ORIGIN AND PHYSICAL FEATURES
The grass cutter belongs to the order Rodent and family Thryonomidae which
contains only genus Thryonomys. Dorst and Dandelete (1979) recognized only
two species which they describe as greater grasscutter
Thryonomys swinderianus Temminck and the lesser grass cutter Thryonomys
gregorianus Temminck. This rodent is widely known through Africa south of
Sahara and it is commonly referred as the grass cutter, cane-rat or Cutting
grass.
They are heavily built, thick set with animals with rounded muzzle, small
round ears, short tails and harsh bristly fur. They have a peculiar bristle
tail which readily fractures near the base if seized, much like the easily
atomized tail of the lizard, a phenomenon that is of tremendous protective
value. The coarse bristly coat has no under-fur, though under magnification
some sparsely scattered extremely fine straight under-fur are visible.
The overall appearance is usually dark brown, speckled with yellow or grey
above butty white below. The chin and throat appear white. The head is a bit
small for the size of the body. The small circular ear is covered strong and
well padded and are armed with powerful straight claws. There are five
digits on the fore feet and four on the hind feet. Females have three pairs
of mammary glands on the belly, while the male testes are not visible
externally like other rodents.
The total body length (head to end tail) ranged from 35 to 60cm and its tail
length ranges from 7 cm to 25cm. Grass cutter grows to a considerable
weight. The mature male sometimes reach more than 9kg while females can
attain between 5-7kg body weight. Its growth rate is less than that of
rabbit of an improved breed and more than that of the local rabbit in a
tropical environment.
The animal has many predators including leopards, mongoose and python, in
addition to man.
MEAT QUALITIES AND USES
The meat qualities of the grass cutter compare favorably with those of
domesticated livestock species. Mature live weight ranges from 5 to 8kg. It
has an average dressing percentage of 65%. However with the consumption of
the head an entrails this can reach 80%.
The nutritional value of grass cutter meat is as good as those from domestic
animals. Beef, Lamb and pork also contain higher fat percentage than meat
from the grass cutter.In fact grass cutter meat is nutritionally superior to
some domestic meat because of its high protein to fat ratio and higher
mineral contents. The meat quality is also leaner and non-cholestrogenic.
The meat is very tasty when compared to both domestic and familiar game
species. The grass cutter also play an important role in traditional African
medicine for preparation of concoctions for fertility etc. In Ghana, the
hair of the grass cutter is used to season food just as much as its stomach
and intestinal contents. Also, the pancreas of the grass cutter contains a
high concentration of insulin which is used in local preparation for the
treatment of diabetes.
Pix of a matured grasscutter (thryonomys swinderianus temminck) as seen in the image below:-
SOCIO-ECONOMIC IMPORTANCE:
In Ghana it has been ascertained that grass cutter contributes to both local
and export earnings. About 73 tonnes of animals are sold in a year and
recent surveys show that is is the Grass cutter that dominates the bush meat
trade.
Most of this quantity is traded locally as fresh or smoked form. Smoked
grass cutter is exported to US and Europe.
Grass cutter can be reared with minimal capital outlay as inputs required
are very low.
Feed requirements for grass cutter in captivity are low and it does not
compete with man for feedstuffs. It can therefore serve as a considerable
income earner for the small scale Peri-urban or rural livestock producer. A
farmer can also integrate grass cutter rearing with other livestock farming
such as pigs, rabbits, sheep, ducks and poultry.
GRASS CUTTER HOUSING:
Grass cutter housing comprised of a stable and cages/pens. stable is the
main building which houses the cages/pens. It is a normal building
constructed in such a way to allow enough light and ventilation (air).
The type of material for its construction depends on the capital available
to the farmer/breeder. cement block, wood, mud, brick, bamboo etc are some
of materials for construction grass cutter house (stable).
Basically there are two rearing methods:
1.Rearing on the floor (floor hutch)
2.Rearing above the floor. (in meshed cages).
Floor hutch is the of rearing cage constructed with either cement block,
brick or mud on the floor. Meshed cage on the other hand is the type of
rearing cage made from combination of wood and wired-mesh.
Both of them however comprised of two compartments which permit easy
movement of animal.
They can also be made into two three tiers (layers) system in order to optimize space.
The hutches are placed within the building, and the dimension with other features can be length can be 2.0 m X 1.5 m width X height 0.75 meters.
COMPARTMENT:-this must be two compartment each of 1.0 meters X 1.5 meters X 0.75 meters, it must have a small opening way of Cm X Cm and must be made at the bottom of the partitioning wall between both compartments.This allows for easy movement of the grass cutters from one room to the other.And the top must be covered with a wire mesh or bamboo with an opening (entrance of 30cm X 25cm).
CAGE HOUSING SYSTEM
A farmer can also rear a grasscutter in a well covered wood wire cage, the designs of cages for grasscutter are different with purposes.The cages dimension and features are:length x width x height i.e 1.6 meters x 0.6 meters x 0.45 meters, it can also be in these ranges 1.5 meters x 1.0 meters x 0.4 meters, and it must have two longitudinal side: lenght x width: 30 cm x 25 cm, you can see the image of the wood wire cage system for grass cutter housing (3 steps: upstair wood wire cage system.
The dimension of the standard individual cages are length x width x height: 0.5 m x 0.5 m x 0.4 m and the entrance must be: 18 cm x 18 cm which must be one on one side only.
here is a sample picture of a standard cage housing system:-
i. Grasscutter above 5 kg: 38 cm x 14cm x 14 cm.
ii. Grasscutter between 1 and 3kg: 30 cm x 10 cm.
iii.Grasscutter between 3 and 5 kgs: 33cm x 13 cm x 13 cm.
In Hutches, 8 grasscutter are kept inside the house, in colony cages we can put between 18 to 24 grasscutters together and same also adult castrated males can be put in the colony cages, and they may be up to 12 per cage.
Image of animal population for one cage floor weaners (between two to four month old).
REPRODUCTION AND BREEDING.
A male and female grass cutters attains their sexual maturity at 5 and 7
months respectively. A male grass cutter can be paired with 3-5
females.There are two methods of mating -permanent and controlled mating
methods. The gestation period is 5 months, meaning that with good
management, the animal an litter twice in a year.
The average litter size is always four. They young ones can be weaned in
about 4-6 weeks, after a resting period of about 10 days mother can be
paired with the male again.
HANDLING.
Grass cutter can be handled either by tails or by the limb. For easy
handling, wire mesh cage can be used to move animal from one place to other.
FEEDS AND FEEDING OF GRASS CUTTER COLONIES.
Whatever be the choice of grass cutter farming embarked upon by farmer
(breeding or fattening), provision of quality and adequate nutrition is
essential to the success of each grass cutter rearing. Balanced feeding that
takes into consideration nutritional requirements and regularity of feeding
are essential factors responsible for the animals' good growth, health and
reproduction.
FEED INGREDIENTS
1)FORAGE
Grass cutters normally prefer grass with succulent stalk and such quality
can be found in the following wild or cultivated grasses among others.
.Elephant grass (pennisetum purpureum)
.Sugar cane (Saccharum spp)
.Guinea grass (Panicum maximum)
.Giant star grass(Andropogon gayanus)
.Maize stem (zea mays)
.Rice stalks (Oryza spp.)
ii)FOOD CROP CULTIVATED/PRODUCTS
.Rice
.Maize
.Guinea Corn
.Millet
.Cassava
NUTRIENTS
Balanced feed can be found in a proportional mixture of the following feed
ingredients that are used in preparing the supplementary feed. Examples of
feed ingredients include:
.Maize/millet------------------ cassava
.Brewers dried grain (BDG)-----Leucaena leucocephala
.Corn bran/wheat offal---------Oyster/snail shell
.Palm kernel cake (PKC)--------Bone meal
.Soyabean cake (SBC)-----------Salt
.Groundnut cake(GNC)-----------Vitamin -mineral premix
DISEASE MANAGEMENT.
As said earlier, good hygiene practice reduces the risk of disease outbreak
in grass cutters rearing. The most important disease in grass cutter rearing
include the following:
1.ENTEROTOXAEMIA: This is caused by a bacterium clostridium perfringens. The
organism produces toxins which are absorbed into the circulatory system of
the grass cutters thereby causing moralities.
The most obvious sign seen is the paralysis/ pedaling of the hind legs.
Other signs are seen during post mortern. vaccine against this condition is
available. Antibiotics (Ciprofloxacin, Enrofloxacin) are used in the
treatment. It is useful to sprinkle some superphosphate on pen floor
bi-monthly to break the development circle of clostridia orgamisms.
2.STAPHYLOCOCCAEMIA:-This is caused by a bacterium, staphylococcus Aurelius.
Most of the signs of this disease are seen at post mortem but discharges
from the nostrils and vagina could be seen. Antibiotics are also employed in
its treatment.
3.COCCIDIOSIS:This is caused by organism of the Eimeria family. Symptoms of
the disease include diarrhea, prostration e.t.c Drugs of the Amprolium
family are used in its treatment.
4.WORM INFECTION:-This is caused by worms and can be gotten from the cane
grass being fed to the grass cutter. This is why the cane grass must be put
in the sum before being fed to the grass cutters in order for the larvae of
the worms to destroyed. Regular deworming should be carried out.
5.ECTOPARASTES: e.g ticks. These could be introduced into the pens through
inadequately dried forage. Administration of Ivomec is used to control
ticks. Chemical bath/dipping of the grass cutters could also be useful.
NUTRITIONAL HYGIENE TIPS TO PREVENT FOOD POISONING AND DIGESTIVE ISSUES.
- Do not serve ripe fruit to the animals.
- Do not serve animals with grass cut the same day i.e the grass cut in late afternoon for the next feeding day.
- Remove leftover forage and concentrate before feeding fresh feed.
- Do not serve supplementary feed before forage in the morning.
- Avoid animals forage that is not yet mature (too young)
- Clean water and feed troughs each day before feeding.
- Provide enough water and feed troughs in the pen.
- Do not feed mouldy forage and concentrate.
- Do not source for grasses from unhygenic places where human waste is deposited.
