74 SUMMER AUTUMN ANALYSIS OF EGG PRODUCTION IN SEPARATE MONTHS GENERAL CHANGES IN SEASONAL DISTRIBUTION OF EGG Fig. 1. Variation in annual egg production; nine year's records. Fig. 2. Changes in mean annual egg production from 1911 to 1919. Fig. 3. Annual changes in the coefficient of variation from 1911 to 1919. Fig. 4. Annual changes in the percentage of pullets laying 104 eggs per year and less. Fig. 5. Annual changes in the percentage of pullets laying 210 eggs per year and more. Fig. 6 Monthly variation in mean egg production, nine years records. Fig. 7. Comparison of low and high producing pullets on the basis of monthly distribution of egg production. Fig. 8. Changes in the proportion of winter to annual egg production 1911-1919. LIST OF TABLES Table 1. Frequency distribution of all Wyandotte pullets on basis of annual egg production. Table 2. Summary of variation constants for annual egg production. Table 3. Constants of variation in first year egg production of Wyandottes at other places. Table 4. Relative frequency of low and high producers in the nine contests. Table 5. Distribution of total egg production by months and years. Table 6. Percentage distribution of total egg production by months and years. Table 7. Table 8. Summary of monthly variation constants. Monthly variation in the efficiency of egg production, nine year mean. Table 9. Monthly distribution of total egg production by fecundity classes, nine year's records. Table 10. Comparison of low, medium, and high producing pullets on the basis of monthly distribution of egg production. Table 11. Percentage of flock laying zero eggs in the separate months. Table 12. The seasonal distribution of egg production by years. Table 13. General trend of seasonal distribution of egg production, 1911-1920. Appendix Table I. Raw data for annual egg production of Wyandotte pullets. Appendix Table II. Frequency distribution of egg production in each month of the pullet year. Appendix Table III. Table for estimating significance of differences between annual means. This is the first of a series of reports on egg production in the four chief breeds of poultry raised and kept in this country for egg production. The material studied consists of the individual trap nest records of all pullets completing a normal year's laying in the first nine international egg laying competitions held at Storrs Agricultural Experiment Station, Connecticut from November 1, 1911 to October 29, 1920. This and other bulletins to be published in this series will, therefore, constitute a summary of egg production in the nine contests, and will present the conclusions drawn from a detailed study of the records. The main facts established from a study of 903 Wyandotte records are: 1. Average egg production for the pullet year-159.3 eggs, 2. Average winter egg production (Nov. 1 to Feb. 28) 35.8 eggs. 3. Average spring egg production 6. Highest individual year's record-308 eggs. 8. Variability in individual egg production has remained high throughout the nine contests. (The coefficient of variation for the nine years was 28 per cent). 9. Average egg production has increased by about 7 eggs from 1911 to 1920. 10. The percentage of annual production occurring in the winter months has increased on the average by about per cent. 8 11. The relative intensities of spring, summer, and autumn production have declined by a similar amount. 12. The percentage of high producers (birds laying 210 eggs and over) has increased slightly in the nine years. 13. The. percentage of low producers (birds laying 104 eggs and under) has decreased slightly in the nine years. 14. These tendencies toward improvement in the breed are more marked if two years of abnormal conditions and low records (1913 and 1918) are omitted. 15. There is no evidence in the records of separate seasonal cycles of egg production in this breed. 16. The improvement of the Wyandotte breed as egg producers has been more rapid in England and the British Colonies and Dominions than in the United States. |