Table 5. Comparison of egg production parameters between Lueyang chickens with and without NC-like haplotypes.

Haplotypes	ATAATA(A/C)Ta	GGAACACT	Δpar (95% CI)b	GGGGCGCC	Δpar (95% CI)	GTA(A/G)TACTa	Δpar (95% CI)	F value	Model
N	42	87		108		75		P valuec
Record N	978	2053		2423		1695
p	0.61 ± 0.016	0.55 ± 0.012	−0.06 ± 0.021	0.51 ± 0.011	−0.10 ± 0.020	0.48 ± 0.013	−0.13 ± 0.022	7.16525	Segmented polynomial
	(0.59, 0.65)	(0.53, 0.57)	(−0.10, −0.00) d	(0.49, 0.53)	(−0.14, −0.06)	(0.46, 0.51)	(−0.17, −0.09)	< 0.000001
s	0.009 ± 0.0013	0.008 ± 0.0010	−0.001 ± 0.0020	0.008 ± 0.0010	−0.001 ± 0.0017	0.006 ± 0.0011	−0.003 ± 0.0020
	(0.006, 0.011)	(0.006, 0.010)	(−0.004, 0.003)	(0.006, 0.010)	(−0.004, 0.002)	(0.004, 0.008)	(−0.006, 0.000)
Tp	25.1 ± 0.38	25.1 ± 0.30	0.0 ± 0.50	25.2 ± 0.30	0.1 ± 0.50	25.0 ± 0.38	−0.1 ± 0.55
	(24.4, 25.8)	(24.5, 25.7)	(−1.0, 1.0)	(24.7, 25.8)	(−0.86, 1.10)	(24.3, 25.8)	(−1.2, 1.0)
tip	4.9 ± 0.69	4.3 ± 0.55	−0.6 ± 0.92	4.8 ± 0.54	−0.1 ± 0.91	4.9 ± 0.70	−0.0 ± 1.01
	(3.6, 6.3)	(3.2, 5.4)	(−2.4, 1.2)	(3.7, 5.9)	(−1.9, 1.7)	(3.5, 6.3)	(−2.0, 1.9)
a	1.00 ± 0.105	0.88 ± 0.071	−0.11 ± 0.13	0.83 ± 0.067	−0.17 ± 0.12	0.75 ± 0.074	−0.25 ± 0.128	7.12442	Yang
	(0.79, 1.20)	(0.74, 1.02)	(−0.36, 0.13)	(0.69, 0.96)	(−0.415, 0.072)	(0.60, 0.89)	(−0.50, 0.003)	< 0.000001
c	1.29 ± 0.223	1.59 ± 0.238	0.30 ± 0.327	1.46 ± 0.201	0.17 ± 0.301	1.34 ± 0.223	0.045 ± 0.316
	(0.85, 1.73)	(1.12, 2.06)	(−0.34, 0.94)	(1.06, 1.85)	(−0.42, 0.76)	(0.90, 1.78)	(−0.57, 0.67)
x	0.019 ± 0.003	0.018 ± 0.0023	−0.000 ± 0.0038	0.018 ± 0.002	−0.000 ± 0.0038	0.017 ± 0.0029	−0.002 ± 0.0042
	(0.013, 0.024)	(0.014, 0.023)	(−0.008, 0.007)	(0.014, 0.023)	(−0.008, 0.007)	(0.011, 0.022)	(−0.010, 0.006)
d	22.7 ± 0.16	23.0 ± 0.11	0.3 ± 0.20	22.9 ± 0.11	0.1 ± 0.20	22.7 ± 0.15	−0.1 ± 0.22
	(22.4, 23.1)	(22.8, 23.2)	(−0.1, 0.7)	(22.7, 23.1)	(−0.2, 0.5)	(22.4, 23.0)	(−0.5, 0.4)
yp	0.62 ± 0.018	0.56 ± 0.013	−0.06 ± 0.022	0.52 ± 0.011	−0.1 ± 0.021	0.49 ± 0.014	−0.13 ± 0.023	7.08413	Persistency
(0.58, 0.65)	(0.53, 0.58)	(−0.11, −0.02)	(0.50, 0.54)	(−0.14, −0.06)	(0.46, 0.51)	(−0.18, −0.09)	< 0.000001
t1	21.0 ± 0.33	21.5 ± 0.25	0.5 ± 0.42	21.4 ± 0.24	0.4 ± 0.41	20.9 ± 0.31	0.2 ± 0.52
	(20.4, 21.7)	(1.1, 2.0)	(−0.3, 1.3)	(0.9, 1.9)	(−0.4, 1.2)	(20.3, 21.5)	(−0.8, 1.2)
t2	24.3 ± 0.34	24.4 ± 0.26	0.1 ± 0.43	24.3 ± 0.25	0.0 ± 0.42	24.3 ± 0.33	0.1 ± 0.53
	(23.6, 25.0)	(23.9, 24.9)	(−0.7, 1.0)	(23.8, 24.8)	(−0.8, 0.9)	(23.6, 24.9)	(−0.9, 1.2)
Persistency	0	0	–	0	–	0	–
b4	−0.009 ± 0.0014	−0.008 ± 0.0010	0.001 ± 0.0017	−0.008 ± 0.0009	0.001 ± 0.0017	−0.006 ± 0.0011	−0.002 ± 0.0021
	(−0.012, −0.006)	(−0.010, −0.006)	(−0.003, 0.004)	(−0.010, −0.006)	(−0.002, 0.004)	(−0.008, 0.004)	(−0.006, 0.002)

^aATAATA(A/C)T were defined as NC-like haplotypes based on their high similarity to the NC haplotypes ATAA(T/C)AAC.

^bΔpar represents difference between parameters of the three haplotype groups (Parcont) and ones of the ATAATA(A/C)T group (Parcase), and was estimated using the models indicated in the Table by reparameterizing Parcont as Parcase + Δpar. The numbers in parentheses indicate the approximate 95% confidence interval (CI) of parameters. The CIs of Δpar that exclude zero (0) indicate that the parameters have significant between two haplotype groups (SAS Institute Inc., 2008).

^cF and P values were determined by the sum of squares reduction test which indicated whether there was a significant difference in the egg-production curves fitted for the different haplotype groups (SAS Institute Inc., 2008).

^dNumbers in bold indicate the 95% CI of Δpar that excluded zero (0), indicating that the corresponding parameters were significantly different between ATAATA(A/C)T and the other haplotype groups.