb.; 3-nitro-4-hydroxyphenylarsonic acid 45 gms.; B vitamins with antibiotic supplement1 1 lb.; and soybean meal to make 50 lbs. 1 Contained: riboflavin 4 gms.; calcium pantothenate 10 gms.; niacin 25 gms.; vitamin B12 12 mgs.; bacitracin 10 gms.; penicillin 10 gms.
was 16%. Before mixing the ingredients were analyzed for protein and after mixing the protein content was analyzed for each diet by the Texas A&M University Analytical Services Laboratory. If necessary to keep the protein levels constant, the diets were remixed. The diet compositions given in Table 1 are the averages for the entire experimental period. In order to keep the four diets on a practical type basis no attempt was made to keep the amino acid relationship the same by the use of a fillertype ingredient. Records on body weight, egg production, egg weight, feed efficiency and mortality were recorded for twelve 28-day laying periods. These records were recorded in the following manner: Body weight—the initial body weight at the beginning of the experiment and the body weight at the end of each of the twelve 28-day laying periods on an individual basis. Egg production—a daily individual henday egg production records were kept. Egg weight—average egg weight was based on the last seven days of each of
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on June 10, 2015
for identification and then reared in confinement as one group on the Texas A&M University Poultry Farm. The pullets were reared on litter in a conventional type brooder house. They were given 1 square foot of floor space to 8 weeks and 2 square feet thereafter until moved into the laying cages at 22 weeks of age. The pullets were vaccinated for Newcastle, intra-ocularly at one day of age, by the water method at 3 weeks and intra-ocularly at 21 weeks. Two pox vaccinations were given at 8 and 21 weeks respectively and bronchitis at 12 weeks. At 22 weeks of age 80 birds from each stock were randomly selected and placed in individual 10" X 18" laying cages. An additional 112 birds from each stock were randomly selected and placed in 3 ^ X 4 foot colony cages with 14 birds per cage. A highly significant stock X protein level interaction was found for body weight, egg production, egg weight and feed efficiency for the two replicates of 14 birds housed in colony cages. No egg quality data were recorded for birds housed in the colony cages. Data on the birds housed in individual cages only are included in this report. In Table 1 the diet compositions used during the laying period are given. One of the four treatment combinations consisted of a constant 17% protein level and one a constant 14% protein level for the twelve 28-day laying periods. The third treatment consisted of a decreasing protein level (17% decreased to 14%) with a decrease of one percent each two months until the 14% level was reached. Thus, the average protein content for the twelve 2 8-day laying periods was 15%. The fourth treatment consisted of increasing the protein level (14% increased to 17%) with an increase of one percent every two months until the 17% protein level was reached. The average protein content for the twelve 28-day laying periods for this treatment
J . W . DEATON AND J . H . QuiSENBERRY
938
Egg quality measurements which consisted of Haugh units and egg shell thicknesses were recorded for eleven of the twelve 28-day laying periods. This was accomplished by taking all of the eggs laid on the fourteenth day for each of the last eleven 28-day laying periods and recording the Haugh units and shell thickness from this. There were two replicates of ten birds for each of the sixteen treatment combinations. The data were statistically analyzed by a split-plot analysis according to Cochran and Cox (1962). Treatment means 2000
were separated according to Duncan's (1955) multiple range analysis. RESULTS AND DISCUSSION
The birds were carried on this experiment for 336 days beginning August 8, 1961. The Leghorn-type egg production stocks used will be identified as 1, 2, 3 and 4. Stock 1 is an incrossbred and stocks 2, 3 and 4 are strain crosses. A highly significant stock X protein level interaction existed for body weight, egg production, egg weight, feed efficiency, Haugh unit score and egg shell thickness, indicating that genetic differences for protein requirements exist for these four commercial egg production stocks. Graphical illustrations of these interactions are given in Figures 1 through 6. Because the nature and degree of interactions are so much more effectively presented in line charts the authors have included one figure to depict the breed X protein level interaction
_
1900
1800
170C _ *
1600
Stock Stock Stock Stock
1 2 3 4
_ _U 17
_1_
17-
U
14+
Percent Protein FIG. 1. Average body weight of four egg production stocks housed in individual cages as influenced by dietary protein levels.
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on June 10, 2015
the twelve 28-day laying periods for each replicate. Feed efficiency—feed efficiency was calculated at the end of each of the twelve 28-day laying periods and was based on the amount of feed required to produce a dozen two-ounce eggs. Mortality—mortality was recorded as it occurred.
PROTEIN LEVEL AND PRODUCTION
939
78 74 70 66
62 58
54 50 46
42 38 17
17-
14-;-
14
Percent Protein FIG. 2. Hen-day production of four egg production stocks housed in individual cages as influenced by dietary protein levels.
for each of the six traits for which interactions were significant; (1) body weight, (2) percent hen-day egg production, (3)
egg weight, (4) feed per dozen 2-ounce eggs, (5) Haugh unit score and (6) egg shell thickness.
60 r-
59
-
58
57
_L
56 17
17-
14
14+
Percent Protein FIG. 3. Egg weight of four egg production stocks housed in individual cages as influenced by dietary protein levels.
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on June 10, 2015
rt
940
J . W . DEATON AND J . H . QUISENBERRY 7.4 7.0 6.6
_
6.2
_
5.8
Stock 1 5.0
Stock 2 O Stock 3
6H
4.6
K Stock 4
_
4.2 3.8
-L
3.4
17
J_ 17-
J_ 14-t
14 Percent Protein
FIG. 4. Feed required to produce a dozen 2-ounce eggs by four egg production stocks housed in individual cages as influenced by dietary protein levels.
When only protein levels were considered, birds receiving the increasing protein level diet (14% increased to 17%) laid
significantly more eggs with a significantly heavier body and egg weight and with a better feed efficiency than the other three
90
86 84 82 80
ffl
78
_
76
_
-O Stock 3 •X S t o c k 4
74
72 h70 i 17
17-
14
14+
Percent Protein FIG.
S. Egg quality as measured by Haugh units of four egg production stocks housed in individual cages as influenced by dietary protein levels.
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on June 10, 2015
5.4
941
PROTEIN LEVEL AND PRODUCTION .0160
r
.0158
_
.0156 .0154 .0152 .0150
Stock Stock Stock Stock
1 2 3 4
.0148 .0146 .0144 .0142 .0140
_L
17
17-
14
14+
Percent Protein
FIG. 6. Egg quality as measured by shell thickness of four egg production stocks housed in individual cages as influenced by dietary protein levels.
treatment groups (Table 2). No significant differences were noted in mortality or shell thickness, but birds receiving the highest protein level diet (17%) had a significantly lower average Haugh unit score. When a comparison was made between the 17% and 14% protein diets (Table 2) no significant difference existed for egg production, but birds receiving the 17% protein diet had a significantly heavier egg weight with a significantly better feed efficiency. Birds receiving the 14% protein diet had a significantly heavier
body weight and a higher Haugh unit score when compared to the 17% protein diet. Significant stock differences were noted for all factors included in this study except shell thickness (Table 3). SUMMARY
When four commercial egg production stocks were subjected to four different protein levels, a highly significant stock X protein level interaction was found for body weight, egg production, egg weight, feed efficiency, Haugh unit score
TABLE 2.—Comparison of average body weight, hen-day production, egg weight, feed efficiency, mortality, Haugh units and shell thickness as influenced by dietary protein level for birds housed in individual cages Protein Average Hen-day iI e v e li body weight production (gms.) (%) 17 1714 14+
1
1,763 a 1,785 b 1,783 b 1,810 c
63.89 65.29 64.36 68.71
a a a b
Mortality
Average egg weight (gms.)
Feed/doz. 2-oz. eggs (lbs.)
No.
%
58.33 a 57.99 a 57.50 b 58.84 c
4.10 a 4.05 ab 4.24 c 3.94 b
11 9 12 9
14 11 15 11
a a a a
Shell thickness (inches)
Haugh units 75.18 78.60 78.23 77.95
a b b b
.0148 .0147 .0147 .0148
a a a a
1 Values having the same letters are not significantly different from each other at the .05 level of probability.
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on June 10, 2015
— O -X
942
J . W . DEATON AND J . H . QUISENBEERY
TABLE 3.—Comparison of average body weight, hen-day production, egg weight, feed efficiency, mortality, Haugh units and shell thickness as influenced by breeding for birds housed in individual cages Average Strain body weight (gms.) 1,702 a 1,834 c 1,752 b 1,860 d
68.11 69.11 62.43 62.36
a a b b
Average egg weight (gms.)
Feed/doz. 2-oz. eggs (lbs.)
Mortality No.
%
58.27 ab 57.98 a 58.57 b 57.93 a
3.91 a 3.92 a 4.14 b 4.40 c
la 13 b 16 b 11 b
1 16 20 14
Haugh units 74.43 a 79.56 b 76.11 c 80.87 d
Shell thickness (inches) .0147 .0147 .0148 .0148
a a a a
1 Values having the same letters are not significantly different from each other at the .05 level of probability.
and egg shell thickness, demonstrating that genetic differences in protein requirements existed for these four egg production stocks. REFERENCES Cochran, W. G., and G. M. Cox, 1962. Experimental Designs. 2nd ed. John Wiley and Sons, Inc., New York and London. Denton, A. A., and R. J. Lillie, 19S9. Effect of protein restriction in growing and laying diets on the performance of White Leghorn pullets. Poultry Sci. 38: 1198. Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics, 11: 1-42. Frank, F. R., and P. E. Waibel, 1959. Effect of dietary energy and protein level and energy source on White Leghorn pullets in cages. Poultry Sci. 38: 1204-1205. Griminger, P., and H. Fisher, 1959. Amino acid requirements of laying hens. 5. Effect of amino acid balance in low protein diets. Poultry Sci. 38: 1210. Harms, R. H., and P. W. Waldroup, 1962. Strain differences in the protein requirement of laying hens. Poultry Sci. 4 1 : 1985-1987. Heywang, B. W., H. R. Bird and M. G. Vavich, 1955. The level of protein in the diet of laying White Leghorns during hot weather. Poultry Sci. 34: 148-152.
Miller, E. C , M. L. Sunde and C. A. Elvehjem, 1956. Minimum protein requirements of laying pullets at different energy levels. Poultry Sci. 35: 1159. Milton, J. E., and G. R. Ingram, 1957. The protein requirements of laying hens as affected by temperature, age, breed, system of management and rate of lay. Poultry Sci. 36: 11411142. Moreng, R. E., H. L. Enos and W. A. Whittet, 1963. An analysis of strain response to dietary protein level. Poultry Sci. 42: 1293. Quisenberry, J. H., and J. W. Bradley, 1962. Effects of dietary protein and changes in energy levels on the laying house performance of egg production stocks. Poultry Sci. 4 1 : 717-724. Reid, B. L., J. H. Quisenberry and J. R. Couch, 1951. Aureomycin, vitamin BJ2, methionine and level of protein in mature fowl nutrition. Poultry Sci. 30: 935-936. Thornton, P. A., L. G. Blaylock and R. E. Moreng, 1957. Protein level as a factor in egg production. Poultry Sci. 36: 552-557. Thornton, P. A., and W. Whittet, 1959. The adequacy of low protein levels for egg production under various conditions. Poultry Sci. 38: 1255. Thornton, P. A., and W. A. Whittet, 1960. Protein requirement for egg production as influenced by management, genetic background and dietary energy level. Poultry Sci. 39: 916-921.
NEWS AND NOTES OHIO NOTES W. P. Jaffe (Ph.D., Edinburgh) from the University of Bristol, England, was appointed Visiting Professor of Poultry Science for the period January through June, 1965. Dr. Jaffe taught courses in the areas of genetic polymorphisms and physiological genetics as a part of the interde-
partmental (Animal, Dairy and Poultry Science) graduate program in animal breeding programs. Jack L. Turk (Ph.D.), Washington State University) was appointed Post-doctoral Fellow in Poultry Nutrition for the period October, 1964 through September, 1965. His teaching duties consist of a course in Market Egg Production as well
Continued on page 956
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on June 10, 2015
1 2 3 4
1
Hen-day production (%)