TABLE 2.

Pathological signs and production parameters for each group of birds^a

Group	% Mortality	% Morbidity	Mean air sac lesion scoreb	% Birds with severe lesions	Mean total cage wt (g) of surviving birds (day 21)	Feed conversion ratioc
1	0.0	0.0	0.0	0.0	19.253 ± 598	2.2 ± 0.2
2	43.5 ± 15.2d	88.8 ± 29.8d	2.6 ± 0.5d	17.8 ± 10.0d	10,082 ± 2,964d	2.8 ± 0.6
3	6.7 ± 8.4d,e	32.3 ± 13.6d,e	0.6 ± 0.4d,e	2.2 ± 3.4e	17,642 ± 1,797e	2.2 ± 0.2e
4	11.0 ± 6.8d,e	45.3 ± 10.6d	0.8 ± 0.3d,e	6.7 ± 6.0d,e	17,607 ± 479d,e	2.1 ± 0.1e
5	16.8 ± 9.3d,e	59.1 ± 12.1d	1.4 ± 0.3d,e	11.3 ± 7.0d	15,487 ± 1,402d,e	2.1 ± 0.3e
6	19.2 ± 16.7d,e	67.5 ± 14.1d	1.6 ± 0.5d,e	12.5 ± 7.9d	16,438 ± 3,174e	2.1 ± 0.3e
7	20.0 ± 8.2d	73.0 ± 0.0d	1.8 ± 0.2d,e	7.8 ± 6.6d	16,041 ± 2,430d,e	2.2 ± 0.3
8	27.2 ± 17.2d	79.3 ± 12.5d	2.1 ± 0.6d	19.9 ± 9.9d	13,023 ± 4,090d	2.6 ± 0.6

^aValues are means ± standard deviations. 

^bAir sac lesions were scored on a scale of from 0 to 4 (see text). 

^cThe feed conversion ratio is calculated for each group of birds by taking the total feed consumed between days −4 and 21 and dividing it by the increase in the mass of the birds over the same time period (data not corrected for dead birds). 

^dSignificantly different from group 1 (P < 0.05). 

^eSignificantly different from group 2 (P < 0.05).