Nutritional Value and Chemical Composition of Corn Silage Depending on Cutting Height and Forage Losses

The study presents the effect of cutting height (10, 15 and 30 cm) on yield, nutritional value and chemical composition of silage corn. The experiment was carried out under dryland conditions and the silage corn was harvested with three types of self-propelled silage harvesters. Cutting height increased linearly with increasing operating speed of silage harvesters. For all types of silage harvesters, the cutting height of 30 cm had a statistically significant (p <= 0.05) effect on losses of yields. The numerical value of the R2 factor (from R2 = 0.8978 to 0.9896) shows a strong dependence in all harvesters for all three cutting heights. The regression coefficients (b) show a significant deviation from the theoretical cutting height at 10 and 15 cm (b = 0.6676 and b = 0.6715), and very significant (b = 2.0249) at the theoretical cutting height of 30 cm. With an increase in cutting height, the nutritional value of silage increased. At a cutting height of 30 cm, during the test period in all types of harvesters, the crude protein (CP) content was significantly (p <= 0.05) higher than at a cutting height of 10 cm (harvester C = 6.94% at 10 cm, harvester B = 8.15% at 30 cm). The cutting height of 30 cm influenced a significantly (p <= 0.05) lower crude fiber (CF) content of harvester Claas Jaguar 850 (21.19%), compared to John Deere 6810 (24.33%) at a height of 10 cm. The crude ash content (CAsh) did not vary significantly under the influence of cutting height. Starch content was statistically higher (p <= 0.05) in all types of silage harvesters during the test at a cutting height of 30 cm (28.2% harvester New Holland FX 28, 33.8% harvester Claas Jaguar 850). The content of calcium (Ca) was significantly higher at a height of 30 cm for harvesters John Deere 6810 and Claas Jaguar 850 in the third year, while no significant difference was found for harvester New Holland FX 28. For phosphorus (P), there was no significant difference depending on the cutting height, but it did exist depending on the year.