Feed for the cattle?
A paper by John Kang’ara and Josiah Gitari, animal nutritionists at KARI, concludes that Opuntia species — the prickly pear or paddle cacti — have extreme tolerance to drought and remain succulent and easily digestible even in times of extreme water shortages, which makes them an excellent source of water and nutrition in harsh conditions.
They found that during a severe drought in 2008–2009, farmers who fed their cattle the cactus paddles (the large, leaf-like parts) lost none of their cattle to drought.
Meanwhile, some farmers, such as the Masai pastoralists in Laikipia North refused to use the cactus as feed and even pleaded with the government to eradicate what they consider to be an invading weed.
I remember reading about in Australia how certain very spiny opuntia escaped and naturalized, and the cattle would eat them during drought and be harmed by the spines. I guess you need a low-spine variety for cattle, or remove the spines yourself before feeding them.