# Observed Trace Mineral Deficiencies in a Group of Locally Harvested Sheep in Hawai’i

## TL;DR

This study found high rates of trace mineral deficiencies in sheep in Hawai’i, highlighting the need for better mineral management in tropical environments.

## Contribution

The study provides the first detailed survey of trace mineral status in Hawai’i sheep, revealing common deficiencies and correlations.

## Key findings

- 47% of sheep were deficient in copper, 46% in iron, and 31% in cobalt.
- Strong positive correlations were found between plasma zinc and magnesium, and between liver molybdenum and selenium.
- 11% of liver samples showed manganese toxicity.

## Abstract

There is a significant gap in the information available about the trace mineral status of sheep in tropical and subtropical environments. This research found that of the animals sampled at harvest, 31% were deficient in cobalt, 47% were deficient in copper, and 45% were deficient in iron. In the broader context, these findings highlight the need for region-specific mineral management strategies that account for environmental challenges such as parasite pressure, which can impair mineral absorption and contribute to widespread deficiencies, even when dietary supply appears adequate. For Hawai’i sheep producers, it is suggested that they be aware of deficiency signs for Co, Cu, and Fe, as they appear to be common in sampled sheep in the state.

Trace minerals (TM) play a critical role in the health and productivity of small ruminants. They are essential for various physiological functions, including growth, reproduction, and immune response, yet research on their status in Hawai’i is notably limited. This study focused on surveying the current trace mineral concentrations of locally raised and harvested sheep to identify common deficiencies and toxicities. Sheep liver (n = 83) and plasma (n = 79) samples were collected over eight months from local harvest facilities and private operations. There was a high percentage of liver samples that were deficient in copper (47%), iron (46%), and cobalt (31%). There was a low percentage of liver samples that were toxic in Mn (11%). Strong positive correlations in plasma zinc and plasma magnesium (r = 0.814, p < 0.0001) and liver molybdenum and liver selenium (r = 0.72, p < 0.0001) were found. With this data, local small ruminant producers will be able to evaluate their nutrition management program. Addressing these gaps is vital for conducting future research studies, improving sheep health, and ensuring the productivity of small ruminant operations in Hawai’i.