The exact and reliable detection of sugar monomers and fructans provides important information for the evaluation of carbohydrate metabolism in plants and animals. Using the HPLC method; a large number of samples and single sugars; with both high sensitivity and selectivity; may be analysed. It was shown that the described method—using a Nucleosil column loaded with Pb²⁺ ions; a refractive index detector (RID); and HPLC-grade water as the eluent—gives precise and reproducible results regarding the detection of individual sugars in extracts of plants and feed materials. The method can be applied for the detection of sucrose; maltose; lactose; xylose; glucose; galactose; arabinose; fructose; ribose; and mannitol. Furthermore; depending on the plant material; the sugars verbascose; stachyose; and raffinose can be separated. The peaks were well resolved and the reproducibility of the analysis; with 94–108% of recovery (RC) and relative standard deviation (RSD) of up to 5%; was very good. The method was successfully applied to a variety of green forages and samples of sugar beet pulp silages. It is also possible to determine fructan with inulin as a standard; together with the other sugars; or alone by a different protocol and column.

Whole-crop cereal silage represents an important component of ruminant diets and is used as a substrate for biogas production. Due to the scarcity of data on whole-crop rye (Secale cereale L., WCR), our study aimed to evaluate the effects of a range of biological and chemical additives of different compositions on the fermentation and aerobic stability of silage made from this species. In addition, the production of various volatile organic compounds (VOCs), which potentially contribute to greenhouse gas emissions, was monitored. Regardless of additive treatment, all WCR silages were well fermented as reflected by the complete absence of butyric acid. Inoculants containing Lactobacillus buchneri and chemical additives reduced dry matter (DM) losses during fermentation for 53 days (p < 0.001), which were closely related with the concentration of ethanol upon silo opening (R² = 0.88, p < 0.001). Silage treated with Lactobacillus buchneri, alone or in combination with a homofermentative strain, had the lowest yeast count (p < 0.001) and, simultaneously, the highest aerobic stability (p < 0.001). Chemical additives outperformed all other additives by largely restricting the formation of ethyl esters of lactic and acetic acids (p < 0.001). The concentration of ethanol strongly correlated with those of ethyl lactate (R² = 0.94, p < 0.001), ethyl acetate (R² = 0.85, p < 0.001), and total ethyl esters (R² = 0.94, p < 0.001). The use of a simple linear regression model exclusively based on the ethanol content proved useful to predict the concentration of total ethyl esters in WCR silage (R² = 0.93, p < 0.001).