Table 9. Effect of beak-trimming and genetic combinations on intra-cellular nuclear DNA damage rate1 in Korean native chickens

Debeaking	Breed	Week 12	Week 30
Debeaked	YDYC	5.86±1.98^de	16.93±0.88^cd
	YDCF	7.29±2.24^bcde	17.47±2.17^bcd
	YDCK	7.44±3.23^bcde	14.95±3.11^d
	YCCK	9.45±2.63^bcde	18.61±5.52^bcd
	CKCF	10.96±1.51^bcde	12.26±1.7^d
	YCCF	11.30±1.61^bc	25.49±1.17^abc
Non-debeaked	YDYC	4.99±1.61^e	15.83±2.52^d
	YDCF	19.50±2.86^a	26.03±7.4^ab
	YDCK	6.40±2.97^cde	18.68±5.27^bcd
	YCCK	11.96±3.24^b	16.19±1.57^d
	CKCF	10.25±3.01^bc	14.65±2.49^d
	YCCF	9.64±1.07^bcde	28.83±5.84^a
P-value		<.0001	<.0001
Debeaked(D) and non-debeaked(ND)
D		8.72±2.90^b	17.48±4.76^b
ND		10.46±5.31^a	20.03±6.97^a
P-value		0.0081	0.0256
Breed(B)
YDYC		5.43±1.76^b	16.38±1.87^bc
YDCF		13.40±6.87^a	21.75±6.84^b
YDCK		6.92±2.97^b	17.28±4.73^bc
YCCK		10.70±3.08^a	17.27±3.78^bc
CKCF		10.60±2.28^a	13.45±2.37^c
YCCF		10.47±1.55^a	27.35±4.55^a
P-value		<.0001	<.0001
D×B		<.0001	0.0539

Intra-cellular nuclear DNA damage rate indicate % DNA in tail by comet assay.
he different letters of superscript within the column significantly differ (P<0.05).