V. Gencurova et al., EFFECT OF MILK SAMPLE TREATMENT BEFORE ME ASUREMENT FOR READING OF SOMATIC-CELL NUMBER BY THE FOSSOMATIC APPARATUS, Zivocisna vyroba, 38(6), 1993, pp. 555-565
For determination of some effects on the number of registrated somatic
cells (SB) in milk three tests were carried out. In the test 1 in fiv
e basin milk samples the effect of time of heating the samples in bath
(15 or 35 minutes) and temperature (40-degrees-C or 50-degrees-C) to
which the samples were heated, in the raw and pasteurized samples for
unpreserved milk (N), milk preserved by potassium bichroman (D) in the
amount of 33 mg per 25 ml of milk and milk preserved by the Broad Spe
ctrum Microtabs microtablets with the bronopol efficient component (B)
in the amount of 10 mg per 25 ml of milk was observed. Observation la
sted nine days, the temperature at storage was 4-degrees-C, the first
measurement was carried out 24 hours after sampling. The samples were
temperature treated before measurement for one hour under the laborato
ry temperature. Each sample was heated in the bath for 15 minutes, it
was measured then, put again to the bath and after 20 minutes another
measurement was carried out. The results show (Fig. 1, Tab. I) that at
time prolongation of heating the samples 40-degrees-C warm from 15 to
35 minutes a number of registrated cells increases for N, D and B. Un
preserved samples showed in the course of two days at shorter time of
heating an increase by 25 %. D and B samples with longer time of heati
ng only by 5 and 6 %, that means for the samples preserved the real nu
mber of cells has been determined as early as in one day after samplin
g and at the heating time of 35 minutes. For the pasteurized samples b
alanced results were found out for both heating times. The differencie
s between raw and pasteurized milks (for N, D, B and two heating times
at the temperature of 40-degrees-C) were recorded as statistically si
gnificant (P < 0.05) in the first day of measurement. At the temperatu
re of 50-degrees-C of the samples (Fig. 2) remarkable differencies are
not obvious for different heating times and for pasteurized or raw mi
lk. During simultaneous sample analyses on the Milko-Scan and Fossomat
ic apparatuses it is necessary to keep 40-degrees-C warm samples in ba
th for 25 minutes, otherwise an analysis of milk substantial compositi
on could be devaluated. In the test 2 dynamics of number of SB in depe
ndence on the time and temperature of the sample heating (Fig. 3) was
observed. The samples of raw and pasteurized milk treated by the N, 1)
and P were measured (24 hours after sampling at 4-degrees-C, before m
easurement of temperature treatment under laboratory temperature). The
lowest number of SB was found out during the first measurement in the
samples 14-degrees-C warm put in the bath. The average values of four
basin samples, measured duplicitously were as follows: 250, 292 and 2
96 thousand per ml for raw milk and 336, 307 and 309 thousand per ml f
or pasteurized milk treated by N, D and P. Each sample was put agam in
to bath after measurement and at about in 11 minutes, when the whole s
et was measured, it was again tested. During cca two hour measurement
relatively balanced results were reached. For the samples of pasteuriz
ed milk higher average numbers were found out against the samples of r
aw milk: for N 351 thousand per ml versus 274 thousand per ml, for D 3
33 thousand per ml versus 309 thousand per ml and for B 339 thousand p
er ml versus 306 thousand per ml. The tests 1 and 2 confirmed that the
higher SB numbers found out in the samples of pasteunzed milk are due
to more intensive colouring reaction, which is at the same time highe
r for preserved samples against unpreserved. In the test 3 where five
basin samples were sampled by four samplers the influence of particula
r samplers was not manifested on the SB number (Tab. II), which howeve
r need not to be of general validity under another conditions.