Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Proceedings
Publication Acceptance Date: 9/12/2003
Publication Date: 1/24/2004
Citation: Hess, B.W., Nayigihugu, V., Mortenson, M.C., Schuman, G.E. 2004. In vitro digestion of forages collected from rangeland interseeded with yellow-flowering alfalfa. Society for Range Management Meeting Abstracts. p. 145.
Technical Abstract: Interseeding alfalfa into rangelands has been studied and practiced as a method of rangeland improvement. Our objective was to evaluate in vitro digestion of perennial forbs, C3 grasses, and other native forages collected from a northern mixed-grass prairie interseeded with yellow-flowering alfalfa (Medicago sativa ssp. falcata). Forage samples were clipped in mid-July 2001 from sites that were interseeded in 1965, 1987, and 1998. Two transects (40 m) were located on a single planted row and two on an adjacent row 152 cm apart on each interseeded site. Four transects were also randomly located on an adjacent native rangeland, while ensuring no interseeding effects from the alfalfa. In general, forage species on the interseeded sites exhibited greater crude protein content. Interseeding alfalfa on the 1965 sampling site increased (P<0.05) protein degradation of the native forages following 4, 8, and 16 h of in vitro incubation, but other in vitro digestion variables collected for native forages were not affected (P=0.07) by interseeding alfalfa in 1965. The 1987 interseeded site exhibited increased (P<0.05) in vitro disappearance of dry matter and protein at 4, 8, 12, and 24 h; however, this effect was not noted (P=0.07) 48 and 96-h post-incubation. Extent of dry matter and protein degradation at 96 h was greater (P=0.01) for native forages collected from the 1998 interseeded site. Interseeding yellow-flowering alfalfa into mixed-grass prairie generally increased digestion of native forages with the greatest effect occurring in the site interseeded in 1987.