Genes are responsible for the features of what your cat will inherit: colour, coat texture, temperament. Eye colour etc. They come in pairs and the letters representing them are as below.

 Dominant Genes are: A = Agouti, B = Black , C = Full colour, D = Density of Pigment, L = Shorthair, O = Red, S = White Spotting Gene, W = full white colour and I = Inhibitor

 Recessive Genes are: a = Non Agouti, b = brown, c = Himalayan pattern, d = Dilute, l = Longhair, o = non red, s = no white spotting, and w = non white.

 Alleles = are different mutations of the same gene

 Homozygous = the cat has the same two identical genes, BB = Seal/black

 Heterozygous = the cat has two dissimilar genes, Bb = Seal/black carrying chocolate

 Phenotype = The external look of the cat.

 Genotype = The internal look of the cat, or what the cat may inherit and carry on through the offspring

 Dominant = Show the effect of the phenotype in the cat, one dominant gene must be present to see this, Bb = Black/Seal carrying brown/chocolate

Recessive = When the effect of the phenotype can not be seen in the cat. When only one gene is present, this same gene must be there twice to show the effect of the phenotype, bb = brown/chocolate.

 The "I" (Inhibitor) and "A" (Agouti) are dominant in all colours. The recessive genes can be carried through numerous generations.

Both "A" and "I" are single and dominant. (what you see is what you get) Keeping in mind that colour is separate from pattern.

 All cats have an agouti pattern "A", visible or not. The "A" brings the bands to the fore, and the yellow, fawn, brown under lying colour. It is the most natural occuring gene going back to nature.

The "A" Agouti gene shows cats in patterns, as Tipped (Abyssinian), Classic (blotched, bulls eye patterns), and Mackerel, (fine tiger bands) and even spots. Introducing a solid colour to agouti can create solids and agouti. Agouti to agouti can also create solids and agouti.

Introducing the Inhibitor gene "I" with the "A" gene will turn the yellow underlaying colour to white/silver, and the shafts of the hair upwards white/silver, hence the banding comes to the fore giving you the silver tabby. The "I" gene with the cat that is not agouti "A" will be a Smoke.

The inhibitor gene, "I", simply 'inhibits' the production of colour on the hair shaft. As a result part of the lower end of the shaft is devoid of colour and appears white or 'silver'.

How you will see the silver is determined by the polygenic activity. Polygenes control the depth of tipping on the hair, varying from 1/4" to 1/2" down the hair shaft, the length of the hair and density.

Due to selective breeding the polygenes can be governed and the results will be foreseen. Polygenes therefore determine how dense the colour appears to the human eye. The more silver, the less tipping of colour present in the hair shaft, the lighter the remaining colour will seem.

 Continually breeding silvers to silvers, can be considered undesirable and would not help to improve the type. Colour defintion can also be lost, in a pointed cat, ie: a Birman, it does take up to 16 weeks sometimes to see if the kitten is ie: seal or blue, and at least another 3 months to really see the combination of silver and colour/pattern. From our silver lines, we have had non silver kittens from silver to silver matings, this means our silver cats are Ii.

I normally can see this from 3 weeks of age, I look at the colour on the hocks, behind the gloves, the nose leathers, the inside edges of the ear, and the back of the tail, if the claws are transparent on new born kittens, this indicates silver! So does the texture and the coat colour, it almost sparkles, and is very soft and silken. Ideally you want a silver Birman, that shouts, "I am silver", and is also easy to identify as seal, or blue, or seal tabby , or blue tabby etc…… in general, it is easier to see the pt colour when they are kittens, as you become more familiar with seeing the Silver Birman in the fur as it matures.

Resulting in a dirty or tarnished silver which is a fault in a silver cat. Shading can occur in all the colours of the Birmans for many different reasons and is completetly different from tarnishing.

Some silver kittens born, with more tipping (pigment) on the hair, can be mistaken for solid colours, even though they are "low grade silvers". Unless they are used for the silver breeding programme, they should be sold as pets. As some breeders now have tabbies, with pedirgrees with the (s) and know the contraversial colour debate, you have the choice of test mating, if you feel you have silver, this may take several matings, ie: to a straight seal, if you get low grade seal smoke, then you have to ask yourself, if you want to continue to breed silver birmans?

As a result of non silver to silver matings, in our breeding programme, the percentage of higher grade silvers per queen would be less then 30%. Lower grades of silver would range from 10% -20%, and mating a low grade silver to a non silver has not produced a high grade to date.

To be a breeder of silvers you have to be clear in your decisions and have no doubts of what the colours are, and registering them as such, and not to sell them on, without being clear on everything to everyone.

To be able to accept advice from other breeders that may have had silver breeding programmes, and to have a open mind. To focus on the high grade silver, and the type as per the standard, is a very exciting and different challenge.

The dual registration for the silver breeding programmes, ie: Blue Silver Tabby = 52 s/FA, Blue Tabby pt = 52 FA(s) is recommended to prevent any argument for breeders not wanting silver in their lines in the future. There are now a few different tabby and non tabby lines with the (s) in the background, being used for breeding, a few of you have had either nightmares or excitement over this, but remember that (s) is only indicating there is silver lineage behind your birman, from persian, chinchilla, domestic, etc.

When you think about tabby……… have a look at the domestic tabby, this may help to give you a feeling of how the silver is there, or not………..more often, it is! Some have the eye to see the lower grades, remembering also that a lot of people can not see certain colours, can also confuse the issue.

In my opinion nothing could be more beautiful than a Silver Birman that sparkles inside and out.

Sandy Steward   Fancypawz Birmans