Newborn kittens should be fed a nutritional substitute called kitten milk replacer, as they cannot eat solid food until they are at least 4 weeks old. It is important to avoid feeding them cows milk, as it can make them sick. Commercial kitten milk replacers are recommended, as they are superior to homemade mixtures. The milk replacer should meet several key nutritional factors, including moisture, dry matter, crude protein, fat, and lactose. Orphaned kittens should be fed on a strict schedule, preferably every 2-4 hours. Small breed kittens should be limited to 10-15mL per feeding during the first week of life to prevent diarrhea. Kittens need to be burped after feeding, and they should be stimulated to go to the bathroom after each feeding. Once the kittens are about 3.5 to 4 weeks old, they can start to be weaned off the bottle gradually. Wet kitten food and moistened kitten chow can be left in the enclosure at all times so the kittens can begin to experiment with it.