The Relationship Between Embryonic and Postnatal Growth in Japanese Quail

THE RELATIONSHIP BETWEEN EMBRYONIC AND POSTNATAL GROWTH IN JAPANESE QUAIL M A I E FOUAD M. ALI AND EDWARD F. GODFREY1 Department of Poultry Science, University of Maryland, College Park, Maryland 20742 (Received for publication December 1, 1969)

For many years, geneticists and physiologists have been interested in possible genetic and/or phenotypic correlations between day-old chick or embryo parameters and subsequent growth. Attempts have been made to correlate the small variations in individual egg weight/chick weight ratios with body weight ages after hatching (Godfrey and Jaap, 1952) but the slight correlations noted were without any significance. Other efforts, such as those of McNally and Byerly (1936), Byerly et al. (1938), Coleman et al. (1964) have been directed towards a study of the line or breed differences in the number of somites during early stages of incubation. Significant differences have been noted, but no correlations with postnatal growth have been observed. Since most of these studies involved non-pedigreed individuals, and since Zervas and Collins (1965) reported some significant sire and line differences in weight of chicken embryos at 14 days of incubation, a study was initiated in an effort to determine whether family differences in embryo weight existed in a line of Coturnix coturnix japonica, and whether these differences could be related to postnatal growth.

TABLE 1.—Rank-order correlations between embryonic wet weight at 12 days of incubation and postnatal weight in Japanese quail Chick age (weeks)

7s*

0 1 2 3 4 5 6

0.109 0.016 0.268 0.300 0.275 0.320 0.233

* Spearman's rank order correlation coefficient.

standard conditions, half of the pedigreed, fertile eggs of each dam were removed from the incubator, and the embryos excised and weighed according to the method outlined by Zervas and Collins (1965). The remaining half of the eggs of each dam family (and hence each sire family) were pedigree hatched, banded, and raised under the usual conditions of management in the Maryland laboratory [see El-Ibiary et al. (1966) for details]. After hatching, the quail chicks were weighed each week, and weights recorded to the nearest tenth of a gram. A total of 636 embryos and chicks were used in the study. RESULTS AND DISCUSSION

PROCEDURE

The Maryland C line of Japanese quail (randombred controls) was used in this study, and the investigation involved a total of 24 sire families and 120 dam families. After 12 days of incubation under 1

Scientific Article No. A-1S68. Contribution No. 4280 of the Maryland Agricultural Experiment Station, Department of Poultry Science.

Spearmen's rank order correlations (Steel and Torrie, 1960) were computed for 12 day embryo weight and postnatal body weight up to six weeks of age. The results (Table 1) show that there is no significant correlations between the weight of sire or dam families at 12 days of incubation and weight at any age to six weeks. Hence families could not be ge-

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RESEARCH NOTES

netically evaluated for postnatal growth on the basis of 12 day embryo weight, at least in this population of Japanese quail. Correlation coefficients between embryo wet weight and postnatal growth (Table 2) also indicate that there is no relationship. From these results, it would appear that differences between embryos in weight are largely due to environmental differences within the egg, and that embryonic and post-natal growth should be considered as two separate stages of the overall growth pattern of the organism after fertilization occurs and development begins. REFERENCES Byerly, T. C , W. G. Halsel and J. P. Quinn, 1938. Growth in weight and cell number. Genetic effects in the chick embryo and chick. J. Exp. Zool. 78: 185-203. Coleman, J. W., H. S. Siegel and P. B. Siegel, 1964. Embryonic development in two lines of White Rocks. Poultry Sci. 43: 453-458. El-Ibiary, H. M., E. F. Godfrey and C. S. Shaffner, 1966. Correlations between growth and repro-

TABLE 2.—Correlation, coefficients (y) between embryo wet weight at 12 days of incubation and postnatal weight in Japanese quail Chick age (weeks)

-y

0 1 2 3 4 5 6

0.188 0.122 0.330 0.281 0.220 0.266 0.296

ductive traits in the Japanese quail. Poultry Sci. 45: 463-469. Godfrey, E. F., and R. G. Jaap, 1952. Evidence of breed and sex differences in the weight of chicks hatched from eggs of similar weights. Poultry Sci. 31: 1108-1109. McNally, E. H., and T. C. Byerly, 1936. Variation in the development of embryos of hen's eggs. Poultry Sci. 15:280-283. Steel, R. G. D., and J. H. Torrie, 1960. Principles and Procedures of Statistics. McGraw Hill Book Company, Inc., New York, N.Y. Zervas, N. P., and W. M. Collins, 1965. Genetic variation in 14-day chick embryo weight. Poultry Sci. 44: 631-636.

EFFECTS OF MASSIVE ORAL DOSAGES OF RABON* ON HENS C. P. YADAVA1, F. R. SHAW2 AND D. L. ANDERSON3 (Received for publication December 4, 1969)

In order to control ectoparasites on fly larvae breeding in poultry manure a number of insecticides have been used. Residual sprays have been commonly applied but more recent investigations have 1 Dept. of Entomology, University Udaipur, jobner, Raj., India. 2 Dept. of Entomology, University of Massachusetts, Amherst, Massachusetts 01002. 3 Dept. Veterinary and Animal Science, University of Massachusetts, Amherst, Massachusetts 01002. * 2-Chloro-l-(2,4,5-trichlorophenyl) vinyl dimethyl phosphate.

suggested the feasibility of including the insecticide in food or water (Dorough and Arthur, 1961; Eversole et al, 1965; Sherman and Komatsu, 1963; Sherman and Ross, 1961; Sherman et al., 1967; and Loomis et al., 1968). Rabon, formerly known as Gardona (Shell SD-8447) is a new insecticide having low mammalian toxicity, but a high toxicity to ectoparasites of animals and fly larvae breeding in animal manure. Since detailed information on the effects of this insecticide on hens was not avail-