Prevalence of subclinical mastitis in Finnish dairy cows: changes during recent decades and impact of cow and herd factors

Table 2 Descriptive data of cows with subclinical mastitis in Finland in 1991, 2001 and 2010

	Year
	1991		2001		2010
	n, cows^a	%, cows with SCM^b	n, cows^a	%, cows with SCM^b	n, cows^a	%, cows with SCM^b
Parity
1	24,791	12.2	104,995	16.2	85,532	14.3
2	25,896	14.5	89,197	17.1	75,156	15.4
3	25,737	23.8	61,749	22.2	52,769	21.8
4	19,642	28.6	37,919	25.4	31,082	25.9
5	11,539	31.9	20,405	27.4	15,833	28.2
6	6235	35.0	10,239	27.6	7110	29.3
7	3150	36.4	4669	30.6	3005	31.9
8	1544	37.7	2034	29.8	1329	31.2
≥9	1224	40.0	1495	31.7	1196	35.5
n/a^d	2645		4633		0
Breed
Ayrshire	99,070	21.4	247,736	19.3	175,583	18.0
Holstein	21,776	26.3	85,704	22.3	93,644	20.8
Others^c	1557	26.9	3872	21.7	3522	18.9
n/a^d	0		23		263
Type of the stall
Tie-stall	0	0	82,688	20.5	108,824	18.7
Free-stall	0	0	9322	21.1	49,837	20.9
Free-stall (AMS)	0	0	0^e	0^e	21,712	22.6
N/a^d	122,403		245,325		92,639
Herd size, number of cows
<20	99,832	22.0	150,611	19.8	49,446	17.5
20–60	21,504	23.6	174,433	20.1	158,661	18.6
>60	584	27.4	7532	23.5	59,430	21.4
n/a^d	483		4759		5475
Average milk yield (kg/year/herd)
<7500	109,083	22.8	116,053	22.8	26,109	23.8
7500–9500	13,048	18.7	195,811	19.0	161,262	19.8
>9500	243	15.2	25,361	16.6	85,618	16.5
n/a^d	29		110		23
Production type
Organic	15	13.3	6300	22.7	4300	22.2
Conventional	122,386	22.3	331,035	20.1	268,450	18.9
n/a^d	2		0		262
Total	122,403	22.3	337,335	20.1	273,012	19.0

^a Total number of the cows of the study year
^b Cows with a composite milk SCC ≥200,000 cells/ml in at least one of the four test milkings of the year
^c Including Finncattle, Jerseys and other breeds
^d Information not available
^e Three AMS barns in 2001 were excluded from statistical calculations

ISSN: 1751-0147