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Initial Internal Temperature Changes of Incubating Eggs
205
LAYING CAPACITY certain egg quality measurements and blood constituents of laying hens. Poultry Sci. 39: 1427-1431. Rako, A., F. Dum'anovsky and K. Mikulec, 1961. Odnos kolicina ukupne bjelancevine i pojedinih njezinih funkcija te aktivnost krvne lipaze prema zavrsnoj tezini u tovu pilica. Vet. arhiv. 3 1 : 319-323.
Stutts, E. C , W. E. Briles and H. O. Kunkel, 1956. Blood glutathione levels and egg production in inbred lines of chickens. Poultry Sci. 35: 727-728. Stutts, E. C , W. E. Briles and H. O. Kunkel, 1957. Plasma alkaline phosphatase activity in mature inbred chickens. Poultry Sci. 36: 269276.
J. W. COLEMAN, 1 ' 2 H. S. SIEGEL2 AND G. F. KRAUSE3 Virginia Polytechnic Institute, Blacksburg (Received for publication July 15, 1963)
MBIENT temperature during and prior i. to incubation significantly alters development. Kosin (1956) reported that preincubation warming of turkey eggs advanced early embryonic development, improved hatchability and shortened incubation time. In a study of the resistance of the chicken embryo to low temperature exposure, Moreng and Bryant (1956) found that at environmental temperatures of 50 to 55°F., four hours were required for the internal temperature of the egg to decline from incubation temperature to the ambient temperature. Law and Kosin (1958) reported that when eggs of initial temperatures of 55°F. and 70°F. were placed on egg flats and put into an incubator at 99%°F., 30 and 10 minutes, respectively, were required for the internal temperature to reach 80°F. The objectives of this experiment were to determine whether egg weight, shell thickness and/or genetics influence the rate of warming and the asymptotic temperature
A
1
Recipient of Grant 21617, Undergraduate Science Education Program, National Science Foundation. 2 Department of Poultry Science. 'Department of Statistics. Present address, Department of Statistics, Kansas State University, Manhattan, Kansas.
attained by eggs during the initial phases of incubation. METHODS
The eggs were placed in a forced draft incubation maintained at 99.5°F. The temperature data were obtained by the insertion of glass shielded, copper-constantin thermocouples into fertile and infertile eggs of White Rock and White Leghorn chickens and Large White turkeys. The White Rock eggs were identified by hen. Individual internal egg temperatures, were recorded through the use of a recording potentiometer. The tip of the thermocouple was placed just proximate to the germinal disc. Thermocouples were also placed in beakers containing water which represented the measured volume of the average sized egg used in the experiment. These were covered with filter paper to simulate the porous effect similar to that of the shell. Prior to incubation, egg weights were determined to the nearest gram and subsequent to incubation, egg shell thicknesses were measured to the nearest .001 inch with an Ames Thickness Gauge. The equation used to describe the change in temperature of the incubating eggs was: A Y= 1 + BA*
Downloaded from http://ps.oxfordjournals.org/ at University of South Dakota and School of Medicine on May 7, 2015
Initial Internal Temperature Changes of Incubating Eggs
206
J. W. COLEMAN, H. S. SIEGEL AND G. F. KRAUSE
where:
Curvilinear regressions were computed through the use of an IBM 1620 Computer. With this equation, multiple correlation coefficients (R) estimating the goodness of fit of the line to actual data were not below .992. The statistics A, B, and A , being distributed normally, were analyzed by Analysis of Variance to determine differences between fertile and infertile eggs, among breeds and species within the fertility classifications, and, for the White Rock chickens, differences among individual hens. Where separation of means was necessary, multiple range tests were applied (Kramer, 1956). Simple (r) and multiple correlations (R) were calculated to determine the significance of relationships between egg weight, shell thickness, and the various components of the regression equation (Snedecor, 1946).
Source of variation
Mean squares Df
A
B
Total 205 1 Fertility 2 Stock w/n fertile 2 Stock w/n infertile
.046 .492* .201
.024 .005 .029
.006 .028** .014**
Error
.143
.011
.002
*<*<0.05.
200
A
**a<0.01.
IOC,
H,0 White Rocks Leghorns Turkeys
RESULTS
Statistically, from Table 1, and graphically from Figure 1, it can be seen that fertile White Leghorn eggs reached a significantly higher asymptotic (A) temperature than did the fertile White Rock or turkey eggs. However, as represented in Table 1, and Figure 2, within infertile eggs, differences among stocks were not significant. As indicated in Table 1, there were no real differences between fertility classes nor among stocks within classes for gain in temperatures of eggs as related to the temperature at the start of incubation (B). The incremental change in temperature
HOURS
12-MINUTE
10 INTERVALS
15
i
FIG. 1. Changes in temperature of fertile eggs during the first 3 hours of incubation. A Y=
, 1+BA*
where Y=internal temperature on eggs A=asymptotic temperature B = Gain in temperature expressed as a multiple of beginning temperature A=rate of change x=time expressed in equal intervals
Downloaded from http://ps.oxfordjournals.org/ at University of South Dakota and School of Medicine on May 7, 2015
Y = Internal temperature of eggs at a given time A = Asymptotic temperature B = Gain in temperature expressed as a multiple of beginning temperature A = Rate of change x=Time expressed in equal intervals
TABLE 1.—Analysis of variance of asymptotic temperature (A), gain in temperature expressed as a multiple of beginning temperature (B), and rate of temperature change (A)
207
TEMPERATURE OF INCUBATING EGGS
TABLE 2.—Simple (r) and multiple correlations (R) showing the effect of egg weight (xi) and shell thickness (x?) on increment of change (A) R
(R 2 ) % of total variation
r Stock
N
XI
X2
Infertile 12 16 29
.378 .721* .486**
.044 .210 - .028
m
White Leghorn White Rock Turkey
.249 .611 .238
32 65 52
.219 .093 .132
- .339 .102 - .254
.445* .144 .317
.198 .021 .100
Fertile White Leghorn White Rock Turkey
*a<0.05. •*a<0.01.
Ambient!
10
5 12- MINUTE
15
_f
INTERVALS
FIG. 2. Changes in temperature of infertile eggs during the first 3 hours of incubation. Equation as in Figure 1.
the equation and therefore as egg weight increases, the increment of temperature change is decreased. DISCUSSION The results indicated that the fertile White Leghorn eggs reached a significantly higher asymptotic temperature than did the fertile White Rock or turkey eggs. It is probable that White Leghorns have a higher metabolic rate than either the White Rock chickens or the Large White turkeys. Thus, if the White Leghorn embryo was metabolizing at a faster rate, then greater heat production could result in a greater incremental change and a higher asymptotic temperature than that observed in the eggs of either of the other two stocks. Egg size was found to be more important in determining the incremental temperature change than was shell thickness.
Downloaded from http://ps.oxfordjournals.org/ at University of South Dakota and School of Medicine on May 7, 2015
( A ) was significantly greater in White Leghorn eggs than in White Rock eggs, which in turn was significantly greater than in turkey eggs. This was true for both fertile and infertile eggs. No real differences were noted among individual White Rock hens for any of the statistics measured. Significant correlations between egg weight (xa) and the increment of temperature change (Table 2) were found among the infertile eggs of White Rock and turkey stocks, while correlations were not significant for the fertile eggs of any of the three stocks. Significant multiple correlation coefficients (R) for egg weight and shell thickness on the increment of temperature change were found for the infertile eggs of White Rocks and turkeys, but in the fertile eggs only in the White Leghorn eggs was the correlation significant. Correlations of shell thickness on increment of temperature change was not significant for any of the three stocks in either fertile or infertile eggs. In the infertile classification, shell thickness and egg weight accounted for a greater proportion of the total variation in increment of temperature change in all three stocks as compared to those of the fertile classification. Rate of temperature change ( A ) was positively correlated to egg weight in Table 2. However, it should be noted that A is in the denominator in
208
J. W. COLEMAN, H. S. SIEGEL AND G. F. KRAUSK
SUMMARY The influence of shell thickness, egg weight, and genetics on the rate of warm-
ing and the asymptotic temperature of incubating was studied. It was found that the asymptotic temperature of fertile White Leghorn eggs was significantly higher than that of fertile White Rock or turkey eggs. The incremental change in temperature was also significantly greater for White Leghorn eggs than for White Rock eggs, which in turn was significantly greater than for turkey eggs. Egg weight was relatively more important in influencing rate of temperature change than was shell thickness. When egg weight and shell thickness were combined, they accounted for a greater proportion of total variation in the infertile eggs compared to the fertile eggs.
REFERENCES Kosin, I. L., 1956. Studies on pre-incubation warming of chicken and turkey eggs. Poultry Sci. 35: 1384-1392. Kramer, C. Y., 1956. Extension of multiple range tests to group means with unequal numbers of replications. Biometrics, 12: 307-310. Law, G. R., and I. L. Kosin, 1958. The rate of temperature change in turkey eggs subjected to short-term incubation and subsequent cooling. Poultry Sci. 37:316-321. Moreng, R. E., and R. L. Bryant, 19S6. The resistance of the chicken embryo to low temperature exposure. Poultry Sci. 35: 753-757. Snedecor, G. W., 1946. Statistical Methods. The Iowa State College Press, Ames. Iowa.
NTD NOTES NEWS AND from page 196) (Continued from sausages. He also recently developed new turkey and chicken patties and turkey and chicken meat loaves, increasing the variety of ways that poultry products could be used on the dinner table. In other research, he has pioneered in studies on response of turkeys to artificial illumination, and range management emphasizing low protein intake and grass-eating habits of turkeys. He also has studied factors affecting the growth and methods of marketing turkeys, and conducted frozen food
studies involving chickens and turkeys. A native of Morrisville, Pennsylvania, Margolf received the Ralston Purina Resident Teaching Award, administered by the Poultry Science Association, in 1954, and the Pennsylvania State University Award for excellence in teaching in 1959. He came to Penn State in 1922 as a Winter Course student, received employment on the poultry farm, and was named Superintendent of the plant a year later. Taking several courses each year
(Continued on page 254)
Downloaded from http://ps.oxfordjournals.org/ at University of South Dakota and School of Medicine on May 7, 2015
Where shell thickness and egg weight were combined, they accounted for a greater percentage of the total variation in the infertile eggs than in the fertile eggs. This is probably a further demonstration of the influence of the metabolizing embryo. If shell color had been a significant factor influencing the rate of warming of these eggs, then it would be expected that the brown shelled eggs (White Rock and turkey) should have had the higher incremental change and higher asymptotic temperatures since this color would absorb heat more readily than the white shell of the White Leghorn eggs. However, as has been noted, White Leghorn eggs had a greater rate of temperature increase and a higher asymptotic temperature than did the two brown shelled stocks. Egg weight was a factor in the rate of warming of infertile eggs, i.e. the greater the mass, the slower the warming, as evidenced by the higher correlation coefficients. This effect was apparently offset by the heat produced by the developing embryo because the correlation coefficients were lower and not significant in fertile eggs.
LAYING CAPACITY certain egg quality measurements and blood constituents of laying hens. Poultry Sci. 39: 1427-1431. Rako, A., F. Dum'anovsky and K. Mikulec, 1961. Odnos kolicina ukupne bjelancevine i pojedinih njezinih funkcija te aktivnost krvne lipaze prema zavrsnoj tezini u tovu pilica. Vet. arhiv. 3 1 : 319-323.
Stutts, E. C , W. E. Briles and H. O. Kunkel, 1956. Blood glutathione levels and egg production in inbred lines of chickens. Poultry Sci. 35: 727-728. Stutts, E. C , W. E. Briles and H. O. Kunkel, 1957. Plasma alkaline phosphatase activity in mature inbred chickens. Poultry Sci. 36: 269276.
J. W. COLEMAN, 1 ' 2 H. S. SIEGEL2 AND G. F. KRAUSE3 Virginia Polytechnic Institute, Blacksburg (Received for publication July 15, 1963)
MBIENT temperature during and prior i. to incubation significantly alters development. Kosin (1956) reported that preincubation warming of turkey eggs advanced early embryonic development, improved hatchability and shortened incubation time. In a study of the resistance of the chicken embryo to low temperature exposure, Moreng and Bryant (1956) found that at environmental temperatures of 50 to 55°F., four hours were required for the internal temperature of the egg to decline from incubation temperature to the ambient temperature. Law and Kosin (1958) reported that when eggs of initial temperatures of 55°F. and 70°F. were placed on egg flats and put into an incubator at 99%°F., 30 and 10 minutes, respectively, were required for the internal temperature to reach 80°F. The objectives of this experiment were to determine whether egg weight, shell thickness and/or genetics influence the rate of warming and the asymptotic temperature
A
1
Recipient of Grant 21617, Undergraduate Science Education Program, National Science Foundation. 2 Department of Poultry Science. 'Department of Statistics. Present address, Department of Statistics, Kansas State University, Manhattan, Kansas.
attained by eggs during the initial phases of incubation. METHODS
The eggs were placed in a forced draft incubation maintained at 99.5°F. The temperature data were obtained by the insertion of glass shielded, copper-constantin thermocouples into fertile and infertile eggs of White Rock and White Leghorn chickens and Large White turkeys. The White Rock eggs were identified by hen. Individual internal egg temperatures, were recorded through the use of a recording potentiometer. The tip of the thermocouple was placed just proximate to the germinal disc. Thermocouples were also placed in beakers containing water which represented the measured volume of the average sized egg used in the experiment. These were covered with filter paper to simulate the porous effect similar to that of the shell. Prior to incubation, egg weights were determined to the nearest gram and subsequent to incubation, egg shell thicknesses were measured to the nearest .001 inch with an Ames Thickness Gauge. The equation used to describe the change in temperature of the incubating eggs was: A Y= 1 + BA*
Downloaded from http://ps.oxfordjournals.org/ at University of South Dakota and School of Medicine on May 7, 2015
Initial Internal Temperature Changes of Incubating Eggs
206
J. W. COLEMAN, H. S. SIEGEL AND G. F. KRAUSE
where:
Curvilinear regressions were computed through the use of an IBM 1620 Computer. With this equation, multiple correlation coefficients (R) estimating the goodness of fit of the line to actual data were not below .992. The statistics A, B, and A , being distributed normally, were analyzed by Analysis of Variance to determine differences between fertile and infertile eggs, among breeds and species within the fertility classifications, and, for the White Rock chickens, differences among individual hens. Where separation of means was necessary, multiple range tests were applied (Kramer, 1956). Simple (r) and multiple correlations (R) were calculated to determine the significance of relationships between egg weight, shell thickness, and the various components of the regression equation (Snedecor, 1946).
Source of variation
Mean squares Df
A
B
Total 205 1 Fertility 2 Stock w/n fertile 2 Stock w/n infertile
.046 .492* .201
.024 .005 .029
.006 .028** .014**
Error
.143
.011
.002
*<*<0.05.
200
A
**a<0.01.
IOC,
H,0 White Rocks Leghorns Turkeys
RESULTS
Statistically, from Table 1, and graphically from Figure 1, it can be seen that fertile White Leghorn eggs reached a significantly higher asymptotic (A) temperature than did the fertile White Rock or turkey eggs. However, as represented in Table 1, and Figure 2, within infertile eggs, differences among stocks were not significant. As indicated in Table 1, there were no real differences between fertility classes nor among stocks within classes for gain in temperatures of eggs as related to the temperature at the start of incubation (B). The incremental change in temperature
HOURS
12-MINUTE
10 INTERVALS
15
i
FIG. 1. Changes in temperature of fertile eggs during the first 3 hours of incubation. A Y=
, 1+BA*
where Y=internal temperature on eggs A=asymptotic temperature B = Gain in temperature expressed as a multiple of beginning temperature A=rate of change x=time expressed in equal intervals
Downloaded from http://ps.oxfordjournals.org/ at University of South Dakota and School of Medicine on May 7, 2015
Y = Internal temperature of eggs at a given time A = Asymptotic temperature B = Gain in temperature expressed as a multiple of beginning temperature A = Rate of change x=Time expressed in equal intervals
TABLE 1.—Analysis of variance of asymptotic temperature (A), gain in temperature expressed as a multiple of beginning temperature (B), and rate of temperature change (A)
207
TEMPERATURE OF INCUBATING EGGS
TABLE 2.—Simple (r) and multiple correlations (R) showing the effect of egg weight (xi) and shell thickness (x?) on increment of change (A) R
(R 2 ) % of total variation
r Stock
N
XI
X2
Infertile 12 16 29
.378 .721* .486**
.044 .210 - .028
m
White Leghorn White Rock Turkey
.249 .611 .238
32 65 52
.219 .093 .132
- .339 .102 - .254
.445* .144 .317
.198 .021 .100
Fertile White Leghorn White Rock Turkey
*a<0.05. •*a<0.01.
Ambient!
10
5 12- MINUTE
15
_f
INTERVALS
FIG. 2. Changes in temperature of infertile eggs during the first 3 hours of incubation. Equation as in Figure 1.
the equation and therefore as egg weight increases, the increment of temperature change is decreased. DISCUSSION The results indicated that the fertile White Leghorn eggs reached a significantly higher asymptotic temperature than did the fertile White Rock or turkey eggs. It is probable that White Leghorns have a higher metabolic rate than either the White Rock chickens or the Large White turkeys. Thus, if the White Leghorn embryo was metabolizing at a faster rate, then greater heat production could result in a greater incremental change and a higher asymptotic temperature than that observed in the eggs of either of the other two stocks. Egg size was found to be more important in determining the incremental temperature change than was shell thickness.
Downloaded from http://ps.oxfordjournals.org/ at University of South Dakota and School of Medicine on May 7, 2015
( A ) was significantly greater in White Leghorn eggs than in White Rock eggs, which in turn was significantly greater than in turkey eggs. This was true for both fertile and infertile eggs. No real differences were noted among individual White Rock hens for any of the statistics measured. Significant correlations between egg weight (xa) and the increment of temperature change (Table 2) were found among the infertile eggs of White Rock and turkey stocks, while correlations were not significant for the fertile eggs of any of the three stocks. Significant multiple correlation coefficients (R) for egg weight and shell thickness on the increment of temperature change were found for the infertile eggs of White Rocks and turkeys, but in the fertile eggs only in the White Leghorn eggs was the correlation significant. Correlations of shell thickness on increment of temperature change was not significant for any of the three stocks in either fertile or infertile eggs. In the infertile classification, shell thickness and egg weight accounted for a greater proportion of the total variation in increment of temperature change in all three stocks as compared to those of the fertile classification. Rate of temperature change ( A ) was positively correlated to egg weight in Table 2. However, it should be noted that A is in the denominator in
208
J. W. COLEMAN, H. S. SIEGEL AND G. F. KRAUSK
SUMMARY The influence of shell thickness, egg weight, and genetics on the rate of warm-
ing and the asymptotic temperature of incubating was studied. It was found that the asymptotic temperature of fertile White Leghorn eggs was significantly higher than that of fertile White Rock or turkey eggs. The incremental change in temperature was also significantly greater for White Leghorn eggs than for White Rock eggs, which in turn was significantly greater than for turkey eggs. Egg weight was relatively more important in influencing rate of temperature change than was shell thickness. When egg weight and shell thickness were combined, they accounted for a greater proportion of total variation in the infertile eggs compared to the fertile eggs.
REFERENCES Kosin, I. L., 1956. Studies on pre-incubation warming of chicken and turkey eggs. Poultry Sci. 35: 1384-1392. Kramer, C. Y., 1956. Extension of multiple range tests to group means with unequal numbers of replications. Biometrics, 12: 307-310. Law, G. R., and I. L. Kosin, 1958. The rate of temperature change in turkey eggs subjected to short-term incubation and subsequent cooling. Poultry Sci. 37:316-321. Moreng, R. E., and R. L. Bryant, 19S6. The resistance of the chicken embryo to low temperature exposure. Poultry Sci. 35: 753-757. Snedecor, G. W., 1946. Statistical Methods. The Iowa State College Press, Ames. Iowa.
NTD NOTES NEWS AND from page 196) (Continued from sausages. He also recently developed new turkey and chicken patties and turkey and chicken meat loaves, increasing the variety of ways that poultry products could be used on the dinner table. In other research, he has pioneered in studies on response of turkeys to artificial illumination, and range management emphasizing low protein intake and grass-eating habits of turkeys. He also has studied factors affecting the growth and methods of marketing turkeys, and conducted frozen food
studies involving chickens and turkeys. A native of Morrisville, Pennsylvania, Margolf received the Ralston Purina Resident Teaching Award, administered by the Poultry Science Association, in 1954, and the Pennsylvania State University Award for excellence in teaching in 1959. He came to Penn State in 1922 as a Winter Course student, received employment on the poultry farm, and was named Superintendent of the plant a year later. Taking several courses each year
(Continued on page 254)
Downloaded from http://ps.oxfordjournals.org/ at University of South Dakota and School of Medicine on May 7, 2015
Where shell thickness and egg weight were combined, they accounted for a greater percentage of the total variation in the infertile eggs than in the fertile eggs. This is probably a further demonstration of the influence of the metabolizing embryo. If shell color had been a significant factor influencing the rate of warming of these eggs, then it would be expected that the brown shelled eggs (White Rock and turkey) should have had the higher incremental change and higher asymptotic temperatures since this color would absorb heat more readily than the white shell of the White Leghorn eggs. However, as has been noted, White Leghorn eggs had a greater rate of temperature increase and a higher asymptotic temperature than did the two brown shelled stocks. Egg weight was a factor in the rate of warming of infertile eggs, i.e. the greater the mass, the slower the warming, as evidenced by the higher correlation coefficients. This effect was apparently offset by the heat produced by the developing embryo because the correlation coefficients were lower and not significant in fertile eggs.