Effect of Nitrogen Fertilization upon the Yield and Digestibility of Aftermath Timothy Forages Fed to Dairy Heifers

Abstract

Effects of using 4 levels of nitrogen fertilization 0, 50, 100, and 200 lb per acre, on the yield and nutritive value of aftermath Climax timothy forage were studied. Digestion trials were conducted with pregnant Guernsey heifers with the chromic oxide indicator technique. Nitrogen fertilization caused marked increases in yield and protein content of these forages. Changes in nutrient digestion included a significant increase in protein digestibility (P<.01) with each increase in nitrogen fertilization, and significant decreases in crude fiber and nitrogen-free extract digestibility (P < .01), when comparing the 0-100 lb of N treatments and the 0-200 lb of N treatments. Acre yields of digestible protein increased with each N treatment from 69 to 200 lb to 307 and to 390 lb. Similar yields of total digestible nutrients were 528, 1337, 1487, and 1528 lb per acre, respectively.