Publication Date
1985
Location
Kyoto Japan
Description
Cattle selectrively graze switchgrass (Panicum virgatum L.) tops prior to the boot stage and prefer vegetative culms and new tillers following heading. Therefore, a study was conducted to evaluate the changes in forage composition of individual leaves and stems during growth to determine if grazing selection may be influenced by aging. Plants were cut periodically at ground level from collaring of the first leaf until anthesis. Leaves (leaf blade plus sheath) of different ages, stems, and the whorl were hand separated at each harvest. Crude protein, in vitro dry matter disappearance (IVDMD), neutral and acid detergent fiber, lignin, and insoluble ash were estimated for each plant part. Crude protein and IVDMD declined as leaves aged; however, leaves that developed early in the season during cooler temperatures had better forage quality at similar growth stages than later developed leaves. The whorl and most recently collared leaf were highest and sterris were lowest in quality. In stem tissue, lignin increased and IVDMD and crude protein decreased dramatically as inflorescences neared emergence. Changes in stem composition appeared to be the primary factor influencing changes in grazing selection during the grazing season. Cultural practices and genetic manipulation that improve stem composition may result in improved switchgrass utilization by livestock.
Citation
Anderson, B, "The Influence of Aging on Forage Quality of Individual Switchgrass Leaves and Stems" (1985). IGC Proceedings (1985-2023). 3.
(URL: https://uknowledge.uky.edu/igc/1985/ses10/3)
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
The Influence of Aging on Forage Quality of Individual Switchgrass Leaves and Stems
Kyoto Japan
Cattle selectrively graze switchgrass (Panicum virgatum L.) tops prior to the boot stage and prefer vegetative culms and new tillers following heading. Therefore, a study was conducted to evaluate the changes in forage composition of individual leaves and stems during growth to determine if grazing selection may be influenced by aging. Plants were cut periodically at ground level from collaring of the first leaf until anthesis. Leaves (leaf blade plus sheath) of different ages, stems, and the whorl were hand separated at each harvest. Crude protein, in vitro dry matter disappearance (IVDMD), neutral and acid detergent fiber, lignin, and insoluble ash were estimated for each plant part. Crude protein and IVDMD declined as leaves aged; however, leaves that developed early in the season during cooler temperatures had better forage quality at similar growth stages than later developed leaves. The whorl and most recently collared leaf were highest and sterris were lowest in quality. In stem tissue, lignin increased and IVDMD and crude protein decreased dramatically as inflorescences neared emergence. Changes in stem composition appeared to be the primary factor influencing changes in grazing selection during the grazing season. Cultural practices and genetic manipulation that improve stem composition may result in improved switchgrass utilization by livestock.
