FARMERS and veterinary
surgeons in the south-west of
England are well aware of the
Healthy Livestock initiative. The
priority diseases are: Johne’s, BVD
and respiratory disease for beef
herds; Johne’s, mastitis, lameness
and BVD for dairy; and lameness,
parasite control and flock health
management for sheep.
Since the autumn of 2010 there
have been 8,500 farmer participants in
the project, 85 veterinary practices
have become
partners of
the initiative
and 545 vets
have received
training to
deliver the
programme.
Underpinning all this activity has
been a grant of £5.24 million but that
money has now gone. The
overwhelming view from delegates at
the Planning for Health and Profit
conference was that there should be a
continuation of the effort with
ongoing enthusiasm and support.
The county status of Johne’s
disease in herds throughout the south-
west ranges from 94% positive to
79% in dairy herds and 94% to 33%
in beef herds. Gloucester has the
highest incidence of Johne’s in beef
herds and Devon and Cornwall the
highest for dairy.
Plenty of detail
Considerable detail is available from
the Duchy College Rural Business
School with charts, percentages and
disease maps. Over half of the dairy
and the beef herds are shown to have
inadequate disease control from
outside the farm and inadequate
limitation of spread within the herd.
Professor Soren Nielsen outlined
the Danish experiences. He explained
how important it is to protect calves
from the manure of adults. The
infection becomes established in the
gut and initially the immune response
of the cow controls the infection but
the immune response is overwhelmed
and destruction of the gut leads to a
general bacteraemia.
Paratuberculosis infection then
spreads via the faeces, milk and the
uterus. The milk yield may not drop
but the cow excretes bacteria for up
to a year, representing a high risk to
the herd.
Cows are categorised according to
their test results as red, green and
yellow. Whatever the test applied -faecal, blood or milk – the advice is to
stick to one form of test and test
frequently.
Cows who have positive results for
the last two tests are red and these
cows are not put in calf. Yellow
identified cows represent a potential
risk to the herd and calve onto clean
bedding with good observance of
biosecurity. Green cows have no
history of the infection and the
farmer can be more relaxed about
calving conditions.
In Denmark only 27% of the
farmers provide a clean calving area
and only 15% cull the red cows. Some
of the farmers just test the cows but
do not use the test results and make
no management changes.
The term paratuberculosis is
preferred to Johne’s disease and there
is no such thing as categorising a herd
as paratb free. A drop of 1%
prevalence per year is the target for
control with an anticipated green herd
in 6-8 years.
The Danish experience has shown
that farmers react better to the
experiences of other farmers. On-
farm meetings of 10 farmers and
employees have been successful in
developing control through farmer-to-
farmer discussions of practical points,
including colostrum management and
reducing infection transfer.
Charles Harrison (a Nuffield
scholar) has studied the disease in
various countries. With 1,200 cows in
milk in three herds, Charles now
recognises that paddock block calving
and colostrum pooling had
contributed to years of financial loss
from Johne’s disease.
New culture of co-operation
Professor Joe Brownlie welcomed the
new culture of farmer co-operation
being exhibited to control and
eradicate bovine viral diarrhoea. Over
600 farmers are participating in the
dairy initiative and over 1,000 beef
farmers.
This is most encouraging but
looking at the disease map shows just
how dense the livestock farms are in
the south-west and the risk of disease
transfer is high. Regional tests indicate
that over 20% of the herds have BVD although there may not be clinical
cases.
The main reservoir of infection is
persistently infected animals, usually a
calf or adolescent. These are born as
a PI and shed BVD virus for the
whole of their life. PIs are unable to
create an immune response, even if
vaccinated, but individual ear tag
samples enable tests for presence of
the virus.
Bulk tank milk samples can be
tested for antibody and virus. A
positive antibody does not necessarily
indicate the presence of the virus and
whole herd milk tests will exclude dry
cows, heifers, calves and bulls.
The culling of PIs, test and
surveillance of herds and vaccination
are successful tools for control of the
virus. Where neighbouring farms
carry out effective control at the same
time, there can be greater confidence
in the outcome.
Best investment
Anthony Rew indicated that the
introduction of calf hutches was “the
best investment on the farm”. His
farm comprises both beef and dairy
and an emphasis on disease control
has proved financially beneficial.
Working in collaboration with the
veterinary practice has improved welfare, reduced
drug use and increased
production. Making use of
the gathering of animals
for the TB test would be
an improved additional
step towards easier testing.
Break-out discussion
groups addressed mastitis,
lameness, bovine
respiratory disease,
emerging diseases and risk-
based health planning. The
delegates selected two
sessions and then came
together for a final question
and answer session.
Dick Sibley is one of the advisers
to the programme and he highlighted
some of the realities of planning for
health. Farmers who had purchased
BVD vaccine have not been highly
successful in its application. The
wrong dose, or administering the
product subcutaneously when it
should be given intramuscularly, or
vice versa, occurred with 21% of the
herds.
One third of farmers never
referred to the data sheet. It is
difficult in practice to give the primary
dose of vaccine prior to first service
in heifers but 24% of farmers managed this targeted approach to
control.
Knowing the risks and knowing
the disease status of a herd are
essential steps. Half of the cattle in
the south-west have access to
watercourses with run-off from other
farms. One third of herds have no
Johne’s and 80% no active BVD, but
this makes them vulnerable and in
need of protection.
Multipliers of disease within a
herd need to be identified and it is
important to manage and monitor
progress. Farmers need to decide
where they want to be in terms of
disease with freedom from disease the
top option, control of disease the
second and tolerance of disease the
third.
It is not always possible to aim for
the top option, depending on the
management and circumstance of the
farm. It is important to have realistic
aims, to invest in health and not pay
for disease.
Richard Soffe and Paul Ward of
the Rural Business School contributed
to the final session and there were
questions about maintaining the
programme. Joe Brownlie appealed
for continuing effort and other
members of the panel reinforced the point that the
success to date
must not be
wasted, as disease
control is a long-
term activity.
Duchy
College is engaged in
maintaining
contact with the
technical teams
and there are
ongoing
discussions with
potential
supporters from the food industry. The role of the
levy bodies, DairyCo and EBLEX, is
unclear but it was felt that not only
should the South West Healthy
Livestock initiative be further
extended and developed but that
other areas of the country would
benefit from learning the lessons from
the programme.
It was strongly voiced that the
tools are available to control
infectious disease but it is action on
the ground that is needed in 2014-15
and not more research.
- Further information is available at
www.duchy.co.uk or telephone
Richard Soffe on 0845 4587485.
