Friday 17 June 2011

At Last it has Rained on Pasture Based Dairyfarms in the UK

It has rained! Photo I know this either doesnt look like a drought or I am putting mouth watering images on the blog..actually it was taken on the Somerset levels which is very heavy low lying country...but it does look seriously good doesnt it! Many of the pasture based dairy farms this week received 20-30mm of rain. It is a huge relief for everyone that it has rained. Hopefully we will get much needed follow up rain.
Most parts of the UK & many areas within the EU have had a long prolonged period of very dry conditions with very little rain. Look at the Spring 2011 graph for rainfall on the Metoffice site below.
It is very important that pastures get time to recover.
There are three important points to make now about grazing management:- Grazing rotations need to stay long until pasture plants have had time to let the parched root systems to recover. Photosynthesis needs water. Photosynthesis is the chemical process driven by light that converts CO2 to plant sugars & carbohydrates. However this process requires water. During the dry months the pasture plant root reserves (read carbohydrates) have been run down. Once water is again available the pasture plants are able to regain strength & build up root reserves. Once the roots have recovered energy reserves fresh leaf growth follows. If you don’t allow the pasture sward this “recovery time” or as Alan Lauder calls “Strategic rest” after rain you will impact severely on total pasture production. This is a timing issue. Carbon Grazing is an Australian concept from a very low rainfall area of Queensland but the basic principles are applicable here after a long unusual dry period.
The second point is another really important grazing principle….when growth is slow grazing rotations need to be long. This is a feed budget issue associated with ryegrass plant growth to the 3 leaf stage. To keep the pasture grazing wedge intact you must keep the grazing rotation long until we are back to a normal season.
The last point to make is that after rain the dry matter % of pasture will fall. Pretty obvious perhaps but this will alter pasture plate meter readings. Photo-Brent Stirling from Cropmark NZ checking heading on a Matrix field in England. In fact the DM% changes daily dependant on sunshine, cloud cover, wind & rain.
Andre Voisin was a French born intensive pasture grazing researcher. He pioneered the concept of the S growth curve which is well known to all pasture based dairy farmers.
Today there are farmers like Abe Collins in the USA who are now pushing this concept even further with Holistic Grazing concepts. Joel Salatin has many videos on YouTube that promote a similar approach to grazing & grass fed food.
Regardless of who you follow of these new pasture grazing gurus they are all working on the same basic principles of pasture growth & pasture resting…..its the timing that is being debated worldwide…..long may the debate continue!!
Chicory & Plantain Herbal Pastures Talking of timing………….the timing for grazing of chicory & plantain pastures is critical to the success of those pastures. The first grazing must NOT occur until there are fully 6 leaves per plant (again this is about the plant building root reserves/energy storage). Now that we are in the growth season for these herbal pastures you must keep on top of them to stop flowering & stem elongation. Target pre grazing covers should be 25-35cm & post grazing residuals should be 5-10cm. Cows will readily graze lower than 5cm but this must not be allowed to happen.At pre grazing heights of 25cm assume total yields of 3000kgDM/ha. A post grazing residue of 5cm will mean the cows have harvested 1500kgsDM/ha. To stop the chicory bolting pre grazing heights of 50cm should not be exceeded. Current UK Pasture Measurements

Pasture growth still very variable dependant on rain. The dissappointing thing is the cold air temperatures & lack of sunshine. Average Farm Covers increased slightly this week post rainfall.
TheAverage Pasture Cover (kgsDM/ha) & Pasture Growth (kgsDM/ha/day)
South Ayrshire, Scotland, AFC 2380 & pasture growth 85
Dumfries, Scotland, AFC 1900, gr 40, demand 45 constant rain but very cold
Cumbria, 2225, growth 62
Derbyshire, 2151, gr35, demand 65, 17mm rain
Herefordshire organic, 2214, gr45, demand 40 rain during week 36mm
Somerset organic, 1900, gr 25, demand 33 rotation 35 days
Dorset 2450, gr80 & demand 45 good rain but grumpy cows???
Dorset organic, 2100, growth 39, Silage fields now back in rotation,reygrass heading
East Sussex Organic, 1508 cover, growth 23 up on last week, lots of rain
Devon, 2220, gr55 feeding silage
South Kilkenny, Ireland, AFC 2039, gr55, demand 49 cover increased this week
Fish Creek, Gippsland Victoria,Australia AFC 2700, growth 32 approaching calving

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