Use of electrolytes to alleviate stress: Desk Top Study

Summary

The joint Meat and Livestock Australia (MLA)/LiveCorp project LIVE.104, “Desk Top Study” is the first stage of a project that aims to deliver recommendations to industry on the best use of electrolytes for alleviating stress in cattle and sheep on board livestock vessels. The desk top study is a review of the scientific literature and live export industry practices to investigate the use and potential benefits of electrolyte supplements during shipping. It identifies sea transport stress factors and describes the physiological and clinical effects of these in cattle and sheep and considers the benefits of electrolyte supplementation in treating these clinical syndromes. Most findings have been drawn from land-based studies and current knowledge of veterinary medicine due to the lack of specific shipboard data.

Recommendations for research are made to enable the development of robust and effective guidelines on the best use of electrolytes. It is proposed that field trials and development of best practice guidelines be carried out in the second stage of this project along with the development of a communication strategy to maximise uptake of the guidelines by industry.

The main functions of electrolytes are to satisfy dietary nutrient requirements and maintain the acid-base balance (neutral pH) of the body. Hence, electrolyte treatments or supplements aim to replenish lost electrolytes and/or correct an acid-base imbalance and there are a number of products currently available in Australia that can do this during the live export of cattle and sheep. To be effective, electrolytes need to alleviate heat and nutritional stress that occurs during live export. Correcting the physiological imbalances that occur as a result of these stresses is the key to the best use of electrolytes.

There is insufficient data to draw any conclusions on the cost-benefits of electrolytes during shipping or to make any recommendations on their best use. In order to determine if there is a cost-benefit of providing electrolytes to cattle and sheep during shipping, two questions need to be answered:

1. What electrolyte formulation is required to alleviate heat and fasting stress during shipping?

2. What are the benefits of providing the correct electrolyte supplement during shipping?

The actual physiological state of cattle and sheep during shipping has not been confirmed. The literature suggests that for cattle, heat stress encountered during shipping will result in metabolic acidosis, while experience suggests that respiratory alkalosis is a significant problem. For sheep, research findings suggest that glucose supplementation may be required to treat inanition, the main cause of deaths during shipping. The current use of electrolytes by the industry is not consistent with these findings.

Land-based studies on the benefits of electrolytes are inconclusive and do not allow any conclusions to be drawn. A general pattern of electrolyte use and industry views on the benefits of electrolytes cannot be determined due to the differences in opinion that exist in the industry. Hence, we recommend that specific research under commercial conditions be conducted into the benefits and costs of electrolyte supplements during shipping. Following are the key findings of this review and recommendations for research to provide the necessary information for guidelines on the best use of electrolytes during shipping to be developed.