In the perspective of animal protection and welfare, the most common and potentially the most frightening events encountered by the domestic fowl are procedures connected with transport. This study provides an evidence that reduction in floor space during crating, which is approximately 10% above requirements given to EEC Directives (accompanied with mixed social and heat stress due to high animal density), induces markedly elevated stress in broilers which is manifested by changes in haematological indices. The experiment was performed on ROSS 308 broilers (total number 70, mean body weight 3.05 kg). At 42 days of age, the broilers were crated for 2-hours either with reduction in floor space to 115 cm2/kg (S115) or 105 cm2/kg (S105) of body weight. The total erythrocyte and leukocyte count, haematocrit, haemoglobin, MCV (mean cell value), MCH (mean cell haemoglobin) and MCHC (mean cell haemoglobin concentration) values were monitored and differential leukocyte count was assessed 20 h following crating. When compared with uncrated control, S105 broilers exhibited highly significant increase in haemoglobin level, MCH and MCHC values, significant increase in MCV values and significant decrease in total erythrocyte count. S115 broilers did not manifest any significant changes in haematological parameters compared with control. When compared with S115 broilers, S105 broilers manifested significantly elevated haemoglobin level and MCV values, highly significantly elevated MCH and MCHC values and depressed erythrocyte count. It follows from results that the reduction in floor space to 115 cm2/kg for 2 hours did not induce any significant changes in both total and differential leukocyte counts in blood of broilers when compared with control chickens. However, reduction in floor space to 105 cm2/kg resulted in highly significant increase in heterophil counts and subsequently also HLR (heterophil/lymphocyte ratio) was significantly elevated. When compared S105 and S115 broilers, mean values of heterophil counts and HLR ratio were higher due to reduction in floor space to 105 cm2/kg. The differences, however, were not statistically significant.

Department of Veterinary Public Health and Toxicology University of Veterinary and Pharmaceutical Sciences Brno Czech Republic