Evaluation of the Persistence of Grazing Alfalfa Varieties

The use of alfalfa (Medicago scitiva L.) for grazing is becoming more common. Alfalfa is the most widely planted legume, and is one of the most nutritional forage crops available. It is proposed that alfalfa was cultivated 4000 to 5000 years ago and produces the most protein per acre of any forage crop. Live weight gains for beef cattle grazing alfalfa average 230 to 360 kg ha-1. There is no cheaper way to harvest and utilize alfalfa than for the animal to harvest it directly. Most of the commercially available alfalfa varieties, however, were developed for hay production and thus do not always persist under grazing management. Recent advances in alfalfa breeding have provided dual purpose cultivars that are now available to producers. A grazing trial was conducted at the Western Kentucky University Agricultural Research and Education Complex in Bowling Green, Kentucky. Persistence and yield of six commercially available grazing-tolerant alfalfa varieties were evaluated to determine their response to rotational stocking by dairy cows. The varieties, Southern States Graze King, WL 324, Garst 645 II, WL 325 HQ, ABT 405, and Spredor III were established March 29, 2000 and harvested three times for hay throughout the year. Grazing was begun in April 2001 and ended in September 2001. Each plot was grazed when alfalfa reached a minimum height of 36 cm. Twelve dairy cows (nine Jerseys and three Holsteins) grazed each plot down to approximately 13 cm. Yield did not differ among varieties (P\u3c0.05); however, there was a significant difference among varieties for stand count. The variety by harvest interaction was significant; when averaged across varieties, stand counts declined 48% during the whole season. Southern States Graze King with 8.8 plants 0.1m-2, was greater only than Spredor III with 6 plants 0.1 m-2