What on earth is a mule?

Mule is an animal, a hybrid of horse and donkey, and the genes of male and female donkeys are more easily combined, so most mules are hybridized in this way. the probability of gene combination between male and female donkeys is very small. some horses take six years to successfully mate and make donkeys pregnant. Male mules and most female mules are infertile because the chromosomes are not paired and germ cells cannot divide normally. The female mule has sexual function, and the uterus can conceive an embryo, but the most difficult thing is to make the female mule pregnant.

Mules can be divided into male and female. The mating of a male donkey and a mare is called a "horse mule". If a male donkey and a female donkey mate, it is called a "donkey mule". The mule's thick head, long ears, thin limbs, small and narrow hooves, short mane absent, chestnuts (horned growth) inside, hocks and tails hairless at the roots look like donkeys, look like horses in height and body, neck shape, roaring coat and teeth, but don't sound exactly like donkeys or horses.

The horse and mule is large, with the weight-bearing and resistance ability of a donkey, and the flexibility and running ability of a horse, especially in remote rural farmland, because the horse mule saves more than the fodder of the horse province, and its strength is greater than that of the horse. It is a kind of livestock that can save food and work, but its weakness is not as fast as a horse, it is not suitable for running, and it is infertile.

The characteristic of donkey mule, of course, is that it combines the advantages of more donkeys and some horses. It not only has strong endurance, great strength, but also average food intake, but it can also be used for about 30 years. Of course, it is also good-tempered, docile and stubborn, and small in stature. It is generally not as powerful and convenient to use as horses and mules, but the difference is that donkeys and mules can sometimes give birth.

The chromosome numbers of horse mule and donkey mule are abnormal, because donkey chromosome 2 is homologous to horse chromosome 1, donkey 13 and horse 11, donkey 14 and horse 13. Donkey 16 and donkey 25 add up to horse 5, and horses have 32 pairs of chromosomes, while donkeys have 31 pairs. Although horses and donkeys are closely related, their gametes can not only combine with each other, but also develop into complete individuals, but the number of chromosomes in their offspring is 32-31, no matter how one chromosome is lonely.