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Age of Dam: Difference between revisions

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Traits affected by a maternal contribution have the potential to have an effect that results from the age of the dam.  BIF has identified the following categories as a standard classification for fixed age-of-dam effects in prediction models.  The categories are also used in determining adjustment factors for some traits.
Traits affected by a maternal contribution have the potential to have an effect that results from the age of the dam.  BIF has identified the following categories as a standard classification for fixed age-of-dam effects in prediction models.  The categories are also used in determining adjustment factors for some traits.
It is clear that the age-of-dam effect can be different in different breeds.  This is likely to be mostly due to the effect of scaling.  If adjusting weights or measures for age-of-dam, different breed or size/scaling effects should be considered. 
It has been observed that some breeders preferentially treat different age of dams differently resulting in a contemporary group by age of dam interaction on some traits where there is a main effect of age-of-dam.  This should be evaluated and considered when performing genetic evaluation analyses where multiple breeds are included.


=Age-of-Dam Categories=
=Age-of-Dam Categories=

Revision as of 04:01, 6 January 2020

Traits affected by a maternal contribution have the potential to have an effect that results from the age of the dam. BIF has identified the following categories as a standard classification for fixed age-of-dam effects in prediction models. The categories are also used in determining adjustment factors for some traits.

It is clear that the age-of-dam effect can be different in different breeds. This is likely to be mostly due to the effect of scaling. If adjusting weights or measures for age-of-dam, different breed or size/scaling effects should be considered.

It has been observed that some breeders preferentially treat different age of dams differently resulting in a contemporary group by age of dam interaction on some traits where there is a main effect of age-of-dam. This should be evaluated and considered when performing genetic evaluation analyses where multiple breeds are included.

Age-of-Dam Categories

Age in days for age-of-dam categories (years of age).

Age-Of-Dam Classification
AOD Low High # of Days
2 639 1003 365
3 1004 1369 366
4 1370 1734 365
5 through 9 1735 3560 1826
10 3561 3925 365
11 3926 4291 366
12 4292 4656 365
13+ 4657