Herbs & Brassicas
Forage brassicas are high quality, high yielding, fast growing crops that are particularly suitable for grazing by livestock. Both tops (stems plus leaves) and roots (bulbs) can be grazed and are very nutritious. All members of the brassica family - turnips, rape, kale, and swedes - produce forage of exceptionally high (often 85-95%) digestibility. While brassicas have been successfully used for centuries all over the world for livestock feed, the following precautions should be noted. Brassicas are very high in crude protein and energy, but extremely low in fiber. Their low fiber content results in rumen action similar to when concentrates are fed; thus the need for proper roughage supplementation. Brassicas therefore should never comprise more than two-thirds of the forage portion of livestock diets with the remainder provided by grass hay or stockpiled pasture. Likewise all brassicas contain low levels of glucosinolate compounds. Again, adequate grass forage supplementation seems to prevent them from causing animal health problems. Excessive fertilization of both nitrogen and potassium should be avoided. Most dairymen have avoided off-flavors in milk by preventing brassica consumption two hours before milking. Others prefer to only feed rapes to lactating dairy animals plus adequate grass roughages. Brassicas offer a means for producers to produce high quality forage either during the critical summer period of slowed pasture growth and/or to extend grazing into the late fall-early winter period.