Ergonomic study of donkeys administered with Pycnogenol® and subjected to packing during the hot-dry season in Northern Nigeria

Abstract

The aim of the study was to determine some ergonomic parameters of donkeys administered with Pycnogenol® (PYC) and subjected to packing during the hot-dry season in northern Nigeria. Fifteen donkeys served as experimental subjects. Group 1 (n = 5) donkeys were subjected to trekking only (control), group 2 (n = 5) donkeys were subjected to packing (P-PYC), and group 3 (n = 5) were administered with PYC (10 mg/kg) and subjected to packing (P+PYC). Each group covered a distance of 10 km. Some ergonomic parameters were evaluated. The duration of work in control, P-PYC, and P+PYC donkeys were 170.0 ± 10 min (2.8 h), 126.6 ± 6.7 min (2.1 h), and 112.0 ± 3.9 min (1.9 h), respectively. The energy expenditure obtained for P-PYC group (88.3 ± 9.8 KJ/s) was significantly higher than the values of 28.3 ± 3.7 KJ/s and 73.5 ± 9.9 KJ/s obtained in control and P+PYC groups, respectively. The output was significantly higher in P+PYC group with the value of 5263.2 ± 135 m/h. In conclusion, packing the donkeys during the hot-dry season was stressful; however, PYC may have served as a potent antifatigue agent to reduce the stress.

Effects of packing on the diurnal rhythms of respiratory and heart rates in donkeys during the hot-dry season

“…The recorded response in the donkeys subjected to both packing and trekking was an adaptive mechanism to sustain the cardiac activities for a longer time and ensure its efficiency [ 26 ]. Based on the HR values, the findings of this study strongly suggest that packing + trekking was more stressful on the donkeys than trekking only [ 16 ], although the effects of both packing + trekking and trekking only were all abolished at least 16 hr after the packing and/or trekking period. This finding demonstrated that donkeys may be exposed to repeated packing without negative effects, at least at 16-hr intervals.…”

“…The results for the RRs immediately after packing + trekking and trekking only show that packing + trekking and trekking only significantly increased the RRs of the donkeys; due to the adverse effects of the stress of packing and trekking on them. Trekking is a form of exercise in donkeys [ 16 ]. Thus, it exerted a significant impact on the donkeys in the hot-dry season by altering their respiration, as evidenced by the increase in their RRs recorded after packing and/or trekking.…”

“…These findings were based on the fact that the cosinor parameters for the RR in both the packing + trekking and trekking-only donkeys did not differ significantly, although the parameters of both groups demonstrated typical dark-light rhythms. The result shows that the RRs of both groups of donkeys were influenced by the prevailing environmental conditions [ 25 ] and that the donkeys used for packing in the zone are relatively adapted not only to the meteorological conditions prevailing in the zone but also to the adverse effects of packing during the hot-dry season [ 3 , 16 ]. Subjecting donkeys to packing and/or trekking during the hot-dry season for 4 hr exerted a transient effect on the RR.…”

Modulatory roles of melatonin on respiratory and heart rates and their circadian rhythmicity in donkeys (Equus asinus) subjected to packing during the hot-dry season

“…The poor performance of donkeys is mostly due to overworking, overloading and exposure to multiple stressors ( Ayo et al, 2013 ). Heat stress, caused by high ambient temperature (AT) and relative humidity (RH), has been reported to lead to reduction in performance in working animals ( Pal et al, 2002 ; Olaifa et al, 2019 ). Moderate stress has been reported in donkeys covering 9 km distance and carrying loads equivalent to the 50% of their body weight ( Pal et al, 2012 ; Legha et al, 2018 ).…”

“…Changes in physiological parameters such as respiratory rate (RR) and heart rate (HR) have been used as indicator of stress in pack donkeys ( Ayo et al, 2008 , 2014 ; Legha et al, 2018 ; Frippiat et al, 2021 ). Increased HR in working donkeys during and after packing indicates physiological responses not only to the load carried, but also the ability of the animals to cope with stresses, generated by trekking over long distances and stressful meteorological parameters ( Olaifa et al, 2019 ). The balance between heat produced plus heat gain from the environment and heat loss in donkeys is enhanced by the adjustment of RR and HR ( Ayo et al, 2008 , 2014 ; Lacetera, 2019 ).…”