Having posts birth deaths in my colony

[theNotoriousDUD]

This is the same line of rats that I have been breeding for 3 years every 8 months I will pick up a male to add different genes. The room temp is 70 gets a bit cooler in the winter sometimes if the outside temp dips to -10 or more. There have been no major changes to my setup except for the adding of additional racks. The rats are on Purinas Rat Chow, with some Puppy Chow and a seed mix occasionally. They are on gravity fed watering sytem.