Browsing by Author "Salakka, Anna"

The objective of the experiment was to study how different additives effect on fermentation quality and aerobic stability of maize silage. Three additives and two maturity stages were used in the labo-ratory scale experiment. Maize silage preserved with different additives was compared to control with no additives. The maize (Pioneer, P7326) used in the study was cultivated at the research farm of the Univer-sity of Helsinki in Viikki on growing season 2018. First silages were made on 21st of August 2018 and after 50 days the second silages were made on 10th of October 2018 92 and 142 days after sowing. The treatments were 1) control 2) formic acid 3) mixture of formic acid, sodium formate, propionic acid and sorbic acid 4) mixture of sodium benzoate and potassium sorbate. Chemical com-positon and buffering capacity of the pre-ensiling maize were determined. Fermentation quality of the silages was also determined. In addition aerobic stability of silages was determined by monitoring the temperature change of silages for 12 days with data loggers. Composition of the maize varied by the maturity stage. Dry matter content in the first maturity stage was 211 g/kg and in the second it was 327 g/kg. Content of water soluble carbohydrates (su-gars) was higher in the first maturity stage. Starch content increased in the second maturity stage considerably. Feed preservation succeeded mainly well and pH of silages in both maturity stages were below four. Sugar content of silages treated with formic acid and mixture of acids was very high in the first maturity stage. Lactic acid content of the control and Na-benzoate and K-sorbate silages was higher than other treatments. Na-benzoate and K-sorbate silage in late maturity stage had noticeably higher acetic acid content. In the silages, there were mainly low content of volatile fatty acids (VFA) and butyric acid was not observed. The silages contained lactic acid as well as acetic acid and only low amount of propionic acid. Silages were aerobically stable except silages of two formic acid silos in the first maturity stage and control silos in the second maturity stage. Temperature started to rise in formic acid silages after 10 days and in control silages after five days from exposure to air. Other silages were aerobically stable during the testing period. The maturity stage affected maize composition and thus ensiling characteristics. Composition differences of maize in different maturity stages cause different challenges in terms of preservation. Different preservation treatments affected the intensity of lactic acid fermentation and silage sugar content and the differences were higher in the first maturity stage. Intensity differences of fermenta-tion and differences in acetic acid content may affect aerobic stability. The use of additives tended to improve aerobic stability of the silages at the late stage of maturity.