Feedback: Experts give insights on crop and livestock issues

Dangers of giving cows avocados: Side effects of avocados on cattle

I have planted avocados on my farm and also have coffee pulp. When I give my cows avocados, they produce red urine. I want to make animal feeds using both avocados and coffee pulp. Please advise.
-Kaburu

If your cows produce discoloured urine when fed avocados, then stop feeding them. I have seen cows feeding on avocado leaves and fruits with no side effects, except choking when they swallow the seeds.

Avocados contain a chemical known as persin, which is responsible for most of the side effects seen when animals (including cows) consume large quantities. All parts of avocado trees contain the chemical.

Some people have reported mastitis (leading to reduction in milk production), weakness, skin colour change, exercise intolerance, difficulty in breathing and death in severe cases.

There is no known amount of avocado one can give to the cow to have side effects and this could be due to variance in immune response in cattle, different varieties of avocados and parts consumed.

If you can avoid it in your rations, the better, but if you must, use small amounts.

Dr Wyckliff Ngetich
Department of Veterinary Surgery, Theriogenology and Medicine,
 Egerton University.

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Killer weed killer

It is only in Kenya where you find a key government official claiming that some pesticides cause cancer then another vehemently refutes this.

Is this because of the might of the manufacturer or it is scientific reasoning? Why do we want to protect a weed killer that has been banned in more sophisticated countries?

There is more than meets the eye in this scenario.

-David Okello, Nairobi

Yes, there are pesticides that cause cancer as it has been proven in other parts of the world and firms have been fined heavily and asked to compensate affected victims.

In these chemicals, the component glyphosate is the main problem. Studies have shown that it causes non-Hodgkin's lymphoma as well as other cancers, including leukaemia and brain cancer.

However, each country has its own protocols when dealing with such issues and would use them in case there is need to ban a chemical.

Carol Mutua
Department of Crops, Horticulture and Soils, Egerton University.

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I want to lease land

How do I find land to lease in Kiambu? I’m worried about security, so land inside a larger farm would be ideal.

-John

I believe you can’t fail to get a person who wants to lease land in Kiambu. Security is important and you can’t just lease the land, cultivate and then leave without having someone to look after the crops you will plant or whichever activity you are going to undertake there.

Thus, you must frequently visit the farm to see what is being done. You can even construct a temporary house and employ someone to be staying on the farm. Start by visiting the area and making inquiries.

Carol Mutua
Department of Crops, Horticulture and Soils, Egerton University.

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Training on keeping rabbits for sale

I would like to venture into commercial rabbit farming but I need some practical training, which I can get at the rabbit training centre in Nairobi headed by Kamau Kerera, a senior livestock production officer.

I don’t have the contacts of Mr Kerera or those of the centre. Please assist. Should you find Mr Kerera, let him give you a clear roadmap beginning from Nairobi city centre all the way to the training centre.

For a farmer to be trained at the centre, what are the initial requirements? Also, is the training conducted monthly or they have a fortnight programme? What are the prices of six-week-old does and bucks that they sell to farmers?

-Martin Okumu

It is a noble decision you have made to seek relevant information before venturing into rabbit farming.

Through this link https://national-rabbit-breeding-and-training-center.business.site/, you will be able to get directions to the National Rabbit and Breeding Centre, Nairobi.

You can also get in touch with them through 0720899299 or 0728410329 to know the minimum requirements you need, the nature of training they offer, when the training is offered and the prices of rabbits.

Ochiel Alvine
Department of Animal Sciences, Egerton University.

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Starting beekeeping

I am thinking of engaging in small-scale bee farming to help in pollination of my orchard but I don’t know where to start. Please enlighten me.

Zack Njuguna

Egerton University’s Animal Sciences Department has various experts on beekeeping, who can take you through types of beehives and how and where to set up an apiary, among other critical aspects of the trade for both honey production and pollination of the fruit trees.

The university also offers training on beekeeping. Please check on our website and enrol.

Ochiel Alvine
Department of Animal Sciences, Egerton University.

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Sukuma wiki diseases: Control of stem rot in sukuma wiki

I would like to inquire about diseases in sukuma wiki (collard greens). The leaves of my crops appear burnt and there is rotting of stems.

What could be the issue and what is the best treatment? 

-Joyce Chelegat

There are two diseases of sukuma wiki that can lead to rotting of the stems and they include:
Black rot (Xanthomonas campenstris): Also called soft rot, it is the most common disease of brassicas and affects all stages of the plants. It is a bacterial disease. The pathogen is seed-borne and spread by debris, wind, water and infected seed. It is favoured by wet conditions.

Symptoms: Yellowing of affected leaves followed by blackening of veins. When the stem is cut, a black ring is observed.

Control: Rotation, seed treatment, use of resistant cultivars, maintaining field hygiene and use of a copper fungicide as soon as the first symptoms are observed.

Black leg (Phoma lingam): Also called dry rot canker, it is a fungal disease. It is seed-borne and spread by debris and water.

It affects the lower part of the stem in seedlings. In mature plants, it affects the stems. The black-brown spots merge on the stems to form a dry rot. If it extends to the roots, the entire plant dries up.

Control: Crop rotation, use of certified seeds, field hygiene and avoid nursery beds in which sukuma wiki or other brassicas had been previously planted.

Carol Mutua,
Department of Crops, Horticulture and Soils, Egerton University.

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Sexing in tilapia

My name is Bernard Kamau from Naivasha. I would like to know how sexing and breeding is done in the pond on fish like tilapia.

Sexing in tilapia is done in two ways, that is, manual hand sexing and hormonal sex reversal.
In hand sexing, sexual features distinguishing males from females are clear when fish is mature, and this occurs at about 10cm.

The males have two orifices; one is the urogenital opening and the other is the anus. Females have three orifices, the genital opening, the anus and the urinary orifice.

Manual sexing should be done early in the morning so that fish is not stressed by high water temperatures.

When breeding tilapia in fish ponds, brood fish is selected and stocked in the ratio of male to female of 1:3. Fries are harvested from the pond every 15 to 21 days depending on the water temperatures, feeds and water quality aspects.

Under pond conditions, spawning or breeding does not normally occur because the final stimulus associated with a rise in water level and inundation of marginal areas does not happen.

However, they can be induced to spawn by hormonal treatment using pituitary glands from donor fish or synthetic hormones. For more information contact 0716573291 or write to

Janice Kimuli,
Agro-Science Park fish farm, Egerton University.

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I want to start a cage fish farm

My name is Bonface Godia from Kisumu. I was encouraged by the response of Paul Mboga on the question concerning how much could be used to start a fish pond.

I am kindly requesting for the breakdown of starting fish cage farming in Lake Victoria, including the cost of a cage that can hold about 5,000 tilapia fingerlings, not forgetting the feeds and how long can they take to mature and be ready for sale.

To get information on cage farming, please contact or 0720978840.

Janice Kimuli, Agro-Science Park fish farm, Egerton University.

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Where can I get calliandra seeds?

I would like to know if you have calliandra seeds.

-Francis Ngugi

Calliandra seeds are available at Kenya Forestry Research Institute (Kefri). You can try reaching them on or 0723 500176.

Carol Mutua,
Department of Crops, Horticulture and Soils, Egerton University.

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Sack gardening

I want to start commercial bag gardening on an 80-by-40ft plot in Ruiru. The plot is fenced and I have a water harvesting tank.

Please advise on the most profitable vegetables to plant and where I can source the bags, shade net and certified seedlings.

- Martin Mbogo

This is a very good idea and given that you already have water, you can produce vegetables throughout the year and thus earn more.

Grow bags are available from Real IPM Co (Kenya) Ltd and you can get in touch with them through

There are so many companies which make shade nets and they include Elgon Kenya (), Shade Net Ltd also sells the nets and you can get them on

You can try vegetables like spinach, sukuma wiki, lettuce, amaranthus (terere), night shade (managu) and spider plant (saget). On top of the bag, you can grow onions, beetroot and herbs (coriander, parsley, celery and others) and on the sides as well.

Most of these vegetables have certified seeds, which you can buy from agrovets and plant in a nursery bed then transplant to the grow bags.
Carol Mutua,
Department of Crops, Horticulture and Soils, Egerton University.

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Snail meal for ducks

Snails have invaded my premises and are eating plants. Now, I have ducks, how can I offer them the snails, do I crush them and get the flesh to feed them?

Ali Mohamed Mwakamsha

If the ducks are young, you have to train them by crushing the snails to remove the shell and then feed them. If the ducks are adults, they can swallow the whole snail, including the shell.

Therefore, you don’t have to crush them.  You should also make sure that they don’t feed on your crops. Remember that snails are most active at night and hide during the day.

You need to know their hiding places or you can use beer traps at night (put beer in shallow containers then bury shallowly.

The snails will drown in the containers and die. Make sure you change the beer regularly). This means that you can only use the ducks during the day.

Carol Mutua,
Department of Crops, Horticulture and Soils, Egerton University.