Number of Daily
Milkings:
Most dairy animals are milked twice daily (usually referred to as 2
x). Hence, for most lactations, no adjustment is necessary. To
convert three-times-a-day milking to a two-times-a-day basis,
multiply by 83% (0.83).
Age and Month of
Calving:
The
age of a dairy animal, as a rule, is always based on her age when
she calved, which is when her record officially begins. In most of
the western countries, at 2 years of age a cow produces about 70 to
80% of her mature production; at
3 years, 80 to 90%; at 4 years 90 to 95%; at 5 years, 96 to 100%;
and at 6 years, she reaches her mature
record. Age-adjustment factors have been developed to standardize 305-day
lactation records to a mature equivalent basis and to
minimize environmental variation due to the month of the year in
which the record began.
Fat-Corrected
Milk (FCM):
For
comparative purposes, the fat content of milk is usually based on
calculating the milk and fat production to 4% fat (4% FCM), but it
may be calculated to any desired fat basis. The formula for 4% FCM
is:
4% FCM = (0.4 x
milk weight) + (15 x fat weight)
|