Yield and nutritional value of permanent grassland forage under simulated rotational grazing

Abstract

A cutting experiment was conducted to test the changes in botanical composition, yield and nutritional value of forage, obtained in conditions of simulated rotational spring grazing on permanent grassland. The experiment was carried out on permanent pasture in vicinity of Sabac, Serbia in 2015 included three cuttings as a simulated rotational spring grazing. The highest share of grasses was noted in the first cut and decreased in the second and third cut, with increased forbs participation, and relatively constant percentage of legumes. The highest dry matter (DM) yield was obtained for the first harvest, followed by the second cut, and the lowest forage production was determined for the third harvest, with only 11.04 and 17.42% of the first and second cut yield. There were not found the significant differences between cuts for herbage DM and crude protein content. Markedly lower value for non-protein N concentration (p<0.05) was determined in the third cut. The fiber content increased during the grazing season (p<0.05), with the highest value determined in the herbage obtained in the second cut. The highest energy values (p<0.05) had the herbage produced in the first cut (DM basis), wherein the lowest values were found in the forage from the second harvest. These results indicate that especially herbage yield of analyzed grassland as chemical composition and nutrition value are highly variable during the growing season. The accurately defined optimal period for using is necessary to provide the high-quality forage for grazing animals.