Water buffalo
The water buffalo (Bubalus bubalis) or domestic water buffalo is a large bovid originating in the Indian subcontinent, Southeast Asia, and China. Today, it is also found in Europe, Australia, North America, South America and some African countries.[1] The wild water buffalo (Bubalus arnee) native to Southeast Asia is considered a different species, but most likely represents the ancestor of the domestic water buffalo.[2]
Two extant types of water buffalo are recognized, based on morphological and behavioural criteria – the river buffalo of the Indian subcontinent and further west to the Balkans, Egypt, and Italy, and the swamp buffalo, found from Assam in the west through Southeast Asia to the Yangtze valley of China in the east.[1][3] The origins of the water buffalo types are debated, although results of a phylogenetic study indicate that the swamp-type may have originated in China and was domesticated about 4,000 years ago, while the river-type may have originated in India and was domesticated about 5,000 years ago.[4] After the domestication of the water buffalo in Southeast Asia, the swamp buffalo dispersed up to the Yangtze River valley between 3,000 and 7,000 years ago.[5]
Water buffaloes were traded from the Indus Valley Civilisation to Mesopotamia, in modern Iraq, 2500 BC by the Meluhhas.[6] The seal of a scribe employed by an Akkadian king shows the sacrifice of water buffaloes.[7]
At least 130 million water buffaloes exist, and more people depend on them than on any other domestic animal.[8] They are especially suitable for tilling rice fields, and their milk is richer in fat and protein than that of dairy cattle. A large feral population became established in northern Australia in the late 19th century, and there are smaller feral herds in Papua New Guinea, Tunisia, and northeastern Argentina.[1] Feral herds are also present in New Britain, New Ireland, Irian Jaya, Colombia, Guyana, Suriname, Brazil, and Uruguay.
Taxonomy
Carl Linnaeus first described the genus Bos and the water buffalo under the binomial Bos bubalis in 1758; the species was known to occur in Asia and was held as a domestic form in Italy.[10] Ellerman and Morrison-Scott treated the wild and domestic forms of the water buffalo as conspecifics,[11] whereas others treated them as different species.[12] The nomenclatorial treatment of the wild and domestic forms has been inconsistent and varies between authors and even within the works of single authors.[13]
In March 2003, the International Commission on Zoological Nomenclature achieved consistency in the naming of the wild and domestic water buffaloes by ruling that the scientific name Bubalus arnee is valid for the wild form.[14] B. bubalis continues to be valid for the domestic form and applies also to feral populations.[15]
Characteristics
The skin of the river buffalo is black, but some specimens may have dark, slate-coloured skin. Swamp buffaloes have a grey skin at birth, but become slate blue later. Albinoids are present in some populations. River buffaloes have comparatively longer faces, smaller girths, and bigger limbs than swamp buffaloes. Their dorsal ridges extend further back and taper off more gradually. Their horns grow downward and backward, then curve upward in a spiral. Swamp buffaloes are heavy-bodied and stockily built; the body is short and the belly large. The forehead is flat, the eyes prominent, the face short, and the muzzle wide. The neck is comparatively long, and the withers and croup are prominent. A dorsal ridge extends backward and ends abruptly just before the end of the chest. Their horns grow outward, and curve in a semicircle, but always remain more or less on the plane of the forehead. The tail is short, reaching only to the hocks. Height at the withers is 129–133 cm (51–52 in) for males, and 120–127 cm (47–50 in) for females. They range in weight from 300–550 kg (660–1,210 lb), but weights of over 1,000 kg (2,200 lb) have also been observed.[1]
Tedong bonga is a piebald water buffalo featuring a unique black and white colouration that is favoured by the Toraja of Sulawesi.[16]
The swamp buffalo has 48 chromosomes; the river buffalo has 50 chromosomes. The two types do not readily interbreed, but fertile offspring can occur. Water buffalo-cattle hybrids have not been observed to occur, but the embryos of such hybrids reach maturity in laboratory experiments, albeit at lower rates than non-hybrids.[17]
The rumen of the water buffalo has important differences from that of other ruminants.[18] It contains a larger population of bacteria, particularly the cellulolytic bacteria, lower protozoa, and higher fungi zoospores. In addition, higher rumen ammonia nitrogen (NH4-N) and higher pH have been found, compared to those in cattle.[19]
Ecology and behavior
River buffaloes prefer deep water. Swamp buffaloes prefer to wallow in mudholes which they make with their horns. During wallowing, they acquire a thick coating of mud.[1] Both are well-adapted to a hot and humid climate with temperatures ranging from 0 °C (32 °F) in the winter to 30 °C (86 °F) and greater in the summer. Water availability is important in hot climates, since they need wallows, rivers, or splashing water to assist in thermoregulation. Some water buffalo breeds are adapted to saline seaside shores and saline sandy terrain.[20]
Diet
Water buffaloes thrive on many aquatic plants. During floods, they will graze submerged, raising their heads above the water and carrying quantities of edible plants. Water buffaloes eat reeds, Arundo donax, a kind of Cyperaceae, Eichhornia crassipes, and Juncaceae. Some of these plants are of great value to local peoples. Others, such as E. crassipes, are a major problem in some tropical valleys and by eating them, the water buffaloes may help to keep waterways clear.
Green fodders are used widely for intensive milk production and for fattening. Many fodder crops are conserved as hay, chaffed, or pulped. Fodders include alfalfa, the leaves, stems or trimmings of banana, cassava, Mangelwurzel, esparto, Leucaena leucocephala and kenaf, maize, oats, Pandanus, peanut, sorghum, soybean, sugarcane, bagasse, and turnips. Citrus pulp and pineapple wastes have been fed safely to buffalo. In Egypt, whole sun-dried dates are fed to milk buffalo up to 25% of the standard feed mixture.[1]
Reproduction
Swamp buffaloes generally become reproductive at an older age than river breeds. Young males in Egypt, India, and Pakistan are first mated at about 3.0–3.5 years of age, but in Italy they may be used as early as 2 years of age. Successful mating behaviour may continue until the animal is 12 years or even older. A good river buffalo male can impregnate 100 females in a year. A strong seasonal influence on mating occurs. Heat stress reduces libido.[1]
Although water buffaloes are polyoestrous, their reproductive efficiency shows wide variation throughout the year. Water buffalo cows exhibit a distinct seasonal change in displaying oestrus, conception rate, and calving rate.[21] The age at the first oestrus of heifers varies between breeds from 13–33 months, but mating at the first oestrus is often infertile and usually deferred until they are 3 years old. Gestation lasts from 281–334 days, but most reports give a range between 300 and 320 days. Swamp buffaloes carry their calves for one or two weeks longer than river buffaloes. It is not rare to find water buffaloes that continue to work well at the age of 30, and instances of a working life of 40 years have been recorded.[1]
Domestication and breeding
Water buffaloes were domesticated in the Indian subcontinent about 5,000 years ago, and in China about 4,000 years ago. Two types are recognized, based on morphological and behavioural criteria – the river buffalo of the Indian subcontinent and further west to the Balkans and Italy, and the swamp buffalo, found from Assam in the west through Southeast Asia to the Yangtze valley of China in the east.[3] The present-day river buffalo is the result of complex domestication processes involving more than one maternal lineage and a significant maternal gene flow from wild populations after the initial domestication events.[22] Twenty-two breeds of the river buffalo are known, including the Murrah, NiliRavi, Surti, Jafarabadi, Anatolian, Mediterranean, and Egyptian buffaloes.[23] China has a huge variety of water buffalo genetic resources, with 16 local swamp buffalo breeds in various regions.[20]
Genetic studies
Results of mitochondrial DNA analyses indicate that the two types were domesticated independently.[24] Sequencing of cytochrome b genes of Bubalus species implies that the water buffalo originated from at least two populations, and that the river-type and the swamp-type have differentiated at the full species level. The genetic distance between the two types is so large that a divergence time of about 1.7 million years has been suggested. The swamp-type was noticed to have the closest relationship with the tamaraw.[25]
Analyses of mitochondrial DNA and single-nucleotide polymorphism indicate that swamp and river buffaloes were crossbred in China.[26]
An analysis of the genomes of 91 swamp and 30 river buffaloes showed that they separated already before domestication about 0.23 million years ago.[27]
Distribution of populations
By 2011, the global water buffalo population was about 172 million.[28]
In Asia
More than 95.8% of the world population of water buffaloes are kept in Asia, including both the river-type and the swamp-type.[20] The water buffalo population in India numbered over 97.9 million head in 2003, representing 56.5% of the world population. They are primarily of the river type with ten well-defined breeds: the Bhadawari, Banni, Jafarabadi, Marathwadi, Mehsana, Murrah, Nagpuri, Nili-Ravi, Pandharpuri, Surti and Toda buffaloes. Swamp buffaloes occur only in small areas in northeastern India and are not distinguished into breeds.[29]
In 2003, the second-largest population lived in China, with 22.76 million head, all of the swamp-type, with many breeds kept only in the lowlands, and other breeds kept only in the mountains; as of 2003, 3.2 million swamp-type Carabao buffaloes were in the Philippines, nearly three million swamp buffaloes were in Vietnam, and 772,764 buffaloes were in Bangladesh. About 750,000 head were estimated in Sri Lanka in 1997.[20] In Japan, the water buffalo is the domestic animal throughout the Ryukyu Islands or Okinawa prefecture. It was also recorded that 889,246 water buffaloes were in Nepal.[citation needed]
The water buffalo is the main dairy animal in Pakistan, with 23.47 million head in 2010.[30] Of these, 76% are kept in the Punjab. The rest of them are mostly kept in the province of Sindh. The water buffalo breeds used are the NiliRavi, Kundi, and Azi Kheli.[31] Karachi has the largest population of water buffaloes for an area where fodder is not grown, consisting of 350,000 head kept mainly for milking.[citation needed]
In Thailand, the number of water buffaloes dropped from more than 3 million head in 1996 to less than 1.24 million head in 2011.[32] Slightly over 75% of them are kept in the country's northeastern region. The statistics also indicate that by the beginning of 2012, less than one million were in the country, partly as a result of illegal shipments to neighboring countries where sales prices are higher than in Thailand.
Water buffaloes are also present in the southern region of Iraq in the Mesopotamian Marshes. The draining of the Mesopotamian Marshes by Saddam Hussein was an attempt to punish the south for the 1991 uprisings in Iraq. After 2003 and the Firdos Square statue destruction, these lands were re-flooded and a 2007 report on Maysan and Dhi Qar shows a steady increase in the number of water buffaloes. The report puts the number at 40,008 head in those two provinces.[33]
In Europe and the Mediterranean
Water buffaloes were probably introduced to Europe from India or other eastern sources. In Italy, the Longobard King Agilulf is said to have received water buffaloes in about the year 600. These were probably a present from the Khan of the Avars, a Turkic nomadic tribe that dwelt near the Danube River at the time. Sir H. Johnston knew of a herd of water buffaloes presented by a King of Naples to the Bey of Tunis in the mid-19th century that had resumed the feral state in northern Tunis.[34]
European water buffaloes are all of the river-type and considered to be of the same breed named the Mediterranean buffalo. In Italy, the Mediterranean type was particularly selected and is called the Mediterranea Italiana buffalo to distinguish it from other European breeds, which differ genetically. Mediterranean buffalo are also kept in Romania, Bulgaria, Greece, Serbia, Albania, Kosovo, and North Macedonia, with a few hundred in the United Kingdom, Germany, the Netherlands, Switzerland, and Hungary. Little exchange of breeding water buffaloes has occurred among countries, so each population has its own phenotypic features and performances. In Bulgaria, they were crossbred with the Indian Murrah breed, and in Romania, some were crossbred with Bulgarian Murrah.[20] Populations in Turkey are of the Anatolian buffalo breed.[23]
In Australia
Between 1824 and 1849, water buffaloes were introduced into the Northern Territory from Timor, Kisar, and probably other islands in the Indonesian archipelago. In 1886, a few milking types were brought from India to Darwin. They have been the main grazing animals on the subcoastal plains and river basins between Darwin and Arnhem Land since the 1880s. In the early 1960s, an estimated population of 150,000 to 200,000 water buffaloes were living in the plains and nearby areas.[35]
They became feral and caused significant environmental damage. Water buffaloes also occur in the Top End. As a result, they were hunted in the Top End from 1885 until 1980. The commencement of the brucellosis and tuberculosis campaign (BTEC) resulted in a huge culling program to reduce water buffalo herds to a fraction of the numbers that were reached in the 1980s. The BTEC was finished when the Northern Territory was declared free of the disease in 1997. Numbers dropped dramatically as a result of the campaign, but have since recovered to an estimated 150,000 animals across northern Australia in 2008.[36]
During the 1950s, water buffaloes were hunted for their skins and meat, which was exported and used in the local trade. In the late 1970s, live exports were made to Cuba and continued later into other countries. Swamp buffaloes are now crossed with river buffaloes in artificial insemination programs, and are kept in many areas of Australia. Some of these crossbreeds are used for milk production. Melville Island is a popular hunting location, where a steady population up to 4,000 individuals exists. Safari outfits are run from Darwin to Melville Island and other locations in the Top End, often with the use of bush pilots. The horns, which can measure up to a record of 3.1 m (10 ft) tip-to-tip, are prized hunting trophies.[37]
The Australian water buffaloes have developed a different appearance from the Indonesian water buffaloes from which they descend.[citation needed] They live mainly in freshwater marshes and billabongs, and their territory range can be quite expansive during the wet season. Their only natural predators in Australia are adult saltwater crocodiles, with whom they share the billabongs, and dingoes, which have been known to prey on water buffalo calves and occasionally adult water buffaloes when the dingoes are in large packs.[citation needed]
Water buffaloes were exported live to Indonesia until 2011, at a rate of about 3,000 per year. After the live export ban that year, the exports dropped to zero, and had not resumed as of June 2013.[38]
In South America
Water buffaloes were introduced into the Amazon River basin in 1895. They are now extensively used there for meat and dairy production. In 2005, the water buffalo herd in the Brazilian Amazon stood at roughly 1.6 million head, of which 460,000 were located in the lower Amazon floodplains.[39] The breeds used include the Mediterranean from Italy, the Murrah and Jafarabadi from India, and the Carabao from the Philippines.
During the 1970s, small herds were imported to Costa Rica, Ecuador, Cayenne, Panama, Surinam, Guyana, and Venezuela.[40]
In Argentina, many game ranches raise water buffaloes for commercial hunting.[citation needed]
In North America
In 1974, four water buffaloes were imported to the United States from Guam to be studied at the University of Florida. In February 1978, the first herd arrived for commercial farming. Until 2002, only one commercial breeder was in the United States. Water buffalo meat is imported from Australia.[40] Until 2011, water buffaloes were raised in Gainesville, Florida, from young obtained from zoo overflow. They were used primarily for meat production, and frequently sold as hamburger.[41] Other U.S. ranchers use them for production of high-quality mozzarella cheese.[42][43][44][45] Water buffaloes are also kept in the Caribbean, specifically in Trinidad and Tobago and in Puerto Rico.
