Here's another look at the goat. In the picture on the right you can just make out the camera on its mast and the antenna in the midle of the goats back.
The picture on the left shows the camera and antenna more clearly. I asked the goats owner how he made it. He says its based on a colour camera available from RadioShack and a low power ATV transmitter he built. The power is supplied by a battery in one of the pockets and the resulting transmission is then pushed through a 'rubber duck' type antenna. The camera also has a microphone so that he can hear whats going on around the goat.
The goats owner told me that the next phase in the GoatCam was to put a GPS receiver in the bag too so that he could see just where the goat had gone when it was roaming around his farm at home.