Influence of rapeseed meal on productivity and health of broiler chicks.

Research was focussed on investigating the influence of different quantities (0, 10, 20 and 30%) of rapeseed meal (RM), 00-cultivar Silvia on production results, as well as on the morphological and pathohistological changes in the internal organs of chicks during the course of the experiment, measured on the 21st and 42nd days of the 42-day experiment. The experiment involved 120 chicks divided into four groups: a control group (C) and three experimental groups (E1-3). It was found that chicks in Groups C, E1 and E2 realised significantly (P < 0.05) higher gains than those in Group E3, both after the test period and at the end of the experiment. No significant differences with regard to feed conversion were found between groups of chicks. Throughout the experiment chicks in Groups E1-3 were found to have a significantly (P < 0.05) heavier liver. Compared to Groups E1-3, Group C chicks had a significantly (P < 0.05) heavier gizzard after 21 days, but following the finisher diet Group E3 had a significantly (P < 0.05) lighter gizzard. Compared with birds in Group C, those in Groups E2-3 had significantly heavier (P < 0.05) unevacuated intestines when fed the starter diet, and those in Groups E1-2 showed a similar result when fed the finisher diet. Chicks in Group E3 had a significantly lower grill weight than those in Groups C, E1 and E2, both in the first half of the experiment and at the end. The starter diet did not result in any differences in the quantity of abdominal fat among groups, but following the finisher diet Groups E2-3 showed significantly less abdominal fat in comparison to Groups C and E1 (P < 0.05). Group C showed a significantly higher carcass yield than Groups E1-3 (P < 0.05) in the first half of the experiment and at the end. Groups E1-3 manifested a slight to medium hypertrophy of thyroid epithelial tissue as well as slight thymus hypertrophy and slight atrophy of the cloacal bursa follicles.