Hematological and Biochemical Responses of Donkeys (Equus asinus) to Packing and Trekking During the Hot-Dry Season.
Authors: Ayo Joseph Olusegun, Ake Ayodele Stephen, Abimbola Ariyo Adelaja
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Working donkeys face significant physiological demands during the hot-dry season, yet their haematological and biochemical responses to combined load-carrying and trekking remain poorly characterised. Researchers compared ten young pack donkeys (aged 2–3 years, ~93 kg) assigned to either packing plus three 20 km treks or trekking alone, measuring blood parameters before and after exertion in conditions where the temperature-humidity index rose from 70 to nearly 80. The packed group demonstrated pronounced haematological stress markers—packed cell volume declined from 30.93% to 27.83%, neutrophil counts increased from 8.63 to 10.59 × 10⁹/L, lymphocytes dropped from 8.58 to 5.23 × 10⁹/L, and the neutrophil-to-lymphocyte ratio elevated to 2.33 (compared with 1.31 in the trekking-only group)—whilst enzyme and electrolyte concentrations remained stable, suggesting acute immune activation rather than widespread tissue damage. These findings indicate that load-carrying compounds heat and exercise stress during hot-dry periods, potentially compromising donkey welfare and work capacity unless management practices such as reduced loading, scheduled rest, or improved hydration are implemented to mitigate the stress response.
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Practical Takeaways
- •Pack donkeys working during hot-dry seasons experience significantly elevated stress markers when carrying loads; monitor work schedules and provide adequate recovery time to prevent performance decline
- •Changes in neutrophil/lymphocyte ratio can serve as a practical field indicator of excessive stress in working donkeys; elevated ratios suggest need for workload reduction
- •Combined heat stress and load-carrying have compounding effects on donkey physiology; management strategies should address both environmental and workload factors, particularly the timing and intensity of work during peak heat
Key Findings
- •Packed cell volume decreased significantly after packing (30.93% to 27.83%, P < 0.05) in loaded donkeys
- •Neutrophil count increased significantly after packing (8.63 to 10.59 × 10⁹/L, P < 0.05) while lymphocyte count decreased (8.58 to 5.23 × 10⁹/L, P < 0.05)
- •Neutrophil/lymphocyte ratio was significantly higher in packed donkeys (2.33) versus trekking-only donkeys (1.31, P < 0.05), indicating greater stress response
- •Packing combined with trekking induced greater physiological stress than trekking alone during hot-dry season conditions