Table 2. Organ indices of the spleen, thymus, and bursa of Fabricius of the SFs and WLs at different ages.

Breed	Age	Spleen	Thymus	Bursa of Fabricius
SF male	2 weeks	0.1180 ± 0.03	0.3808 ± 0.12	0.2801 ± 0.06**
WL male		0.1751 ± 0.04	0.3156 ± 0.05	0.4203 ± 0.04
SF female		0.1250 ± 0.01*	0.3976 ± 0.07	0.1720 ± 0.06**
WL female		0.2604 ± 0.10	0.2650 ± 0.00	0.4590 ± 0.02
SF male	3 weeks	0.1717 ± 0.07	0.3112 ± 0.12	0.2088 ± 0.15
WL male		0.3317 ± 0.08	0.2736 ± 0.07	0.2899 ± 0.12
SF female		0.1785 ± 0.04	0.3136 ± 0.04	0.2538 ± 0.02
WL female		0.2087 ± 0.03	0.2949 ± 0.04	0.1953 ± 0.02
SF male	4 weeks	0.2207 ± 0.02	0.3423 ± 0.05	0.1600 ± 0.02
WL male		0.2835 ± 0.07	0.3823 ± 0.05	0.1794 ± 0.01
SF female		0.1982 ± 0.02	0.3424 ± 0.13	0.1149 ± 0.01
WL female		0.3236 ± 0.06	0.2774 ± 0.06	0.1596 ± 0.02
SF male	6 weeks	0.1240 ± 0.03*	0.1963 ± 0.07	0.0890 ± 0.02
WL male		0.2126 ± 0.03	0.2767 ± 0.12	0.1120 ± 0.05
SF female		0.1779 ± 0.03	0.1744 ± 0.05**	0.0880 ± 0.02
WL female		0.1999 ± 0.05	0.2569 ± 0.05	0.1671 ± 0.09
SF male	10 weeks	0.1551 ± 0.02	0.2826 ± 0.07	0.1073 ± 0.03
WL male		0.2388 ± 0.08	0.2251 ± 0.04	0.2629 ± 0.06
SF female		0.2023 ± 0.06	0.2283 ± 0.06	0.0861 ± 0.02
WL female		0.2483 ± 0.06	0.2403 ± 0.08	0.1824 ± 0.09
SF male	23 weeks	0.1114 ± 0.02	0.1068 ± 0.02	0.0186 ± 0.00**
WL male		0.1420 ± 0.03	0.0976 ± 0.02	0.0023 ± 0.00
SF female		0.0593 ± 0.00	0.0316 ± 0.00	0.0079 ± 0.00**
WL female		0.1809 ± 0.06	0.0349 ± 0.00	0.0002 ± 0.00

Note: **P <0.01 and *P <0.05 indicates statistically significant differences between SF and WL in the same gender.