The butter produced in New Zealand is of a salted type and, because the cows are fed almost entirely on grass, it has a high carotene content which makes it yellower than the butter from countries where cows are fed indoors for much of the year. The cheese exported is a cheddar, although a little of other kinds is made for local sale. Milk powders include those made from whole milk or from separated milk and buttermilk, by-products of buttermaking. Lactose is made from whey, a by product of cheesemaking. At one time skim milk, buttermilk, and whey were almost entirely fed to pigs; but in recent years more has been dried, and the pig industry, which depended on dairy by products, has been declining.