PHYTOMILK
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Effects of storage time and silage preservation methods on FA composition and concentrations of tocopherols and carotenoids on four organically managed forage species
In the same experiment as in Task 4, a silage experiment will be conducted at one site. First cut of a birdsfoot trefoil/timothy mixture and a red clover/timothy mixture is harvested at the heading stage of timothy in 2007. Each mixture is replicated three times in the field. Forages are wilted to 30% dry matter before ensiling, without an additive or with an addition of a bacterial inoculant or an acid, in laboratory silos. The silos are opened after 1.5, 3, 6 and 9 months. Forages will be analysed for FA composition, α-tocopherol and carotenoids before and after wilting and after each storage period. Chemical composition of wilted forage before ensiling and of silage at three months of storage (incl. fermentation characteristics) will be assessed according to the NorFor system.
Progress of work
Mixtures of birdsfoot trefoil/timothy and red clover/timothy were harvested on June 4, 2007 in three field replicates and wilted to 22% dry matter before ensiling. The relatively low DM concentration of the wilted forage depended on cloudy and rainy conditions during wilting. The wilted forage was chopped to 15-20 mm particle length and treated with additives. The additives used were Siloferm Plus (Pediococcus acidilactici, Lactobacillus plantarum and cellulase and hemicellulase (enzyme activity of 54 000 HEC/g)) at an application rate of 768 000 cfu/g herbage (Medipharm Inc., Kågeröd, Sweden) and Proens (2/3 formic acid and 1/3 propionic acid; Perstorp Inc., Perstorp, Sweden) at a rate of 5 l/Mg herbage. The additive-treated silages were compared with an untreated control without additive. Forage mixtures were ensiled in 1.7-litre glass jars equipped with fermentation traps on the lids. Forages were packed to an average density of 137 kg DM/m3 in the jars. The filled silos were weighed at ensiling and at opening after 1.5, 3, 6 and 9 months of storage. The silage samples are frozen for later analysis of FA composition, vitamins, and other chemical composition. The work is carried out according to the original plan.
Forage samples ready for analyses of carotenoids. Photo: Annika Höjer |
