Sentence:  She decided to dig her way under the fence into their chook house and had great fun running around and biting the necks of about eight <WSD>chooks</WSD> and leaving them half-dead and bleeding. The neighbour was furious, and unfortunately it was Dad′s birthday, so when he arrived home from work, Mum said ‘Happy birthday andsic darling. Guess what? Your dog has half-killed most of the neighbour′s <WSD>chooks</WSD>. 
Meaning of the word marked with <WSD> tags:  A chicken, especially a hen.