Sentence:  date of laying , length of <WSD>incubation</WSD> period , number of chicks reaching the first week , second week , fifth week , weight of hen , size of rooster 's wattles and so on , all scrawled out in a hand that looked more Chinese than English , the most jagged and sprawling Alex had ever seen . 
Meaning of the word marked with <WSD> tags:  the period between infection and the appearance of symptoms of the disease