Bovine leukemia virus proviral load is more strongly associated with bovine major histocompatibility complex class II DRB3 polymorphism than with DQA1 polymorphism in Holstein cow in Japan

Table 1 Samples collected from Japanese BLV-positive farms (over 60% positive rate in the test prior to collection for this study) and distribution of proviral load in BLV-positive cow

	Year				Total
	2011	2012	2013	2014	Total
Number of animals
Collected	322	390	290	288	1290
BLV-positive	222	275	199	214	910
High risk spreader*	137	160	133	139	569
Low risk spreader**	85	115	66	75	341
Distribution of age in BLV positive cow (month)
Average of age	57.1	58.0	56.0	55.3	56.7
Maximum age	148	191	142	134	191
Minimum age	12	11	15	17	11
Standard deviation of age	24.2	28.6	24.7	22.2	25.3
Distribution of proviral load in BLV positive cow (copies per 10⁵ cells)
Average	33564	27,927	42,850	42,014	35,878
Maximum	137,905	135,662	154,306	135,950	154,306
Minimum	0	0	0	0	0
Standard deviation	32,786	28,945	38,382	39,536	35,285

ISSN: 1742-4690