Apparently the grass on Muppet's side of the fence wasn't quite tasty enough and lacked in iron so he started sucking on this bloudraad fence to get that great iron taste in the back of his mouth.
Bloudraad, in case you don't know, literally translated from Afrikaans means blue wire and, as you may guess, got its name because of its blue hue. Afrikaaners have a saying "'n boer maak 'n plan" which basically means that boers (farmers) are extremely resourceful and - much like McGyver - are able to solve problems on their farm (normally with little more than a piece of bloudraad and a pair of pliers).
I'm not exactly sure how the phrase originated, but if you spend time on a South African farm and take careful note you'll see many weird and wonderful ways in which farmers solve interesting problems with the most basic of resources... 'n boer maak 'n plan! :)
I took this photo of Muppet (not his real name) somewhere out the back of Durbanville.