ABSTRACT
Alfalfa (Medicago sativa L.) is an autotetraploid (2n = 4x = 32), allogamous, cool-season perennial legume. Sometimes referred to as Lucerne, alfalfa is called the “queen of the forages.” Alfalfa hay is used primarily as animal feed for dairy cows, but also for horses, beef cattle, sheep, chickens, turkeys, and other farm animals. It is the fourth most widely grown crop in the United States, behind corn, wheat, and soybean, and occupies double the cotton acreage. There are 8.7 million ha of alfalfa cut for hay with an average yield of 8.4 Mg/ha (USDA National Agricultural Statistics Service 2007). Alfalfa can be compressed into cubes and/or pellets, which are used in feed for smaller pet animals, including rabbits, hamsters, guinea pigs, etc. Alfalfa is sometimes grown in mixtures with forage grasses and other legumes. The acreage of all hay harvested per year, including alfalfa, is 25 Mg/ha (USDA National Agricultural Statistics Service 2007).
