Aim: Little is known about the serum levels of trace elements in donkeys and horses in Saudi Arabia. This study aimed to investigate the levels of some trace elements in these two species in the eastern region of Saudi Arabia and to compare the obtained results with the reference values.

Materials and Methods: Seventeen Arabian horses and twenty eight Hassawi donkeys were randomly selected for this study. All of the studied healthy animals were kept under a uniform feeding protocol without any minerals supplementations. Atomic absorption spectrometer is used to estimate the serum concentrations of selenium (Se), manganese (Mn), chromium (Cr), copper (Cu), iron (Fe), and zinc (Zn) in the analyzed samples.

Results: Significant differences between horses and donkeys were observed in three of the studied elements (Se, Mn, and Cr). Statistically significant differences were found in serum Se and Cr between male and female horses. The male donkey showed higher Mn, Cu, and Zn levels than female animals.

Conclusion: The obtained results of trace element levels in serum of Hassawi donkeys and Arabian horses in Saudi Arabia are considered as the first values to be published for these breeds. When compared to other animals, the measured amounts of Se, Mn, Cr, Cu, Fe, and Zn in the serum of horses and donkey are often differed, possibly because of the varying living or feeding conditions. Moreover, there were some differences in some of the trace elements concentrations related to animal's gender and species (horses and donkeys), which will be considered in the interpretation of the laboratory data.

Keywords: donkey, horse, serum, trace elements.

1. Balamurugan, B., Ramamoorthy, M., Ravi, J., Keerthana, G., Gopalakrishnan, K.M., Kharayat, S., Chaudhary, G.R. and Rahul, K. (2017) Mineral an important nutrient for efficient reproductive health in dairy cattle. Int. J. Environ. Sci. Technol., 6(1): 694-701.

2. Elrod, C.C., Van Amburgh, M. and Butler, W.R. (1993) Alterations of pH in response to increased dietary protein in cattle are unique to the uterus. J. Anim. Sci., 71(3): 702-706. [Crossref]

3. Topczewska, J. (2012) Effects of seasons on the concentration of selected trace elements in horse hair. J. Cent. Eur. Agric., 13(4): 671-680. [Crossref]

4. Humann-Zehank, E., Genter, M., Hennig-Pauka, I. and Binder, A. (2008) Trace mineral status and liver and blood parameters in sheep without mineral supply compared to local roe deer (Capreolus capreolus) populations. Small Rumin. Res., 75: 185-191. [Crossref]

5. Prashanth, L., Kattapagari, K.K., Chitturi, R., Baddam, V. and Prasad, L. (2015) A review on role of essential trace elements in health and disease. J. NTR Univ. Health Sci., 4(2): 75-78. [Crossref]

6. Laven, R.A., Livesey, C.T., Harmon, R.J. and Scaletti, R. (2006) Factors affecting the relationship between caeruloplasmin activity and plasma copper concentration in cattle. Vet. Rec., 159(8): 250-251. [Crossref]

7. Forrer, R., Wenker, C.H., Gautschi, K. and Lutz, H. (2001) Concentration of 17 trace elements in serum and whole blood of plains viscachas (Lagostomus maximus) by ICP-MS, their reference ranges, and their relation to cataract. Biol. Trace Elem. Res., 81(1): 47-62. [Crossref]

8. Stanek, M., Jaworski, Z., Sobotka, W., Lipinski, K. and Olenkowicz, R. (2016) Influence of an organic supplement of copper, zinc and manganese in feed rations on concentrationsof these elements in the coat of Polish Konik horses. J. Elem., 21(2): 549-558.

9. Ciftci, T.U., Ciftci, B., Yis, O., Guney, Y., Bilgihan, A. and Ogretensoy, M. (2003) Changes in serum selenium, copper, zinc levels and cu/zn ratio in patients with pulmonary tuberculosis during therapy. Biol. Trace. Elem. Res., 95(1): 65-71. [Crossref]

10. Neve, J. and Palmieri, P. (2000) First symposium on human health related aspects of selenium research in Europe. J. Trace Elem. Med. Biol., 14: 116-121. [Crossref]

11. Cefalu, W.T. and Hu, F.B. (2004) Role of chromium in human health and in diabetes. Diabetes Care, 27(11): 2741-2751. [Crossref]

12. Schuschke, D.A. (1997) Dietary copper in the physiology of the microcirculation. J. Nutr., 127(12): 2274-2281. [PubMed]

13. Maggini, S., Wintergerst, E.S., Beveridge, S. and Hornig, D.H. (2007) Selected vitamins and trace elements support immune function by strengthening epithelial barriers and cellular and humoral immune responses. Br. J. Nutr., 98: S29-S35. [Crossref]

14. Oppenheimer, S.J. (2001) Iron and its relation to immunity and infectious disease. J. Nutr., 131: 616S-635S. [PubMed]

15. Hambidge, M. (2000) Human zinc deficiency. J. Nutr., 130 5S Suppl: 1344S-1349S.

16. Caulfield, L.E., Zavaleta, N. and Figueroa, A. (1999) Adding zinc to prenatal iron and folate supplements improves maternal and neonatal zinc status in a Peruvian population. Am. J. Clin. Nutr., 69(6): 1257-1263. [PubMed]

17. Fraker, P.J., King, L.E., Laakko, T. and Vollmer, T.L. (2000) The dynamic link between the integrity of the immune system and zinc status. J. Nutr., 130 5S Suppl: 1399S-1406S.

18. Shawaf, T., Almathen, F., Al-Ahmad, J. and Elmoslemany, A. (2016) Morphological characteristics of hassawi donkey, eastern province, Saudi Arabia. Alex. J. Vet. Sci., 49: 178-183.

19. Passlack, N., Mainzer, B., Lahrssen-Wiederholt, M., Schafft, H., Palavinskas, R., Breithaupt, A. and Zentek, J. (2015) Concentrations of strontium, barium, cadmium, copper, zinc, manganese, chromium, antimony, selenium, and lead in the liver and kidneys of dogs according to age, gender, and the occurrence of chronic kidney disease. J. Vet. Sci., 16(1): 57-66. [Crossref] [PMC]

20. Al-Bulushi, S., Shawaf, T. and Al-Hasani, A. (2017) Some hematological and biochemical parameters of different goat breeds in Sultanate of Oman "a preliminary study". Vet. World, 10(4): 461-466. [Crossref] [PubMed] [PMC]

21. Roubies, N., Panousis, N., Fytianou, A., Katsoulos, P.D., Giadinis, N. and Karatzias, H. (2006) Effects of age and reproductive stage on certain serum biochemical parameters of chios sheep under greek rearing conditions. J. Vet. Med. A Physiol. Pathol. Clin. Med., 53(6): 277-281. [Crossref] [PubMed]

22. Soylak, M., Saracoglu, S., Tuzen, M. and Mendil, D. (2005) Determination of trace metals in mushroom samples from Kayseri Turkey. Food Chem., 82: 649-652. [Crossref]

23. Waegeneers, N., Pizzolon, J.C., Hoenig, M. and De Temmerman, L. (2009) Accumulation of trace elements in cattle from rural and industrial areas in Belgium. Food Addit. Contam., 26(3): 326-332. [Crossref] [PubMed]

24. Muirhead, T., Wichtel, J., Stryhn, H. and McClure, J. (2010) The selenium and Vitamin E status of horses in Prince Edward Island. Can. Vet. J., 51: 979-985. [PubMed] [PMC]

25. Richardson, S.M., Siciliano, P.D., Engle, T.E., Larson, C.K. and Ward, T.L. (2006) Effect of selenium supplementation and source on the selenium status of horses. J. Anim. Sci., 84(7): 1742-1748. [Crossref] [PubMed]

26. Fantuz, F., Ferraro, S., Todini, L., Mariani, P., Piloni, R. and Salimei, E. (2013) Essential trace elements in milk and blood serum of lactating donkeys as affected by lactation stage and dietary supplementation with trace elements. Animal, 7(11): 1893-1899. [Crossref] [PubMed]

27. Okumura, M., Asano, M., Tagami, M., Tsukiyama, K. and Fujinaga, T. (1998) Serum copper and ceruloplasmin activity at the early growing stage in foals. Can. J. Vet. Res., 62(2): 122-126. [PubMed] [PMC]

28. Sharkawy, A.A., Rateb, H.Z. and Abdel-Mohsen, M. (2002) Evaluation of some heavy metals in blood and tissues of male camels as indicator of environmental pollution and its relation to age. Assuit Univ. Bull. Environ. Res., 5: 73-81.

29. Hasegawa, M., Yoshida, K., Wakabayashi, H. and Sudo, A. (2012) Cobalt and chromium ion release after large-diameter metal-on-metal total hip arthroplasty. J. Arthroplasty, 27(6): 990-996. [Crossref] [PubMed]

30. Maia, L., Souza, M.V., Fernandes, R.B.A., Fontes, M.P.F., Viana, M.W.S. and Luz, W.V. (2006) Heavy metals in the horse blood, serum, and feed in Minas Gerais. J. Equine Vet. Sci., 26: 578-583. [Crossref]

31. De Souza, M., Paulo, M., Fontes, F., Braganca, R. and Fernandes, A. (2014b) Heavy metals in equine biological components. R. Bras. Zootec., 43(2): 60-66. [Crossref]

32. Zaeemi, M., Razmi, G.R., Mohammadi, G.R., Abedi, V. and Yaghfoori, S. (2016) Evaluation of serum biochemical profile in Turkoman horses and donkeys infected with Theileria equi. Rev. Med. Vet., 167(11-12): 301-309.

33. Dierenfeld, S., Shirley, A. N., Craig, A., Karen, C., Walker, W., Jurgen, S. and Marcus, C. (2005) Mineral concentrations in serum/plasma and liver tissue of captive and free-ranging Rhinoceros Species. Zoo Biol., 24: 51-72. [Crossref]

34. Auer, D.E., Ng, J.C. and Seawright, A.A. (1988) Assessment of copper and zinc status of farm horses and training Thoroughbreds in South-East Queensland. Aust. Vet. J., 65: 317-320. [Crossref] [PubMed]

35. Birick, H., Ocal, N., Gucus, A.I., Ediz, B. and Uzman, M. (2005) Seasonal changes of some mineral status in mares. J. Equine Vet. Sci., 25: 346-348. [Crossref]