33 
lately accurate the total production of milk is nearly 1,120 million 
allons and the yield per head of the dairy herd 416 gallons, 
bis estimated that on this basis the total production in 1908 was 
robably about 975 million gallons and the yield per head of 
he dairy herd about the same as for 1925. As has been previous] 
stated, these sets of figures, although subject to the large margin 
Of error inherent in a calculation of this kind, are probably nearer 
the truth than those calculated solely on the fully complete 
eturns. In any case it would appear that the total productio 
of milk in this country has increased by about 150 million gallon 
Since 1908, while the average yield per head of the dairy herd is 
about the same. 
Having regard to the greater attention given to dairying and 
to milk yields in recent years, it may be a matter for surprise 
that the yield per head of the dairy herd does not show an increase. 
The yield per head of the dairy herd is, however, a theoretical 
figure, which does not indicate the available production from an 
average full lactation of a unit of the dairy herd. For example, 
the dairy herd returned on 4th June includes not only a large 
umber of cows which go to the butcher during the succeeding 
twelve months and consequently do not give a full lactation 
but also the heifers in calf at the beginning of the year which do 
not in the aggregate give anything like a full lactation in the 
following year. The proportion of heifers in calf to the total 
dairy herd was, it is believed, greater in 1925 than in 1908, so 
that the yield per head of the total dairy herd would tend to be 
less in the later year. . 
The only satisfactory comparison of the milk yield is a com- 
Parison of the yield of an average full lactation. In 1925 the 
Average lactation yield is estimated at approximately 482 gallons 
®Xclusive of whole milk fed to calves or pigs. Cows and heifers 
Were not separately distinguished in 1908 so that a comparison 
on these lines with that year is impossible. The absence of such a 
figure for 1908 also makes it impossible to corroborate the evident 
dications of an actual increase in the average lactation yield. 
It is hoped, however, that the figure calculated in connection 
With the present inquiry may form a satisfactory basis of 
“Omparison for future years. 
It is of interest to note that on the assumption that 10 per 
‘ent. of the milk produced is fed to calves or pigs the estimated 
WVerage lactation yield of 482 gallons given above is raised to 
935 gallons. This figure compares with the average yield per 
“OW recorded for the full year 1924-25, under the Milk Recording 
Scheme, of 670 gallons. 
1924 to 
ths June : 
ilk in the a in the following 
The production of an Divisions is 
in the var 
May 1925 in t 
table