Essential fatty acids (like omega 3 and omega 6 fatty acids) and fat soluble vitamins (Vitamin A, Vitamin E, Vitamin, D, Vitamin K). The plain fat is a nutrient too.
Kittens, generally, can begin to use a litter box at about four weeks of age, and a kitten being raised without its mother or adult cat will take slightly longer to litter train; so, keep this in mind when you begin the task of litter training your kitten. - Place the kitten in the box 1/2 hour after play or meals.
i have a litter of 5 kittens, and they are 5 weeks old, i make i can of wet food with a bowl full of dryfood and water so it is mushy, then i put it in thier bowl and mom and kittens all eat it! they aso stated using the litterbox at the same time. they started 4 days ago.