HYGIENE ASSESSMENT OF ENVIRONMENT FOR LAYING HENS IN A SEMI NATURAL BUILDING IN THE SUMMER

H. Hristev, A. Nikolov, Rumjana Ivanova, Kalinka Kuzmova

Abstract
A hygienic assessment of the environment for laying hens from a local population, living in a semi-captive environment-friendly building, has been performed. The egg productivity of the birds has been traced against changes in temperature and salt balance of the ration. Applying the Summers and Leesson index that measures danger from heat stress, showed that laying hens during the summer are under such stress. Reduced egg productivity during the warm period of the year is provoked by the low saline balance of the ration which is 13,8g MЭK/100 instead of 20-25g MЭK/100. To save all year egg laying the hens requires additional heating in winter and cooling in summer.

Key words: laying hens, heat stress, salt balance rations