Effects of Housing Systems on Biochemical Indicators of Blood Plasma in Laying Hens

The aim of this study was to compare biochemical indicators of blood plasma of laying hens housed in three different housing systems (conventional cage system, enriched cage system and deep litter system). In each housing system, 12 ISA Brown laying hens were observed during the laying period from week 22 to 75 of age. Blood samples for determination of biochemical indicators in plasma were collected during this period in week 22, 47 and 75. Indicators of blood plasma metabolic profile of laying hens of all monitored groups during the laying period ranged in intervals stated for healthy animals. In some cases, significant differences between housing systems were found, however, these differences do not give clear evidence of the influence of the housing system on the health of animals. The differences were apparently due to different efficiency of each group during the laying period.