Abstract
It was postulated that naturally occurring phenolic compounds obtained from various plant species may have potential use as feed additives for poultry. Therefore the aim of the study was to compare extracts of hesperidin, diosmin, quercetin and resveratrol in terms of their health-promoting (particularly immunostimulatory) effect on turkeys at different ages. The experiment was conducted on 720 Big 6 turkey hens assigned to 6 experimental groups of 120 individuals (6 repetitions with 20 birds each). The turkey hens in group G-C were the control, receiving a basal compound feed with no experimental additives. The turkey hens in the remaining groups, from the first to the 16th week of life, received a basal diet containing hesperidin (group G-H), diosmin (group G-D), quercetin (group G-Q) or resveratrol (group G-R) in the amount of 200 g per tonne of feed. Ht, Hb, RBC, WBC, lysozyme activity, %PC, IgA, IL-6, GLU, TP and minerals were determined in blood samples. The addition of quercetin or resveratrol in the amount of 200 g per tonne of feed was found to have a beneficial effect on haemoglobin synthesis and phosphorus availability, and may also modulate immunity in turkey hens.