Table 1 Descriptive statistics of egg-laying performance in purebred Beijing-You chickens, purebred White Leghorns and their reciprocal crosses
Trait | Abbreviation | NA | NO | Mean | SD | CV (%) |
|---|---|---|---|---|---|---|
Egg weight (g) | ||||||
First three eggs | FEWt | 1186 | 3485 | 43.35 | 4.81 | 11.9 |
28Â weeks of age | EWt28 | 1142 | 3320 | 51.33 | 5.08 | 9.9 |
32Â weeks of age | EWt32 | 1075 | 2977 | 53.16 | 4.84 | 9.1 |
36Â weeks of age | EWt36 | 1025 | 3033 | 54.62 | 5.00 | 9.2 |
40Â weeks of age | EWt40 | 990 | 2654 | 56.18 | 5.03 | 9.0 |
44Â weeks of age | EWt44 | 1000 | 4708 | 56.76 | 5.01 | 8.8 |
48Â weeks of age | EWt48 | 897 | 2569 | 58.03 | 5.12 | 8.8 |
52Â weeks of age | EWt52 | 869 | 2517 | 58.14 | 4.99 | 8.6 |
56Â weeks of age | EWt56 | 852 | 2314 | 59.19 | 5.06 | 8.6 |
60Â weeks of age | EWt60 | 825 | 1928 | 60.86 | 5.11 | 8.4 |
64Â weeks of age | EWt64 | 835 | 1931 | 60.96 | 5.08 | 8.3 |
68Â weeks of age | EWt68 | 823 | 4080 | 60.98 | 5.22 | 8.6 |
72Â weeks of age | EWt72 | 734 | 2022 | 60.35 | 5.22 | 8.7 |
76Â weeks of age | EWt76 | 598 | 1230 | 61.47 | 5.38 | 8.8 |
86Â weeks of age | EWt86 | 640 | 1793 | 61.06 | 5.69 | 9.3 |
100Â weeks of age | EWt100 | 578 | 1689 | 62.25 | 5.90 | 9.5 |
Egg production | ||||||
Age at first egg (day of age) | AFE | 1116 | 1116 | 167.72 | 11.86 | 7.1 |
Oviposition period (hours) | OP | 1103 | 1103 | 25.27 | 1.11 | 4.4 |
Egg production till 43Â weeks of age | ||||||
Cumulative egg number | EN43 | 936 | 936 | 110.87 | 18.52 | 16.7 |
Number of clutches | NC43 | 961 | 961 | 18.54 | 7.92 | 42.7 |
Average clutch length (days) | ACL43 | 948 | 948 | 7.56 | 6.09 | 80.6 |
Average pause length (days) | APL43 | 939 | 939 | 1.25 | 0.44 | 34.7 |
Egg production till 72Â weeks of age | ||||||
Cumulative egg number | EN72 | 735 | 735 | 245.51 | 44.01 | 17.9 |
Number of clutches | NC72 | 752 | 752 | 53.11 | 20.23 | 38.1 |
Average clutch length (days) | ACL72 | 748 | 748 | 5.46 | 3.55 | 65.0 |
Average pause length (days) | APL72 | 751 | 751 | 1.61 | 1.58 | 97.8 |
Egg production till 100Â weeks of age | ||||||
Cumulative egg number | EN100 | 702 | 702 | 340.94 | 76.78 | 22.5 |
Number of clutches | NC100 | 714 | 714 | 90.28 | 31.28 | 34.7 |
Average clutch length (days) | ACL100 | 712 | 712 | 4.19 | 2.16 | 51.6 |
Average pause length (days) | APL100 | 712 | 712 | 2.14 | 2.28 | 106.4 |
Egg quality at 32Â weeks of age | ||||||
Egg shape index | ESI32 | 1078 | 3152 | 76.42 | 2.93 | 3.8 |
Eggshell colour (%) | ESC32 | 1077 | 3168 | 64.62 | 13.21 | 20.5 |
Eggshell strength (kg/cm2) | ESS32 | 1072 | 3123 | 3.80 | 0.67 | 17.8 |
Eggshell thickness (mm) | EST32 | 1076 | 3145 | 0.34 | 0.03 | 8.1 |
Eggshell ratio | ESR32 | 1071 | 2957 | 9.98 | 0.71 | 7.1 |
Yolk ratio | YR32 | 1074 | 2883 | 29.07 | 2.47 | 8.5 |
Yolk colour | YC32 | 1075 | 3023 | 5.91 | 1.29 | 21.9 |
Haugh unit | HU32 | 1074 | 2952 | 66.88 | 9.57 | 14.3 |
Egg quality at 54Â weeks of age | ||||||
Egg shape index | ESI54 | 856 | 2380 | 73.63 | 2.93 | 4.0 |
Eggshell colour (%) | ESC54 | 855 | 2408 | 66.31 | 11.53 | 17.4 |
Eggshell strength (kg/cm2) | ESS54 | 855 | 2395 | 3.54 | 0.74 | 20.9 |
Eggshell thickness (mm) | EST54 | 854 | 2405 | 0.34 | 0.03 | 8.2 |
Eggshell ratio | ESR54 | 854 | 2377 | 9.30 | 0.77 | 8.3 |
Yolk ratio | YR54 | 855 | 2350 | 30.45 | 2.32 | 7.6 |
Yolk colour | YC54 | 855 | 2383 | 4.70 | 0.86 | 18.3 |
Haugh unit | HU54 | 856 | 2377 | 75.54 | 6.91 | 9.1 |
Egg quality at 72Â weeks of age | ||||||
Egg shape index | ESI72 | 734 | 2047 | 73.22 | 3.28 | 4.5 |
Eggshell colour (%) | ESC72 | 733 | 2061 | 61.52 | 11.15 | 18.1 |
Eggshell strength (kg/cm2) | ESS72 | 732 | 2043 | 3.42 | 0.80 | 23.5 |
Eggshell thickness (mm) | EST72 | 733 | 2051 | 0.32 | 0.03 | 10.1 |
Eggshell ratio | ESR72 | 732 | 1990 | 9.09 | 1.06 | 11.6 |
Yolk ratio | YR72 | 734 | 1977 | 30.70 | 2.54 | 8.3 |
Yolk colour | YC72 | 735 | 2030 | 6.76 | 1.38 | 20.4 |
Haugh unit | HU72 | 733 | 1990 | 73.41 | 9.60 | 13.1 |
Egg quality at 86Â weeks of age | ||||||
Egg shape index | ESI86 | 645 | 1831 | 72.76 | 3.55 | 4.9 |
Eggshell colour (%) | ESC86 | 644 | 1829 | 59.60 | 9.97 | 16.7 |
Eggshell strength (kg/cm2) | ESS86 | 644 | 1816 | 3.20 | 0.91 | 28.3 |
Eggshell thickness (mm) | EST86 | 632 | 1585 | 0.34 | 0.03 | 9.9 |
Eggshell ratio | ESR86 | 628 | 1527 | 8.75 | 0.98 | 11.1 |
Yolk ratio | YR86 | 638 | 1739 | 30.94 | 2.48 | 8.0 |
Yolk colour | YC86 | 636 | 1616 | 6.33 | 1.61 | 25.5 |
Haugh unit | HU86 | 642 | 1760 | 67.98 | 11.95 | 17.6 |
Egg quality at 100Â weeks of age | ||||||
Egg shape index | ESI100 | 580 | 1674 | 72.80 | 3.82 | 5.2 |
Eggshell colour (%) | ESC100 | 576 | 1686 | 57.30 | 9.76 | 17.0 |
Eggshell strength (kg/cm2) | ESS100 | 581 | 1656 | 2.96 | 0.83 | 28.1 |
Eggshell thickness (mm) | EST100 | 580 | 1658 | 0.30 | 0.04 | 15.0 |
Eggshell ratio | ESR100 | 576 | 1620 | 8.03 | 1.21 | 15.1 |
Yolk ratio | YR100 | 567 | 1550 | 30.31 | 2.69 | 8.9 |
Yolk colour | YC100 | 574 | 1597 | 5.81 | 1.65 | 28.4 |
Haugh unit | HU100 | 574 | 1581 | 65.51 | 13.14 | 20.1 |