Neki pokazatelji kvalitete silaže kukuruza stare godinu dana

master's thesis

• Author: Ivoslav Turkalj
• Mentor: Darko Grbeša (mentor)
• Committee member: Darko Grbeša (predsjednik povjerenstva)
• Committee member: Goran Kiš (član povjerenstva)
• Committee member: Zlatko Svečnjak (član povjerenstva)
• Committee member: Marija Duvnjak (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Animal Nutrition); Zagreb
• Defense date and country: 2016-09-23, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

Siliranje je proces konzerviranja biljnih materijala fermentacijom ugljikohidrata topivih u vodi uslijed djelovanja homofermentativnih i heterofermentativnih bakterija mliječne kiseline. Proizvodnja organskih kiselina, od kojih u najvećem dijelu mliječna kiselina, snižava pH koji inhibira nepoželjne mikroorganizame i konzervira silirani materijal. Najnovija istraživanja ukazuju da unatoč niskom pH mikrobna aktivnost ustraje i u stabilnoj fazi čime može doći i do promjena u kvaliteti silirane mase. Cilj ovog istraživanja je bio utvrditi utjecaj vremena i dva tipa dodataka (dodatak inokulanta i dodatak mliječne kiseline) na promjenu glavnih parametara (suhe tvari, mliječne kiseline, vodotopivih šećera, pH vrijednosti i pufernog kapaciteta) silaže cijele biljke kukuruza tijekom osam uzorkovanja u periodu produljenog siliranja od godine dana. U silaže je prilikom siliranja dodan inokulant Bio-Sil koji u sebi sadrži liofilizirane kulture Lactobacillus plantarum 8862 i 8866 kao i dodatak mliječne kiseline u linearnom rasponu od 1 % do 7 % ST mase silaţe. Kod određivanja vodotopivih šećera koristila se modifikacija Luff-Schoorlove i Nelson- Somgyjeve metode. Sadržaj mliječne kiseline u vodenim ekstraktima uzoraka silaža određen je spektrofotometrijskom metodom. Tijekom 364 dana siliranja svi ispitivani parametri silaža osim suhe tvari bilježe promjenu. Silaže s dodatkom inokulanta imale su nagli porast mliječne kiseline (s 3,99 na 51,23 g/kg ST) i pad pH (s 5,47 na 3,82) u prvim danima siliarnja dok je isto biljeţeno u kasnijim fazama siliranja u silaţama s dodatkom mliječne kiseline. Kontrolne silaţe imale su najniže vrijednosti mliječne kiseline, nešto višu količinu vodotopivih šećera te viši pH kroz cijeli period siliranja. U svim silažama u ispitivanom period bilježimo pad vodotopivih šećera i porast pufernog kapaciteta što je neposredno vezno uz sintezu mliječne kiseline. Rezulati ukazuju da je dodatak inokulanta i mliječne kiseline povoljno djelovao na siliranje u odnosu na kontrolnu kukuruznu silažu te da silaža cijele biljke kukuruza bilježi promjene tijekom cijelog jednogodišnjeg perioda čuvanja silaža iako u fazi stajanja su one usporene.

Abstract (english)

Silage is the plant material preservation process guided by homofermentative and heterofermentative lactic acid bacteria fermentation of carbohydrates soluble in water. Production of organic acids, mostly lactic acid, lowers the pH which inhibits undesirable microorganisms and preserves ensiled material. The latest research shows that, despite low pH value, microbial activity can persists in a stable phase, which can lead to changes in the quality of the silage mass. The focus of this research was to determine the effect of ensiling time and two types of additives (inoculant and lactic acid additive) on main corn silage quality parameters (dry matter, lactic acid, water soluble sugars, pH value and buffering capacity) during eight sampling periods of extended ensiling up to one year. Added inoculant Bio-Sil contained lyophilized cultures of Lactobacillus plantarum 8862 and 8866 and added lactic acid was in the linear range from 1% to 7% of DM silage mass. Water-soluble sugars were determined by modification of the Luff-Schoorl and Nelson- Somogy methods. The content of lactic acid in the silage samples was determined by the spectrophotometric method. During 364 days of ensiling all tested quality parameters of whole plant corn silage, except dry matter, recorded change. Silages with added inoculant had a sudden increase in lactic acid (from 3.99 to 51.23 g/kg DM) and decrease in pH value (from 5.47 to 3.82) in the first days of ensiling while the same results were recorded in the later stages of ensiling in silages with the added lactic acid. The controlled silages had the lowest values of lactic acid, slightly higher amounts of water-soluble sugars and higher pH values throughout the whole ensiling period. In all silages during examined period we recorded decrease in water soluble sugars and increase of the buffer capacity which is directly related to synthesis of lactic acid. The results imply that the addition of the inoculant and lactic acid had favourable impact on the silage quality when compared to controlled corn silage and that in whole plant corn silage quality parameters are continuously changing during the whole ensiling period although in stable phase the changes are minimal.

• Keywords: silaža kukuruza; dugotrajno siliranje; inokulant; mliječna kiselina; pH; vodotopivi šećeri
• Keywords (english): corn silage; long-term ensiling; inoculant; lactic acid; pH value; water-soluble sugars
• Language: croatian
• URN:NBN: urn:nbn:hr:204:042092
• Study programme: Title: Animal Nutrition and Feed Science; Study programme type: university; Study level: graduate; Academic / professional title: magistar/ magistra inženjer/inženjerka hranidbe životinja i hrane (magistar/ magistra inženjer/inženjerka hranidbe životinja i hrane)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-03-28 12:03:33