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Maendeleo Vijijini
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Seated behind his desk in his farm office, Julius Wokabi
scratches his head several times as he works out some figures in a book.
The
52-year-old father of two, who works as an accountant in Nairobi, farms
in Othaya, Nyeri, where he keeps some 200 pigs and further grows tea,
coffee and eucalyptus trees.
However, it is the pig
venture on his 12-acre farm christened Jidlaph that make it tick.
Despite keeping the many animals, Wokabi has managed to maintain high
standards of hygiene, with nothing going to waste as he makes biogas
from the droppings.
It all starts with the way the
farmer has constructed the pigsties. Each shed is subdivided into two to
hold a sleeping and a dunging area as pigs should not sleep on a dirty
environment, despite the perception that they love dirt.
The
watering system in the shed is also automated to avoid wastage and uses
displacement method where the inflow is equal to the amount consumed.
Waste
from the dunging area finds its way to a collecting point through pipes
and gravity, where it is mixed in a ratio of 1:1 and the slurry is
added to the bio-digester for biogas generation.
“These pigs have come as a blessing ever since I started keeping
them in October last year. I used to spend up to Sh320,000 on
fertiliser alone, Sh80,000 on tea which is on two acres and Sh240,000 on
coffee that is on six acres. The two cash crops require constant
fertiliser, which becomes expensive, but this is now in the past,”
offers Wokabi, noting he went into pig farming because of their high
breeding rate, which makes them profitable.
To start,
Wokabi consulted experts from Farmers Choice and was advised on housing
and feeds before he invested into 20 mature pigs, with the venture
costing him about Sh1.2 million in total.
“One thing I
was warned about is sub-standard feeds. Even if you have a genetically
right breed, substandard feeds only lead to wastage in terms of time,
money and labour as the animal will not attain the required weight on
time and the female may not go on heat.”
Once
his piglets are born, he clips the teeth in the first 15 minutes to
prevent them from biting and inflicting pain on the sow while suckling
leading to infection of the udder.
John Kihumba, an
extension officer with the Ministry of Agriculture in Othaya, explains
that in the first two weeks, if the piglets are more than six, they
should be separated from their mother to suckle in turns so that the sow
may not trample on them.
“The piglets should also be
castrated within 21 days to avoid inbreeding and hygiene be maintained
to keep diseases at bay,” Kihumba adds.
Wokabi weans the piglets at six weeks, feeding them with 0.75g of concentrate per pig, per day so that they can add about 400g daily.
Wokabi weans the piglets at six weeks, feeding them with 0.75g of concentrate per pig, per day so that they can add about 400g daily.
PLANS TO PRODUCE ELECTRICITY
In
the seventh week, he adds the concentrate to 1kg per pig, per day and
by the fourteenth week, the piglets now referred to as pokers are fed up
to 1.7kg, which is in three equal portions, at 7am, at noon and at 4pm
to add about a kilo a day.
At 22 weeks, during the
beconer stage, the pigs are fed 2.5-2.7kg and are ready to be served in
seven months where they will be fed 25 per cent of their body weight. To
supplement the commercial concentrate, Wokabi also grows vegetable and
sweet potato vines.
“A pig if properly fed should weigh 100kg by the fifth month,” Kihumba says.
Wokabi
sells his pigs to Farmers Choice at an average of Sh18,000 for a 100kg
animal. “I sell about 20 animals a month though there are high and low
seasons. To be contracted as a supplier of Farmers Choice, volumes
matter most,” he offers.
Wokabi constructed the biogas
plant, which cost him Sh600,000, and the pig shed at the same time even
before installing the pigs, therefore, he did not have any challenge
with pig waste, which experts warn should not be used on food crops.
“I
produce a minimum of 25 and a maximum of 32 cubic metres of gas per
day, with the pig offering about 500kg of poo a day. I use the gas for
cooking, lighting and warming the pigsties using heaters. I plan to
install a gas generator that runs on biogas to produce electricity,”
says Wokabi, noting he manages to save around Sh20,000, which would have
gone on fuel.
Edward Mugambi, an engineer with Green
Energy Revolution, says that pig waste produces more gas than cow’s as a
kilo generates up to 60 litres of biogas as compared to cow dung that
offers 40 litres.
Pig waste, according to Mugambi, has a high total solid waste than cow dung, which is more watery.
However,
for the initial feeding of pig waste to the digester, a farmer can
incorporate cow dung to balance the nitrogen level, which is quite high
in pig waste.
Mugambi further adds that, “Biogas
production can be optimised by mixing different types of substrates to
ensure that the optimum concentration of nitrogen is achieved for
production of quality biogas.”
PIG FERTILISER NOT TO BE APPLIED ON FOOD CROPS
Waste
from goats, rabbits and chickens can also be used for biogas production
as long as they are first sorted to remove sawdust and inorganic matter
before being fed into the bio-digester.
Dr Jane Maina,
a veterinarian from the Faculty of Veterinary Medicine and Surgery,
Egerton University, notes that pig waste, whether in slurry or raw form
should not be used on food crops like vegetables.
“For
trees, coffee and tea, that is fine, but for food crops, unless proper
precautions are followed, pig manure can be harmful to human health. The
composting process that can kill organisms harmful to man requires high
temperatures and special composting conditions not available locally.”
“The
primary hazard present in pig manure is parasites such as roundworms
and tapeworms that can be passed on to man. Some resistant bacteria such
as listeria and staphylococcus found in pig may also survive the
composting process and have been responsible for disease outbreaks in
agricultural and livestock workers,” she adds.
***
BIOGAS PRODUCTION
- Biogas production is influenced by the carbon/nitrogen (C/N) ratio among other factors like the PH, temp and hydraulic retention time.
- C/N ratio varies for different organic matter with agricultural residues having a high C/N ratio as compared to animal waste.
- The ideal C/N ratio that optimises biogas production is in the range of 20-30.
- A higher C/N ratio outside the above range causes low biogas production as nitrogen is rapidly consumed by the methane thus not reacting on surplus carbon in the material, a thing that can be corrected by adding nitrogen in animal urine effect of the same causes reduced biogas production.
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