Using a linear-threshold model to investigate the genetic relationship between survival and productive traits in Japanese quail

Figures & data

Table 1. Descriptive statistics of studied traits.

Trait	Mean	SD	Minimum	Maximum
EW	12.91	1.35	7.16	16.91
BWG0–7 (g)	2.78	0.80	0.56	7.02
BWG7–14 (g)	3.87	1.29	0.10	10.71
BWG14–21 (g)	4.88	2.04	0.33	12.31
BWG21–28 (g)	5.27	1.67	0.10	14.64
BWG28–35 (g)	5.87	1.97	0.02	14.51
BWG35–42 (g)	4.04	1.90	0.14	12.77
S0–7	0.999	0.024	0	1
S0–14	0.903	0.296	0	1
S0–21	0.875	0.330	0	1
S0–28	0.744	0.436	0	1
S0–35	0.694	0.461	0	1
S0–42	0.519	0.498	0	1

EW, BWG and S are egg weight, body weight gain and the birds’ survival, respectively; indices show the age range.

Table 2. Variance components and heritability ± standard deviation of survival and egg weight traits.

Traits	${\sigma }_{\mathrm{a}}^2$	${\sigma }_e^2$	${\sigma }_{\mathrm{p}}^2$	${\mathrm{h}}^2$
EW	0.372 ± 0.199	8.884 ± 0.355	9.256 ± 0.323	0.040 ± 0.021
S0–7	0.663 ± 0.403	1	1.663 ± 0.462	0.399 ± 0.148
S0–14	0.472 ± 0.479	1	1.472 ± 0.479	0.321 ± 0.110
S0–21	0.471 ± 0.260	1	1.471 ± 0.266	0.320 ± 0.110
S0–28	0.160 ± 0.084	1	1.160 ± 0.095	0.138 ± 0.062
S0–35	0.208 ± 0.084	1	1.208 ± 0.095	0.172 ± 0.059
S0–42	0.429 ± 0.134	1	1.429 ± 0.139	0.300 ± 0.068

${\mathrm{\sigma }}_{\mathrm{a}}^2$: additive genetic variance; ${\mathrm{\sigma }}_e^2$: residual variance; ${\mathrm{\sigma }}_{\mathrm{p}}^2$: phenotypic variance; ${\mathrm{h}}^2$: heritability; EW and S are egg weight and the birds’ survival, respectively; indices show the age range.

Table 3. Genetic correlation of egg weight with the birds’ survival at different ages.

EW with	Genetic correlation	Standard deviation
S0–7	0.087	0.215
S0–14	−0.704	0.269
S0–21	−0.672	0.269
S0–28	−0.099	0.102
S0–35	−0.336	0.320
S0–42	−0.602	0.232

EW and S are egg weight and the birds’ survival, respectively; indices show the age range.

Table 4. Variance components and heritability of survival and body weight gain traits.

Trait	${\sigma }_{\mathrm{a}}^2$	${\sigma }_e^2$	${\sigma }_{\mathrm{p}}^2$	${\mathrm{h}}^2$
BWG0–7	0.296 ± 0.029	0.212 ± 0.017	0.508 ± 0.022	0.583 ± 0.040
S0–7	0.703 ± 0.356	1	1.703 ± 0.426	0.413 ± 0.045
S0–14	0.414 ± 0.409	1	1.414 ± 0.409	0.293 ± 0.041
S0–21	0.421 ± 0.258	1	1.421 ± 0.258	0.296 ± 0.115
S0–28	0.154 ± 0.083	1	1.154 ± 0.083	0.133 ± 0.062
S0–35	0.210 ± 0.086	1	1.210 ± 0.086	0.173 ± 0.059
S0–42	0.449 ± 0.139	1	1.449 ± 0.140	0.310 ± 0.068
BWG7–14	0.103 ± 0.034	0.787 ± 0.038	0.890 ± 0.033	0.116 ± 0.036
S0–14	0.426 ± 0.320	1	1.426 ± 0.320	0.299 ± 0.108
S0–21	0.429 ± 0.253	1	1.429 ± 0.253	0.300 ± 0.114
S0–28	0.144 ± 0.083	1	1.144 ± 0.083	0.126 ± 0.064
S0–35	0.210 ± 0.089	1	1.210 ± 0.089	0.174 ± 0.062
S0–42	0.424 ± 0.137	1	1.424 ± 0.137	0.298 ± 0.070
BWG14–21	0.423 ± 0.089	1.220 ± 0.074	1.643 ± 0.067	0.257 ± 0.048
S0–21	0.406 ± 0.253	1	1.406 ± 0.253	0.289 ± 0.115
S0–28	0.163 ± 0.089	1	1.163 ± 0.089	0.140 ± 0.065
S0–35	0.220 ± 0.094	1	1.220 ± 0.094	0.180 ± 0.064
S0–42	0.456 ± 0.144	1	1.456 ± 0.144	0.313 ± 0.070
BWG21–28	0.484 ± 0.179	2.346 ± 0.158	2.830 ± 0.125	0.171 ± 0.059
S0–28	0.146 ± 0.085	1	1.146 ± 0.085	0.127 ± 0.064
S0–35	0.219 ± 0.091	1	1.219 ± 0.091	0.180 ± 0.062
S0–42	0.447 ± 0.142	1	1.447 ± 0.142	0.309 ± 0.070
BWG28–35	0.380 ± 0.142	2.364 ± 0.145	2.744 ± 0.121	0.138 ± 0.049
S0–35	0.222 ± 0.089	1	1.222 ± 0.089	0.181 ± 0.060
S0–42	0.460 ± 0.138	1	1.460 ± 0.138	0.315 ± 0.068
BWG35–42	0.430 ± 0.286	3.087 ± 0.260	3.517 ± 0.189	0.122 ± 0.077
S0–42	0.447 ± 0.138	1	1.447 ± 0.138	0.309 ± 0.068

${\sigma }_{\mathrm{a}}^2$: additive genetic variance; ${\sigma }_e^2$: residual variance; ${\sigma }_{\mathrm{p}}^2$: phenotypic variance; ${\mathrm{h}}^2$: heritability; BWG and S are body weight gain and the birds’ survival, respectively; indices show the age range.

Table 5. Genetic correlation of daily weight gain with the birds’ survival at different ages.

First trait	Second trait	Genetic correlation	Standard deviation
BWG0–7	S0–7	0.638	0.399
	S0–14	0.015	0.013
	S0–21	0.034	0.014
	S0–28	0.031	0.048
	S0–35	0.039	0.014
	S0–42	0.148	0.079
BWG7–14	S0–14	0.148	0.137
	S0–21	0.155	0.107
	S0–28	0.344	0.322
	S0–35	0.355	0.229
	S0–42	0.362	0.182
BWG14– 21	S0–21	0.332	0.225
	S0–28	−0.321	0.263
	S0–35	−0.058	0.099
	S0–42	−0.027	0.045
BWG21–28	S0–28	0.263	0.257
	S0–35	−0.087	0.033
	S0–42	−0.139	0.162
BWG28–35	S0–35	−0.162	0.152
	S0–42	−0.235	0.183
BWG35–42	S0–42	−0.176	0.115

BWG and S are body weight gain and the birds’ survival, respectively; indices show the age range.

Data availability statement

The data that support the findings of this study are available from the corresponding author, [Mohammad Rokouei], upon reasonable request.