Table 2. Estimation of regression equations of the body weight (Y) on the chicken age (X) for Korean native Samgye chicken breeds

Breeds1	Regression equation2	R-square	Estimated number of days to reach 850 g weight (days)
KNC-SCYC	Y = 10.324X2 + 52.172X + 41.5	0.9977	46.7±1.8b
KNC-SCYD	Y = 9.6195X2 + 49.081X + 41.5	0.9963	48.8±2.8a
KNC-SDYC	Y = 10.302X2 + 49.426X + 42.6	0.9944	47.4±0.6b
KNC-SDYD	Y = 11.209X2 + 46.567X + 40.9	0.9933	46.7±0.9b
KNC-SYYC	Y = 11.44X2 + 48.136X + 41.2	0.9960	45.9±0.5b
KNC-SYYD	Y = 11.765X2 + 46.744X + 41.5	0.9973	45.8±0.5b
GSP-Hanhyup	Y = 15.196X2 + 69.624X + 39.4	0.9953	37.5±1.3c
Baeksemi	Y = 27.059X2 + 30.226X + 45.5	0.9974	34.5±1.2d

In breeds, KNC-SCYC; Korean native chicken-SCYC combination, GSP-Hanhyup; GSP-Hanhyup Korean native chicken, Baeksemi; White semi-broiler.
In regression equations, X is chicken age (weeks) and Y is predicted values of body weight (g).
The different letters of superscript within the column significantly differ (P<0.01) and the values are mean±standard deviation.