Study of packed erythrocyte volume in selected andunselected lines of White Leghorn

Packed erythrocyte cell volume (PCV) of two populations of White Leghorn viz., a long-tenn selected strain (PL2) and an unselected control line (PL3) was studied at 16, 36 and 40 weeks of age. PCV at 16 weeks of age exhibited a distinct sexual dimorphism, with males having significantly higher (39.6±0.68%) haematocrit than females (35.1±0.46%) across both the lines. The selected and unselected lines did not significantly differ in packed cell volume at 16 weeks of age. However, at 36 and 40 weeks of age females of PL2 strain had significantly higher haematocrit values with those of controlline (PL3) by 15.3 and 12,2% respectively. Strain PL2 was heavier at 20 and 40 weeks of age by 145 and 30g respectively), early maturing (by 18.1 d) and had higher egg weight (by 3.9g) and egg number (by 13.7 eggs). Heritability estimates for packed cell volume in selected strain were 0.102 and 0.176 from sire component; and 0.053 and 0.165 from dam component at 36 and 40 weeks of age respectively.