Table 2.

Results of the bivariate analysis of potential risk factors associated with Campylobacter fetus subsp. venerealis infection in breeding bulls and extensive beef cattle herds in Spain.

Variable		Category	Cfv status			P-value
			Na	Infected (%)	Non-infected (%)
Bull level	Bull ageb	<3 years old	748	49 (6.6)	699 (93.4)	0.025
		≥3 years old	2,239	199 (8.9)	2,040 (91.1)
	Bull breedc,	Native	1,411	137 (9.7)	1,274 (90.3)	0.119
		Non-Spanish	1,731	146 (8.4)	1,585 (91.6)
	Period of sampling	2011–2013	761	50 (6.6)	711 (93.4)	0.124
		2014–2016	2,161	157 (7.3)	2,004 (92.7)
		2017–2019	2,260	193 (8.5)	2,067 (91.5)
Herd level	Type of herd managementd	Mountain	1,488	149 (10)	1,339 (90)	< 0.001
		“Dehesa”	462	87 (18.8)	375 (81.2)
	Bull-to-cow ratio in the herde	<1:25	151	22 (14.6)	129 (85.4)	0.484
		≥1:25	474	72 (15.2)	402 (84.8)
	Herd size (No. cows)f	≤ 100	360	26 (10)	334 (90)	< 0.001
		>100	260	22 (21.2)	238 (78.8)
	BT herd statusg	Positive	339	57 (16.8)	282 (83.2)	0.003
		Negative	1,611	179 (11.1)	1,432 (88.9)
	Reproductive disorders in the herdh	Yes	387	50 (12.9)	337 (87.1)	0.269
		No	460	52 (11.3)	408 (88.7)

N, number of examined bulls and herds.

^aMissing values omitted.

^bBull age data were recorded for 2,987 bulls out of 5,182 bulls tested.

^cBull breed data were recorded for 3,142 bulls out of 5,182 bulls tested. The native breeds documented were “Parda pirenaica” (n = 582), “Asturiana de los valles” (n = 375), “Asturiana de la montaña” (n = 252), “Lidia” (n = 64), “Retinta” (n = 59), “Avileña” (n = 54), “Bruna de los Pirineos” (n = 9), “Berrendo en colorado” (n = 7), “Morucha” (n = 6), “Blanca cacereña” (n = 3) and “Rubia Gallega” (n = 1). The non-Spanish breeds documented were Limousin (n = 944), Charolais (n = 617), Blonde d'Aquitaine (n = 57), Brown Swiss (n = 25), Aberdeen angus (n = 19), Salers (n = 18), Fleckvieh (n = 15), Holstein (n = 15), Belgian blue (n = 13), Black angus (n = 3), Aubrac (n = 2) and Wagyu (n = 2).

^dOut of the 1,950 herds analyzed 1,488 belonged to mountain systems and 462 belonged to “dehesa systems.

^eBull-to-cow ratio data were recorded for 625 herds out of 1,950 herds tested.

^fHerd size data were recorded for 620 herds out of 1,950 herds tested.

^gHerd BT status data were recorded for 1,950 herds out of 1,950 herds tested.

^hReproductive disorders in herd data were recorded for 847 herds out of 1,950 herds tested.

The bold value means the results that showed significant differences in the bivariate analysis.