| Popis: |
This study aimed at evaluating the influence of strain and stocking density on welfare, haematological and serum biochemical indices of broilers in a 28-day trial. Two hundred and seven 4-week old birds each of Anak Titan and Arbor Acre genetic provenience were randomly allocated to three housing densities of 8.3, 11.1 and 14.3 birds/m2.These corresponded to 17, 22 and 30 birds per pen ( 2.01 × 1.00 m ) in a 2x3 factorial experiment. Each treatment group was replicated three times. The welfare parameters estimated were gait score, feather score, foot and hock burns, pecking, pushes, chases, fights and mortality. Blood samples were tested for packed cell volume (PCV), red blood cells (RBC), white blood cells (WBC), haemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC). Similarly, sera were utilized for the determination of total protein, albumin, globulin, glucose, cholesterol, and creatinine contents. There were no genotype-associated differences (P > 0.05) in the welfare indicators examined. However, placement density significantly (P < 0.05) influenced incidence of pushes, chases and fights, with higher values in most cases recorded for birds housed at the highest density. The strains and population densities were similar (P > 0.05) in haematological profile. Strain and stocking density also exerted no influence (P > 0.05) on serum biochemical components. Strain × stocking density interaction effects were not observed in all the parameters. Consequently, the two strains could be reared at a density of 14.3 birds/m2 since density did not lead to a great degree of stress. |
