Dr R K Patel
Hybrid in animals refers to the offspring resulting by sexual reproduction from genetically dissimilar parents or animals of different varieties, species, or races. Various kind of animal hybrids are highlighted in the articles.
- Mule is the offspring of a male donkey and a female horse. However, Hinny is the offspring of a male horse and a female donkey. Horses and donkeys are different species, with different chromosome numbers. The somatic cells of horse and donkey have 64 and 62 respectively. Whereas hybrid mule/hinny have 63 chromosomes. Mules and Hinnies are mostly sterile. Very exceptionally (1 out 1 billion cases) hybrids produced fertile offspring. In China (1981), when hinny was bred to donkey, they produced “Dragon Foal” resembling to the mule. Hinnies are slightly smaller than mules. Similarly when mule bred to donkey (2003) in Morocco, they produced male offspring genetically similar to Dragon foal. Various combinations producing hybrids are mentioned below:
|Father (sire)||Mother (dam)||Offspring||Male offspring||Female offspring|
|Donkey (Jack) 2n= 62,XY||Horse (Mere) 2n= 64XX||Mule (sterile) 2n= 63,XY or XX||Horse mule or John mule,||Mere mule or Molly|
|Horse (Stallion), 2n= 64,XY||Donkey (Jenny), 2n=62XX||Hinny (sterile) 2n=63,XX or XY||Horse hinny||Mare hinny|
- Zebroid is hybrid of Zebra and donkey and horse, also known as zedonk, zorse, zebra mule, zonkey, and zebrule. Zorse is mostly sterile. In most cases, the sire is a zebra. Offspring of a donkey sire and zebra dam, called a zebra hinny, or donkra. Similarly the offspring of Zebra sire and horse dam are called Zorse, Zebrula, zebrule or zebra mule. Zebroid is used for all type of Zebra hybrid. Zebra has 32 to 46 chromosomes depending on species. Various combination of hybrids are given below:
|Father (sire)||Mother (dam)||Offspring|
|Donkey (Jack) (2n=62,XY)||Zebra (2n=32 to 46,XX)||Zonkey, Donkra, Zebra hinny (2n=47 to 54)|
|Zebra stallion (2n=32 to 46XY)||Horse (mere) 2n=64,XX||Zorse, Zebrula, Zebrule, Zebra mule|
|Zebra Stallion||Pony mere||Zony|
- Dzo is a hybrid of yak and domestic cattle. Dzo refers to male hybrid where as female hybrid is called as dzomo or zhom. Females are fertile whereas males are sterile. They are larger and stronger than yak or cattle. The diploid chromosome number in Yak is 60 (2n =60). All autosomes are acrocentric, X-is submetacentric similar to cattle but Y is metacentric whereas it is acrocentric and submetacentric in Bos taurus (exotic) and Bos indicus (zebu) respectively
- Beefalo are a fertile hybrid offspring of domestic cattle (Bos taurus) and the American bison (Bison bison) usually called buffalo in the US. The hybrid was created to produce beef. Beefalo are primarily cattle in genetics and appearance. The Karyotype of Bison exhibits 60 chromosomes (2n=60). All the autosomes and the X-chromosome were similar to corresponding chromosomes of exotic cattle (Bos Taurus); the Y chromosome was acrocentric similar to the zebu cattle (Bos indicus).
- Sheep and goat hybrid is generally still born due to their chromosome numbers as goat and sheep possesses 60 and 54 diploid number of chromosomes respectively. The goat and sheep belong to different genus; Capra and Ovis respectively. A live birth was obtained by crossing male sheep with female goat in Botswana. Although infertile, the hybrid had a very active libido, mounting both ewes and does even when they were not in heat. A male sheep impregnated a female goat in New Zealand, resulting in a mixed litter of kids and a female sheep-goat hybrid which was with 57 chromosomes. The hybrid was subsequently shown to be fertile when mated with a ram.
- Liger is a hybrid cross between a male lion and a female tiger. A similar hybrid, the offspring of a male tiger and a female lion is called a tigon. A liger resembles a tiger with diffused stripes. Male tigons and ligers are sterile, but female hybrids can produce cubs (Moscow times and BBC news 11th and 18th September, 2012). Lion and tiger both have 38 chromosomes in their somatic cells. A liger comprise of a total of 38 chromosomes, 19 of these chromosomes come from the lion (father) whereas 19 come from tiger (mother). For tiger (2n=38), its autosomes are divided into three groups: the first group (1 to 11th pairs) is metacentric; the second group (12th-16th pairs) is submetacentric; and the third group (17th-18th pairs) is acocentric. The chromosome X is metacentric and chromosome Y is so small that its centromere cannot easily be identified. The chromosome number of lion was found to be 38. The chromosomes can be divided into six groups, which consist of submetacentric, metacentric and acrocentric chromosomes. Ligers are fertile as Russian Zoo announced the birth of a liliger, which is the offspring of a liger mother and a lion father. Various combinations of crosses between Tiger and Lion are as under:
|Father (sire)||Mother (dam)||offspring|
- Leopon is the result of breeding a male leopard with a female lion. The male offspring is fertile. Female liguar, offspring of a female jaguar and male lion is fertile. The head of the animal is similar to that of a lion while the rest of the body carries similarities to leopards. The leopon has the size and strength of a lion. But, unlike the lion, they have extraordinary climbing abilities like the leopard. The karyotype (2n=38) of leopard consist of 6 groups; A-type has 4 large and 2 medium submetacentric, B-type has 6 large and 2 medium size acrocentric, C-type has 4 large metacentric, D-type 8 small submetacentric, E-type has 8 small metacentric, F-type has 2 telocenric chromosomes. The X-chromosome is medium submetacentric whereas Y- is the smallest submetacentric (Tanomtong et al., 2008).
There are many hybrids between canines, domestic and wild cats, camels etc.
Reference: Patel, R. K. (2014). Hybrid animals- an interesting update. Blue Cross Book. 30: 94-98.