Dairying notes June 2007

Early turnout and excellent grazing conditions during May allowed herds to graze out most swards well.  With low residual grass covers after grazing, (around 1800 KGs DM/ha) re-growths are coming back leafy. Provided these re-growths are being grazed off at covers of no more than 3300 KGs DM/ha, cows will be capable of producing 23-24 litres of milk off grass alone during June. Allow 21-22 litres for heifers.  

At sward covers above 3300 KGs DM/ha, the proportion of stem builds up, reducing the feeding value of the grass.  Where cows are forced to graze out heavy covers (above 4000 KGs DM/ha) their performance will suffer.  If covers are getting ahead of the herd, close off these heavier swards for big-bale silage production and skip to paddocks with a more suitable pre-grazing cover.

If only one or two paddocks have heavy covers consider mowing down the sward the day before grazing. This will encourage good intakes by the herd, maintaining performance and encourage leafy re-growth. The alternative is to graze lightly and then top or follow with dry-stock to graze the swards down.

If swards have not been well grazed out top now to ensure leafy re-growths for the rest of the season.  Given present growth conditions, this can be done with little risk of running short of grass. In three or four weeks time growth conditions may not be as favourable. Quality grazing is essential in order to cost effectively maintain the higher yields most producers seem to be obtaining this year.

Docks will be growing strongly four to five weeks after first cut, with a large area of leaf cover  – an ideal time to apply herbicide.  

If the survival of clover is not considered important sprays based on the chemicals fluxopyr, triclopyr or dicamba/mecoprop mixtures should be  used.  Scorch damage caused by these herbicides will check grass growth  but yield loss will be lower than with a treatment before first cut.  If clover is considered important use sprays based on Asulam or Thifensulfuron-methyl.  Remember in most circumstances treatment is most effective where a second treatment takes place within a 12 month period.

Swards well greened up after second cut but no slurry spread – you may still have a chance to spread without the risk of heavy sward contamination at harvest.  Applying slurry using a trailing-shoe system provides the opportunity to put on a heavy application (>25,000 litres/ ha)  without coating the grass.  

A number of contractors have invested in the equipment. Although their charges will be higher to compensate for the lower work rate, the saving in fertiliser nitrogen requirement due to the increased efficiency of utilisation of slurry nitrogen should cover this extra cost.   Recent work at AFBI, Hillsborough showed that where 44 cubic metres / ha (4000 gallons/ acre) of slurry was applied, fertiliser N use could be cut by 48KGs n/ha (38 units/ acre) – a financial saving of over £20/ha (£8/acre).

How good is the fertility performance of your herd ?.  Fertility benchmarking is a recent initiative, which allows you to assess the performance of your dairy herd and compare it with other herds of a similar calving pattern. The programme gives you the opportunity to identify ways to improve fertility and so increase overall dairy herd profitability.

Fertility benchmarking is an online application available through the rural portal at www.ruralni.gov.uk .  Herd fertility information can be uploaded from existing commercial software packages including Agridata, Farm Wizard, and Kingswood or by manually entering the data online.  

The programme identifies key areas where improvements are needed, and provides an estimate of the potential for increasing herd profit through improving fertility performance.  Contact your local Dairying Development Adviser for further information on how fertility benchmarking can help in the management of your herd.