I feed Harlan 2914, plus a variety of daily vegs, and occasionally: a piece of fruit, blueberries, cooked whole grain oatmeal, cooked quinoa, organic pumpkin seeds, kumet puffs, veg & barley & mixed bean soup I make for them, a few cooked chick peas or a few cooked beans, etc (See our Reference Thread for information on nutrition and diet)
Oxbow, and Harlan 2014 are the recommended blocks for rats.
Jorats (founder of this group) looked at Science Select and said it looks good too.
Jorats has been doing secondary research into good diets for rats for many years - since I met her in a rat group in 2004
Mazuri is not a good block for rats. For example, rats need a diet that is 10% protein while Mazuri's rat blocks are 23% protein and there formula for breeder rats is 18%
Rat & Mouse Diet Food | MazuriĀ® Exotic Animal Nutrition
High levels of protein cause health issues in rats and research has found that it is best if it comes from plant sources
Mazuri is owned by Land O Lakes which also does Purina. Purina is not a good brand name for any pet food.
I assume that many people feed Mazuri because it is inexpensive. Members of this forum who fed their rats Mazuri have reported that they saw a huge difference in their rat's appearance and health after they switched from Mazuri to Oxbow
Good information on diet and nutrition can be found in our Reference Thread
REFERENCE Thread - Read Only
https://www.ratshackforum.com/threads/food-dos-and-donts.22782/#post-343892