Browsing by Subject "aerobinen stabiilisuus"

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  • Puhakka, Laura (Helsingfors universitet, 2011)
    Tämän maisterin tutkielman tarkoituksena oli testata eri maitohappobakteerien ja niiden annostustason vaikutusta säilörehun käymislaatuun ja aerobiseen stabiilisuuteen. Biologisilla säilöntäaineilla eli ympeillä säilöttyjen rehujen laatua verrattiin kontrolleina toimiviin painorehuun ja muurahaishapolla tehtyyn rehuun. Koerehut tehtiin Helsingin yliopiston Maataloustieteiden laitoksella 7.6.2010. Timotei (Phleum pratense) - nurminata (Festuca pratensis) kasvusto korjattiin tähkimisen alkuvaiheessa D-arvon ollessa 711 g/kg ka. Nurmikasvuston kuiva-ainepitoisuus oli 170 g/kg heti niiton jälkeen määritettäessä ja neljän tunnin esikuivauksen jälkeen 208 g/kg. Rehuraaka-aine jaettiin kuuteen erään, joihin lisättiin säilöntäaine. Säilöntäainekäsittelyt olivat: 1) ei säilöntäainetta (painorehu), 2) muurahaishappo (100 %:na 4 l/t), 3) Lactobacillus plantarum ja Pediococcus acidilactici 1x10? pmy/g sekä pektinaasi-, ksylanaasi- ja sellulaasientsyymi, 4) L. plantarum 1x10? pmy/g, 5) L. plantarum 1x10? pmy/g ja 6) L. plantarum ja L. buchneri 2x10? pmy/g. Rehut säilöttiin laboratoriosiiloissa kolmena rinnakkaisena. Laboratoriosiilojen lisäksi rehua säilöttiin jokaisesta säilöntäainekäsittelystä kuuteen rinnakkaiseen minisiiloon säilönnän alkuajan fermentaation ja rehujen pH:n muutoksen seuraamiseksi. Minisiiloista seurattiin kaasuntuotantoa 21 päivän ajan. Raaka-aineen koostumus ja rehujen säilönnällinen laatu sekä aerobinen stabiilisuus määritettiin. Säilörehujen kuiva-ainepitoisuus oli suhteellisen pieni (n. 210 g/kg), jotta voitiin testata biologisten säilöntäaineiden tehoa märässä rehussa. Kosteassa rehussa biologisten säilöntäaineiden toiminnan onnistuminen on haastavaa. Koska raaka-aineen sokeripitoisuus oli kuitenkin erittäin suuri (196 g/kg ka), onnistui ymppirehujen säilöntä hyvin. Kaikkien koerehujen pH oli alle 4:n. Painorehu ei täyttänyt hyvän rehun kriteerejä ammoniumtypen osalta. Muurahaishapporehu oli laadultaan tyydyttävää etikkahapon pitoisuuden osalta. Rehussa tapahtui epätyypillistä etanolikäymistä hiivojen toimesta, jonka johdosta rehussa muodostui suuri määrä kaasua säilönnän aikana. Muurahaishapporehu ei kuitenkaan lämmennyt aerobisen stabiilisuuden mittauksen aikana, johtuen todennäköisesti suuresta etikkahapon määrästä ja toisaalta pienestä sokerin määrästä. Maitohappobakteerisäilöntäaineilla saatiin käymislaadultaan parempaa säilörehua verrattuna painorehuun, lukuun ottamatta maitohappobakteeri-entsyymirehua. Entsyymilisäyksestä ei todennäköisesti ollut hyötyä rehun säilöntälaadun kannalta. Raaka-aineen suuren sokeripitoisuuden johdosta säilörehussa oli koko säilönnän ajan tarpeeksi sokeria maitohappobakteerien käytettäväksi ja sokeri toimi siten substraattina haitallisille mikrobeille tuottaen suuren etikkahappopitoisuuden. Maitohappobakteeri-entsyymiseoksella tehty rehu oli etikkahappopitoisuuden perusteella heikkolaatuista. Lactobacillus plantarumin molemmilla annostustasoilla (1x10? ja 1x10? pmy/g rehua) saatiin laadultaan hyvää rehua. Suuri sokeripitoisuus molemmissa rehuissa johtui todennäköisesti raaka-aineen tavallista suuremmasta sokerin määrästä. Molempien rehujen maitohappo-etikkahappo-suhde oli melko korkea, viitaten homofermentatiiviseen maitohappokäymiseen. Lactobacillus buchneri –lisäyksellä rehu oli säilönnälliseltä laadultaan hyvää. Heterofermentatiivisen ympin lisäys nosti tyypillisesti rehun pH:ta sekä pienensi maitohappoetikkahappo-suhdelukua verrattuna homofermentatiiviseen ymppiin. L. buchneri –lisäys paransi hieman säilörehun aerobista stabiilisuutta verrattuna homofermentatiivisella maitohappobakteerilla säilöttyyn rehuun, mutta tulos ei ollut tilastollisesti merkitsevä.
  • Kuusisto, Katja (Helsingin yliopisto, 2015)
    The aim of this study was to investigate the ensilability of field pea and faba bean bi-crop with spring wheat when ensiled as whole-crop with different additives. In this study we attempted to clarify use of pea – wheat and faba bean – wheat bi-crop in organic farming. Forages was sown at 4th to 7th of June in Luonnonvarakeskus (Luke) Ruukki and forages were ensiled in laboratory silos at 26th of August 2013. Silages were ensiled without additive (PR), with formic acid (MH) and with two different heterofermentative inoculants (B1 and B2) as additive. Each treatment were made three replicants. Silos were opened after 106 ensiling days at 9th of December in Luke Jokioinen. Chemical and microbiological compositions were determined from samples of herbage. From silage samples were analysed fermentation quality, microbiological composition and aerobic stability. All samples were wet. Faba bean – wheat bi-crop was a little wetter than field pea – wheat bi-crop. Field pea – wheat forage contained more crude protein, water-soluble carbohydrates, starch and had stronger buffering capacity than faba bean – wheat. Faba bean – wheat bi-crop contained more neutral-detergent fiber (NDF) and had also lower digestibility. Both of crops were easy to ensile and growth stage were different between crops. All samples included lot of micro-organism especially yeast, moulds and epiphytic lactic acid bacteria. Field pea – wheat silage contained more fermentation products than faba bean – wheat silage. MH- treated silages had better fermentation quality than other silages although there were higher pH values in MH silages. MH silages contained less lactic and acetic acids and ammonium nitro-gen. Inoculant treated silages mostly did not differ from PR treatment in fermentation parameters. That is probably due to high epiphytic lactic acid bacteria account in herbage. Silages contained only a little butyric acid. Microbiological quality of silages predisposed them to aerobic deteriora-tion because there were considerable high amounts of yeasts and moulds. Field pea –wheat silages were more aerobically stable than faba bean - wheat. This is probably due to higher concentration of fermentation acids in field pea-wheat silages. MH treatment was the most aerobically stable of field pea – wheat silages. B2 treatment was the most stable of field pea – wheat silages. Mixed ration of these silages were more prone to aerobically deterioration than silages.
  • Salakka, Anna (Helsingin yliopisto, 2019)
    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.
  • Niemi, Tea (Helsingin yliopisto, 2018)
    This master’s thesis is part of “Valkuaisfoorumi” project executed in co-operation with Häme University of Applied Sciences (HAMK) and Natural Resources Institute Finland (Luke). Main goal of “Valkuais-foorumi” is to increase self-sufficiency of protein by increasing the cultivation area and to search possibili-ties to utilize protein plants in crop rotation and to increase the use of locally produced protein feeds for domestic animals, both ruminants and monogastric animals. There is a rising interest of using faba bean in food industry and as a feedstuff for domestic animals. Experiment 1: Optimizing harvesting time for whole-crop faba bean. Optimal harvesting time was determined by collecting samples from three different faba bean varieties five times at two-week intervals during growing period and analysing changes in nutritional value and crop yields. Optimal harvesting time is after the pods are starting to fill and the plant is still green, leafy and not rotten. Crop yield grows within time but harvesting is recommended before autumn rains as humid condi-tions increase risk of losses during harvesting and preservation. Experiment 2: Crimped faba beans were ensiled using different additives based on lactic acid bacteria or additives restricting fermentation. Nutritional value, microbiological and fermentation quality, aerobic stability and reduction of the antinutritional factors were determined. Additives improved quality of ensiled crimped faba bean. Amounts of vicin and convicin decreased during fermentation process. Amount of tannins varied among treatments and antimicrobial chemical addi-tive was the most efficient in reducing tannins compared to ensiling without additives. Aerobic stability was good with all additives and with antimicrobial chemical treatment the 2-degree temperature rise could not be reached during the measurement period of 210 h. Lactic acid bacteria based inoculant improved fermen-tation quality of feed by decreasing the number of harmful microbes. Chemical additive restricted the fer-mentation of feed and fermentation losses were minute. By ensiling crimped faba bean it is possible to harvest the crop in earlier stage of maturity and using adidtives improves the nutritional and microbial qual-ity. Avainsanat
  • Kylmämaa, Laura (Helsingin yliopisto, 2015)
    The aim of this study was to investigate how the quality of silage affects the silage intake of reindeer. There were two growth stages of primary growth and regrowth silage in the study. Aerobic stability of silage was observed after opening the silage bales. The experimental silages were made at the fields of MTT Agrifood Research Finland in Apukka, Rovaniemi. The study was conducted at the reindeer pen of Lapland Vocational College. There were four groups of female reindeer, six animals in each, and one silage type per group. Feeding trial lasted eight weeks with two weeks pre-period before. Reindeer were fed ad libitum in the mornings. The biggest differences of chemical composition of silages were between primary growth and regrowth silage. The growth stage did not affect to the chemical composition. Aerobic deterioration of silages was not observed during three weeks exposure to air because ambient temperature remained above zero almost constantly. Silage residue had lower D-value, crude protein, AAT and PBV content and higher concentration of NDF-fiber compared to the given feed. The selection of feed differed between primary growth and regrowth silage based on crude protein and water-soluble carbohydrate (WSC) contents. This is may be because of the excess of crude protein and WSC relative to nutrient requirements of reindeer or that the variables are correlated with the other variables which explain the intake. Silage intake was higher when dry-matter content was higher and lower when crude protein content was higher. WSC had slightly positive effect to the intake. Intake seemed to be curvilinearly related to the content of fermentation products. Effective utilization of silage requires analyses on the chemical composition of silage.