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Endemic Ruminant Livestock
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N’Dama cattle is the most representative "Bos Taurus" breed in West Africa. The origin of this breed is located in the Fouta-Djallon highlands of Guinea (Conakry). From there the N'Dama has spread in the sudanian and guinean regions. Being trypanotolerant, it has been used for large scale dissemination for grazing savannah in Congo, Central Africa, Gabon, Nigeria and DRC, especially in the regions infested by the tse-tse fly.
The N'Dama is a hardy breed, medium size type (100 cm at shoulder height for cows; 120 cm for bulls) with a large and strong head and with lyre-shaped horns. Its skin, with short and thin hair, is fawn colored but varies from sand to black color, sometimes spotted.
Cows produce only 2 to 3 liters milk per day during 7 to 8 months. The N'Dama breed is used for meat and the ratio carcass/liveweight is around 50%. The meat has a very good flavor without much fat. The average liveweight for a mature steer varies between 250 to 300 kg. In West Africa, to date there are approximately 7 million head of N'Dama.
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Djallonke sheep inhabit the area south of latitude 14° N including the coastal areas of west and central Africa. These include Nigeria, Benin, Ghana, Ivory Coast, Guinea, Senegal, Cameroon, Gabon, Congo and Southern Mali. They are generally white coloured although usually spotted with black or red colours. A tan with black belly is also common. They have a wither height of 40-60 cm and a body weight of 20-30 kg; these measurements indicate their characteristic small size.
The Djallonke sheep are used for meat. They have good reproductive capacity; age at first lambing is 18.8 months and lambing interval 10 months. Djallonke have an average litter size of 1.22. The Djallonke sheep are known for their adaptation to the tropical hot and humid environment of West Africa, and are considered tolerant to trypanosomosis infections.
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The West African Dwarf goat is a small breed of domestic goat. Dwarf goats are precocious and polyestrous breeders; bearing one to four young every nine to twelve months after a five month gestation period. Does are usually bred for the first time at about twelve to eighteen months, although they may conceive as early as two months if care is not taken to separate them early from bucklings. Newborn kids will nurse almost immediately, begin eating grain and roughage within a week, and are weaned by three months of age. Dwarf goats tend to be more robust and breed more continually throughout the year.
Females, called does, weigh 23 to 34 kg (51 to 75 lb) and males, called bucks, weigh 27 to 39 kg (60 to 86 lb). Wither height ranges from 16 to 23 in (41 to 58 cm). Their color can range from white, dark grey, solid black, and brown agouti. West African Dwarf goats are utilized for their meat and milk and are highly valued due to their tolerance of trypanosoma.
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Additional Reading
M Murray, DJ Clifford, G Gettinby, WF Snow and WI McIntyre
The use of trypanotolerant livestock is considered to be an important strategy for the control of African animal trypanosomiasis. In order to define the extent of the differences in susceptibility and productivity, 10 Zebu cows (a breed considered trypanosusceptible) and 10 N'Dama cows (a breed recognised for trypanotolerance) were exposed to a natural field challenge from Glossina morsitans submorsitans Newstead. The animals were two-and-a-half to three years old and had not been previously exposed to trypanosomiasis. All Zebu died of trypanosomiasis within eight months of first exposure. In contrast, only three N'Dama died of trypanosomiasis; they had all been suckling calves before they succumbed 11 to 14 months after initial exposure. The prevalence, level and duration of parasitaemia were significantly less in the N'Dama, which, unlike the Zebu, did not become febrile during parasitaemia. The differences in parasitaemia were largely attributable to Trypanosoma vivax. The N'Dama also developed much less severe anaemia than the Zebu. The mean and standard deviation of the packed red cell volume of the N'Dama was not significantly different between eight months after exposure when all Zebu were dead, and 21 months when the experiment was terminated. The relative productivity of the N'Dama was impressive. In addition to reduced mortality, the N'Dama experienced no abortions and produced five calves, three of which were alive at the end of the experiment, at which time three of the surviving N'Dama were pregnant. In the Zebu, in marked contrast, abortions occurred both in early and late pregnancy and no live calves were produced. The study confirmed that N'Dama cattle are innately less susceptible to trypanosomiasis than Zebu cattle and can survive and be productive in endemic areas of trypanosomiasis where Zebu perish.
RW Paling, SK Moloo, JR Scott, G Gettingby, FA Mcodimba, and M Murray
The susceptibility of N'Dama cattle (Bos taurus) to four consecutive infections with different tsetse-transmitted clones of Trypanosoma congolense was compared with that of Borans (Bos indicus). All animals were aged 13 months al the start of the study and had been born and raised free from trypanosomiasis under the same management and nutritional conditions, thereby limiting environmental factors that could have influenced susceptibility. While cattle of both breeds were equally susceptible to the establishment of trypanosome infections, the N'Damas exhibited superior resistance. Despite infection with virulent parasites, the N'Damas gained weight at the same rate as uninfected control animals, they did not develop anaemia to the extent that trypanocidal drug treatment was required, and all made a spontaneous recovery to normal hacmatological values within two to four months. In contrast, all the Borans needed treatment during the course of the four infections because of severe anaemia and showed markedly reduced liveweight gains. These clinical differences in the N'Damas were associated with two repcatable characteristics, namely, the ability to control parasitaemia and to‘resist’ anaemia, processes that did not appear to be linked. Also in contrast to the Borans. the N'Damas were able to mount accelerated haemopoietic responses, resulting in the reduced severity of anaemia following a primary infection. These findings pose the question as to whether the ability to control parasitaemia and to‘resist’ anaemia could be used as criteria for identifying resistant or trypanotolerant cattle.
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Endemic Ruminant Livestock