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The Effect of Temperature and Position in the Incubation of Turkey Eggs*
T h e Effect of Temperature and Position in the Incubation of Turkey Eggs* J. HOLMES MARTIN AND W. M. INSKO, JR. Kentucky Experiment Station, Lexington (Presented at Annual Meeting August 7-10, 1934)
T
* The investigation reported in this paper constitutes a portion of a project of the Kentucky Agricultural Experiment Station and is published by permission of the Director.
proved successful mentions that "the machines were run at 103 or slightly under," obviously referring to other than forceddraft incubators. He fails to mention the position of the thermometer. The Oklahoma Station (1933) recommends 9 9 ^ ° to 100°F. for the forced-draft incubators and "102 to 103°F. at the top level of the eggs" for the sectional type. Mussehl and Ackerson (1934) found that the rate of air movement and humidity apparently exerted a greater influence on hatchability during the last four days than during the first twenty-four days of incubation. They secured higher hatchability when the eggs were transferred from a cabinet type incubator to a gravity-ventilated machine on the twenty-fourth day of incubation. PROCEDURE A large share of the eggs used in this experiment came from the flock of R. E. Nute, Valley Station, Kentucky, and were shipped approximately 100 miles by express to the Station laboratories. All eggs were gathered daily and placed, small end down, in chicken egg cases equipped with duck-egg fillers (200 eggs per case). Each day's gathering was kept separate so that the eggs were divided equally among the four lots with respect to age of egg. While accumulating the week's lay, the eggs were held in a wellventilated cellar. No eggs were more than eight nor less than two days old when set. A few of the eggs came from the Station flock at the Robinson Substation, Quick-
[152]
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HE same temperature that has given best results for chicken eggs is usually recommended for the incubation of turkey eggs. With the forced-draft type of incubator there is no necessity to move the thermometer, but in the sectional type it is usually suggested that the bulb be raised to the level of the top of the turkey eggs when recommendations for chicken egg temperatures are followed. Others recommend following the manufacturer's directions and do not give any specific temperatures. Graybill (1921) suggests that the temperature be "maintained as nearly as possible at 103°F." but does not state the position of the thermometer. The Kansas Station (1932) recommends a temperature of 99°F. in a forced-draft machine and 100°, 101°, 102°, and 103°F. for the first, second, third, and fourth weeks, respectively, for the sectional type, the bulb of the thermometer resting on a level with the top of the eggs. Mussehl (1932) in speaking of sectional incubators says that "best results are obtained when the temperature at the top of the egg is maintained at from 102° to 103°F., which insures an average of the temperatures at the bottom of the eggs of about 100°F., or slightly below." His recommendation for the cabinet (forced draft) incubators is 99^4° to 100° F. Burr (1932) in reporting practical trials in England that
MAY,
1935.
TABLE 1.—Effect
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XIV, No. 3
153
of differences in temperature on hatchability of turkey eggs (Jamesway incubator)
Mean Temperature 1st 2nd 3rd 4th week week week week 1—100.5-101.4-102.6-103.0° 2—101.0-101.9-102.9-103.4° 3—101.3-102.0-102.7-103.1° 4—100.9-101.1-101.3-101.4°
F. F. F. F.
Total number eggs set
Percentage fertile
Number good poults*
Percentage hatchability
740 743 632 576
86.6 88.7 86.7 85.2
496 453 416 346
77.4 68.7 75.9 70.5
2691
Total
* Weaklings or spraddle-leg poults not counted as good poults and excluded from fourth-week embryo mortality (see Table 2).
Ground yellow corn Bran Middlings Ground oats Gluten feed Meat scrap Dried skimmilk Alfalfa leaf meal Bone meal Salt Cod liver oil concentrate
200 100 100 100 100 100 50 50 16 A1/* 1
pounds pounds pounds pounds pounds pounds pounds pounds pounds pounds quart
The Robinson flock was self-fed shelled corn throughout the breeding season and also received in open hoppers a dry mash of mixed wheat feed (shipstuff) 300 lbs., ground yellow corn 100 lbs., meat scrap 100 lbs. and salt 5 lbs. In one series of experiments 2,691 eggs from Bronze turkeys were divided among four lots incubated at the following temperatures: Lot Lot Lot Lot Lot
1— l— 2— 3— 4— 4—
1l 0 0 - ^ ° 1101° 11 0 1 - ^ ° 1101°
101-^2° 102° 102° 101°
0
102-1^ 103° 102-^ 0 101°
103°F. 104°F. 103°F. 101°F.
While these are temperatures at which it was attempted to control each compartment the first, second, third, and fourth week,
respectively, the actual average temperature each week (of four readings daily) is given in Table 1. A sectional incubator (Jamesway) depending entirely on gravity for air circulation was used. Thermometers which had been tested for accuracy were placed in the same relative position, one in each compartment, so that the bottom of the bulb was 1% inches above the egg tray. Previous measurements had shown this to be the average height (short axis) of the turkey eggs when resting on their sides. It may be noted from Table 1 that the fertility was high and uniform in all four groups (85.2 percent to 88.7 percent). This proved true of both flocks. A study of the hatchability of the four lots (Table 1) indicates that 101°F. throughout the hatch hardly supplies sufficient heat for the best results (70.5 percent hatchability) whereas a mean temperature of 103.4°F. the last week supplies more than the optimum amount of heat (68.7 percent hatchability). Obviously the optimum temperature for incubating turkey eggs in a sectional type incubator, bulb on the level with the top of the eggs, lies between 100^° and 103°F., as the best hatches were in lots 1 and 3. However, whether there is any advantage in starting the hatch as low as 1 0 0 ^ ° or 101° F. remains for further experiments to determine.
Downloaded from http://ps.oxfordjournals.org/ at Kainan University on May 10, 2015
sand, Kentucky, and were shipped by express approximately 100 miles, to the incubation laboratories. The breeding flock of Mr. Nute was fed cracked corn and wheat each evening and a mash of the following formula was available in self-feeders at all times throughout the year:
154
POULTRY
SCIENCE
TABLE 2.—Effect of differences in temperature on distribution of turkey embryo mortality (Jamesivay incubato Percentage mortality
Number fertile eggs*
1st week
2nd week
3d week
4th week
Total
1 2 3 4
641 659 548 491
5.0 6.4 4.2 4.3
1.4 2.1 0.9 1.4
1.1 1.4 1.3 1.8
9.2 16.4 12.6 12.6
16.7 26.3 19.0 20.1
Total
2339
Lot
* Only the eggs that hatched good poults or failed to hatch and were broken and found to be fertile were included in this column (see footnote to Table 1).
chicken eggs on end, the egg trays being transferred on the eighteenth day to the nursery without the labor of candling. They have claimed not only a saving of labor, but an actual increase in hatch. In order to check the results of this method of hatching with turkey eggs, eight trays of turkey eggs were hatched large end up in a forced-draft machine (Smith), the trays being left full (113 to 116 eggs per tray) as set and no candling done. An equal number of comparable trays was candled on the twentyfifth day, the remaining eggs hatching on their sides. The first group gave 79.2 percent hatchability while the second group gave 77.9 percent which is not a significant difference (see Table 3). In the first hatch of this series, it was noted that only with great difficulty could the poults emerge from the shells when the eggs were on end, several poults dying in the struggle, from exhaustion. Hence, it was decided to "skim"
TABLE 3.—Hatchability of turkey eggs incubated in a forced-draft incubator {Smith)*
Treatment
Candled Not candled Undivided (90-96 per tray) Divided (45-48 per tray) Total
Total eggs set
Percentage fertile
1st wk.
2nd wk.
3d wk.
966 906 641 649
84.7 86.6 84.2 84.9
5.4 3.7 5.2 4.4
1.0 0.5 1.1 0.5
1.6 1.4 0.9 1.3
Percentage mortality
Percentage Number poults hatchability 4th wk. 12.6 13.5 9.1 8.9
637 621 427 431
77.9 79.2 79.1 78.2
3162
* Operated at temperature of 99°F., relative humidity 61 percent until twenty-fifth day of incubation and 70 percent thereafter until hatch completed.
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That a mean temperature of 103.4°F. the fourth week of incubation is detrimental to the developing embryos is clearly shown in Table 2. It should be noted that the highest weekly embryo mortality was in lot 2 (16.4 percent of fertile eggs) the fourth week. Since this lot showed no higher mortality the third week than lot 3 which was run only slightly lower that week, obviously the decided increase in embryo mortality the last week was due to heat beyond the optimum incubation level. The relative humidity calculated daily for one section of the sectional (Jamesway) incubator varied between 58 and 65 percent. The machine was located in a basement with a concrete floor and the water jacket was heated by natural gas. The eggs were turned five times daily. Hatching on End Certain manufacturers of cabinet incubators have recently recommended hatching
1935.
155
both groups as the hatch progressed, removing both the loose ends of shells and the newly hatched poults every few hours. On account of the necessity of frequent removal of poults from the trays hatching with the eggs on end, this additional labor more than offset the labor of candling on the twenty-fifth day, when the operator had more time at his disposal. Hence the hatching of uncandled eggs large end up (trays full) is not recommended for turkey eggs. The weekly distribution of embryo mortality as given in Table 3, fails to show any difference between these two lots the last week, and as they were incubated and handled under identical conditions up to the twenty-fifth day, the slight difference the first week is due to biological variation.
these two lots in any one of the four weeks; the incubation conditions being identical, however, up to the twenty-fifth day.
VOL.
Additional Hatching Space In another series, the eggs remaining on the trays after candling (95 to 100 per tray of Smith incubator) were compared, with those of comparable origin, reduced to half the number per tray (45 to 48 eggs) from the twenty-fifth to the twenty-eighth days; all of the eggs resting on their sides at hatching. Table 3 shows that the additional room and ventilation had no effect on the hatch. The divided trays gave 78.2 percent hatchability and the undivided trays 79.1 percent, not a significant difference. Obviously, the ventilation provided by a forced-draft incubator (Smith) supplied sufficient oxygen for the embryos contained on a tray comfortably filled with fertile eggs resting on their sides. Also, the additional room for the newly hatched poults gained by cutting the number of eggs per tray in half, was of no value. The distribution of the embryo mortality by weeks, as shown in Table 3 failed to show any significant difference between
SUMMARY In a sectional incubator, the highest hatchability with turkey eggs was secured when the average temperature was 100.5°, 101.4°, 102.6°, 103°F. the first, second, third, and fourth weeks, respectively (bulb of thermometer level with top of eggs). A temperature of 101° F. throughout the hatch did not give as high hatchability as the group mentioned above. A temperature above 103°F. the fourth week of incubation increased the embryo mortality that week. Hatching turkey eggs large end up in a forced-draft incubator (trays full) without candling did not increase the hatch and necessitated extra labor at hatching time to avoid loss of poults. If the hatching trays of a forced-draft incubator are comfortably filled with eggs resting on their sides, there is nothing to be gained by reducing the number of eggs per tray to half and thereby allowing more room and air for the newly-hatched poults. REFERENCES
Burr, Edmond, 1932. The management of turkeys. Harper Adams Util. Poul. Jour. 14 :S44-SS2. Graybill, H. W., 1921. The artificial incubation and brooding of turkeys. N. J. Exp. Sta. Bui. 347 :111. Kansas Agr. Exp. Sta., Jan., 1932. The artificial hatching and brooding of turkeys. Mimeo. Leaf. C. Form 10:1-3. Mussehl, F. E., 1932. Hatching turkey eggs. Nebr. Exp. Sta. Bui. 269:1-7. Mussehl, F. E., and C. W. Ackerson, 1934. Some observations on humidity and weight loss in the incubation of turkey eggs. Nebr. Exp. Sta. Research Bui. 74. Oklahoma Agr. Exp. Sta., 1933. Incubating turkey eggs. Mimeo. Leaf. No number.
Downloaded from http://ps.oxfordjournals.org/ at Kainan University on May 10, 2015
XIV, No. 3
MAY,
T
* The investigation reported in this paper constitutes a portion of a project of the Kentucky Agricultural Experiment Station and is published by permission of the Director.
proved successful mentions that "the machines were run at 103 or slightly under," obviously referring to other than forceddraft incubators. He fails to mention the position of the thermometer. The Oklahoma Station (1933) recommends 9 9 ^ ° to 100°F. for the forced-draft incubators and "102 to 103°F. at the top level of the eggs" for the sectional type. Mussehl and Ackerson (1934) found that the rate of air movement and humidity apparently exerted a greater influence on hatchability during the last four days than during the first twenty-four days of incubation. They secured higher hatchability when the eggs were transferred from a cabinet type incubator to a gravity-ventilated machine on the twenty-fourth day of incubation. PROCEDURE A large share of the eggs used in this experiment came from the flock of R. E. Nute, Valley Station, Kentucky, and were shipped approximately 100 miles by express to the Station laboratories. All eggs were gathered daily and placed, small end down, in chicken egg cases equipped with duck-egg fillers (200 eggs per case). Each day's gathering was kept separate so that the eggs were divided equally among the four lots with respect to age of egg. While accumulating the week's lay, the eggs were held in a wellventilated cellar. No eggs were more than eight nor less than two days old when set. A few of the eggs came from the Station flock at the Robinson Substation, Quick-
[152]
Downloaded from http://ps.oxfordjournals.org/ at Kainan University on May 10, 2015
HE same temperature that has given best results for chicken eggs is usually recommended for the incubation of turkey eggs. With the forced-draft type of incubator there is no necessity to move the thermometer, but in the sectional type it is usually suggested that the bulb be raised to the level of the top of the turkey eggs when recommendations for chicken egg temperatures are followed. Others recommend following the manufacturer's directions and do not give any specific temperatures. Graybill (1921) suggests that the temperature be "maintained as nearly as possible at 103°F." but does not state the position of the thermometer. The Kansas Station (1932) recommends a temperature of 99°F. in a forced-draft machine and 100°, 101°, 102°, and 103°F. for the first, second, third, and fourth weeks, respectively, for the sectional type, the bulb of the thermometer resting on a level with the top of the eggs. Mussehl (1932) in speaking of sectional incubators says that "best results are obtained when the temperature at the top of the egg is maintained at from 102° to 103°F., which insures an average of the temperatures at the bottom of the eggs of about 100°F., or slightly below." His recommendation for the cabinet (forced draft) incubators is 99^4° to 100° F. Burr (1932) in reporting practical trials in England that
MAY,
1935.
TABLE 1.—Effect
VOL.
XIV, No. 3
153
of differences in temperature on hatchability of turkey eggs (Jamesway incubator)
Mean Temperature 1st 2nd 3rd 4th week week week week 1—100.5-101.4-102.6-103.0° 2—101.0-101.9-102.9-103.4° 3—101.3-102.0-102.7-103.1° 4—100.9-101.1-101.3-101.4°
F. F. F. F.
Total number eggs set
Percentage fertile
Number good poults*
Percentage hatchability
740 743 632 576
86.6 88.7 86.7 85.2
496 453 416 346
77.4 68.7 75.9 70.5
2691
Total
* Weaklings or spraddle-leg poults not counted as good poults and excluded from fourth-week embryo mortality (see Table 2).
Ground yellow corn Bran Middlings Ground oats Gluten feed Meat scrap Dried skimmilk Alfalfa leaf meal Bone meal Salt Cod liver oil concentrate
200 100 100 100 100 100 50 50 16 A1/* 1
pounds pounds pounds pounds pounds pounds pounds pounds pounds pounds quart
The Robinson flock was self-fed shelled corn throughout the breeding season and also received in open hoppers a dry mash of mixed wheat feed (shipstuff) 300 lbs., ground yellow corn 100 lbs., meat scrap 100 lbs. and salt 5 lbs. In one series of experiments 2,691 eggs from Bronze turkeys were divided among four lots incubated at the following temperatures: Lot Lot Lot Lot Lot
1— l— 2— 3— 4— 4—
1l 0 0 - ^ ° 1101° 11 0 1 - ^ ° 1101°
101-^2° 102° 102° 101°
0
102-1^ 103° 102-^ 0 101°
103°F. 104°F. 103°F. 101°F.
While these are temperatures at which it was attempted to control each compartment the first, second, third, and fourth week,
respectively, the actual average temperature each week (of four readings daily) is given in Table 1. A sectional incubator (Jamesway) depending entirely on gravity for air circulation was used. Thermometers which had been tested for accuracy were placed in the same relative position, one in each compartment, so that the bottom of the bulb was 1% inches above the egg tray. Previous measurements had shown this to be the average height (short axis) of the turkey eggs when resting on their sides. It may be noted from Table 1 that the fertility was high and uniform in all four groups (85.2 percent to 88.7 percent). This proved true of both flocks. A study of the hatchability of the four lots (Table 1) indicates that 101°F. throughout the hatch hardly supplies sufficient heat for the best results (70.5 percent hatchability) whereas a mean temperature of 103.4°F. the last week supplies more than the optimum amount of heat (68.7 percent hatchability). Obviously the optimum temperature for incubating turkey eggs in a sectional type incubator, bulb on the level with the top of the eggs, lies between 100^° and 103°F., as the best hatches were in lots 1 and 3. However, whether there is any advantage in starting the hatch as low as 1 0 0 ^ ° or 101° F. remains for further experiments to determine.
Downloaded from http://ps.oxfordjournals.org/ at Kainan University on May 10, 2015
sand, Kentucky, and were shipped by express approximately 100 miles, to the incubation laboratories. The breeding flock of Mr. Nute was fed cracked corn and wheat each evening and a mash of the following formula was available in self-feeders at all times throughout the year:
154
POULTRY
SCIENCE
TABLE 2.—Effect of differences in temperature on distribution of turkey embryo mortality (Jamesivay incubato Percentage mortality
Number fertile eggs*
1st week
2nd week
3d week
4th week
Total
1 2 3 4
641 659 548 491
5.0 6.4 4.2 4.3
1.4 2.1 0.9 1.4
1.1 1.4 1.3 1.8
9.2 16.4 12.6 12.6
16.7 26.3 19.0 20.1
Total
2339
Lot
* Only the eggs that hatched good poults or failed to hatch and were broken and found to be fertile were included in this column (see footnote to Table 1).
chicken eggs on end, the egg trays being transferred on the eighteenth day to the nursery without the labor of candling. They have claimed not only a saving of labor, but an actual increase in hatch. In order to check the results of this method of hatching with turkey eggs, eight trays of turkey eggs were hatched large end up in a forced-draft machine (Smith), the trays being left full (113 to 116 eggs per tray) as set and no candling done. An equal number of comparable trays was candled on the twentyfifth day, the remaining eggs hatching on their sides. The first group gave 79.2 percent hatchability while the second group gave 77.9 percent which is not a significant difference (see Table 3). In the first hatch of this series, it was noted that only with great difficulty could the poults emerge from the shells when the eggs were on end, several poults dying in the struggle, from exhaustion. Hence, it was decided to "skim"
TABLE 3.—Hatchability of turkey eggs incubated in a forced-draft incubator {Smith)*
Treatment
Candled Not candled Undivided (90-96 per tray) Divided (45-48 per tray) Total
Total eggs set
Percentage fertile
1st wk.
2nd wk.
3d wk.
966 906 641 649
84.7 86.6 84.2 84.9
5.4 3.7 5.2 4.4
1.0 0.5 1.1 0.5
1.6 1.4 0.9 1.3
Percentage mortality
Percentage Number poults hatchability 4th wk. 12.6 13.5 9.1 8.9
637 621 427 431
77.9 79.2 79.1 78.2
3162
* Operated at temperature of 99°F., relative humidity 61 percent until twenty-fifth day of incubation and 70 percent thereafter until hatch completed.
Downloaded from http://ps.oxfordjournals.org/ at Kainan University on May 10, 2015
That a mean temperature of 103.4°F. the fourth week of incubation is detrimental to the developing embryos is clearly shown in Table 2. It should be noted that the highest weekly embryo mortality was in lot 2 (16.4 percent of fertile eggs) the fourth week. Since this lot showed no higher mortality the third week than lot 3 which was run only slightly lower that week, obviously the decided increase in embryo mortality the last week was due to heat beyond the optimum incubation level. The relative humidity calculated daily for one section of the sectional (Jamesway) incubator varied between 58 and 65 percent. The machine was located in a basement with a concrete floor and the water jacket was heated by natural gas. The eggs were turned five times daily. Hatching on End Certain manufacturers of cabinet incubators have recently recommended hatching
1935.
155
both groups as the hatch progressed, removing both the loose ends of shells and the newly hatched poults every few hours. On account of the necessity of frequent removal of poults from the trays hatching with the eggs on end, this additional labor more than offset the labor of candling on the twenty-fifth day, when the operator had more time at his disposal. Hence the hatching of uncandled eggs large end up (trays full) is not recommended for turkey eggs. The weekly distribution of embryo mortality as given in Table 3, fails to show any difference between these two lots the last week, and as they were incubated and handled under identical conditions up to the twenty-fifth day, the slight difference the first week is due to biological variation.
these two lots in any one of the four weeks; the incubation conditions being identical, however, up to the twenty-fifth day.
VOL.
Additional Hatching Space In another series, the eggs remaining on the trays after candling (95 to 100 per tray of Smith incubator) were compared, with those of comparable origin, reduced to half the number per tray (45 to 48 eggs) from the twenty-fifth to the twenty-eighth days; all of the eggs resting on their sides at hatching. Table 3 shows that the additional room and ventilation had no effect on the hatch. The divided trays gave 78.2 percent hatchability and the undivided trays 79.1 percent, not a significant difference. Obviously, the ventilation provided by a forced-draft incubator (Smith) supplied sufficient oxygen for the embryos contained on a tray comfortably filled with fertile eggs resting on their sides. Also, the additional room for the newly hatched poults gained by cutting the number of eggs per tray in half, was of no value. The distribution of the embryo mortality by weeks, as shown in Table 3 failed to show any significant difference between
SUMMARY In a sectional incubator, the highest hatchability with turkey eggs was secured when the average temperature was 100.5°, 101.4°, 102.6°, 103°F. the first, second, third, and fourth weeks, respectively (bulb of thermometer level with top of eggs). A temperature of 101° F. throughout the hatch did not give as high hatchability as the group mentioned above. A temperature above 103°F. the fourth week of incubation increased the embryo mortality that week. Hatching turkey eggs large end up in a forced-draft incubator (trays full) without candling did not increase the hatch and necessitated extra labor at hatching time to avoid loss of poults. If the hatching trays of a forced-draft incubator are comfortably filled with eggs resting on their sides, there is nothing to be gained by reducing the number of eggs per tray to half and thereby allowing more room and air for the newly-hatched poults. REFERENCES
Burr, Edmond, 1932. The management of turkeys. Harper Adams Util. Poul. Jour. 14 :S44-SS2. Graybill, H. W., 1921. The artificial incubation and brooding of turkeys. N. J. Exp. Sta. Bui. 347 :111. Kansas Agr. Exp. Sta., Jan., 1932. The artificial hatching and brooding of turkeys. Mimeo. Leaf. C. Form 10:1-3. Mussehl, F. E., 1932. Hatching turkey eggs. Nebr. Exp. Sta. Bui. 269:1-7. Mussehl, F. E., and C. W. Ackerson, 1934. Some observations on humidity and weight loss in the incubation of turkey eggs. Nebr. Exp. Sta. Research Bui. 74. Oklahoma Agr. Exp. Sta., 1933. Incubating turkey eggs. Mimeo. Leaf. No number.
Downloaded from http://ps.oxfordjournals.org/ at Kainan University on May 10, 2015
XIV, No. 3
MAY,