Please be sure to compare animals evaluated to the same genetic base. Insist that PD82 evaluations be made available. Modified Contemporary Deviation. Two age groups are used. First-lactation animals are in one group while all later lactation animals are in another.
Modified contemporaries are in the other age group from the animal in question.
This change had very little impact on the PD of most bulls. However, if a bull had daughters in herds where contemporary sires' average repeatability was low, that bull's MCD could be affected. Projecting completed records of less than 305 days Many cows' records used in sire evaluations are for lactations with less than 305 days. The cow has not completed her record and is still in milk, 2. The cow was culled, removed from test, or died before 305 days, 3.