Biology Reference
In-Depth Information
platform temperature (mean of seven sensors) and to the ST. Relative humidity was
recorded only at departure and arrival. BW was measured at the Polish farms, in the
transit center before departure, and after arrival in Italy.
BW data were analyzed according to a linear model that considered the seasonal
and transport (repeated measurements) effects. The influence of the AT and truck
temperature on RT and ST was investigated by linear regression to determine
significance. After evaluation of the correlation matrix, a nonlinear regression
was made between AT and RT, which showed an increased value of the coefficient
of determination (
R
2
).
10.3 Results
No transported calves showed any trauma or cutaneous injury; no primary or
secondary skin lesions were observed. In July, an AT of 14
C was observed at
departure from Poland and of 29
C after arrival in Italy with 65% and 55% relative
humidity, respectively. In January, ATs of
5
C at departure and 6
C after arrival
were observed with 89% and 72% relative humidity, respectively (Fig.
10.1a
).
Despite these marked variations, the inside truck temperature slightly changed
(Fig.
10.1b
). In these climatic conditions, the calves maintained an RT control in
both transports by superficial (skin thermic receptors) and deep thermoregulation
(hypothalamic centers connected with the regulation of respiration, circulation, and
other essential functions) without any pathological signs. In fact, RT was
38.8-39.9
C in the summer and 38.3-39.6
C in the winter (Fig.
10.2a
) within the
normality range of 38.5-39.5
C (Radostis et al.
2007
). The greatest increases in RT
were observed after unloading. A significant linear correlation was found between
AT and RT (
R
2
0.001), but not between AT and ST (
R
2
¼
0.57;
P
¼
<
0.19;
P
0.10) as reported in Fig.
10.2a, b
. ST showed a slight variation between 38.4
and 38.9
C in July, and between 38.1 and 38.7
C in January (Fig.
10.3a
).
Before departure, the calves showed a decrease in BW equal to 7.0% in July and
4.9% in January compared with values recorded at the Polish farm. After arrival in
>
a
b
35
35
30
Summer
Winter
Summer
Winter
30
25
25
20
20
15
15
10
10
5
5
0
0
-5
-5
-1 0
Fig. 10.1 AT (
left
)(a) and truck temperature (
right
)(b) according to transport schedule
