title: A dose-response evaluation of spray-dried yeast cell wall supplementation of diets fed to adult dogs: effects on nutrient digestibility, immune indices, and fecal microbial populations.
abstract: The yeast cell wall (YCW) preparation, Safmannan, was evaluated as a dietary supplement for adult dogs. Using a 5 x 5 Latin square design with 14-d periods, adult dogs cannulated in the terminal ileum were supplemented with 0, 0.05, 0.25, 0.45, or 0.65% YCW based on daily food allowance. Apparent ileal nutrient digestibility responded cubically (P = 0.07 to 0.10) to YCW supplementation. Ileal nutrient digestibility tended (P = 0.09) to be greater with YCW supplementation compared with control. Apparent total tract digestibility responded cubically (P < 0.05) to YCW supplementation. Total white blood cell and eosinophil counts tended (P < 0.09) to decrease quadratically with YCW supplementation, with the lowest counts at the 0.25% supplementation level, whereas monocyte counts decreased (P < 0.05) linearly with YCW supplementation. Serum immunoglobulin A (IgA) concentrations tended (P = 0.09) to respond cubically to YCW, with the lowest value at the 0.25% supplementation level. Ileal IgA tended (P < 0.09) to respond quadratically, with the greatest ileal IgA concentration at 0.25% YCW. Using serial dilution and plating enumeration techniques, fecal Escherichia coli concentrations decreased linearly (P = 0.01) with YCW supplementation, whereas Clostridium perfringens responded cubically (P = 0.09). Cubic trends were noted for E. coli (P = 0.10) and lactobacilli (P = 0.08) concentrations, as evaluated by quantitative PCR analysis. Total fecal DNA was most similar to the control treatment at 0.25% YCW. Although the effects on immunological indices appear limited, our results suggest that YCW supplementation in dogs at less than 1% may affect ileal and total tract nutrient digestibility, and the colonization of the gut by E. coli may be decreased.
authors.affiliation: Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
authors.forename: I S
authors.initials: IS
authors.lastname: Middelbos
authors.forename: M R
authors.initials: MR
authors.lastname: Godoy
authors.forename: N D
authors.initials: ND
authors.lastname: Fastinger
authors.forename: G C
authors.initials: GC
authors.lastname: Fahey
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002404:Catheterization / Q000662:veterinary; D002473:Cell Wall; D019587:Dietary Supplements; D004063:Digestion / Q000187:drug effects* / Q000502:physiology; D004285:Dogs / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D004305:Dose-Response Relationship, Drug; D004804:Eosinophils / Q000276:immunology; D004926:Escherichia coli / Q000254:growth & development; D005243:Feces / Q000382:microbiology*; D005260:Female; D005285:Fermentation; D007082:Ileum / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D007070:Immunoglobulin A / Q000276:immunology*; D007778:Lactobacillus / Q000254:growth & development; D007958:Leukocyte Count / Q000662:veterinary; D011897:Random Allocation; D015003:Yeasts / Q000737:chemistry*
chemical_list: D007070:Immunoglobulin A