Somatic cell counting (SB) indicates a health state in the herd and it
is an indicator for the dairy industry of technological value of milk
. Somatic cell count was during a year in the bulk milk samples in 212
herds. Total 3,219 samples were analyzed. The herds were composed of
combined and dairy breeds of cattle, i.e. Bohemian Spotted breed, impr
oved breeds Ayrshire and Red Holstein (Red and White breed) and Black
and White breed with various degrees of transfer crossing from Bohemia
n Spotted breed with a share of Holstein breed (Black and White breed)
. Somatic cell count (SB) content was first measured (three months) by
electronic cell counter, type Coulter Counter, Industrial D (produced
by the company Coulter Electronic Ltd., England). Further measurement
was conducted on the apparatus Fossomatic 90 (A/S N. Foss Electric, D
enmark), operating on the principle of optoelectronic determination. A
n average value from average of 212 herds represented 241,000 +/- 83,0
00 per 1 ml for the area under study. Fig. 1 shows the share of bulk m
ilk samples in the grade up to 300,000 somatic cells per 1 ml and up t
o 500,000 somatic cells per 1 ml. It is evident that the region is on
a good level and that economic pressure forces the farmers to reduce s
omatic cell counts below 300,DOO per 1 ml. In view of variants of bree
ding factors the homogenity test (chi2) was used to examine conditions
in bulk averages of somatic cell counts marginal frequency ranges (<
xBAR - s(x), > xBAR + s(x)). The breed group had a significant effect
on somatic cell content (P < 0.01); Black Pied cattle exhibited a high
er somatic cell count against Red Pied breed. It follows from Tab. I t
hat the production region had no significant effect on the counts of s
omatic cells. The effect of the level of average efficiency was record
ed as statistically significant (P < 0.0005). The shift to higher soma
tic cell counts is evident in herds with lower efficiency. The lactati
on parity (P < 0.0005) was manifested as an important factor where low
er somatic cell counts were detected in first calvers An introduction
of grass into feed ration had a significant effect (P < 0.05) - and he
rds with grass manifested higher counts of somatic cells. The predomin
ance of single type of silage and round-the-year incorporation of maiz
e silage to the feed ration had no significant effects on somatic cell
counts. Somatic cell count was not influenced statistically significa
ntly by disinfection prior to milking, nor after milking, however, the
result may be affected by random effects. A significant relation (P <
0.10) to somatic cell count was found for service period from indicat
ors of reproduction. In extension of service period over 90 days, the
shift to higher somatic cell values was recorded. The first A. I. gest
ation percentage and A. I. index had no significant relation to the so
matic cell count, but a shift to higher cell counts was visible in cas
e when A. I. index was higher than 1.7.