Rat breeding

[ingie]

Wokka, when you say males can be more aggressive, what do you mean by that? Do you mean they compete for resources more fiercely, or literally they are more aggressive and kill off litter mates?
In my experience, if you are breeding rats for larger sized frozens, then you ideally want to select for litter sizes around 12, so that each litter mate has a fair chance to have unlimited access to milk, and the litter all reach their full potential in terms of growth rate. If you are wanting pinkies and fuzzies, then you would be better off selecting for larger litter sizes, as the mums don't need to raise them all and they won't be competing for resources (milk).

Any kind of actual aggression, should be selected away from. There is no reason to put up with siblings killing other baby rats or any killing going on at all, regardless of age, sex or scenario.

 

[ingie]

We don't modify genes, we only select from what is already there. Anything we could select for is also able to be selected for in the wild population, if such selection forces existed naturally.

I keep making shocking spelling and grammatical errors because I am typing at lightening speed on my phone, while I am meant to be shopping.

 

[wokka]

Wokka, when you say males can be more aggressive, what do you mean by that? Do you mean they compete for resources more fiercely, or literally they are more aggressive and kill off litter mates?
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I should have been clearer. I was saying that although mammals produce 50:50 that may not translate to the adult population becuase of losses along the way. You can often exstrapolate information across differing mammals.My observation with rats is that we end up with 50:50 sex ratio at weaning, but as previously mentioned captive rats are normally selected for temperament which is highly heretable..