Effect of Limestone on Digestibility of Feedlot Diets

Story in Brief Two levels oflimestone (.7 and 2.0 percent) were fed with two levels of chopped alfalfa hay (10 and 50 percent) to 22 Hereford steers (517 lb). The diet also contained whole shelled corn and supplement. Animals were fed individually at a level equal to 2.5 percent of body weight daily in two equal meals. Organic matter, fiber and nitrogen digestibility were increased with added limestone. Fiber and nitrogen digestibility also increased as alfalfa was added to the diet. Beneficial effects of additional limestone involved increased fiber and nitrogen digestibility primarily, not increased starch digestibility. If increased fiber digestion speeds Clearance from the rumen, limestone supplementation beyond nutritional requirements may increase feed intake as well as digestibility of higher roughage diets.