Page 25 - ACV Journal DECEMBER 2015
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Scientific
more common in the last 2 minutes of milking The environment
• The average overmilking time was 4 mins 20 sec as The environment was considered to be the major factor contributing
observed which was consistent with the VaDia recordings (4 to the mastitis problem on this farm. There were many areas which
mins 29 sec) made udders muddy including around troughs, drains, dairy exit and
cows loitering on tracks close to the dairy after milking. Cows dropped
• Often the farmer appeared to be holding clusters and down into approximately 30cm of mud immediately upon exiting the
waiting for cows to “finish” even after milk flow had stopped dairy (Figure 4) which then splashed up onto udders as they moved
some minutes before through it. In addition, were observed congregating and lying on the
track after milking which was heavily contaminated with both mud
• Cluster alignment was generally good except when the and faeces. These were considered to be major risks due to the lack
front cows were squashed up and this was reflected in the of natural defenses (e.g. teat plug formation) in the 2-hours following
occasional high strip yields in some cows milking (Countdown Downunder Technotes, 2000).
• Teat disinfectant was mixed using the correct rate,
measuring jugs were used and components were stored out
of direct sunlight
• 20L batches of teat disinfectant was mixed up
approximately once weekly and was exposed to air as
shown in Figure 3.
• Chanel water (not passed through hot water service) was
used to mix teat disinfectant
• Active iodine concentration measured on farm was low
(0.4%) but calculated emollient in the mix was appropriate
(5.6%)
Figure 3. Figure 4.
Storage of teat disinfectant solution following mixing. Deep mud at exit of dairy and muddy tracks on which cows sit down
on after milking.
Clinical cases and culling
Summary of findings
Clinical case detection on the case study farm was by observation/
palpation of swollen quarters post-milking. Given that 40% of Once all the necessary data had been collected, the herd mastitis
clinical cases of S. uberis present with changes in the milk only dynamics chart (Section A7 of MIP) was completed in order to
it was likely that the farmer was missing clinical cases (Technote redefine the problem and highlight the most important factors
1) (Countdown Downunder Technotes, 2000). The farmer was contributing to this problem. The new, redefined problem was as
using Forte V for treatment of clinical cases and often deviated follows:
from label recommendations (e.g. reduced treatment interval
and increased number of treatments). This was highlighted as The herd has had a high BMCC throughout the lactation (i.e. not
a major concern for potential antibiotic residue breaches. The associated with calving periods) predominantly due to environmental
policy for culling on this farm has been three or more clinical bacteria (S. uberis).
cases during a lactation and culling of the highest two ICCC
cows on each herd test. The investigating team agreed that the key priorities for tackling the
mastitis problem included:
www.ava.com.au/cattle The Australian Cattle Veterinarian | volume 77 | December 2015 25
