Effects of egg weight on egg quality traits in partridge (Alectoris Chukar)

Figures & data

Table 1. The effect of egg weight on external egg quality traits.

	Egg weight groups
Traits	≤19.0 g	19.1–20.0 g	20.1–21.0 g	≥21.1 g
Egg length (mm)	38.67 ± 0.19^a	39.72 ± 0.15^b	40.00 ± 0.12^b	40.62 ± 0.12^b
Egg width (mm)	29.44 ± 0.12^a	30.15 ± 0.06^b	30.59 ± 0.05^c	31.03 ± 0.05^d
Shell weight (g)	2.08 ± 0.03^a	2.15 ± 0.02^a	2.23 ± 0.01^b	2.32 ± 0.02^b
Shell ratio (%)	11.48 ± 0.20^b	10.97 ± 0.10^a	10.96 ± 0.07^a	10.74 ± 0.09^a
Sharp region thickness (mm)	0.256 ± 0.00^b	0.256 ± 0.00^b	0.250 ± 0.00^a	0.249 ± 0.00^a
Blunt region thickness (mm)	0.237 ± 0.00^b	0.236 ± 0.00^b	0.231 ± 0.00^a	0.228 ± 0.00^a
Equatorial region thickness (mm)	0.247 ± 0.00^b	0.246 ± 0.00^b	0.241 ± 0.00^a	0.239 ± 0.00^a
Average shell thickness (mm)	0.247 ± 0.00^b	0.246 ± 0.00^b	0.241 ± 0.00^a	0.238 ± 0.00^a
Shell surface area (cm^2)	33.02 ± 0.16^a	34.66 ± 0.05^b	35.72 ± 0.04^c	36.92 ± 0.05^d
Unit surface shell weight (g/cm^2)	0.063 ± 0.00^a	0.062 ± 0.00^a	0.063 ± 0.00^a	0.063 ± 0.00^a
Shape index (%)	76.24 ± 0.49^a	76.03 ± 0.40^a	76.54 ± 0.33^a	76.41 ± 0.32^a
Egg volume (cm^3)	18.54 ± 1.78^a	19.92 ± 0.76^b	20.61 ± 0.54^c	21.51 ± 0.77^d

Note: Means in rows with different letters differ significantly at P < 0.01.

Table 2. The effect of egg weight on internal egg quality traits.

	Egg weight groups
Traits	≤19.0 g	19.1–20.0 g	20.1–21.0 g	≥21.1 g
Yolk weight (g)	7.67 ± 0.12^a	7.77 ± 0.07^a	8.12 ± 0.07^b	8.45 ± 0.09^b
Yolk height (mm)	14.24 ± 0.10^a	14.40 ± 0.07^a	14.64 ± 0.08^b	14.94 ± 0.08^b
Yolk width (mm)	29.60 ± 0.15^a	30.46 ± 0.08^b	30.86 ± 0.12^b	31.30 ± 0.14^c
Yolk index (%)	48.19 ± 0.42^a	47.29 ± 0.25^a	47.55 ± 0.35^a	47.80 ± 0.34^a
Yolk ratio (%)	42.19 ± 0.72^b	39.62 ± 0.35^a	39.63 ± 0.35^a	39.15 ± 0.38^a
Albumen height (mm)	4.53 ± 0.14^a	4.86 ± 0.07^a	5.08 ± 0.09^b	5.26 ± 0.09^b
Albumen width (mm)	39.39 ± 0.60^a	39.51 ± 0.70^a	39.99 ± 0.20^a	40.89 ± 0.26^a
Albumen length (mm)	51.27 ± 0.60^a	52.31 ± 0.30^a	52.65 ± 0.30^a	53.45 ± 0.30^b
Albumen weight (g)	8.46 ± 0.17^a	9.67 ± 0.08^b	10.14 ± 0.08^c	10.79 ± 0.09^d
Albumen index (%)	10.05 ± 0.33^a	10.69 ± 0.20^ab	11.03 ± 0.20^b	11.19 ± 0.18^b
Albumen ratio (%)	46.33 ± 0.76^a	49.40 ± 0.36^b	49.57 ± 0.37^b	50.02 ± 0.40^b
Yolk/albumen ratio (%)	91.67 ± 2.93^b	80.86 ± 1.30^a	80.69 ± 1.35^a	78.89 ± 1.48^a
Haugh unit	85.14 ± 0.86^a	86.33 ± 0.41^a	87.07 ± 0.49^a	87.58 ± 0.51^a

Note: Means in rows with different letters differ significantly at P < 0.01.

Table 3. The Pearson correlation coefficients among the internal and external quality traits of eggs.

Traits	SW	YW	YH	YWDT	AH	AWDT	AL	EWDT	EL	ST	AI	YI	SI	SFA	SR	HU	EVL	AW	Y/A	YR	AR
EW	.512**	.455**	.384**	.539**	.339**	.149*	.245**	.802**	.494**	–.425**	.229**	–.038	.062	1.00	–.294**	.019**	.905**	.760**	–.276**	–.250**	.296**
SW		.277**	.131	.162*	.091	.109	.211**	.479**	.167*	–.107	.008	–.002	.139*	.512**	.598**	.013	.472**	.239**	.004	–.084	–.074
YW			.141*	.404**	–.068	–.054	.080	.322**	.368**	–.285**	–.048	–.146**	–.126	.452**	–.080	–.146*	.465**	–.220**	.717**	.741**	–.688**
YH				.075	.437**	.055	.164*	.196**	.454**	–.042	.395**	.755**	–.271**	.380**	–.171*	.395**	.414**	.324**	–.139	–.137	.156*
YWDT					.065	.076	.237**	.404**	.539**	–.293**	.015	–.583**	–.015	.542**	–.284**	–.019	.486**	.320**	.002	0.34	.026
AH						.146*	.149*	.196**	.313**	–.015	.903**	.310**	–.149*	.335**	–.170*	.987**	.331**	.424**	–.326**	–.023**	.352**
AWDT							.156*	.171*	–.004	–.067	–.209**	.001	0.91	.146*	–.002	.131	.132	.191**	–.147*	–.150*	.161*
AL								.137	.253**	–.038	–.069	–.014	–.125	.244**	.004	0.120	.248**	.193**	–.078	–.081	.073
EWDT									.080	–.326**	.107	–.110	.528**	.803**	–.201**	.074	.826**	.628**	–.262**	–.251**	.261**
EL										–.186**	.256**	.179*	–.797**	.494**	–.208**	.253**	.627**	.289**	–.007	.016	.026
ST											.026	.131	–.032	–.404**	.192**	.053	–.345**	–.275**	.048	–.011	–.065
AI												.306**	–.153*	.227**	–.174*	.903**	.231**	.297**	–.233**	–.229**	.255**
YI													–.221**	–0.044	0.043	.330**	.020	.054	–0.111	–.131	.109
SI														0.063	0.048	–.171*	–.039	.138	–.160*	–.172*	.144*
SFA															–.294**	.187**	.905**	.762**	–.280**	–.253**	–.299**
SR																–0.128	.269**	–.383**	.243**	.129	–.327**
HU																	.202**	.319**	–.296**	-.297**	.320**
EVL																		.649**	–.201**	–.180*	.212**
AW																			–.828**	–.799**	.841**
Y/A																				.985**	–.987**
YR																					–.967**

EW, egg weight; SW, shell weight; YW, yolk weight; YH, yolk height; YWDT, yolk width; AH, albumen height; AWDT, albumen width; AL, albumen length; EWDT, egg width; EL, egg length; ST, shell thickness; AI, albumen index; YI, yolk index; SI, shape index; SFA, shell surface area; SR, shell ratio; HU, Haugh unit; EVL, egg volume; AW, albumen weight; Y/A, yolk/albumen; YR, yolk ration; AR, albumen ratio.

* P < 0.05; **P < 0.01.