Life's
a beach for Cornish Dairy Cows
£20-100
savings per cow per year are made by Cornish dairy producers using recent
advances in welfare friendly cow cubicle division design combined with
comfortable Calcareous Seasand bedding.
The
deep sand bed is ideal for the cow and particularly the large arable and
grassland based dairy unit. Where
applicable on most Cornish dairy units I would prefer concrete and mats to be
taken away and replaced with deep seasand beds.
Careful
building design and attention to specific soil type will allay many a dairy
producers traditional concerns about the large-scale use of sand.
Glacial and river sand are the US comfort bedding of choice by extension
workers and farmers - rivalled only by well bedded mattress for comfort - but
not cost effectiveness. £20
- 100 per cow cost savings
annually
are achieved over lime vs. sand manuring and straw vs. sand bedding material.
For Cornwall, annual costs of straw purchase (1.5-2t/ cow = £60-£80), handling
and storage (£20/ cow), cannot be withstood in straw yard systems.
The
necessary daily application of 2.5-3kg long straw over concrete or 1.5-2kg
chopped straw over mats & mattresses is prohibitive versus a 7-10 day
application of Seasand in deep beds and 3 day in shallower beds.
Hock abrasion is non-existent in well-managed deep sand beds.
Mastitis
Alkaline
seasand is not the natural substrate for mastitis organisms to grow.
Nevertheless at the rear end of any cubicle bedding not kept dry &
clean bugs will eventually grow. That said seasand does have a head start over
organic forms of bedding - straw, sawdust et al. It is important annually to ensure no hard compacted seasand
build up is left at the rear end of the cubicle. Liming
Value
Seasand
has a neutralising value (NV) typically 35-45 versus Limestone at 50-55 NV. Normal Padstow supplies of sea sand in Cornwall are
sufficiently fine to allow over a 6-week period the same rise in field pH as
ground limestone. Thus 1.3t Cornish
sea sand is equivalent to 1t ground lime. Usage
Most
dairy farms should need no supplemental spreader applied sand /lime on
accessible fields. 100 cows should
use about 120 - 150 tons per winter, (6 - 7 kg per cow per day) - sufficient to
maintain lime status on 240-360 acres dependant on artificial fertiliser usage
and crop offtake. In many cases A typical dairy units bedding requirement will
lead to a rising soil pH on cropped and silage areas.
Concrete bed cubicles
Cubicle & Deep Bed DesignShould
be a minimum 5-6 inches deep, no concrete & no fall, A brisket board is
essential at 5'6" to 5'10 dependant on cow size measured from the outside
edge of the heel stone.
Excess
Sea Sand application to land.
With
the exception a few well-defined soil types or localities, a soil pH at 7 to 7.5
will not be an issue for a majority of dairying and mixed arable systems.
Indeed farming at high soil pH is practiced regularly without problem
naturally and by design in many areas.
Dont
forget the off lying grazing areas or slopes.
Speed
of handling
The larger unit copes with a 3-10 day sand filling frequency with the converted Howard 100 rota spreader, or front bucket. For ease of handling in tight spaces the AG Engineering Sand Spreader £2300 rear mounted hydraulically driven belt hopper is superb. For
the very large herd the US imported trailed "McLanahan Stall Filler"
beds 70 cubicles in 2.5 minutes accurately delivering to 15ft in head to head's.
Slurry
Handling
Lagoons:
the sand usually separates to a solid bottom layer - it cannot be pumped and
must be guzzled or rota spread. Tower
Slurry Stores
usually sediment-requiring side opening and emptying on a 1-3 year basis
depending on volume of sand and dilution of slurry. There is much higher wear
and tear on pumps - difficult to put a figure on it - but producers tolerate. Weeping
wall pits: -
concentration of sand can be such that it cannot be pumped by umbilical. Slurry
Channels:
where yard or gutter water enters the channel, sand separates &
the channel blocks. Always have
removable lids over the entire length of the channel - preferably in weld mesh
reinforced concrete. Umbilical
or slurry irrigation
systems will usually not handle neat-sanded or drained slurry.
Separation either by long term weeping wall or mechanical separator prior
to pumping the liquid fraction resolves this issue. Parlour
Washdowns if running
to drains will block, standings are best hosed into the main scraped passages.
In the pit itself, a small mesh grid over the drain will prevent the
little sand that enters. Sand
Separation:
A
US innovated sand separator is available for import for reuse of sand.
Designed By Bill Bickert of Michigan State University & Andrew Wedel
of McLanahan Pennsylvania it may be applicable on the very large dairy unit
seeking to minimise excess Seasand / sand applications or reduce machinery
abrasion elsewhere. Particle size
and density of sand source is critical for Mechanical separation.
Sugar bag sized samples
can be sent for examination to McLanahan.
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