Effects of Stocking Rate on Forage Nutrient Composition of Nebraska Sandhills Upland Range When Grazed in Early Summer and the Effects of Grazing on Nebraska Sandhills Meadow Forage Nutrient Compostion

Twelve Nebraska Sandhills upland range paddocks were utilized in a two year study to determine effects of stocking rate on grazed forage nutrient composition in early summer. Stocking rates consisted of control, light, and heavy stocked at 0, 0.57, and 0.85 animal unit months per hectare respectively. Three esophageally fistulated cows per paddock collected diet samples on May 14 (d 0), May 21 (d 7), May 28 (d 14), and June 4 (d 21) in 2013 and 2014. Ten quadrats per paddock were clipped and separated into current year growth or previous year growth on each diet sampling date. Diet and clipped samples were analyzed for CP, NDF, and IVDMD and adjusted to an in vivo OM basis (IVOMD). Diet samples had significant treatment x date interactions (P < 0.01) for CP, NDF, and IVOMD. However, treatment and date did not interact (P > 0.05) for clipped samples. Diets collected in control paddocks had greater IVOMD, CP and lower NDF compared with light and heavy stocking rate paddocks on d 7, 14, and 21 (P < 0.05). Diet samples collected from light stocking rate paddocks did not differ (P > 0.05) in IVOMD, CP, or NDF compared with heavy stocked pastures. Previous year growth IVOMD, CP, and NDF were not affected (P > 0.05) by treatment. Current year growth IVOMD and CP were not affected (P > 0.05) by treatment, however, control paddock CP was lower (P = 0.02) compared with light and heavy on d 21. Current year growth NDF did not differ (P