Quantifying Secondary Compounds in Common Pasture Vegetation for Behavior Based Grazing Management in Hawaii

2010 Annual Report for FW09-308

Project Type: Farmer/Rancher
Funds awarded in 2009: $41,760.00
Projected End Date: 12/31/2012
Region: Western
State: Hawaii
Principal Investigator:
Dr. Mark Thorne
University of Hawaii at Manoa

Quantifying Secondary Compounds in Common Pasture Vegetation for Behavior Based Grazing Management in Hawaii


Work in 2010 included researching and compiling information on the ecology, toxicology and distribution of selected species of weeds and brush common to Hawaii’s range and pasturelands. The information was compiled into a database that allowed detection of where gaps in knowledge exist and helped focus field research efforts. Field sampling was conducted on Maui in April. Samples were collected from various pastures on Haleakala and Hana Ranch. Samples were either dried and ground for analysis or were pressed to be mounted for display in extension office herbariums.

Objectives/Performance Targets

The specific objectives for this project are:

1) develop an online database accessible to the public, listing common range and pasture plants, their nutritional value, secondary compounds and recommended grazing practices for utilization;

2) establish a plant collection of the species in the database for identification and educational purposes that will be held in herbariums located at the county extension offices in Hawaii;

3) produce a field manual for producers and land managers providing information on the plants in the database that will be useful for field identification of the plants and will also provide a summary of secondary compounds, forage value, recommend targeted grazing practices and cautions for utilization of the plant; and

4) develop targeted, behavior-based grazing practices for the plants in the database that will be presented in a series of fact sheets and extension service workshops.


Currently the database includes information on 20 plants, with research being conducted on another 10. Samples of 10 weed species have been collected from pastures on Maui. These samples are being prepared for mounting and display in the county extension offices on Maui and Hawaii island. Other samples have been dried and ground and are currently being stored in preparation for analysis of secondary compounds. Work on a field manual, extension factsheets and targeted, behavior-based grazing practices has not begun.

Impacts and Contributions/Outcomes

Nothing to report at this time.


Amber Starr

General Manager
Hana Ranch Partners, LLC
P.O. Box 1447
Makawao, HI 96768
Office Phone: 8085736444
Greg Friel

Livestock Operations Manager
Haleakala Ranch Company
529 Kaelaloa Av.
Makawao, HI 96768
Office Phone: 8085721500
Lani Petrie

Kapapala Ranch
P.O. Box 1639
Hilo, HI 96721
Office Phone: 8089288403