[1] While sheep and goats are similar and can be mated, they belong to different genera in the subfamily Caprinae of the family Bovidae.

Despite widespread shared pasturing of goats and sheep, hybrids are very rare, demonstrating the genetic distance between the two species.

In Darwinism – An Exposition of the Theory of Natural Selection with Some of Its Applications (1889), Alfred Russel Wallace wrote: [...] the following statement of Mr. Low: "It has been long known to shepherds, though questioned by naturalists, that the progeny of the cross between the sheep and goat is fertile.

Nothing appears to be known of such hybrids either in Scandinavia or in Italy; but Professor Giglioli of Florence has kindly given me some useful references to works in which they are described.

p. 163) was the first to mention, I believe, that in different parts of South America the ram is more usually crossed with the she-goat than the sheep with the he-goat.

In Chile such hybrids are called 'carneros lanudos'; their breeding inter se appears to be not always successful, and often the original cross has to be recommenced to obtain the proportion of three-eighths of he-goat and five-eighths of sheep, or of three-eighths of ram and five-eighths of she-goat; such being the reputed best hybrids.

Hybrid male mammals are often sterile, demonstrating a phenomenon known as Haldane's rule.

The Haldane phenomenon may apply even when the parent species have the same number of chromosomes, as in most cat-species hybrids.

Hybrid female fertility tends to decrease with increasing divergence in chromosome similarity between parent species.

this is due to mismatch problems during meiosis and the resulting production of eggs with unbalanced genetic complements.

[7] In France, natural mating of a doe with a ram produced a female hybrid carrying 57 chromosomes.

This animal backcrossed in the veterinary college of Nantes to a ram delivered a stillborn and a living male offspring with 54 chromosomes.

[1] There was reported case of a live birth of a sheep–goat hybrid on a farm in Tábor in Czech Republic in 2020.

Although the individual cells in interspecies chimeras are entirely of one of the component species, their behaviour is influenced by the environment in which they find themselves.