Inheritance of packed erythrocyte cell volume, juvenile body weights and their interrelationships in two selected and a control line of Japanese Quails

Packed erythrocyte volume (PCV) and juvenile body weights of two body weight selected strains and a contemporarily reared control line of Japanese quail were studied on a total of 1113 quails. Packed cell volume pooled over strains and sexes, averaged to be 46.4% at 4 weeks of age. PCV of the two growth selected strains (45.1 and 45.5%) was significantly lower than the control line (48.2%) indicating that selection for 4-week body weight has resulted in reduction in the haematocrit status. On strain-pooled basis, males and females had same PCV values. The selected strains had significantly higher body weight at day-old, 2-week and 4-week of age (6.14, 84.6 and 196g) respectively than the control line. The superiority of selected lines over the control line for the body weight at three ages was 21.6, 63.5 and 64.7%. Distribution of haematocrit was characterized by slight negative skewness and positive kurtosis while the distribution of body weights was essentially symmetrical. PCV, on strain-pooled basis, had low heritability (0.08). Selected lines had higher heritability (0.12) as compared to control line (0.04) and heritability was slightly higher (0.16) in males than in females (0.10). Heritabilities for body weights and growth rates were high with no differences in the estimates between the sexes and the strains. PCV at 4-weeks of age had high positive genetic correlation with body weights at day-old and 2 weeks of age (0.58 and 0.71) while its genetic correlation with 4 week body weight was moderate (0.31). The genetic correlation of PCV with relative growth rates was negative (−0.22 to –0.76).