Table 4.

Variance components^a and heritabilities^b of monthly^c and cumulative^d egg numbers during early part laying period in Horro chickens (for hens survived to 44 weeks of age)

Trait	Period (weeks)	Animals, n	Records, n	Sires, n	Dams, n	σ2a	σ2e	h2 (±SE)
M1	21–24	203	176	23	69	0.1	0.2	0.32 (0.13)
M2	25–28	203	176	23	69	2.6	10.2	0.20 (0.16)
M3	29–32	203	176	23	69	15.5	12.2	0.56 (0.15)
M4	33–36	203	176	23	69	7.1	21.8	0.25 (0.14)
EP12	21–28	203	176	23	69	3.8	11.9	0.24 (0.16)
EP36	29–44	203	176	23	69	67.6	174.3	0.28 (0.15)
EP16	21–44	203	176	23	69	115.9	216.5	0.35 (0.16)
AFE		203	176	23	69	31.5	458.5	0.06 (0.15)

AFE age at first egg (in days)

^aσ²_a, σ²_c, and σ²e, additive genetic, common environmental, and residual variances, respectively

^bh², heritability of direct genetic and common environmental effects, respectively

^cM1, M2, M3, and M4, egg numbers in the first, second, third, and fourth months, respectively

^dEP12, EP36, and EP16, cumulative number of eggs produced from months 1 to 2, 3 to 6, and 1 to 6, respectively