Moorit (Sheep Colours as it relates to my flock - Part 1)

What is moorit?

~ Moorit is a brown colour, occurring in some sheep.
~ Genetically, it is not the same as black. Although many people use terms like "black" and "brown" to describe any/all coloured sheep, truly moorit-coloured sheep are not "black" and most so-called "black" sheep are not actually "moorit"!

Genetics of moorit

First, basic genetics (which is about all I know!)...
A sheep should inherit one "allele" at each "locus" from each parent. Which means that they get two "alleles" for each locus (one from each parent). If they inherit two alleles the same at that locus, they are "homozygous" for that trait. If they inherit two different alleles at that locus, they are heterozygous for that trait.

All sheep (even white ones) have genetic information for "black" vs. "brown", at the "B-locus".
Black is the dominant allele. Moorit brown is recessive to black...
~ If a sheep inherits moorit from both parents, it will be moorit. As it has two alleles for moorit, it can only pass on moorit alleles to its offspring.
~ If a sheep inherits black from both parents, it will be black. As it has two alleles for black, it can only pass on black alleles to its offspring.
~ But... if it inherits black from one parent and moorit from the other, the black overrides the moorit and the sheep is black... BUT it still carries both black and moorit - and it can pass on either to its offspring (only one to any given offspring).

Moorit in my flock

This is why I mostly use moorit-coloured rams - I know that if every lamb born has at least one moorit-coloured parent, I know that every lamb born will carry moorit.
Sometimes I have used a ram that is not moorit (whether black or white) - but when I do, I try to only put them over moorit-coloured ewes, so that their lambs will inherit moorit from their dams.

Currently:
~ ALL my flock carry moorit
~ 1/2 of my flock ARE moorit (inc the ram hogget)
~ 1/3 of my flock are black
~ 1/6 of my flock are white

That will change with lambing. However...
~ I used only moorit rams this breeding season, so all lambs born will inherit moorit from at least one parent.
~ Moorit ewes will all have moorit lambs.
~ Black ewes could have either black or moorit lambs
~ White ewes could have white, black, or moorit lambs (but statistically can be expected to have 50% white, 25% black & 25% moorit)



Photos (all from previous years):

Two pet lambs - moorit brown one on the left, black one on the right

Three pet lambs - moorit lamb in the middle

Pet twin lambs - both moorit, but one was always darker in colour than the other...
and in this photo they have lightened significantly since birth

A black ewe with twins - one black and one moorit
Note the ewe's nose colour is distinctly black (compare with the lambs in the 3rd photo & the ewe in the last photo),
even though her black fleece has "bleached" a bit in colour, and looks quite brown

Another black ewe (her fleece was still darker as she was younger), also with twins where one is black & one is moorit

A white ewe with triplets - inc one moorit lamb and two black lambs

A moorit ewe with triplets - also inc one moorit and two black