Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: January 21, 2003
Publication Date: January 21, 2003
Citation: Martin, N.P., Hatfield, R.D., Mertens, D.R. 2003. Redesigning alfalfa for dairy cattle. In: Land O Lakes Feed Division Leading Producer Conference, January 21, 2003, Wisconsin Dells, Wisconsin. p. 1-3. Technical Abstract: Alfalfa (Medicago sativa), often called the "Queen of the Forages," is the most important forage legume grown in the U.S. In 2001, farmers harvested 91 million tons of hay- equivalent forage from 25.7 million acres of alfalfa. Alfalfa is the third major crop behind corn and soybeans in commodity value in the U. S. (hay production valued at $7.5 billion). Alfalfa hay is valued by nutritionists for its relatively high energy value which supports milk production, its rapid ruminal digestion of structural fiber which stimulates feed intake, its coarse structural fiber that stimulates ruminative chewing and salivation, which results in rumen buffering, its structural fiber which has high buffering capacity, its high protein level which supports animal protein needs, and the relatively high proportion of its protein that escapes the rumen undegraded which minimizes dietary requirements for high cost protein supplements. In spite of these outstanding characteristics, critical factors remain that limit the increased utilization of alfalfa in sustainable dairy production systems. Factors limiting increasing use of alfalfa by dairy cattle are low digestion of plant cell wall, especially lignified cell wall, excessive protein if harvested as silage or harvested early to obtain high energy, and excessive leaf loss from harvest or leaf drop during maturation or excessive leaf disease infestation. We believe alfalfa can be genetically redesigned into varieties that have greater cell wall digestibility, less protein degradation during ensiling, increased bypass protein, and increased yield without quality loss to fit the needs of the high-producing dairy cows.