ISSN:
1435-0653
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Panicum virgatum L.) populations and which aspects of fiber digestion dynamics caused in vitro dry matter disappearance (IVDMD) differences of six switchgrass populations. This study was conducted in 1993 near Ames, IA, and Mead, NE. The experimental design was a randomized complete block design with a split-plot arrangement of treatments with four replicates at each location. Whole plots were populations and subplots were sward maturity. 'Trailblazer', 'Pathfinder', 'Cave-in-Rock', and three experimental switchgrass populations were used in this study. Populations were harvested on 9 June, 19 July, and 27 August at Ames and on 10 June, 27 July, and 26 August at Mead. Fiber composition and digestibility were determined on leaf blade, leaf sheath, and stem fractions of the primary growth stages. Significant differences for theoretical true digestibility (TD) and neutral detergent fiber (NDF) existed for morphological components at each sward maturity. However, digestion characteristics of the sward components were not stable across primary growth stages. Rate of fiber digestion was faster for most sward components at Ames than Mead, although stem of elongating tillers from elongating swards digested faster on plants grown at Mead than Ames. Rate of fiber digestion of stems was typically slower than either leaf blades or sheaths, but in several instances they were similar or stems had faster rates of fiber digestion.. Although phenotypic selection can increase fiber digestibility, plant maturity remains an important factor, and selection may required evaluation at different stages of morphological development. Thus, improvements in forage digestion, at least in switchgrass, may only be manifested for the growth stage at which it was selected.
Type of Medium:
Electronic Resource
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