Table 3.

Prevalence of T.suis infection in pigs from different growth period groups and different raising systems in Hunan province, China

Raising system	Pig category	No. tested	No. positive	Prevalence (%)	Average intensity	χ2 testc	P-value
Ia	Weaners	242	7	2.89	800	25.7362	<0.0001
	Growers	358	22	6.15	1,000
	Fatteners	240	35	14.58	2,100
	Breeding boars	93	6	6.45	1,000
	Breeding sows	194	15	7.73	1,300
IIb	Weaners	314	14	4.46	800	25.3812	<0.0001
	Growers	308	37	12.01	1,400
	Fatteners	234	38	16.24	2,200
	Breeding boars	30	6	20.0	2,700
	Breeding sows	254	22	8.66	900
I	Subtotal	1,127	85	7.54	1,300	4.8399	0.0278
II	Subtotal	1,140	117	10.26	1,700
	Total	2,267	202	8.91	1,700

^aIntensive pig farms (the number of reared pigs>300).

^bExtensive pig farms (the number of reared pigs≤300).

^cQualitative data between different groups.