Editing Donkey (section)

==Donkey hybrids==
The earliest documented donkey hybrid was the [[kunga (equid)|kunga]], which was used as a draft animal in the Syrian and Mesopotamian kingdoms of the second half of the 3rd millennium BCE. A cross between a captive male [[Syrian wild ass]] and a female domesticated donkey (jenny), they represent the earliest known example of human-directed animal hybridization. They were produced at a breeding center at Nagar (modern [[Tell Brak]]) and were sold or given as gifts throughout the region, where they became significant status symbols, pulling battle wagons and the chariots of kings, and also being sacrificed to bury with high-status people. They fell out of favor following the introduction of the domestic horse and its donkey hybrid, the [[mule]], into the region at the end of the 3rd millennium BCE.<ref>{{cite journal|first1=E. Andrew |last1=Bennett |first2=Jill |last2=Weber |first3=Wejden |last3=Bendhafer |first4=Sophie |last4=Chaplot |first5=Joris |last5=Peters |first6=Glenn M. |last6=Schwartz |first7=Thierry |last7=Grange |first8=Eva-Maria |last8=Geigl |title=The genetic identity of the earliest human-made hybrid animals, the kungas of Syro-Mesopotamia |journal=Science Advances |year=2022 |volume=8 |number=2 |pages=eabm0218 |doi=10.1126/sciadv.abm0218|pmid=35030024 |pmc=8759742 |bibcode=2022SciA....8..218B |s2cid=245963400 }}</ref>

A male donkey (jack) crossed with a female horse produces a [[mule]], while a male horse crossed with a jenny produces a [[hinny]]. Horse–donkey [[Hybrid (biology)|hybrids]] are almost always [[infertility|sterile]] because of a failure of their developing gametes to complete meiosis.<ref>{{cite journal |last1=Li |first1=X. C. |last2=Barringer |first2=B. C. |last3=Barbash |first3=D. A. |title=The pachytene checkpoint and its relationship to evolutionary patterns of polyploidization and hybrid sterility |journal=Heredity |volume=102 |pages=24–30 |year=2009 |issue=1 |doi=10.1038/hdy.2008.84 |pmid=18766201 |s2cid=2176510 |doi-access=free |bibcode=2009Hered.102...24L }}</ref> The lower progesterone production of the jenny may also lead to early [[embryonic loss]]. In addition, there are reasons not directly related to reproductive biology. Due to different [[mating]] behavior, jacks are often more willing to cover mares than stallions are to breed jennies. Further, mares are usually larger than jennies and thus have more room for the ensuing foal to grow in the womb, resulting in a larger animal at birth. It is commonly believed that mules are more easily handled and also physically stronger than hinnies, making them more desirable for breeders to produce.{{Citation needed|reason=to make this statement, one needs data indicating the greater prevalence of mules|date=August 2009}}

The offspring of a [[zebra]]–donkey cross is called a zonkey, [[zebroid]], zebrass, or zedonk;<ref name=zorse/> ''zebra mule'' is an older term, but still used in some regions today. The foregoing terms generally refer to hybrids produced by breeding a male zebra to a female donkey. ''Zebra hinny, zebret'' and ''zebrinny'' all refer to the cross of a female zebra with a male donkey. Zebrinnies are rarer than zedonkies because female zebras in captivity are most valuable when used to produce full-blooded zebras.<ref name=zedonk/> There are not enough female zebras breeding in captivity to spare them for hybridizing; there is no such limitation on the number of female donkeys breeding.