This study was aimed to investigate the effect of machine milking
on behaviour, milk production and milk quality of jennies.
Four Martina Franca and four Ragusana jennies were used. Five
jennies had no experience of machine milking (group NE),
whereas other three had (group E). Milking was performed by a
portable milking unit once a week from 20 to 140 days in milk
and residual milk was dripped by hand. Before milking foals were
separated from the mothers at different time intervals. The
behaviours, recorded from the attachment to the removal of milking
cluster, were step (foot lifted less than 15 cm off of the
ground) and kick (raised more than 15 cm off of the ground, even
if a clear kick was not visible). In addition, defecation, urination
and vocalisation were recorded as a single behavioural activity,
but this activity was observed so rarely that was not included in
the statistical analysis. Duration of milking, milk yield and quantity
of dripped milk were also registered. Data were analysed by
using the mixed procedure of SAS with day of lactation as repeated
factor, experience as non repeated factor and time of separation
of foal as covariate. The jenny was considered random. In
addition, Pearson correlation coefficients (r) were used to determine
the correlation between variables. The number of steps
(1.29±0.56 vs 1.61±0.43 n/min; for groups E and NE, respectively)
and kicks (0.34±0.26 vs 0.56±0.20 n/min; for groups E and
NE, respectively) expressed by jennies during machine milking was very low. These variables along with duration of milking
were not affected by experience (2.87±0.29 vs 2.94±0.22 min; for
groups E and NE, respectively). Conversely, time of separation
from foals had a significant influence on duration of milking and
number of kicks (P<0.01). Duration of milking increased with
the time of separation (r=0.294; P<0.01), whereas, even if not
significantly, the number of kicks decreased as the time of separation
from foals increased (r=-0.147). It can be concluded that
jennies rapidly habituate to machine milking, although their
behavioural response may be affected by the time of separation
from foals