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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 ar 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 would 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, it will 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.

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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 ba 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 1919-1920. This tendency to increase is just as evident when data for the years 1913 and 1918 are omitted as

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Fig. 8. Changes in the proportion of winter to annual egg production 1911-1919.

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shown by the equations in the right hand columns of Table 13. It signifies undoubtedly, that the efforts of the competing breeders to increase winter egg production in their fowls are meeting with some success. Improved methods of winter feeding have perhaps contributed toward the advance, although the management of the birds has changed but little, while the effects of other factors which tend to increase winter egg production such as lighting, heating, etc. are ruled out by their absence. A better knowledge of the proper time to hatch chicks in order to have them come into laying at the beginning of the contest has perhaps improved the general winter production. In the absence of hatching time data for the fowls submitted, this point cannot be investigated further. The results are, however, important enough to be considered more fully in a later section.

The figures given in Table 12 are independent of the absolute numbers of eggs involved, the total egg production being regarded in each year as 100. Therefore, any increase in the percentage of eggs laid in one season must be compensated for by a decrease in the percentage laid in one or more of the other seasons. If we examine the course of intensity of production in the other seasons, we find that the increase in winter intensity is compensated mainly by losses in spring and summer production, and by a small loss in autumn production. These seasons have not been illustrated graphically but the equations to the straight lines describing changes in proportional production in them during all nine years and during the seven normal years are given below. (Table 13).

The compensation is, of course, necessarily complete as is shown by the cancellation of plus and minus values of x and of 9x. How little of the increase in winter production has been paid out of autumn production can be seen from the small valas of x for the autumn straight line, which indicates that the percentage of the total eggs which are laid in the fall has remained almost stationary during the nine years.

TABLE 13

GENERAL TREND OF CHANGES IN THE SEASONAL DISTRIBUTION OF

EGG PRODUCTION 1911-1919.

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Winter
Spring
Summer
Autumn

y=17.496+.930x y=-17.109+1.235x|+8.370 +8.645 y=36.034.413x y=35.850 .536x143.7171–3.752 y=30.774.409xy=30.390— .301x1-3.681 -2.107 y=15.681—108x y=16.631— .396x|- .972 42.772

ANALYSIS OF CHANGES IN THE SEPARATE WINTER MONTHS

The most significant fact established by the analysis of changes in the seasonal distribution of egg production during the nine years is the gradual and steady increase in the percentage of total production which occurs in the winter period (November 1 to the last day of February). Before an explanation for this change can be offered, it will be necessary to examine the situation in the several months which make up the winter period. Is the tendency toward increase common to all these months or is the total tendency contributed by only one or two months? If the latter, are these months at the beginning of the winter period, (and therefore, at the commencement of reproductive activity of the fowls) or at the end of the winter period? If the increase is peculiar only to the beginning month of production, it will indicate probably a tendency toward increasingly earlier maturity on the part of the birds submitted; if the increase is confined to the latter part of the period it will indicate more probably a progressive change in the genetic constitution of fowls toward an increased ability for winter production. The importance to the poultry breeding industry of deciding between these alternatives has led us to make a careful analysis of egg production in the months of November, December, January, and February.

The percentage of total production occurring in these months for the nine separate years is given in Table 6, the con

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