Degree Type

Dissertation

Date of Award

1999

Degree Name

Doctor of Philosophy

Department

Agronomy

First Advisor

Kenneth J. Moore

Abstract

Complete information on the forage nutritive value of amaranth is not available. The objective of this study was to evaluate forage yield, quality, and canopy development of various species of amaranth at different developmental stages. Seven amaranth accessions were established in 1997 and 1998 near Boone, Iowa. Plots were established in a randomized complete block design and subplots were harvested at two-week intervals, starting at 28 days after planting (DAP). In vitro dry matter digestibility (IVDMD), neutral detergent fiber (NDF), crude protein (CP), nitrate, acid detergent fiber (ADF), and acid detergent lignin (ADL), and protein and fiber digestion were determined;Greatest yields were observed after 70 DAP, averaging 5500 kg ha --1. Two-week regrowth at 28 DAP ranged from 668 kg ha --1 for A. hybridus (Greece) to 152 kg ha --1 for A. hybridus (Zambia). Accession and DAP affected leaf area index (LAI). Amaranthus hybridus (Greece) had a season high LAI of 3.9 at 84 DAP;Averaged over accessions, IVDMD decreased from a high of 780 g kg --1 at 42 DAP to 680 g kg--1 at 112 DAP. Highest IVDMD was observed in Amaranthus hybridus (Greece) and A. hybrid (Puebla, Mexico). At 42 DAP average CP level was 270 g kg--1 then decreased drastically to 100 g kg --1 at 112 DAP. Neutral detergent fiber levels increased from 3 10 g kg--1 at 42 DAP to 43 0 g kg--1 at 112 DAP. Amaranthus cruentus (Zimbabwe) had the greatest average NDF (390 g kg--1). Acid detergent fiber and ADL were lower than reported for alfalfa and oats. Observed range of undegraded intake protein for Amaranthus cruentus (Zimbabwe), A. cruentus (Rwanda) and A. hybrid (Puebla, Mexico) was 17--38, 11--32, and 9--21%, respectively. True digestibility was high, averaging 850 g kg--1 dry matter and ranging from 793--929 g kg--1 DM at 42 DAP to 834--905 g kg--1 DM at 112 DAP;The yield and forage nutritive value taken together indicates that amaranth has great potential as a forage of equal, and in some cases better quality than commonly used forages. Also, its regrowth potential would be advantageous to a producer utilizing a multiple cut system.

DOI

https://doi.org/10.31274/rtd-180813-13446

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Byron Barrington Sleugh

Language

en

Proquest ID

AAI9940241

File Format

application/pdf

File Size

105 pages

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