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

Effect of packing (load carrying) on body temperatures and their circadian rhythms in donkeys (Equus asinus) during the hot-dry season

The study aimed to evaluate the effects of packing (load carrying) on rectal and body surface temperatures and their circadian rhythmicity in donkeys during the hot-dry season. Twenty pack donkeys of both sexes (15 males and 5 non-pregnant females), aged 2-3 years, with average weight of 93 ± 2.7 kg and divided into two groups randomly, served as experimental subjects. Group 1 donkeys (packing + trekking) were subjected to packing in addition to trekking, while group 2 (trekking only) did not carry any load. All the donkeys were trekked, covering a distance of 20 km. The procedure was repeated three times within the week, one day apart. During the experiment, dry-bulb temperature (DBT), relative humidity (RH) and temperature-humidity index (THI), wind speed and topsoil temperature were recorded; and rectal temperature (RT) and body surface temperature (BST) were measured before and immediately after packing. Starting from 16 h after the last packing, circadian rhythms of RT and BST were recorded at 3-h intervals for 27-h period. The RT and BST were measured by digital thermometer and non-contact infrared thermometer, respectively. The DBT and RH, especially after packing (35.83 ± 0.2 °C and 20.00 ± 0.0%, respectively), were outside the thermoneutral zone for donkeys. The RT value (38.63 ± 0.1 °C) in packing + trekking donkeys recorded immediately (15 min) after packing was higher (P < 0.05) than the value obtained in trekking only donkeys (37.27 ± 0.1 °C). The overall mean RT recorded during the continuous 27-h period of measurement, starting from 16 h after the last packing procedure was higher (P < 0.05) in packing + trekking donkeys (36.93 ± 0.2 °C) compared with trekking only donkeys (36.29 ± 0.3 °C). The BSTs recorded in both groups were higher (P < 0.05) immediately after packing when compared with pre-packing values, but insignificant 16-h post-packing. The RT and BST values were generally higher in the photophase and lower during the scotophase in both groups of donkeys during the continuous recordings. The eye temperature was the closest to the RT, followed by scapular temperature, while the coronary band temperature was the farthest. The mesor of RT in packing + trekking donkeys (37.06 ± 0.2 °C) was significantly higher than in donkeys that were trekked only (36.46 ± 0.1 °C). The amplitude of RT in trekking only donkeys (1.20 ± 0.1 °C) was wider (P < 0.05) than that obtained in packing + trekking donkeys (0.80 ± 0.1 °C). The acrophase and bathyphase occurred later in packing + trekking donkeys (18:10 ± 0.3 h and 6:10 ± 0.3 h, respectively), compared to the trekking only donkeys (16:50 ± 0.2 h and 4:50 ± 0.2 h, respectively). In conclusion, exposure to thermally stressful prevailing environmental conditions during packing increased the body temperature responses, especially in packing + trekking donkeys. Packing significantly influenced the circadian rhythms of body temperatures in working donkeys, as evidenced by differences in circadian rhythm parameters in packing + trekking group, compared with trekking only donkeys during the hot-dry season.

Donkey Heart Rate and Heart Rate Variability: A Scoping Review

Heart rate (HR) and heart rate variability (HRV) are commonly used physiological measures in animals. While several studies exist on horse HRV, less information is available for donkeys. This scoping review aims to understand the extent and type of published evidence on donkey HR and HRV, their clinical and research applications, the devices used, and the analysis performed. Only quantitative primary studies published in English were considered. Four different databases were queried through the Web of Science platform, with additional evidence identified by citation chasing. After a two-stage screening phase, data were extracted considering study and population characteristics, information on HR/HRV analysis, and applications. The majority of the 87 included articles (about 80%) concerned a sample size of up to 20 individuals and were published since 2011 (about 65%). Forty-one articles employed an electronic device for signal acquisition (mainly electrocardiographs and heart rate monitors), yet only two articles reported HRV parameters. The literature on donkey HRV is lacking, and this gap can be filled by gaining knowledge on donkey characteristics and finding useful tools for welfare assessment. Comparison with what is known about the horse allows a discussion of the technical and interpretative difficulties that can be encountered with donkeys.

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

This study aimed to evaluate the effects of packing (load carrying) on the diurnal rhythms of respiratory and heart rates in donkeys during the hot-dry season. Twenty 2- to 3-years-old donkeys weighing 93 ± 2.7 kg were divided into two groups to serve as subjects: Group 1 was subjected to packing + trekking, while group 2 was subjected to trekking only. All donkeys trekked 20 km on each experimental day. The procedure was repeated three times at one-day intervals. Thermal environmental parameters were recorded. Respiratory rate (RR) and heart rate (HR) were measured before and immediately (15 min) after the packing and/or trekking period. Continuous recordings of parameters were performed for 27 hr at 3-hr intervals beginning 16 hr after the last packing and/or trekking period. The RR rose significantly (P<0.05) immediately after packing + trekking and trekking only, from 30.15 ± 0.5 and 27.52 ± 0.5 cycles/min before packing + trekking and trekking only, respectively, to 43.78 ± 3.0 and 46.30 ± 1.8 cycles/min after them, respectively. The HR (76.63 ± 4.5 beats/min) in the packing + trekking donkeys was higher (P<0.05) than that of the trekking-only donkeys (62.33 ± 2.7 beats/min). The acrophase and bathyphase of the HR in both groups were recorded during the photophase and scotophase, respectively, with higher values (P<0.05) in the packing + trekking donkeys than in the trekking-only donkeys. The circadian rhythms of RR and HR did not differ between the groups of donkeys. In conclusion, packing + trekking was more stressful to the donkeys, significantly increasing the HR of donkeys subjected to packing + trekking, compared with trekking only.