The aim of the study was to determine the normal range of some physiological, haematological and serum biochemical parameters and how these vary with sex, age and location under tropical savannah conditions in Northwestern Nigerian donkeys. The study was conducted by taking vital signs and blood samples from 125 donkeys across three states in Northwestern Nigeria. The donkeys were grouped according to their locations, sex and age. The physiological, haematological and serum biochemical profiles obtained from donkeys reared in Northwestern Nigerian were consistent with previous reports and within the recommended reference range established in some tropical countries across the world. There was a significant difference (P < 0.05) in respiratory rate between male and female donkeys, with female donkeys having the higher value (26.70 breaths/minute) than male
(25.77 breaths/minute). Significant difference (P < 0.05) also existed in rectal temperature, respiratory rate and pulse rate among different age groups. Younger donkeys had the highest values of 37.85oC, 27.39 breaths/minute and 56.95 beats/minute for rectal temperature, respiratory rate and pulse rate respectively, compared to 37.61 oC, 25.84 breaths/minute and 48.36 beats/minute in adult donkey and 37.51oC, 25.50 breaths/minute and 48.86 beat/minute in old donkeys. Location also had effect on rectal temperature and pulse rate of donkeys. Zamfara donkeys had significantly higher rectal temperature value (37.73oC) than Jigawa (37.68oC) and Katsina (37.55oC) donkeys, while Katsina donkeys had higher respiratory rate (53.66 breaths/minute) than Jigawa (50.51 breaths/minute) and Zamfara (49.29 breaths/minute) donkeys. There were significant differences (P < 0.05)
between male and female donkeys in the counts of neutrophils, lymphocytes and eosinophils. Packed cell volume, hemoglobin, white blood cells (WBC), neutrophils, lymphocytes, eosinophils, and basophils were significantly affected by age. Only WBC counts differed significantly (P < 0.05) among donkeys in different locations. Biochemical parameters of glucose, total serum protein, potassium, creatinine and uric acid differed significantly (P < 0.05) between male and female donkeys. There were significant difference (P < 0.05) between young, adult and old donkeys for glucose, activities of aspartate amino transaminase, alanine amino transaminase and alkaline phosphatase,
concentrations of albumin, sodium, potassium, bicarbonate, urea, creatinine and uric acid.Location also had effect on activities of ALT and ALP, total serum protein, albumin, globulin, sodium, bicarbonate, urea, creatinine, calcium and uric acid concentrations. It can be concluded that physiological, haematological and serum biochemical parameters varied according to age, sex and location. Further investigations should be conducted across geopolitical zones of Nigeria in order to determine the effect of season, management system and develop a larger data to establish the normal reference range of physiological,
haematological and serum biochemical profile of Nigerian donkeys.
In Nigeria, like anywhere else, donkey (Equus asinus) has been used as a work animal mainly for transportation; conveying farm produce to the market or pulling of carts and other farm tillage equipment (Starkey and Starkey, 2004; Blench et al., 2004; Hassan et al., 2013) and of recently for production of milk for children, who are allergic to bovine milk (Carrocio et al., 2000; Caldin et al., 2005; Mansueto et al., 2013), and in animal assisted therapy and activity in humans (Borioni et al., 2012). However, donkey production is constrained by many production factors such as poor nutrition, disease, poor genetic potential, management and harsh environmental factors (Ademosum, 1994; Yilma et al., 1997; Simenew et al., 2011). Of all the factors, poor nutrition and disease conditions are rampant with significant impact on the performance of animals (Ademosum, 1994; Crane, 1997). Donkeys are known to survive
with little management. Their body conditions may fluctuate during the year as feed supply fluctuates resulting in poor body condition, weight loss and delay in resumption of ovarian cycles after parturition (Pearson et al., 1999). The low productivity of livestock on pasture-based extensive grazing systems needs to be improved, and this entails an evaluation of their nutritional status. The assessment of nutritional and health status of animals can be made by determining the concentrations of certain blood metabolite such as non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHB), glucose and cholesterol (Ndlovu et al., 2007). Their concentrations indicate the extent of the
metabolism of energy, proteins and other nutrients in the animals (Pambu-Gollah et al., 2000; Agenas et al., 2006). Changes in the concentration of circulating nutrient-sensitive metabolites are important signals of the metabolic status of the animal and the organs function (Lindsay et al., 1993; Wettemann et al., 2003). Other blood metabolites, such as total protein,albumin, globulin, creatinine and urea, are indicators of the protein status. Factors including the physiological status of an animal, health status, breed, nutrition, season and age may affect the concentration of these metabolites in the blood (Ndlovu et al., 2007). It has been established that rectal temperature, respiratory rate and heart rate are
relevant body parameters for immediate evaluation of stress and health status and adaptability of animals (Ayo et al., 1996; Minka and Ayo 2007; Dey et al., 2010). Disease diagnosis in animals is largely dependent on physiological examination and laboratory results expected to reflect biological variations. This in turn requires understanding of the basal physiological, haematological and serum biochemical profiles of an apparently healthy animal whose measurement provides invaluable information concerning the health status of an animal (Mori et al., 2003; Mori et al., 2004). Haematological evaluations were carried out for a variety of reasons such as screening procedure to determine the general health and nutritional status of the animal, as an adjunct to an infection and to ascertain the progress of disease conditions (Friday et al., 2014) and distinguish between normal and stress conditions (Olabanji et al., 2007). Haematological
values provide baseline information for comparison in conditions of nutrient deficiency, physiology and health status of farm animals (NseAbasi et al., 2014) and help in providing information on the relationship between blood characteristics and the environment (Ovuru and Ekweozor, 2004; Isaac et al. 2013). However, unlike other livestock species, there is very scanty information on the baseline physiological, haematological and serum biochemical parameters of the donkey in Nigeria, some of the works published includes; Yakubu and Chafe (2005); Garba et al. (2015); Zakari et al. (2015) and Zakari et al. (2016). Therefore, a study on the donkey to
determine the parameters is necessary, and it will be the basis for providing interventions that may improve the productivity of the donkey.