1College of Animal Science, Inner Mongolia Key Laboratory of Equine Genetics, Breeding and Reproduction, Equine Research Center, Inner Mongolia Agricultural University, Hohhot 010018, China
2College of Agronomy, Liaocheng University, Shandong Engineering Technology Research Center for Efficient Breeding and Ecological Feeding of Black Donkey, Shandong Donkey Industry Technology Collaborative Innovation Center, Liaocheng 252059, Shandong Province, China
3National Engineering Research Center for Gelatin-based Traditional Chinese Medicine, Dong-E-E-Jiao Co. Ltd., Dong-E County 252201, Shandong Province, China
4Shandong Vocational Animal Science and Veterinary College, East Shengli Street, Weifang 261061, China
5Faculty of Veterinary Science, University of Agriculture, Faisalabad, Pakistan