Cricetomys farming for improving animal production …...1 Cricetomys farming for improving animal production in developing countries Malekani J.M., Ph.D. Department of Biology, Faculty

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Cricetomys farming for improving animal production in developing countries

Malekani J.M., Ph.D.

Department of Biology, Faculty of Science, University of Kinshasa, DRC

E-mail: [email protected]

1. INTRODUCTION: MINILIVESTOCK AND ITS IMPORTANCE IN ANIMAL PRODUCTION

There is a great need to enhance food production in the developing countries.

According to Paarlberg (2000), the U.N.'s Food and Agriculture Organization (FAO) recently

reported that one out of every five citizens from the developing countries, totalling

approximately 828 million people, still suffers from chronic malnutrition. The situation may

even be more disastrous for the whole of the African continent, with an estimated population

of about 776 million inhabitants (FAO, 2002a). Most of these people live under deplorable

conditions, with little or no hope of any significant future development in sight. The shortage

of protein-rich food resources in some areas has reached serious levels. In stark contrast,

protein deficiency in the developed nations is very rare.

Protein is an essential constituent of our daily diet. Like fat and carbohydrate, protein

can also serve as a source of energy for the body. However, protein is also the only source

of the amino acids, especially essential amino acids. A regular, daily protein intake is

absolutely necessary to replace expended nitrogenous materials (e.g. protein, nucleic acids,

etc.) in the tissues. Proteins are essential for numerous functions in the human body and

processes associated with growth, reproduction, health and longevity. The average daily

dietary protein allowance for healthy adults is approximately 0.8 g/kg of body weight (Reeds

& Beckett, 1996; Williams, 1999; Sizer & Whitsay, 2000). The safe daily requirement for a 19-

24 years old person, weighing approximately 72.5 kg can therefore be calculated to be

approximately 58 g of protein per day.

It has been reported that by the year 2005 more than the half of the world population

will be living in cities (FAO, 2002b). Food sources of animal protein like meat, milk, eggs and

even fish remain rare and expensive in developing countries, in the cities as well as in the

villages. In cities, especially those in developing countries, the number of poor people often

exceeds 50 per cent of the total urban population. Malnutrition affects the majority of the

population, especially pregnant and lactating women and children. Based on a calculation

that an average grown-up needs a mean protein intake of approximately 52.5 g per day, the

annual meat shortage for Central Africa has been estimated at 5,331,884 metric tons without

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considering the fish protein production (Table 1). Available bush meat in various forms (fresh,

smoked, salted, biltong) that should help to eradicate the shortage is unequally distributed

throughout the continent.

One of the most feasible means to solve the problem of the availability of meat is to

develop animal husbandries, employing animal species that are not yet widely reared, or are

still just hunted or collected by people for their subsistence. The National Research Council

(NRC) of U.S.A. (1991) published a book on "microlivestock" with the intention of attracting

the attention of people to the utilization of a number of small animals as food sources and to

stimulate initiatives on animal production all over the world. Subsequently, the progressive

term "minilivestock" was coined (Hardouin, 1993) pertaining to farming with little-known small

sized animals that can be used effectively in the enhancement of animal protein production

and can eventually provide inhabitants in developing countries with a regular and stable

source of income.

Minilivestock can include small domestic animals like chickens, rabbits or goats, but

may also involve several animal species of wildlife that still need to be domesticated and for

which the proper production techniques still have to be established. Among them there are

invertebrates, like gastropods (e.g. snails: Archachatina marginata), insects (e.g. termites:

Macrotermes bellicosus; crickets: Brachytrupes membranaceus, butterfly caterpillars:

Lobohunaea goodi, etc.). Vertebrate species with potential for microlivestock husbandries

can include reptiles (e.g. lizards: Green iguana: Iguana iguana), birds (e.g. guinea fowls:

Numida meleagris; quails: Coturnix coturnix) and the very abundant class of mammalian

species that may be exceptionally suitable for husbandry, the rodents (e.g. cricetomas:

Cricetomys emini and C. gambianus as well as the grasscutters: Thryonomys swinderianus;

agoutis: Dasyprocta spp.; capybaras: Hydrochoerus hydrochaeris; coypus: Myocastor

coypus). Small antelopes (e.g. duikers: Blue duiker: Cephalophus monticola), bucks (e.g.

Marshbuck or Sitatunga: Tragelaphus spekei) and bush pigs (e.g. River hog: Potamochoerus

porcus; Forest hog: Hylochoerus meinertzhageni; Wart hog: Phacochoerus aethiopicus;

peccaries: Tayassu tajacu, T. pecari), are equally suitable minilivestock candidates.

All these different species of which some are already being promoted as

minilivestock, can be reared to produce sufficient meat in their various distribution areas.

Farming with these potential bush-meat species can also facilitate the protection of these

animals against over-hunting and, in so doing, help to preserve their respective ecosystems

(Malekani, 1995 & 1997). In fact, in some African countries, like in the Democratic Republic

of Congo, Equatorial Guinea, Botswana, etc., people already consume more bush meat than

domestic meat (Ntiamoa-Baidu, 1997; Table 1). It has been reported that 80 % of fresh meat

consumed by the population in Ghana is derived from wildlife (Thomson, 1992). If the

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Table 1 Evaluation of meat shortage in Central Africa (bush meat and domestic meat sources), estimated from animal production figures for 1999.

COUNTRY

AREA OF THE COUNTRY2

OCCUPIED BY THE FOREST1

(%) (km2 )

POPULATION OF THE COUNTRY4

CONSUMING BUSH MEAT IN FOREST

AND CITIES1

(%) (number of inhabitants)

POPULATION DENSITY

(inhabitants/km2)

BUSH MEAT CONSUMED1/

DOMESTIC MEAT PRODUCED3

(metric tons/year)

OPTIMUM AMOUNT OF MEAT NEEDED

FOR NATIONAL CONSUMPTION (metric tons/year)

ESTIMATED SHORTAGE FOR CENRAL AFRICA (metric tons/year)

Cameroun 32.7

155,330

24.5 3,638,620

31.3 78,077.2 209,406 Subtot. 287,483.2

1,425,307 1,137,823.8

Central African Republic

8.4 52,236

20.5 759,275

6 12,976.5 83,230 Subtot. 96,206.5

356,135 259,928.5

Congo, Democratic Republic

50.8 1,190,737

50.8 25,909,369

21.7 1,067,873.5 233,700 Subtot. 1,301,573.5

4,881,455 3,579,881.5

Congo, Republic

62.4 213,400

48.5 1,465,028

8.8 16,325.3 26,970 Subtot. 43,295.3

289,162 245,866.7

Equatorial Guinea

60.6 17,004

89.8 410,500

16.3 9,762.8 523 Subtot. 10,285.8

43,786.5 33,500.7

Gabon

84.9 227,500

62 763,140

4.6 11,380.6 31,586 Subtot. 42,966.6

117,849.5 74,882.9

TOTAL

45.50 1,856,207

44.4 32,945,932

18.2 1,196,395.9 585,415 Part.tot. 1,781,810.9

7,113,695 5,331,884.1

References: 1 Inamdar et al., 1999:2-3; 2 Anon., 1985:111 & 118; 3 FAO, 1999; 4 FAO, 2000.

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husbandry of some the most exploited wild animal species, like the cricetomas (Cricetomys

emini and C. gambianus) is not undertaken soon, this source of wildlife protein may be

exhausted in a number of places in the very near future.

2. IMPORTANCE OF THE CRICETOMYS MINILIVESTOCK AS A SOURCE OF FOOD 2.1. Acceptance of the Cricetomys meat as food by people

Cricetomys meat is habitually consumed in most of Africa where these rodents are

still occurring naturally. A study carried out in Nigeria showed that 71.4 % of the people find it

acceptable to use this animal as food (Ajayi & Olawoye, 1974). Despite taboos and

prohibitions that exist in some areas of DRC, the meat of Cricetomys is generally well

appreciated. A survey carried out in selected cities and villages of the country on the

acceptance of this meat revealed that 76.3 % of 455 individuals questioned consume this

meat in their homes as a type of venison. In addition, 64 % of the questioned subjects in the

survey reported that the taste of the cricetoma meat is excellent (Malekani & Paulus, 1989:

142). Fitzsimons et al. (1920) reported that a significant number of people in South Africa

also enjoy the meat of Cricetomys. Because of over- hunting, these animals have become

relatively rare and have even disappeared in several areas close to the villages and cities

(NRC, 1991; Malekani, 2001) in DRC.

2.2 Importance of the Cricetomys meat among other bush meat sources

Cricetomys rodents are considered to be the most common animals to be employed

as a meat source in Africa (Den Hartog & De Vos, 1973). Heymans and Codjia (1988)

reported that these rodents are among the most hunted animals in West Africa. According to

the study of Wetshi et al. (1988), the C. emini species itself was found to represent 39.1 % of

all the mammalian game sold in Kisangani, the third largest city in DRC. According to Knight

(1987), Cricetomys should also be considered as an alternative source of protein in South

Africa, because cattle meat production will probably no longer be sufficient in the near future.

Besides conventional livestock and game, African countries need to find relatively

inexpensive, renewable meat sources to provide for their growing populations. The

consumption of wild Cricetomys meat is already relatively high throughout most of Africa and

the development of husbandries of these rodent species would be one of the easiest ways to

increase animal production and help to protect them against over-hunting.

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3. BIOLOGY OF CRICETOMYS GAMBIANUS/C. EMINI 3.1 Systematic position, appearance, common and local names

Cricetomys gambianus (Waterhouse, 1840) belongs to the subfamily Cricetomyinae

(Roberts, 1951), family Cricetidae (Rochebrune, 1883), superfamily Muroidea (Miller and

Gidley, 1918), suborder Myomorpha (Brandt, 1855), order Rodentia (Bowditch, 1821), class

Mammalia (Kingdon, 1984; Haltenorth & Diller, 1985). It is difficult to distinguish C.

gambianus from the closely related C. emimi (Wroughton, 1910), the only other species of

the genus Cricetomys. The two species appear rat-like, grow to a very large size (~1.400 kg),

and have cheek pouches. C. gambianus (Plate 1) is thickset and has a browner and coarser

fur with a dark mask round the eyes, while C. emini (Plate 2) is slightly more slender and has

a grey and soft fur with a white ventral part (Kingdon,1984; Haltenorth & Diller, 1985). The

fur of C. emini is short (5-10 mm) and sparse, while that of C. gambianus is longer (10-15

mm) with a dense furry undercover (Genest-Villard, 1967; Misonne, 1971).

The Cricetomys rodent is commonly called “cricetoma” in English, instead of “giant

rat”. Alternative names for these rodents are “cricétome” in French, “cricétomo” in Spanish,

“cricetomie” in Dutch and Flemish. In some African languages, these rodents share

appropriate names like “kachimba bulongo” or “buku” in Swahili, “nkumbi” in Kikongo and

“motomba” in Lingala (Haltenorth & Diller, 1985; Malekani, 1987 & 1989). In a survey on the

consumption of these rodents not less than 84 different names were recorded for the two

species, in 78 different languages spoken in D.R.C. (Malekani & Paulus, 1989).

3.2 Ecological and geographical distribution Cricetomys gambianus mainly lives in the savannahs, around the edges of forests

and in the mountains up to 3,500 m above sea level. It can also be found in sub-Saharan

Africa from Senegal to Sudan and southwards to Angola and the north-eastern region of

South Africa as far south as the Transvaal and KwaZulu-Natal. C. emini is found in the

whole of the rain forest area, from Sierra Leone to Lake Tanganyika, through the Democratic

Republic of Congo and up to the north-east shore of Lake Victoria in Uganda and in Bioko,

ex-Fernando Po, Equatorial Guinea (Genest-Villard, 1967; Misonne, 1971; De Graaff, 1981;

Haltenorth & Diller, 1985; NRC, 1991). The two species of Cricetomys are endemic in Africa

(Fig. 1).

3.3 Ethology Cricetomys gambianus, like C. emini, is a solitary animal, with nocturnal habits and

prefers to live in burrows. This rodent is more omnivorous than vegetarian and relatively easy

Plate 1 A Cricetomys gambianus male (the savannah species); weight: 1.288 kg with a

thickset shape and a brown, coarse fur coat (Malekani, 1990).

Plate 2 A Cricetomys emini female (forest species); weight: 1.356 kg with a slender

shape and a grey, short, soft fur coat (Malekani, 1990).

to feed in captivity. It feeds on a large variety of plant and animal foods, such as tubers (e.g.

cassava, sweet potatoes, etc.), grains and nuts (e.g. maize, groundnuts, palm nuts,

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coconuts, cola nuts, etc.), fruits (e.g. papayas, avocadoes and various wild fruits, etc.),

legumes (e.g. leaves of sweet potatoes, wild spinach: Talinum triangulare, and other wild

leaves, etc.), roots, stems, young shoots of plants, mushrooms, scrap food and by-products

or waste materials from food factories (e.g. wheat bran, palm kernel cake, draff, etc.) (Plate

3). This rodent also consumes small animals such as earthworms, insects (e.g. ants,

termites, grasshoppers, caterpillars, etc.), snails, lizards, rats and small birds or fish. In

captivity C. emini displays the same dietary habits than C. gambianus (Malekani, 1990 &

2001).

In its natural habitat C. gambianus is a very prolific breeder. The duration of gestation is

approximately one month and the number of pups per litter can vary between one and five,

with three to four pups on average. A female can reproduce six times in one year, eventually

giving birth to between 18 and 24 pups per year. The young animals become sexually

mature at five to six months of age (Ajayi, 1975a). The reproductive characteristics of C.

gambianus are similar to those of C. emini (Malekani, 2001).

3.4 Parasitology A study carried out on some helminths in a group of C. emini (17 specimens) and C.

gambianus (13 specimens) caught in the field or born in captivity in DRC indicated a rate of

23.3 % of hepatic capillariasis infection (Malekani, 1990). In the development of this study, it

was reported that none of the animals born in captivity appeared to be infected, while 17.7 %

of the wild C. emini and 30.8 % of the wild C. gambianus specimens were infected with this

parasitic worm. This was the first report of the presence of Capillaria hepatica in C. emini and

C. gambianus in DRC that become a new geographical record of the parasite. It is known

that this parasite may reduce the fecundity and even may induce the death of the infected

animal host. It is a known fact that capillariasis can become zoonotic, and that it may pose

some public health risks.

In addition, a number of other helminthic parasites could be identified of which three

cestode (Hymenolepis diminuta, H. nana, H. microstoma) and 16 nematode species

(Strongyloides ratti, Trichuris muris, Nematospiroides dubius, Nippostrongylus brasiliensis,

Trichostrongylus affinis, etc.). The H. diminuta, N. dubius, Trichostrongylus and

Strongyloides species were some of the most dangerous species identified in captive

animals. Treatment was executed with known anthelmintics, e.g. levamizole (7.5 mg/day/kg

body weight for two days) and mebendazole (60 mg/day/kg body weight for three days)

against nematodes; praziquantel against cestodes (50 mg/day/animal for two days);

oxfendazole against cestodes and nematodes (single dose of 0.05 mg/animal). Traditional

Fig. 1 Distribution of Cricetomys gambianus and C. emini in Africa (Genest-Villard,

1967).

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medication with medicinal plants was also employed to cure and control helminthic parasites

in the husbandry. Among the naturopathic medications employed, treatment with a dose of

10 g of fresh papaya seeds/animal/day for 12 days was the most effective.

Finally, Kilonzo and Mhina (1982) reported that C. gambianus did not appear to be

infested by plague during an outbreak of the epidemic in Tanzania.

4. CONCLUSION

Cricetomys is suitable for farming in local conditions. African people can take

easily a decision for slaughtering for their own needs. Farming Cricetomys on a large

scale can make a quick and cheap way to enhance the production of meat in DRC

and elsewhere in developing countries.

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