Zebu

Both scientific names Bos taurus and Bos indicus were introduced by Carl Linnaeus in 1758, with the latter used to describe humped cattle in China.[3]

The zebu was classified as a distinct species by Juliet Clutton-Brock in 1999,[5] but as a subspecies of the domestic cattle, Bos taurus indicus, by both Clutton-Brock and Colin Groves in 2004 and by Peter Grubb in 2005.[6][7] In 2011, Groves and Grubb classified it as a distinct species again.[8]

The American Society of Mammalogists considers it part of the species Bos taurus in analogy to Sanga cattle (Bos taurus africanus Kerr, 1792).[2] The ICZN has not yet published a ruling on the classification of domestic derivatives and no scientific body advocates the abolition of the Biological Species Concept for domestic animals.

A Pillar of Ashoka, dating to the 3rd century BCE, depicting a zebu

Zebu pictured on a coin of the Indo-Scythian king Azes II, late first century BC

Zebu cattle were found to derive from the Indian form of aurochs and have first been domesticated between 7,000 and 6,000 YBP at Mehrgarh, present-day Pakistan, by people linked to or coming from Mesopotamia.[9][10][11][12] Indicine cattle farming is understood to have spread across much of South Asia by 2000 BCE.

Its wild ancestor, the Indian aurochs, became extinct during the Indus Valley civilisation likely due to habitat loss, caused by expanding pastoralism and interbreeding with domestic zebu.[4][13] Its latest remains ever found were dated to 3,800 YBP, making it the first of the three aurochs subspecies to die out.[14][15][16]

Archaeological evidence including depictions on pottery and rocks suggests that humped cattle likely imported from the Near East was present in Egypt around 4,000 YBP. Its first appearance in the Subsahara is dated to after 700 AD and it was introduced to the Horn of Africa around 1000.[17]

Phylogenetic analysis revealed that all the zebu Y chromosome haplotype groups are found in three different lineages: Y3A, the most predominant and cosmopolitan lineage; Y3B, only observed in West Africa; and Y3C, predominant in south and northeast India.[18]

Female zebu in Sri Lanka

Zebu, but also many Sanga cattle have humps on the shoulders, large dewlaps and droopy ears.[19] Sanga cattle can be distinguished from purebred zebu by their having smaller humps located farther forward.

Compared to taurine cattle, zebus are well adapted to the hot savanna and steppe environments. These adaptations result in higher tolerance for drought, heat and sunlight exposure.[20] Unlike many Sanga cattle however, zebu does not exhibit trypanotolerance, making it susceptible to nagana,[21][22] as evidenced by the pattern of zebu introgression into African cattle.[21]

Furthermore, another important characteristic of the Zebu is that they are able to defend against parasites and diseases quite well.[23]

Zebu are generally mature enough to give birth when they are 29 months old. This is based on the development of their bodies to withstand the strain of carrying and lactation. Early reproduction can place too much stress on the body and possibly shorten lifespans. Carrying time of the calf averages at 285 days, but varies depending on the age and nutrition of the mother. The sex of the calf may also affect the carrying time, as male calves are carried for a longer period than females. Location, breed, body weight, and season affect the overall health of the animal and in return may also affect the carrying period.[20]

Studies on the natural weaning of zebu cattle have shown that the cow weans her calves over a 2-week period, but after that, she continues to show strong affiliatory behavior with her offspring and preferentially chooses them for grooming and as grazing partners for at least 4–5 years.[24]

Zebu are very common in much of Asia, including Pakistan, India, Nepal, Bangladesh and China. In Asia, taurine cattle are mainly found in the northern regions such as Japan, Korea, northern China and Mongolia. In China, taurine cattle are most common in northern breeds, zebu more common in southern breeds, with hybrids in between.[25][26]

Zebu market in Madagascar

Zebu were imported to Africa since the Bronze Age and crossed with taurine cattle. Genetic analysis of African cattle found higher proportions of zebu genes along the East African coast, with hardly any taurine component on Madagascar, either implying that the method of dispersal was cattle transported by ship or the zebu may have reached East Africa via the coastal route (via Pakistan, Iran, Yemen).

Partial resistance to rinderpest caused a further increase of zebu breeds in Africa.

Geneticists at the International Livestock Research Institute (ILRI) in Nairobi, Kenya and in Addis Ababa, Ethiopia discovered that cattle had been domesticated in Africa independently of domestication in the Near East. They concluded that the southern African cattle populations derive originally from East Africa rather than from a southbound migration of taurine cattle.[27] The results are inconclusive as to whether domestication occurred first in Africa or the Near East.[28]

Other scientists consider the African Sanga cattle breeds to have originated from hybridization of zebu with indigenous African humpless cattle leading to the Afrikaner, Red Fulani, Ankole, Boran and many other breeds.

Some 75 breeds of zebu are known, split about evenly between African and Indian breeds.

Hariana breed of zebu type cattle in north India

Other breeds of zebu are quite local, like the Hariana from Haryana, Punjab[30] or the Rath from Alwar district, Rajasthan.[31]

Zebu, which are adapted to high temperatures,[32] were imported into Brazil in the early 20th century. Their importation marked a change in cattle ranching in Brazil as they were considered "ecological" since they could graze on natural grasses and their meat was lean and without chemical residues.[33]

In the early 20th century in Brazil, Zebu were crossbred with Charolais cattle, a European taurine breed. The resulting breed, 63% Charolais and 37% zebu, is called the Canchim. It has a better meat quality than the zebu and better heat resistance than European cattle. The zebu breeds used were primarily Indo-Brazilian with some Nelore and Guzerat. Another Charolais cross-breed with Brahmans is called Australian Charbray and is recognised as a breed in some countries.

From the 1960s onwards, Nelore which is an off breed of Ongole Cattle became the primary breed of cattle in Brazil because of its hardiness, heat-resistance, and because it thrives on poor-quality forage and breeds easily, with the calves rarely requiring human intervention to survive. Currently more than 80% of beef cattle in Brazil (approximately 167,000,000 animals) are either purebred or hybrid Ongole Cattle which is originated from Ongle region of Andhra Pradesh.

Draft zebu pulling a cart in Mumbai, India

Zebu are used as draught and riding animals, beef cattle, dairy cattle, as well as for byproducts such as hides, dung for fuel and manure, and horn for knife handles and the like. Zebu, mostly miniature zebu, are kept as pets.[34] In India, the number of draft cattle in 1998 was estimated at 65.7 million head.[35]

Zebu cows commonly have low production of milk. They do not produce milk until maturation later in their lives and do not produce much. When zebus are crossed with taurine cattle, milk production generally increases.[20]

In 1999, researchers at Texas A&M University successfully cloned a zebu.[36]

Jallikattu in India is a bull taming sport differing from European bullfighting in that humans are unarmed and the bulls are not killed.

• List of Indian cattle breeds
• List of animals with humps
• List of cattle breeds