2013-12-18   facebooktwitterrss
Winter Rotational Grazing Reduces Feed Costs

‘All-Grass Wintering’ is a rotational grazing system where a pregnant ewe flock is grazed at a high stocking density in electric-fenced paddocks to improve grass utilisation.

Ewes can be moved daily or in three or four day shifts to cover the period from around three weeks after mating to three weeks before lambing (just over 100 days).

Sheep Grazing

Last winter, an EBLEX-funded project with SAC Consulting demonstrated the system on seven farms in the south of England, with estimated feed savings of £15 per ewe. Dead material and weed grasses were notably reduced, as the intensive grazing pressure tidied up the fields.

How to determine whether there is sufficient grass for all-grass wintering

First, measure the farm’s grass supply with a calibrated sward stick or plate meter, to get kilograms of dry matter per hectare (kg DM/ha) and calculate average farm cover. Then estimate flock demand: a ewe pre-scanning requires 1.5% of her body weight, post-scanning this increases to 2% or above depending on grass quality.

This information is used to calculate a winter feed budget for low and moderate grass growth scenarios. The example below is for a farm with 950 ewes and a 100ha grazing area:

Eblex Sheep Grazing Table

The target is to end with more than 1500kg DM/ha average grass cover, therefore in the low grass growth scenario above, feed supply is tight (leaving 1372kg DM/ha), but at moderate growth it is sufficient. In this case, the system could be feasible with additional forage reserves if grass runs short.

Dividing fields; worked example for 4ha field with a cover of 2,300kg DM/ha

The aim pre-scanning is to leave 900kg DM/ha to ensure pasture recovery for spring (increasing to 1200kg DM/ha post-scanning):

2300-900 = 1400 kg DM/ha available feed x 4 ha = 5,600kg DM available in the field

Pre-scanning, 950 ewes, weighing 65kg, require 1.5 % of their bodyweight per day
65 x 0.015 x 950 = 950kg DM/day flock demand (rounded up)

5,600 ÷ 950 = 6 days of feed available.

Therefore, split the 4ha field into six daily paddocks or two three-day paddocks. It remains vital to body condition score regularly and observe flock behaviour to check they have sufficient grazing.

Eblex

Related Links
link Higher Lambing Percentage Increases Lowland Sheep Flock Margins
link NSA Urges Retailers to Look After UK Sheep Farmers
link Young Farming Couple Receive 2013 NSA Cymru/Wales Achievement Award
link Potential to Improve Sheep Meat Supply Chain Efficiencies
link Sheep Breeders


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