Three or so generations, I reckon, of you breeding, picking, and keeping both sides of the pedigree, before you can think of it as yours. The first couple of generations are really just building on what you were given, and if you have decent stock you’d have to work hard to fuck it up that quickly. By the third generation, your selection pressures and husbandry are going to start having a decent amount of influence on the babies you produce.
I don’t like the idea of a formal mentor-mentee relationship as I have seen it go wrong so many times, and even when it doesn’t end up in a relationship breakdown, it often ends awkwardly. If you are creating a formal mentor relationship, you are creating an expectation – the expectation that the mentor will give to the mentee a certain amount of time and effort and often rats, and quite often their name as almost a “shield” to wear. In return, the mentee will probably be following the advice given to them – the way they feed, their husbandry, their methods and the ethics of their mentor. When the mentee develops their own methods and ideas, do they need to ask for permission to “formally end” the relationship? What if the mentor doesn’t think they’re ready? Minefield!
Probably the one thing I am entirely confident on with rats is that there are as many different and equally correct ways to do things as there are rat breeders. I am always happy to have people over to just come and chat about rat breeding – come and see my setup, talk about how I do things. But I’d also encourage them to go and visit other breeders too and find out how they do things. My way isn’t the best way – but it’s the best way for me and my rats. Your way isn’t the best either, it’s just the best way for you and yours.
The best new rat breeders aren’t the one who had the best/most prestigious mentors – they’re the ones who felt most supported in their journey, who have been given the information and help they need to feel confident in the decisions they’re making (and why). Supporting new breeders is the job of every other breeder they come into contact with in the fancy. I do always feel thrilled and like I’ve done my job as a rat breeder when new breeders thank me or give me some credit towards their success, there is no better ego boost to your heart than to see someone doing something awesome and tell you that you had a hand in it!
I breed for show and pet in equal measure. I don’t think there’s any benefit to rats if we breed for anything less than the full package, and so I think every mating should be taking into account temperament, health, type, and the paint job (deliberately listed in that order).
It is hugely unusual to see anyone reputable offering kittens for homes that are only a couple of weeks old. Breeders should be interested in selecting which kittens they keep back for future breeding on the basis of best possible temperament, type, and colour/markings.
When you are looking at kittens that are very young, you know what variety they have and what markings, but you cannot properly evaluate temperament or type. So that means you are only selecting on what variety they are – not even the quality of it, since the colour and markings can change rapidly in the next few weeks.
If you do have an interest in breeding to improve temperament/type/colour, you should make decisions on the kittens you are keeping and those you are not as late as possible. This would allow you more time to properly evaluate the kittens, and it’s also better for those purchasing kittens, as you can tell them more about the personality of the rats involved rather than it just being about what they look like.
By properly selecting the rats you keep as potential breeders in the first place, you’ll be able to breed to improve, rather than breed just to create more kittens of a particular variety.
You will often see written that there is an upper age limit in breeding a doe, but there are certainly no increased risks of breeding a rat under a year old – and realistically if the rat is in peak health and fitness at any age, a litter isn’t going to be an increased risk no matter what the calendar says (and if she wasn’t in peak condition why are you breeding from her anyway?).
Your main issue with breeding older does tends to be that if the line has been bred from at the lower end of the breeding window for multiple generations, you may have accidentally selected for early onset infertility, and so find it difficult to get older does pregnant. I always select for later fertility as it makes my life easier as a breeder.