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WORKING
TOGETHER
FOR A HEALTHIER FUTURE...
13
LIVESTOCK MATTERS
Veterinary surgeon
James Marsden
XLVets practice
Shropshire Farm
Veterinary Practice
HERD HEALTH
He explains: ‘One study has shown that as
many as one in three bulls may be sub-fertile!
Here at the practice, we collated the findings
of our bull breeding examinations in 2015,
including the re-testings, and more than 1 in
6 bulls had been diagnosed as unsuitable for
breeding.
‘Bulls may also suffer physical injuries, prior
to, or during the breeding season, and some
bulls may simply develop to be unfit for
breeding‘
Fit bull payback
James explains: ‘The standard quoted is that
a fertile bull should be capable of impregnating
90% of a group of 50 normal, disease-free,
cycling females within a 9-week service
period.
‘So when bulls have passed the breeding
soundness exam, we expect at least 65% of
cows to calve within the first three weeks of
the block, and over 90% to calve within 9
weeks.
‘There are several advantages to this. In
spring-calving herds, having more calves
born early on means they have more time to
grow before they are weaned. Their dams’
milk comes from grazed grass, and not
bought-in feeds.
‘Industry figures suggest that for a 3-week slip
from a 9-week to a 12-week calving period,
there’s a loss of around £7,000 per 100
cows through having lighter calves at
weaning.
‘On top of this there are disease costs to
consider. Regardless of whether calving is in
spring or autumn, the tighter the block, the
smaller the difference in ages of calves. So
the younger calves will be less prone to
contracting diseases cycled up from older
calves because there has been less
contamination of the environment.
‘In fact, for every 3-week delay in the birth
of a calf, there will not only be a higher
disease challenge but a consequent increase
in remedial treatments for diseases such as
coccidiosis, cryptosporidiosis, or pneumonia.
‘So, as well as lighter calves, extended
calving periods also create a greater risk of
disease which challenges calf survival rates.
‘But for only around one hour’s vet work, all
this can be avoided by giving every bull an
MOT before the breeding period.‘
The MOT
Bulls should be given an MOT or Bull
Breeding Soundness Examination (BBSE) at
6-8 weeks before the start of the breeding
period. This allows time to treat the bull if
required, or source another. Sometimes a bull
may simply need to be rested, and then
re-tested.
JAMES MARSDEN,
SHROPSHIRE FARM VETS
Check bulls for fitness
and fertility or else risk
extended calving periods
Before turning any bull out with a group of cows or heifers, it should be
tested for fitness and fertility, says vet James Marsden of Shropshire
Farm Vets, near Shrewsbury.
Bull fitness needs to be checked throughout the
breeding period
The tighter the calving block, the more even the
calves and less risk of disease transfer from older
to younger animals