As an Australian I would have to advise these researchers to be very cautious in regards to the use of the prickly pear. This species almost brought Australian agriculture to a complete standstill in the 1920's. It agressively invaded land and was rapidly spread by farmers using it for cattle fodder.

It was only brought under control when a moth was also introduced to combat it.

I strongly support Glenn's comment. In Latin America and SW USA Opuntia are a real pest, wide stretches of rangeland are virtually unusable. In Mexico, e.g. it is used as cattle feed but the economics of it is doubtful and certainly the danger entailed does hardly justify its introduction. Nutritive values are available in literature.

In many cases we speak about invasive species when noticing invasion in agricultural lands, rangelands, gardens etc. But what about introducing 'edible' food or fodder crops in areas where nothing is growing, e.g. desert-like regions. I see Spineless Opuntia plantations in deserts as a perfect opportunity to produce fodder for the herds of nomads or refugees in their camps. Any other fodder solution ?

As at now we are not discussing about introduction of opuntia. It is already there in many parts of Laikipia,Tharaka,Nyeri North and Baringo Districts of Kenya, and it is viewed by pastoralist as noxious weed. What we want to promote is its the utilisation as fodder especially during drought to reduce famine related deaths of livestock in arid and semi arid lands. Its intensive use will control the spiny cactus and promote the development of the spineless cactus. What the farmers need to know is how to handle the spiny cactus and to remove the spines and glochids how to feed (the feeding methods) and packages for utilizing cactus efficiently. My opinion is similar to Willernvan Cotthem, considering the number of livestock that were lost in the year 2008-2009 drought.

I am among the people who lost their livestock as a result of this Opuntia. It has displaced people, other local vegetation's disapeared as a result of the plant's dense invasive nature and most of our animals are either blind or one eyed. We have never seen any good of this plant but have been living with its lethal effects. before its invasion we used to have droughts but this time round the cactus has made our livestock more vulnerable to diseases and arid conditions. The KARI report has no relevance in our pastoral lifestyle, we should not be compared or sampled with the NYERI community , they own private lands and manage their livestock in zero grazing methods - we own land communally and we keep large herds of shoals and also our land is drier and we dont share the same environmental conditions! Livestock is part of our cultural heritage and anything that threatens it as well threatens our livelihoods. </p>
<p>We have been crying to our government and state sponsored Research agencies like KARI but no one think CACTUS is a real danger to the Nomadic people. I strongly oppose any long term utilization of the said plant but support any initiative to utilize it with eradication in mind. it is displacing local vegetation and having in mind its vulnerability to insect and other organism make think that we should remain with our own vegetation rather than adoring this setller-brought plant, they brought it as a fencing and recreational plant not as alternative fodder. Thanks Merinyi imerinyi@gmail.com

Dear All--Especially Kangara and Merinyi: Both of you may be right. What bothers me is if Cactus is edible by cattle, then the animals would be going for them automatically on their own volition.

May I know from Kangara whether the livestock eat them,when prompted or on their own? The Spiny type's thorn is lethal, hence causing blindness to any animal that dares nib at them. But if cattle can eat them ONLY when it is introduced to them, then the scientists should say this. And if its the spineless that should be introduced, then Kangara should state this very clearly, other than generalizing or sounding that a blanket use of all of them is okay. The perception given is that all cactus plant types--spiny & non-spiny--all are applicable gives a wrong impression, please. However, its ability to grow and survive in harsh hot, dry climatic conditions and rough landscape-mostly stony, sandy desert and semi-desert rocky soils, also goes a long way to illustrate how this plant can be very useful with genes may that could confer drought-tolerance to our crops that are vulnerable to drought- impacts. Biotech scientists should explore this. Also medicinal properties may be found in the cactus too. These could be opportunities worth confirming. Thank you. Let the debate continue. Peter Wamboga-Mugirya (Scifode--UGANDA) Freelance journalist, SciDev.Net, Kampala, Uganda and Events Manager, Open Forum on Agro-Biotechnology in Africa (OFAB)--Uganda Chapter. Email: pwamboga@gmail.com

Agropastoralist livestock-keepers in semiarid northern Tigray, e.g. the Irob, have been using Opuntia (locally known as "beles") for well over 100 years; the plant had been introduced by missionaries. The Irob regard beles as a saver of lives of both livestock and people in times of shortage of pasture and food. They now deliberately plant beles for feed and food. In less dry parts of Tigray, beles can easily become a weed if it is not used intensively. There can be no blanket recommendations about the use of this plant; it depends on the specific local conditions. But my main point is that, once again, some scientists are “discovering” what many farmers and pastoralists have known and have been practising for a very long time. Several scientists in Tigray have also done research on beles, starting already in the 1990s. I hope that the Kenyan scientists are aware of this earlier work.

It is true that Opuntia can be fed to livestock. Those animals use to it really relish it and tend to come home early to eat as opposed to feeding in natural pasture. Herders in Mariagat district, former Baringo fed it to their livestock in the 1999/2000 drought and lost no livestock to drought, although I should say few of them used it. There must also be a trained animal since livestock are not used to this herb.

I would like to add that many Opuntia species are considered weeds in Australia EXCEPT for the Opuntia ficus indica. This is a cactus that should be looked at for its potential innovative uses and not put into the same category as the other cactuses that have caused problems in the past.