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TABLE 10 RISON OF Low, MEDIUM AND High PRODUCING HENS ON THE BASIS OF MONTILY DISTRIBUTION OF EGG PRODUC
A-ACTUAL DISTRIBUTION OF Ecos
Class Frequency Nov. Dec. Jan.
164 303 383
109 1112 1816 1955
Feb. Mar. Apr.
May 549 1089 1184 1132 8875 12557 12652 12629
1969 2397 2429 2496 11393 160-13 16265 16257
June July Aug. Sept. Oct.
Total 918 683
559 293 7974 11328 10311 10565 9897 6938 110912
2399 2213 2220 2196 1842 25044 14675 13207 13472 12652 9073 143930
Winter Spring Summer Autumn Total
21.67 34.12 29.04 15.17 100.00 High 109 27.36 29.24 27.28 16.12 100.00
which have not yet begun to lay; in the months after May this group although small is made up in large part of birds in which reproduction has taken place and then ceased until the next spring. The other group is characterized by a mode (as determined by observation only) of from 16 to 22 or 23 eggs. These are the good layers, and they are least numerous of course in the winter and fall months when the lower group is largest.
TABLE 11 PERCENTAGE OF FLOCK LAYING ZERO EGGS IN THE SEPARATE
GENERAL CHANGES IN THE SEASONAL DISTRIBUTION
OF EGG PRODUCTION In this section an answer is to be sought to the questions; Are there any indications of a general tendency on the part of the Wyandottes submitted during the nine years to lay a larger or smaller proportion of their eggs in any particular month or season? Has the seasonal distribution of egg production remained the same throughout the contests or has it changed and if so, how? Ever since fowls have been bred particularly for egg production, breeders have tried to change the normal seasonal distribution by increasing fecundity in the months when eggs are scarce and consequently high in price. Various systems of feeding and housing, the equalization of the length of days throughout the year by means of artificial lighting and the selection of high winter layers as breeders are all efforts in this direction. The last named effort together with practices concerned with hatching time and selection of entries about to lay are probably the only factors which could have any affect on seasonal changes in these contest birds, since lights have not been used in any of the contests, and feeding and housing have been fairly uniform from year to year. How far then have these efforts succeeded?
For a study of these questions the total egg production has been tabulated by months and years and is presented in Tables 5 and 6 in which the number of eggs laid in each month by all the Wyandottes in the nine years is given above and the percentage of the total eggs which were laid in each month is given below. The figures for any month through the nine years are not comparable in Table 5, because of the different numbers of birds and the different totals of eggs laid. When reduced to a percentage basis, however, (Table 6) each month may be compared with the corresponding month in the other years. It must be understood that these tables give only the gross egg production by months. They do, however, show the general character and changes from year to year of seasonal intensity in egg production of a whole flock. Changes are evident in the monthly production from year to year. The percentage of the total eggs laid in December and January appear to have increased from 1911 to 1919. The percentage laid in February has remained stationary or declined slightly. March intensity has certainly declined, April has probably declined a little, May has perhaps held its own. From gross examination it
appear that there has been a slight shifting of intensity from the spring and summer and possibly from the fall months toward the winter months. If this can be established,
mean that in general Wyandottes of the sort entered in the contest are becoming better winter egg producers, an important consideration for the commercial producer, since in this season high prices prevail. Birds which lay a larger percentage of their eggs at this time are of course more profitable than those which concentrate their production in seasons of low prices.
We have, therefore, inquired further into this matter and arranged the data of Table 6 by seasons in Table 12. The percentage of eggs laid in the winter is simply the sum of the percentages laid in the months of November, December, January, and February, etc. Now the indications of Table õa toward increased winter intensity are very plainly confirmed. The percentage of winter eggs increases steadily from 1911 to 1919, with only one pause in the increase in 1916. These changes are shown graphically in Fig. 8 and the straight line most nearly describing the advance has been fitted. The theoretical origin of this line is 17.496 per cent in 1910 (one year previous to the actual first year of the data) and the winter percentage increases on an average by .93 per cent each year, reaching a theoretical value of 25.866 per cent in 1919. The equation of the line is hence y=17.496+.930x (Table 13). The absolute amount of this advance is considerable, a gross change in the nine years of 8.37 per cent. The most remarkable aspect of this advance is that it is so persistent, seemingly unaffected by the low general production of 1913 and 1918 or by the long hard winter of 1919-19:20. This tendency to increase is just as evident when data for the years 1913 and 1918 are omitted as