I. Physiological Characteristics and Ventilation at Different Ages
1-14 days: heat production is less than heat loss -- prioritize a conservative approach -- err on the side of less rather than more
14-21 days: heat production equals heat loss -- prioritize a conservative approach -- err on the side of less rather than more
21-28 days: heat production is greater than heat loss -- transition period
28-35 days: heat production is greater than heat loss -- do not be conservative -- err on the side of more rather than less
35-41 days: heat production exceeds heat loss—do not err on the conservative side; bigger is better
II. How chicken houses feel at different ages
1-7 days: stuffy and hot; stuffy and hot both above and below
7-14 days: hot and stagnant; hot and stagnant both above and below
15-21 days: neither stagnant nor stuffy; a warm, humid feel both above and below
22-28 days: ventilated and warm; ventilated above and warm below
28-35 days: ventilated and not cool; ventilated above and not cool below
35-42 days: cool and refreshing throughout, cool and refreshing both inside and out.
III. Respiratory tract analysis by age in days
Respiratory issues are quite common now, so there are several key points to keep in mind when using medication.
1. Generally speaking, before 18 days of age, it is usually a wind-cold cold.
2. From 18 to 25 days of age, respiratory issues are generally due to damp-heat and are viral.
3. At around 30 days of age (later stage), it is an internal-heat cold; without internal heat, how could there be an external attack?