Partridge Brahma & BYM

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2021 HATCH

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BREEDING VARIOUS COLORS:

The color differences between Darks, Blue Darks, Partridge and Blue Partridge are produced by the presence or absence of two dominant genes; the autosomal, incompletely dominant gene Blue (Bl) and the sex-linked gene Silver (S). The alternatives to Bl and S are bl (black) and s (gold) respectively. The expected outcomes from mating Dark and Blue Dark and Partridge and Blue Partridge are the same as you would expect from mating Blue to Black. These outcomes are listed below.

Dark x Dark = 100% Dark

Dark x Blue Dark = 50% Dark and 50% Blue Dark

Dark x Splash Dark = 100% Blue Dark

Blue Dark x Blue Dark = 25% Dark, 50% Blue Dark and 25% Splash Dark

Blue Dark x Splash Dark = 50% Blue Dark and 50% Splash Dark

Splash Dark x Splash Dark = 100% Splash Dark

Splash Dark males will look similar to a Splash (produced from a Blue), generally you will see some light blue feathers or parts of feathers on a mostly white bird.

Partridge x Partridge = 100% Partridge

Partridge x Blue Partridge = 50% Partridge and 50% Blue Partridge

Partridge x Splash Partridge = 100% Blue Partridge

Blue Partridge x Blue Partridge = 25% Partridge, 50% Blue Partridge and 25% Splash Partridge

Blue Partridge x Splash Partridge = 50% Blue Partridge and 50% Splash Partridge

Splash Partridge x Splash Partridge = 100% Splash Partridge

Males of Splash Partridge will look like a Pile male but some feathers or parts of feathers will have light blue or blue instead of being white. Female Splash Partridge will appear mostly white but with red patterning in the feathers and patches of light blue or blue in some feathers.

The expected percentage of colors hatched is not affected by the sex of the birds mated together as the Bl gene is autosomal (located on chromosomes not involved in specifying sex). E.g. a black rooster can be mated with a blue hen and vice versa and the expected ratios of colors in the hatch is always the same.

Where expected percentages of colours hatched will be affected by the sex of the birds mated together is when birds carrying the sex-linked gene Silver (S) and its counterpart gold (s) are involved. E.g. when a Partridge is crossed to a Dark and vice versa. This also applies to Blue Partridge, Blue Darks and other combinations. The expected outcomes from such crosses are listed below.

Dark male x Partridge female = 100% Dark (hiding Partridge) males x 100% Dark females

Partridge male x Dark female = 100% Dark (hiding Partridge) males and 100% Partridge females

Dark male (hiding Partridge) x Dark female = 25% Dark males, 25% Dark males (hiding Partridge), 25% Dark females and 25% Partridge females

Dark male (hiding Partridge) x Partridge female = 25% Partridge males, 25% Dark males (hiding Partridge), 25% Dark females and 25% Partridge females

Dark males (hiding Partridge) will look like a Dark male because the Silver gene is dominant over its alternative the Gold gene. So heterozygotes for Silver and Gold look like a Dark. However, the gold can sometimes ‘leak’ through in the plumage, particularly on the wing and around the neck and saddle hackle. This is not always a certainty and sometimes Dark males (hiding Partridge) can appear to be a pure Dark male. In this instance the males genetic makeup is only revealed when some of his daughters turn out to be Partridge even though he was mated to a Dark female. At first, the results of these crosses may seem odd but if we think about the inheritance of sex-linked genes it makes sense. Remember males can possess two copies of either the Silver or Gold gene or a combination of both genes whilst females can only possess one of the alternatives. Because females can only posses one Silver or one Gold gene they are called hemizygous and not heterozygous.

This is because the Silver and Gold genes are located on chromosomes which determine the sex of an individual, termed sex chromosomes. The two sex chromosomes in chooks are called Z and W. Females have a Z and W (ZW) chromosome and males have two Z chromosomes (ZZ). The W chromosome in females is very small and does not carry the same genetic information as the larger Z chromosome. In humans we call our sex chromosomes X and Y and the pairing of these chromosomes is reversed between the sexes. So human females have two X chromosomes (XX) and males have an X and a Y chromosome (XY), with the Y chromosome being small and carrying less genetic information.

We call the sex possessing two copies of the same sex chromosome the homogametic sex and the sex possessing one of each type of sex chromosome the heterogametic sex.

Information from: http://www.brahmacochin.org

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