Estimation of Fecal Output and Particulate Passage Rate with a Pulse Dose of Ytterbium-Labeled Forage
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CitationKrysl, L. J., McCollum, F. T., & Galyean, M. L. (1985). Estimation of fecal output and particulate passage rate with a pulse dose of ytterbium-labeled forage. Journal of Range Management, 38(2), 180-182.
PublisherSociety for Range Management
JournalJournal of Range Management
AbstractTwelve rumen-cannulated lambs (avg. wt. 40 kg), fed long-stem alfalfa or prairie hay in a crossover design (two, 15-day periods) were used to compare estimates of fecal output from a pulse dose of ytterbium (Yb)-labeled forage and fecal collection bags. Estimates of fecal output (g/day) with Yb-labeled forages were not different (P>.05) from total collection values for lambs fed either alfalfa or prairie hay. Fecal output from a pulse dose of Yb was 100 +/- 2% of total collection for lambs fed alfalfa and 103 +/- 3% for lambs fed prairie hay. Particulate passage from the rumen was faster (P<.01) in lambs fed alfalfa (7.0%/hr) then in lambs fed prairie hay (3.9%/hr). A pulse dose of Yb-labeled hay appears to prove reliable estimates of fecal output as well as passage rate estimates, but validation of techniques in free-grazing ruminants is needed.