Alfalfa (Medicago sativa) is grown as an important forage crop in the United States and other countries. The crop is known as alfalfa in the United States but is referred to as lucerne in other countries. Alfalfa is a legume, meaning that it is able to fix nitrogen from the air. This capability helps improve soil quality and results in a high-protein crop. Alfalfa is widely grown as a forage crop for cattle and other ruminants. Most alfalfa is harvested as hay, although it can be grown as a pasture crop. Also, dehydrated alfalfa is available as a feed ingredient.
The use of alfalfa in diets for monogastric animals typically is limited by its high fiber content. Enzyme supplementation of alfalfa has not been shown to be effective in improving performance of broiler chickens fed alfalfa-containing diets. Alfalfa is, however, a natural source of xanthophylls, which are the pigments that give the yellow color to chicken skin and egg yolks.
High levels of alfalfa have been used in molting diets for egg layers. It has been reported that using molting diets high in alfalfa reduces the level of Salmonella excreted in the feces of hens. Dietary fiber is used by Lactobacillus and Bifidobacteria species, resulting in the production of lactic acid and short-chain fatty acids. Production of these acids reduces the pH in the intestines, helping the body maintain the normal collection of microorganisms in the digestive tract and, thereby, helping prevent the establishment of Salmonella and other pathogens. At the same time, however, dietary fiber reduces the speed with which feed passes through the digestive tract.
Other benefits of using alfalfa instead of other substances in molting diets exist. Wheat middlings have been used as an alternative to feed withdrawal for inducing a molt in an egg production flock; however, research shows that hens fed wheat middlings show the same level of hunger as hens on a feed withdrawal program. This result does not appear to be the case when alfalfa is used as the molt diet. Research has shown that feeding alfalfa is equally effective as withdrawing feed. The eggs produced post-molt are comparable between the two molting methods.