Risk factors associated with cystic ovarian disease in Norwegian dairy cattle

Table 2 Distribution of lactations with cystic ovarian disease by parity, calving season, geographic distribution and culling

Variable	Class	N lactations	n	COD %
Total material		597,722	4,758	0.82
Parity	1	213,006	845	0.40
	2	153,532	1251	0.81
	3	99,647	1211	1.21
	4	56,706	780	1.36
	> 4	53,073	671	1.25
Calving season	December, January, February	115,394	834	0.72
	March, April, and May	135,188	525	0.39
	June, July and August	141,096	1,025	0.72
	September, October, and November	183,356	2,374	1.28
Geographic distribution	Østfold, Akershus, Vestfold	27,751	132	0.47
	Hedmark, Oppland, and Buskerud	118,559	1,109	0.93
	Telemark, and Agder	22,330	130	0.58
	Rogaland	99,651	635	0.63
	Hordaland, Sogn og Fjordane	68,616	649	0.94
	Møre og Romsdal and Trøndelag	181,556	1,635	0.89
	Nord-Norge	56,451	468	0.82
Lactation ended with:	New calving	340,498	2,643	0.77
	Culling	234,466	2,115	0.89

ISSN: 1751-0147