title: Evaluation of titanium dioxide as a digestibility marker for cattle.
abstract: Three studies were conducted to evaluate titanium dioxide (TiO2) as a digestibility marker for cattle. In Exp. 1, eight steers consumed prairie hay ad libitum with or without dietary supplements. Fecal recovery of TiO2 averaged 93% and was not affected (P = 0.47) by supplement. Digestibilities calculated with reference to TiO2 were not different (P = 0.15) from those based on total fecal collections. In Exp. 2, two steers were limit-fed corn-based diets. Fecal recovery of TiO2 averaged 95% and that of chromic oxide (Cr2O3) averaged 113%. Digestibilities calculated with reference to TiO2 were underestimated (P < 0.01) by 1.1 percentage units relative to those based on total fecal collections, and those calculated with reference to Cr2O3 were overestimated (P < 0.01) by 2.0 percentage units. In Exp. 3, eight steers in a replicated 4 x 4 Latin square consumed corn-based diets ad libitum. Fecal recovery of TiO2 averaged 90%, whereas that of Cr2O3 averaged 98%. Digestibilities calculated with reference to TiO2 were underestimated (P < 0.01) by 1.6 to 4.3 percentage units, whereas those calculated with reference to Cr2O3 were not different (P = 0.31) from those based on total fecal collections. Future research is warranted to determine the usefulness of TiO2 in measuring digestibility in cattle.
authors.affiliation: Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506-1600, USA. etitgeme@oznet.ksu.edu
authors.forename: E C
authors.initials: EC
authors.lastname: Titgemeyer
authors.forename: C K
authors.initials: CK
authors.lastname: Armendariz
authors.forename: D J
authors.initials: DJ
authors.lastname: Bindel
authors.forename: R H
authors.initials: RH
authors.lastname: Greenwood
authors.forename: C A
authors.initials: CA
authors.lastname: Löest
mesh_terms: D000821:Animal Feed; D000818:Animals; D015415:Biomarkers; D002417:Cattle / Q000502:physiology*; D017608:Chromium Compounds / Q000032:analysis; D004063:Digestion; D005243:Feces / Q000737:chemistry; D008297:Male; D011897:Random Allocation; D014025:Titanium / Q000032:analysis*
chemical_list: D015415:Biomarkers; D017608:Chromium Compounds; C009495:titanium dioxide; D014025:Titanium; C023600:chromic oxide