Why does milk clot quicker in the stomach wiv rennin?

Milk clots quicker in the stomach with rennin because rennin, an enzyme produced in the stomach of young mammals, specifically acts on casein, the main protein in milk. This enzyme causes the casein to coagulate, forming curds and separating whey. This process aids in digestion by allowing the milk to remain in the stomach longer, facilitating nutrient absorption. Additionally, the clotted milk creates a more concentrated source of nutrients for the young animal.