Basic HTML Version
Herd dynamics
‘But there's not just the individual cow to
consider,’ said Ger. ‘There's a pecking order
in herds and the dominant cows have an
influence on the way the whole herd moves.
‘When walking on a roadway, around half
the dominant cows will be in the front third of
the herd. The rest are spread throughout the
group. These cows control the walking pace
of the herd.
‘Dominant cows draw cows behind them as
they walk forward and cause cows in front of
them to move along, often by butting them. If
a dominant cow stops, then the cows behind
will bunch up and stop too. Cows in front
also tend to slow down and even stop,
apparently waiting.
‘Pushing the cows at the back of the herd to
hurry up - using quad bikes or dogs - will only
cause the herd to bunch up in the middle.
The “pacemaker” cows at the front, will be
largely unaffected.
Ger warned: ‘Cows need to be allowed to
walk at their own pace. Hassling the rear
of the herd will not get the first cow to the
parlour any sooner!
‘Secondly, giving them the time to see where
they are placing their front feet will prevent
hoof damage from stones and the possibility of
lameness from white line disease developing.’
He added: ‘When cows have a level,
well-drained non-abrasive surface to walk on
that is wide enough for the size of the herd,
the average flow rate may be up to three
miles per hour.’
Teagasc's Tom Ryan specialises in design
and construction of farm buildings and
roadways.
He explained: ‘Having a good system
of roadways and cow tracks on a farm
has many benefits; grazing management
is easier, less grass is spoiled, cow flow
is faster, and overall efficiency is improved.
Cow tracks can be narrower (1.8m to
2.4m) than the main farm roadways, and
the layer of hardcore material, shallower
(15 to 20cm). Cow tracks are a
cost-effective way to improve access to
grass, particularly on heavy land, where
a more intensive roadway system
is necessary.
‘A good roadway will be raised above the
grazing area and have a smooth surface,
a crossfall to shed water, and sweeping
bends at corners and junctions. It also needs
to be sufficiently wide for the herd, typically
4-6m. Ideally, it's also best to avoid sharp
bends, narrow sections, muddy areas, and
distractions such as water troughs.’
Tom said that for paddock-grazing systems,
as a rule of thumb, the area taken up by a
farm roadway system should be 1.3% of the
grazing area it services, and the paddock
should extend no more than about 150m
towards the fence at the back. On heavier
soils, ideally roadways should take up 2%
of the area and extend about 100m to the
back of each paddock.
Farm roadway design
Tom explained: ‘The voluntary walking
speed of the herd is also affected by the
quality and uniformity of the walking surface
because cows will be looking to find a
“safe” spot to place each foot.
‘The material used to make the “dusty”
surface layer should have a pebble size no
larger than 5mm. Limestone is not a good
choice as it dissolves in rainwater. Instead
consider using shale, red sandstone or
greywacke dust. But take a look first before
buying, as quality can vary!’
See panel opposite for more advice on
designs of roadways and tracks.
Road surface quality
XLVETS CONFERENCE
11
LIVESTOCK MATTERS
WORKING
TOGETHER
FOR A HEALTHIER FUTURE...