EFFECT OF A HARVEST DATE AND CUTTING HEIGHT ON THE CONCENTRATIONS OF CAROTENOIDS AND TOCOPHEROLS IN VIRGINIA FANPETALS (SIDA HERMAPHRODITA) HERBAGE AND SILAGE.

The aim of this study was to determine the effect of a harvest date and cutting height on the concentrations of carotenoids and tocopherols in Virginia fanpetals (Sida hermaphrodita Rusby L.) herbage and silage. First-cut Virginia fanpetals herbage was harvested in the budding stage, on 11, 18 and 25 June 2017. Herbage was cut at 15, 25, 35 and 45 cm above the ground, after which it was chopped and ensiled in vacuum bags. The content of β-carotene and tocopherols (α-, β-, γ-, δ-) was determined in samples of fresh herbage and silage. Herbage cut at a height of 45 cm and silage made from herbage cut at a height of 25 cm had a higher (P≤0,01) content of β-carotene (113.93 and 44.90 mg kg^-1 DM, respectively), α-tocopherol (87.20 and 3.50 mg kg^-1 DM, respectively) and total tocopherols, and a higher value of vitamin E equivalent (Vit. EEq) than the remaining samples. Herbage harvested on the last date (25 June) and silage made from herbage harvested on the first date (11 June) were characterized by higher concentrations of β-carotene (88.30 and 38.27 mg kg^-1 DM, respectively) and a-tocopherol (70.91 and 2.82 mg kg^-1 DM, respectively) compared with samples harvested at the remaining dates, but the noted differences were not statistically significant. Positive interactions were found between cutting height (45 cm) vs. β-carotene content and Vit. EEq value in herbage, and cutting height (25 cm) vs. α-tocopherol content and Vit. EEq value in silage. The content of β-carotene and total tocopherols (α-, β-, γ-, δ) and a decrease in their concentrations during ensiling (in silage, average loss of β-carotene and a-tocopherol reached 56% and 96%, respectively) were comparable with the values reported for grasses and legumes. The results of this study indicate that Sida herbage and silage can be a valuable source of livestock feed. [ABSTRACT FROM AUTHOR]