Effects of dietary zinc chloride hydroxide and zinc methionine on the immune system and blood profile of healthy adult horses and ponies.

The research article covers a study on the effects of dietary zinc supplements on the immune systems and blood profiles of healthy horses and ponies. It was found that high doses of dietary zinc, specifically zinc chloride hydroxide and zinc methionine, had noticeable effects, many of which varied based on the specific supplement used.

Study Design and Methodology

• The study involved eight healthy adult ponies and two healthy adult horses, which were assigned to six feeding periods, each lasting four weeks.
• The horses and ponies were given diets supplemented with either zinc chloride hydroxide or zinc methionine. The amounts of these supplements were gradually increased over the course of the feeding periods.
• Blood samples were collected from the animals at the end of each feeding period to measure certain immune variables and create a blood profile.

Findings and Results

• Increasing the amount of dietary zinc chloride hydroxide led to higher glutathione concentrations in the erythrocyte concentrate and enhanced activity of glutathione peroxidase in the erythrocyte lysate.
• This increase also resulted in decreased counts of total leukocytes and granulocytes in the blood, as well as lower interleukin-2 concentrations in plasma.
• When increasing doses of zinc methionine were supplemented, there was a boost to the activity of peripheral blood mononuclear cells stimulated by mitogen. However, it also caused a decrease in glutathione concentrations in the erythrocyte concentrate and in the activity of glutathione peroxidase in plasma.
• The study also revealed a decrease in the percentage of blood monocytes with oxidative burst following stimulation with increasing dietary zinc concentrations, regardless of the type of zinc compound used.
• The blood profile revealed that the zinc supplements affected red blood cells and bilirubin metabolism in the horses and ponies. However, these effects require further investigation.

Conclusion

• The study shows that high doses of dietary zinc do influence the immune system in equines. However, the type of zinc compound used also appeared to play a significant role in these effects.
• Though the findings provide a better understanding of how dietary zinc impacts equine health, further studies will be necessary to fully uncover the potential benefits and drawbacks of zinc supplementation.