Time of Emergence of Turkey Embryos

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RESEARCH NOTES

and calcium metabolism. Proc. West Virginia Acad. Sci. 35: 51-4. Hogan, A. G., W. O. Regan and W. B. House, 1950. Calcium phosphate deposits in guinea pigs and the phosphorus content of the diet. J. Nutr. 41: 203-13. Huggins, C. B., 1931. The formation of bone under the influence of epithelium of the urinary tract. A.M.A. Arch. Surg. 22: 377-408. Huggins, C. B., and J. F. Sammett, 1933. Function of the gall bladder epithelium as an osteogenic

stimulus and the physiological differentiation of connective tissue. J. Expt'l Med. 58: 393-99. Levander, G., 1938. A study of bone regeneration. Surg. Gynecol. Obstet. 67: 705-14. Wulgen, R., and A. M. Bahrs, 1941. Effects of milk diets on guinea pigs. Am. J. Physiol. Proc. 133: 500. Migicovsky, B. B., and A. M. Nielson, 1952. Bone implantation as a means of studying vitamin D action. Science, 115 (2987): 354-55.

F.

L.

CHERMS

Department of Poultry Science, University of Wisconsin, Madison, Wisconsin 53706 (Received for publication November 5, 1968)

Abbott and Craig (1960) reported that turkey embryos exhibit greater variation in the amount of time from pipping to emergence than either pheasants or quail. Those who are concerned with the hatching of turkey eggs are quite aware of the wide differences in hatch time of this species. This is a report of a study designed to examine more closely emergence time in turkey embryos and its relation to subsequent poult performance. Eggs from a trapnested Broad Breasted Bronze flock were held for 15 days at 12.5°C. (55°F.) prior to setting. They were placed in the incubator so that the proper incubator temperature was reached at 4 p.m. on the day set. Beginning at 624 hours from this point, and at 8-hour intervals thereafter up to 680 hours, the incubator was opened for appropriate observations on emergence from the egg. A total of 4 hatches were examPublished with the approval of the Director of the Wisconsin Agricultural Experiment Station, College of Agricultural and Life Sciences, Madison.

ined from January to May with various observations made in each hatch. The frequency distribution of emergence time for eggs of different ages when set may be seen in Table 1. The average times of emergence for eggs 2-15 days, 2 8 days, and 9-15 days of age when set were 650, 646, and 653 hours respectively. Not only did the older eggs emerge later, but there was also greater variation in this group. Differences in body weight at 672 hours (Table 1) were significantly related to emergence time ("r" = .981), however at one week of age, this relationship was not apparent in the birds that survived to this age. These differences probably were the results of degree of yolk absorption. Body weight at the other ages also was not related to emergence time. Poults that emerged at each extreme from the mean emergence time exhibited the highest mortality during the first two weeks of life. When these data are combined, the poults in the 624, 632, 664, and 672 classes had a 9.8% mortality while those in the 640, 648, and 656 classes had

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RESEARCH NOTES

TABLE 1.—Frequency distribution, body weigM for combined sexes at several ages, and mortality to two weeks of age for poults with emergence times of 624 to 680 hours of incubation Body weight (gm.) Time of emergence (hours)

Frequency {%) 2-15 day 2-8 day 9--15 day 4.0 9.1 33.3 30.5 15.7 4.8 1.6 1.1

1.5 5.5 16.1 28.6 22.9 14.5 7.7 3.1

55.3 57.4 57.6 57.3 58.4 56.7 55.9 54.3

2,506

1,060

937

1,308

4

3

2

3

TABLE 2.—Sex ratio as related to time of emergence Time of

Female

Male

(hours)

No.

%

No.

%

624 632 640 648 656 664 672

29 63 243 304 113 64 33

70.7 52.9 53.6 49.4 42.6 39.5 57.9

12 56 210 311 152 98 24

29.3 47.1 46.4 50.6 57.4 60.5 42.1

a 4.7% mortality. This may be a partial reason for so-called "starve-out" problem in turkeys. It has been reported that in chickens, females emerge 1.2 hours earlier than males (Zawalsky, 1962). The data in Table 2 indicate a similar condition in tur-

Mortality (%) to 2 weeks 672 hours 1 week

13 week

49.2 50.5 52.2 53.8 54.7 55.4 55.9

83.1 84.8 82.1 82.1 80.9 84.3 81.2

•

•—

—

—

2,456

1,533

1,025

2,659

4

4

1

4

—

3,541 3,723 3,723 3,768 3,814 3,768 3,314

13.3 7.7 3.9 4.9 5.2 9.3 11.5

keys where there were more females prior to 648 hours and more males after this time. The average emergence time of 646.9 hours for females was 1.7 hours earlier than that for males. Observations were also made to determine if either egg weight or shell thickness were related to emergence time. However, no differences could be attributed to either trait when tested with correlation procedures. REFERENECS Abbott, U. K., and R. M. Craig, 1960. Observations on hatching time in three avian species. Poultry Sci. 39: 827-830. Zawalsky, M., 1962. The effect of sex, egg weight, and preincubation storage on hatching time and chick weight. Poultry Sci. 41:1697.

NEWS AND NOTES {Continued from page 330) suiting from the meeting of the Technical Advisory Committee is being sent to Veterinary College Deans, Experiment Station Directors, Poultry Science Departments, poultry trade publications and various publications in the field of veterinary medicine. Members of the Technical Advisory Committee are:

Dr. D. E. Davis, Caroline Foods, Federalsburg, Maryland 21632-Chairman. Dr. B. R. Burmester, Regional Poultry Research Laboratory, U. S. Department of Agriculture, 3606 E Mt. Hope Road, East Lansing, Michigan 48823. Dr. Morris S. Cover, Ralston Purina Co., Checkerboard Square, St. Louis, Missouri 63199.

{Continued on page 355)

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2.9 8.0 23.4 27.5 19.5 10.1 5.6 3.0

624 632 640 648 656 664 672 680 Number of Poults Number of Hatches

Time of emergence