title: Effects of Euphorbia esula L. (leafy spurge) on cattle and sheep in vitro fermentation and gas production.
abstract: BACKGROUND
  Euphorbia esula L. (leafy spurge) is indigenous to Eurasia and has been known to cause grazing aversion in ruminant species. As a result, E. esula encroachment has negatively impacted rangelands in the Northern Great Plains and Intermountain West of the USA, as well as southern Canada. Our objectives were to evaluate the effect of increasing concentrations of E. esula on in vitro dry matter digestibility (DMD) and gas production. Two ruminally-cannulated cows and ewes were used as rumen inoculum donors. To accomplish objectives, two studies were conducted. In study 1, animals were fed exclusively a barley hay (12% crude protein (CP), 55.4% neutral detergent fiber (NDF), DM basis) diet; whereas in study 2, animals were fed a diet of 15% E. esula (21.9% CP, 48% NDF, DM basis) and 85% barley hay based on previous day intake.
  
  
  RESULTS
  The 24 and 48 h in vitro and 96 h gas production indicate that, regardless of inoculum source or substrate fermented, DMD was not influenced. Differences, however, were consistently observed across studies for NDF disappearance.
  
  
  CONCLUSIONS
  Regardless of inoculum source NDF disappearance was greater when substrate being fermented contained 0%, 80%, or 100% E. esula.
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Fort Keogh Livestock and Range Research Laboratory, Miles City, MT 59301-4016, USA. richard.waterman@ars.usda.gov
authors.forename: Richard C
authors.initials: RC
authors.lastname: Waterman
authors.forename: Kimberly D
authors.initials: KD
authors.lastname: Richardson
authors.forename: Shanna L
authors.initials: SL
authors.lastname: Lodge-Ivey
mesh_terms: D000222:Adaptation, Physiological; D000821:Animal Feed / Q000009:adverse effects; D000818:Animals; D002417:Cattle / Q000378:metabolism* / Q000382:microbiology; D004043:Dietary Fiber / Q000008:administration & dosage; D004063:Digestion; D028481:Euphorbia / Q000009:adverse effects; D005260:Female; D005285:Fermentation; D005414:Flatulence / Q000517:prevention & control / Q000662:veterinary*; D005766:Gastrointestinal Contents / Q000382:microbiology; D009009:Montana; D018515:Plant Leaves / Q000009:adverse effects; D012417:Rumen / Q000382:microbiology; D034561:Sheep, Domestic / Q000378:metabolism* / Q000382:microbiology; D013997:Time Factors