Table 3. Longitudinal analysis of ev21-related K specific sequences presence in chickens at 12 and 35 weeks of age

Chicken breeds	Feathering phenotypes1	No. of chicks2	PCR results3 by age		Concordance rate of PCR results between 12 and 35 weeks of age (%)
			Week 12	Week 35
Korean Native Chicken-Red strain	EF	100	all −	all −	100
	LF	53	all +	all +	100
Black Cornish	EF	20	all −	all −	100
	LF	20	all +	all +	100
Rhode Island Red	EF	20	all −	all −	100
	LF	20	all +	all +	100

“EF” denotes early-feathering chickens, while “LF” signifies late-feathering chickens.
The number of chicks includes both males and females.
In the PCR results, a ‘+’ indicates the presence of a positive band at 230 bp, while ‘−’ indicates the absence of a band.