title: The effect of sulphate on thiamine-destroying activity in rumen content cultures in-vitro.
abstract: The effect of sulphur on thiamine-destroying activity was studied in native or thiamine-spiked rumen content cultures. The treatments consisted of water [control (Ctrl)], sodium chloride (NaCl) and sodium sulphate (Na2SO4). A net gain (relative to 0 h) of thiamine in native cultures was observed for at least 48 h at levels of S ranging from 0.25 to 8 mg S added per ml of the culture and also in the Ctrl and respective NaCl cultures. However, after 48 h of incubation thiamine concentration was lower (p < 0.05) in native cultures treated with Na2SO4 relative to Ctrl and NaCl treatments. There was a linear (p < 0.03) time trend indicating an effect of Na2SO4 over time on changes in thiamine concentration in native rumen cultures. In thiamine-spiked rumen content cultures, the cultures treated with Na2SO4 produced higher (p < 0.05) thiamine-destroying activity. There was no effect of cation (Na) on thiamine-destroying activity. Initial heat treatment of thiamine-spiked cultures inactivated part of the thiamine-destroying activity. There were no differences among treatments in heat treated cultures. It is concluded that sulphate increases thiamine-destroying activity in the rumen content and the destructive mechanism involves thermolabile factor(s), however, the ruminal synthesis of thiamine is not affected by sulphate.
authors.affiliation: Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, Canada.
authors.forename: A A
authors.initials: AA
authors.lastname: Olkowski
authors.forename: B
authors.initials: B
authors.lastname: Laarveld
authors.forename: J F
authors.initials: JF
authors.lastname: Patience
authors.forename: S I
authors.initials: SI
authors.lastname: Francis
authors.forename: D A
authors.initials: DA
authors.lastname: Christensen
mesh_terms: D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D056890:Eukaryota / Q000187:drug effects; D005260:Female; D006358:Hot Temperature; D066298:In Vitro Techniques; D008297:Male; D012417:Rumen / Q000187:drug effects* / Q000382:microbiology / Q000469:parasitology; D013431:Sulfates / Q000494:pharmacology*; D013831:Thiamine / Q000378:metabolism*
chemical_list: D013431:Sulfates; D013831:Thiamine