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

Table 3 Descriptive data of cows with chronic subclinical mastitis in Finland in 1991, 2001 and 2010

	Year
	1991		2001		2010
	n, cows^a	%, cows with CSCM^b	n, cows^a	%, cows with CSCM^b	n, cows^a	%, cows with CSCM^b
Parity
1	9676	7.8	41,444	11.3	39,148	10.5
2	24,582	12.2	73,130	13.3	59,752	13.0
3	24,041	20.3	47,476	16.7	39,401	18.2
4	18,206	25.4	27,959	19.3	22,286	21.9
5	10,538	29.5	14,563	20.9	11,136	24.2
6	5699	31.1	7190	21.6	4934	26.0
7	2857	32.6	3233	22.8	2112	27.9
8	1387	35.8	1421	22.4	886	26.1
≥9	1101	35.9	1063	25.3	843	33.9
N/a^d	2174		2875		59
Breed
Ayrshire	81,185	19.1	162,484	14.5	116,443	14.6
Holstein	17,796	25.9	55,415	18.6	61,879	18.8
Others^c	1280	24.4	2455	15.8	2235	15.3
N/a^d	0		0		0
Type of the stall
Tie-stall	0	0	74,974	15.0	99,417	14.8
Free-stall	0	0	8444	16.1	45,098	16.6
Free-stall (AMS)	0	0	0^e	0^e	19,595	21.3
N/a^d	100,261		136,936		16,447
Herd size, cows
<20	81,533	19.8	98,895	15.1	33,118	14.0
20–60	17,838	22.4	113,134	15.6	105,203	15.4
>60	508	32.1	4847	19.7	38,738	19.8
N/a^d	382		3478		3498
Average milk yield (kg/year/herd)
<7500	89,100	20.9	73,763	18.0	14,635	19.5
7500–9500	10,954	16.5	129,343	14.4	105,937	16.4
>9500	207	15.5	17,248	13.1	59,985	14.6
N/a^d	0		0		0
Production type
Organic	14	14.3	4028	18.8	2933	18.4
Conventional	100,247	20.4	216,326	15.5	177,624	16.0
N/a^d	0		0		0
Total	100,261	10.4	220,354	15.5	180,557	16.1

^a Total number of the cows of the study year
^b Cows with a composite milk SCC ≥200,000 cells/ml in three or all four of the test milkings of the year
^c Including Finncattle, Jerseys and other breeds
^d Information was not included to the original recording (missing value)
^e Three AMS barns in 2001 were excluded from statistical calculations

ISSN: 1751-0147