Effect of Genotype and Transport on Tonic Immobility and Heterophil/Lymphocyte Ratio in Two Local Italian Breeds and Isa Brown Hens Kept Under Free-Range Conditions

Abstract

This study was undertaken to investigate the effect of transport and genotype on the welfare and fear response of laying hens through a comparison of three breeds reared in free-range conditions: a commercial strain, the Isa Brown (IBh), and two local chicken breeds, the Bionda Piemontese (BPh) and the Bianca di Saluzzo (BSh). After a journey of 67 km (75 min) from the farmhouse of origin to the experimental station, ninety hens, divided according to breed, were free-range reared for two months. Body weight (BW), tonic immobility (TI), red and white blood cells, heterophil to lymphocyte (H/L) ratio and 1-acid glycoprotein (AGP) were assessed at four different sampling times: at the farmhouse of origin (T1), at 1 day (T2), 15 days (T3) and at 2 months (T4) after arrival at the experimental station. No statistical differences were found between the four sampling times for BW, total red and white blood cells or for AGP. An increase in the H/L ratio (P<0.05) was recorded at time T2 for IBh and BSh, compared to BPh (P<0.05). TI was significantly higher (P<0.05) for the local breeds, BPh and BSh, than for the commercial strain IBh. The results of this study suggest that genetic and adaptive differences can affect both, physiological and ethological parameters.