During the first three weeks, the air in the shed was heated by an external firewood heating system engaged to a hot air injection system to ensure uniform heating and maintenance of the temperature inall rooms. In the first three days the temperature was keptat 38 ± 2◦C and was then gradually reduced by 1◦C everythree days. From the third week on, animals were kept innatural environmental conditions and a mean temperature of 24 ± 3◦C was recorded in the shed.