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There is increasing interest in Finland to cultivate maize for silage, although the climatic conditions are in the borderline for maize due to the short and cool growing season. This may result in an immature crop that differs from typical maize for ensiling by having low dry matter (DM) and starch concentrations. We evaluated the preservation characteristics of forage maize during 2019 and 2020 harvested in Helsinki, Finland, at two stages of maturity. The DM concentration of the crops ranged from 230 to 360 g kg-1, and starch concentration from 179 to 283 g kg-1 DM. The crops were ensiled in laboratory scale using four different chemical organic acid based additives or a heterofermentative lactic acid bacteria inoculant. A control silage without additive treatment was also included. All silages were well fermented with low pH (average 3.75) and proportion of ammonia N in total N (average 47 g kg-1). Formic acid based additives restricted silage fermentation and most chemical additives improved the aerobic stability of maize silages compared to the control and inoculant treated silages that, under the conditions of the current study, did not differ from each other.

Forage maize (Zea mays L.) yield and nutritional quality fluctuate markedly in Northern Europe due to weather conditions. A field experiment was conducted in Southern Finland (Helsinki, 2018–2020) and in Central Finland (Maaninka, Kuopio, 2019–2020) to study the effect of harvest time and use of mulch film, in order to optimize the dry matter (DM) yield and quality. Treatments included oxo-biodegradable mulch film and no mulch, and three harvest times (the latter only in Helsinki). Mulch film increased DM yield on average by 2.3 Mg ha-1 in Helsinki and by 3.8 Mg ha-1 in Maaninka. Mulch film had a minor effect on the quality, and overall, the quality improved, although DM yield accumulation had already ceased. Nevertheless, the starch contents fluctuated and remained mostly below the target rate – 300 g kg-1 DM – especially in Central Finland. The results indicate that mulch film improves forage maize yield, but a late harvest is still required to improve forage quality. However, climate conditions still restrict starch accumulation to ears in Northern European climate conditions, especially in the important milk production area in Central Finland.

Vegetable by-products could potentially be suitable to be used as feeds in animal diets, which in general would strengthen the sustainability of both food and feed systems. Two experiments were performed with the objective to evaluate the aerobic spoilage via visual inspection and short term ensiling process of carrot by-products with silage additives (lactic acid bacteria [LAB] inoculants or formic acid [FA]). In the first experiment (Exp. 1), carrot by-product was treated with five additives including a control without additive, two commercial LAB inoculants (heterofermentative and homofermentative), an in-house isolated LAB mixture and a commercial FA based product. Second experiment (Exp. 2) used a 2 × 3 factorial design (type of raw material [carrot by-product with or without pieces] and additive treatment [control, heterofermentative LAB inoculant or FA based product]). Use of FA restricted lactic acid fermentation indicated by the high residual water soluble carbohydrate concentration while simultaneously stimulating ethanol production. LAB inoculants were not able to efficiently affect quality of ensiled carrot by-products. Use of FA also delayed the spoilage of the fresh carrot by-product particularly in Exp. 1.

The objective of the present study was to evaluate the potential of pressurized hot water extracted hemicellulose fractions from various wood species as feeds for ruminants. In Experiment 1, the fermentability of several hemicellulose extracts was screened using an in vitro gas production method. The samples were extracted from spruce (Picea abies) including mainly galactoglucomannan (GGM), from birch (Betula pendula) consisting mainly of xylan and from larch (Larix sibirica) consisting mainly of arabinogalactan. The GGM and xylan samples were readily fermented by rumen microbes while arabinogalactan was not. Based on the in vitro study, GGM was chosen for an in vivo digestibility trial using sheep, where it was fed at increasing proportions of diet dry matter (0, 47, 94 and 141 g kg-1) in a Latin Square design. The in vivo organic matter digestibility of GGM was relatively low, 0.58, but PHWE extracted hemicellulose has some potential as a feed for ruminants.