Breeding for colour (shading/markings)

Having sat down to think about this in more detail, I realise that I have backed myself into an impossible corner - the only way to do justice to the topic of breeding for colour would be to launch in to a series of genetic articles (which may indeed follow). I think that all that is left for me to say is that a good basic knowledge of the genetics of colour (and other traits) inheritance is essential when contemplating breeding. Either that, or place yourself under somebody's wing who has a reasonable understanding. This is one situation where 'doing your homework' will bring great dividends. If you choose to just jump in and put two nice rats together-watch out! You may well end up with a litter of equally nice agoutis, not the pretty rats you were anticipating. Not that agoutis aren't pretty, of course. It's also wise to learn about specific genetic inheritance patterns relating to the variety you want to breed. For instance one might think that all is lost when the beautiful dumbo doe who you purchased to potentially breed from turns out to have two waffly ears. Not so. A quick information seeking tour round those who breed dumbos will tell you that if mated to a buck with good smooth ears you will in fact produce a mixture of waffly eared and smooth eared rats (and some with one of each!). Almost everything can be bred away from with time. One thing that I have never read anywhere (and I have read a lot of genetic articles!) is that carrying lots of unwanted recessive colour genes changes and dilutes coat colour, (as can some marking genes), giving rats that are not quite the colour they are meant to be. This can be seen clearly in the dull, dark agoutis thrown up from blue agouti lines, the paled blacks from marked lines and the insipid cinnamons from topaz lines. Nothing seems to demonstrate this more beautifully that the dumbo lines. Because of the way rats are bred on the continent the imported dumbos came to the UK carrying lots of recessive colour genes. Some matings have produced surprise rainbow litters, but often the colours are not true to the required standard (for showing). It seems the way to produce show quality rats is to colour breed for generations - that means choosing which variety you want to breed and sticking with it. This often seems unattractive to the novice breeder, who actively wants a rainbow litter, and certainly not a little family of 16 minks and cinnamons. If you're a purist that might even read minks *or* cinnamons!

A genetics series will surely follow, but I want to end this series by re-stating what I passionately believe, and what I began with... A pretty rat who is unhealthy or unfriendly (either to you or to its fellow rats) is just about useless as a pet, which should be a pleasure to own. A pretty and healthy rat who is unfriendly may win prizes at shows (so long as he doesn't bite the judge), but he will never provide pleasure as a pet.

Temperament is all. Health, fitness and longevity are the goal; harder to work towards, and probably as much down to care, as to breeding. Type is pleasing-a big strong buck, with lovely eyes, ears, tail and beautiful shape is something to behold. Colour and markings may win you prizes. The breeder makes the choices as to which to prioritise, but so does every one who purchases a rat. It is common for an enquiry to begin with something like "I am looking for a blue and a blue agouti doe and I want to be able to show them." Sadly, no-one can guarantee "show quality" at 6 weeks of age. Obviously some rats will never be show quality - some might, but I would argue that even the prettiest kitten might grow into an unremarkable adult.

Just stop for a minute and think what you are asking for you are prioritising looks over temperament or health. Better to contact a breeder and say - "I want a rat from lines of superb temperament who regularly reach 2 years having lived a healthy life, I'd like them to be fit and strong, and I prefer such and such a colour."

A rat whose parents have both won prizes in pet shows (where they are judged primarily on health, temperament and condition), is more likely (not guaranteed) to produce offspring who will not just look pretty but be great all round pets. We all need to learn to ask the right questions - of ourselves and of our breeders.

Alison Campbell