title: Influence of a Fusarium culmorum inoculation of wheat on the progression of mycotoxin accumulation, ingredient concentrations and ruminal in sacco dry matter degradation of wheat residues.
abstract: The Fusarium head blight (FHB)-susceptible winter wheat cv. Ritmo was inoculated with spores of Fusarium culmorum at the beginning of full blossom. Samples of whole wheat plants were taken once weekly from anthesis until harvest and subsequently fractionated into straw, glumes and spindles, which were examined for deoxynivalenol (DON) and zearalenone (ZON). Additionally, the content of crude protein (CP) and non-starch polysaccharides (NSP) was scrutinized. Synthesis of the Fusarium toxins DON and ZON generally differed in terms of date of formation and concentration. Final mean DON concentrations of 37.5, 28.1 and 5.0 mg/kg DM were measured in glumes, spindles and straw, respectively, at the time of harvest. At this time, maximal mean ZON concentrations of 587, 396 and 275 microg/kg DM in spindles, glumes and straw, respectively, were determined. Moreover, Fusarium infected wheat residues contained higher CP but lower NSP contents at the last three sampling dates. In addition, collective samples of wheat straw and chaff were taken to investigate the effect of the Fusarium contamination on their in sacco DM degradation in dairy cows. Samples were analysed for mycotoxins and selected quality parameters. The dried and milled collective samples of straw and chaff were weighed into nylon bags and subjected to ruminal incubation for 4, 8, 16, 24, 48, 72, 96 and 120 h in two dairy cows equipped with a permanent rumen cannula. Marked differences in level of mycotoxin contamination as well as in ingredient composition between the variants of straw and chaff were detected. Moreover, after 120 h rumen incubation the in sacco DM degradation of inoculated straw and chaff were lower compared to the accordant controls. The soluble fraction was increased in inoculated samples, whereas a diminishment in the potentially degradable but insoluble fraction was more pronounced. Thereby, a decrease in the potential degradability was obtained for inoculated straw and even if less pronounced for chaff compared to the non inoculated corresponding controls. In conclusion, infection with F. culmorum of wheat involves an increased risk of mycotoxin contamination in straw. Also, a Fusarium infection may have an impact on chemical composition and may result in Fusarium growth-related modifications of host cell wall components.
authors.affiliation: Institute of Animal Nutrition, Federal Agricultural Research Centre (FAL) Braunschweig, Germany.
authors.forename: Ute
authors.initials: U
authors.lastname: Brinkmeyer
authors.forename: Sven
authors.initials: S
authors.lastname: Dänicke
authors.forename: Mauricio
authors.initials: M
authors.lastname: Lehmann
authors.forename: Hana
authors.initials: H
authors.lastname: Valenta
authors.forename: Peter
authors.initials: P
authors.lastname: Lebzien
authors.forename: Margit
authors.initials: M
authors.lastname: Schollenberger
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Südekum
authors.forename: Joachim
authors.initials: J
authors.lastname: Weinert
authors.forename: Gerhard
authors.initials: G
authors.lastname: Flachowsky
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle; D004063:Digestion; D005260:Female; D005504:Food Analysis; D005506:Food Contamination / Q000032:analysis*; D005670:Fusarium / Q000378:metabolism*; D009183:Mycotoxins / Q000032:analysis*; D012417:Rumen / Q000378:metabolism*; D012995:Solubility; D014255:Trichothecenes / Q000032:analysis; D014908:Triticum / Q000737:chemistry / Q000382:microbiology; D015025:Zearalenone / Q000032:analysis
chemical_list: D009183:Mycotoxins; D014255:Trichothecenes; D015025:Zearalenone; C007262:deoxynivalenol