title: Effects of added chelated trace minerals, organic selenium, yeast culture, direct-fed microbials, and Yucca schidigera extract in horses. Part I: Blood nutrient concentration and digestibility.
abstract: The objective of this study was to test the hypothesis that feed additives such as chelated minerals, organic Se, yeast culture, direct-fed microbials, and Yucca schidigera extract would improve nutrient digestibility when included in an equine diet. Horses (Quarter Horse geldings 4.5 to 16 yr of age; mean BW 522 kg ± 46 kg) were acclimated to 100% pelleted diets formulated with (ADD) and without (CTRL) commercially available sources of the aforementioned additives followed by a 14-d collection period of feces and urine. Chelated sources of Cu, Zn, Mn and Co were utilized versus sulfated forms, at a 100% replacement rate. No significant differences among apparent the digestibility of DM, ADF, or NDF (P= 0.665, P = 0.866, P = 0.747, respectively) were detected between dietary treatments. Likewise, no differences in apparent digestibility of Cu (P = 0.724), Zn (P = 0.256), Mn (P = 0.888), Co (P = 0.71), or Se (P = 0.588) were observed. No differences were observed in serum Cu, Mn, or Co concentrations between ADD and CTRL at acclimation or collection time points (P > 0.05). While no difference in serum Zn concentrations were observed between ADD and CTRL groups at acclimation (P > 0.05), they were statistically higher at the collection time period for horses consuming CTRL (P < 0.0001). Whole blood Se concentration was greater in the CTRL group versus the ADD group both at acclimation (P = 0.041) and collection (P = 0.005) time periods. In reference to time, serum Cu concentrations increased (P = 0.012) for animals consuming CTRL, but not ADD (P > 0.05). Serum Zn concentrations of horses consuming both ADD (P = 0.021) and CTRL (P < 0.0001) increased over time from acclimation to collection time points. No time differences (P > 0.05) were observed in serum Mn concentrations. Serum Co concentrations increased over time in horses consuming both ADD (P = 0.001) and CTRL (P = 0.021). From acclimation to collection, whole blood Se concentration increased for horses consuming CTRL (P = 0.01) but not for ADD (P > 0.05). The results of this study indicate no effect on nutrient digestibility due to the inclusion of chelated minerals, organic Se, yeast culture, direct-fed microbials, and Yucca schidigera extract for horses at maintenance.
authors.affiliation: Purina Animal Nutrition, 100 Danforth Drive, Gray Summit, MO 63039, USA. MEGordon@landolakes.com
authors.forename: M E
authors.initials: ME
authors.lastname: Gordon
authors.forename: M S
authors.initials: MS
authors.lastname: Edwards
authors.forename: C R
authors.initials: CR
authors.lastname: Sweeney
authors.forename: M L
authors.initials: ML
authors.lastname: Jerina
mesh_terms: D000818:Animals; D018592:Cross-Over Studies; D004063:Digestion / Q000502:physiology; D006736:Horses / Q000097:blood* / Q000502:physiology*; D008297:Male; D009753:Nutritive Value; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D012643:Selenium / Q000494:pharmacology*; D014131:Trace Elements / Q000494:pharmacology*; D015003:Yeasts; D027623:Yucca / Q000737:chemistry*
chemical_list: D010936:Plant Extracts; D014131:Trace Elements; D012643:Selenium