Development of Individual Free-Choice Mineral Supplementation Program for Sustainable Grazing Management of Hawaii’s Rangelands

2016 Annual Report for SW16-023

Project Type: Research and Education
Funds awarded in 2016: $332,601.00
Projected End Date: 12/31/2019
Grant Recipient: University of Hawaii at Manoa
Region: Western
State: Hawaii
Principal Investigator:
Dr. Mark Thorne
University of Hawaii at Manoa

Development of Individual Free-Choice Mineral Supplementation Program for Sustainable Grazing Management of Hawaii’s Rangelands


The primary purpose of this project is to: 1) compare the relative palatability and costs of individually supplied minerals (individual free-choice) to commercial pre-mixed mineral widely available in Hawaii; 2) determine if individual free-choice mineral is as effective or better at meeting the nutritional needs of range cattle as a commercial pre-mixed mineral; and 3) provide workshops and field day programming to educate Hawaii livestock producers on the importance of mineral supplementation, and assistance through a project developed decision support tool in developing a mineral supplementation program.

The project involves five different ranch operations of various herd sizes.  Two ranches are on the island of Maui, and three are located on Hawaii island.  One cooperating rancher on the island of Hawaii has been using an individual free-choice mineral supplementation program for many years and was a catalysis in the development of the proposal and project design.  Each ranch is providing range herds for one or both of the project supplementation trials.  The herd sizes range from 50 to 600 head.   

The official start date of this project was April 1, 2016.  Once funds were available (mid-July) the project PI began submitted a “Request for Bids” through SuperQuotes (August 3), as required by University of Hawaii Procedures, for the acquisition of the first year’s supply of mineral. The purchase order for the project minerals was awarded on September 22, 2016.  It was decided to purchase all of the mineral needed for the first year trial at one time to avoid in any potential shipping delays that might occur with multiple purchases.  However, this created an unexpected consequence in that it took the awarded company several months to consolidate the amount of product being purchased for the project and have it shipped from the mainland U.S. to Hawaii.   All the mineral had arrived in Hawaii by December 20.  As of January 12, 2017 the mineral for the two Maui ranches has been delivered while delivery to the three Hawaii island ranches is pending.  The first of the two mineral trials is scheduled to begin February 1, 2017 and will be carried out for one year. 

In October the Project PI began collecting soil samples from the various pastures that will used for the cow herds on the two Maui ranches.  These soil samples will be analyzed for soil mineral composition and used in a mineral profile database for each ranch.  Similar soil samples on the Hawaii island ranches have not been collected yet.   

On January 11, 2017 the Project PI held an online conference call with project partners to begin planning for a spring field day program (objective 3).  The field day program will be provided to producers in the counties of Kauai, Maui, and Hawaii during the week of May 21 – 27, 2017.  The focus of the workshop will be to introduce producers to the project, the importance of a planned mineral supplementation program, and provide assistance in evaluating mineral supplementation choices.

Objectives/Performance Targets

The specific objectives of the project are:

1. Conduct two trials on five ranches across the State (three ranches Hawaii County, two ranches Maui County) over the first two years of the project (one trial each of year one and two) to: a) quantify the relative palatability of various mineral components when offered free choice compared to a commercial pre-mix mineral ration (Trial 1); and b) evaluate the performance of different herds offered either an individual free-choice minerals or a commercial pre-mix mineral ration (Trial 2).

2. Develop a database of seasonal forage quality and mineral composition profiles for rangelands in Hawaii using the forage mineral composition data (June 2018 – June 2019).

3. Conduct a risk-adjusted partial budget analysis of mineral supplementation alternatives and develop a computer-based mineral supplementation decision support tool (June 2018 – June 2019).

A tentative start date of the first trial was originally set for June 2016.  However, logistical complications have necessitated moving the start date of the first trial to February 1, 2017.  Even with this considerable delay, there is sufficient time in the project period to complete both trials by January 31, 2019.  Work on objectives 2 and 3 will be ongoing as data is collected over the course of the two years of trials and thus it is expected that the products will be completed by the end of the project period (March 31, 2019). 


Mineral has been ordered and received a start date for trial one has been set for February 1, 2017. 

Instructions and guidelines for mineral trials developed for each ranch  providing a summary of the trials, objectives, ranch commitments, and a table of mineral supplement components and relative feed rates and costs. 

Soil samples have been collected for two of the five ranches in pastures that will be used for the range herds on trial. 

Planning has started for the series of workshops and field day programs to be provided to livestock producers in Kauai, Maui, and Hawaii Counties May 21-27, 2017. 

Impacts and Contributions/Outcomes

Nothing to report at this time.


Lani Petrie

[email protected]
Kapapala Ranch
PO Box 537,
Pahala, Hawaii 96777
Office Phone: 808-928-8403
Dwayne Cypriano

[email protected]
Hawaii Low-line Cattle Co.
46-3930 Pauono Road
Honokaa, Hawaii 96727
Office Phone: 808-443-4415
Jimmy Gomes

[email protected]
Ranch Manager
Ulupalakua Ranch
HC1 Box 901
Kula, Hawaii 96790
Office Phone: 808-878-1202
Greg Friel

Ranch Manager
Haleakala Ranch
529 Kealaloa Ave.
Makawao, Hawaii 96768
Office Phone: 808-572-1500
Freddy Rice

[email protected]
Freddy Rice Cattle Co.
P.O. Box 98
Kamuela, Hawaii 96743
Office Phone: 808-936-1851
Glen Fukumoto

[email protected]
Livestock Extension Agent, Hawaii County
University of Hawaii-Manoa
Kona Extension Office
79-7381 Hawaii Belt Road
Kealakekua, Hawii 96750
Office Phone: 808-322-0165
Matthew Stevenson

[email protected]
Livestock Extension Agent, Kauai County
University of Hawaii-Manoa
Kauai Extension Office
State Office Bldg., 3060 Eiwa Street, Rm 210
Lihue, Hawaii 96766
Office Phone: 808-274-3471
John Hewlett

[email protected]
Extension Educator
University of Wyoming
Dept. Agriculture and Applied Economics Dept 3354
Agriculture Bldg, 1000E, University Ave.
Laramie, Wyoming 82071-3354
Office Phone: 307-766-2166
Jay Parsons

[email protected]
Associate Professor
University of Nebraska-Lincoln
Dept. of Agricultural Economics
208A Filley Hall
Lincoln, NE 68583