Ársrit Ræktunarfélags Norðurlands - 01.01.1960, Blaðsíða 150

158
ers are very inaccurate and not to be appreciably relied on.
In Table XVII comparisons are made of recorded milk
and weighed-in milk to the Dairy. The results here are far
from poorer than with the Cattle Rreeding Federation in
Sealand, where the control of records is very strict.
2. It is often maintained, that improvements in products
of the S. N. E. dairy herd are due only to better treatment
and feeding methods, but not to improvement in breed.
Examination of the highest daily yield of first calf heifers
and cows fully in milk during different periods under the
auspices of S. N. E., and also comparisons made between
heifers sired by different bulls, adduce strong arguments
that the rise in yield of cows is in many respects obtained
through improvement of breed, even though better treat-
ment and feeding methods have naturally accompanied the
improvement of breed (see Table XVIII).
3. Lastly it is asserted that poor health has been bred
into the cow herd, lowering greatly the mean age of the
cows since the S. N. E. started operation. Investigation of a
great number of cows for slaughtering and their ages in the
S. N. E. territory during 1939, 1949 and 1959 nevertheless
revealed that there is no actual basis for this assertion. Only
minor alterations seem to have occurred in regard to the
mean age of the cows, see Table XIX. Examinations of the
enlargement of the dairy farms in the S. N. E. area since
it commenced operation were also made, see Table XX.