Someone in the Community might be able to help if you provided more information about your study, and if you showed what you have tried so far (in other words, your MIXED code).
For example,
What is your subject, on which you took repeated measurements?
How many BREEDs? How many subjects in each BREED?
What is TIME, how many levels does it have, are you using TIME as a classification or numeric variable?
What is WEEK, how many levels does it have, are you using WEEK as a classification or numeric variable?
What is the relationship between TIME and WEEK?
I hope this helps.