An aggressive runaway cow that knocked over a cyclist and damaged several fences in the northern German city of Celle had to be shot dead by a hunter after all attempts to calm down the animal were unsuccessful, police said on Tuesday. The cyclist was unharmed. Several people reported a cow galloping through the city, some 40 kilometres north-east of Hanover, on Monday evening. Officers then spotted the animal in a residential area and, aided by farmers, passers-by and the owner, tried to calm and catch the runaway for over an hour. When their attempts failed, a hunter shot the cow on the grou…