Feed wedge

After balance date the feed wedge is the best tool to manage pasture. A feed wedge shows the current pasture situation by ranking the paddocks based on average pasture cover. It allows you to make proactive decisions to manage a surplus or deficit.

• Data for a feed wedge should be obtained from a weekly pasture assessment where pasture is measured.
• Pastures are then ranked from highest to lowest. Adding a target line makes it clear where there is likely to be a surpluses or deficit in feed.
• The wedge identifies the grazing plan for the next round in terms of the sequence in which paddocks will be grazed.
• A feed wedge allows you to identify and anticipate a surplus (or a deficit) 10-14 days in advance

For more information see the pasture feed wedges page.

Identifying a pasture surplus

Surplus management is one of the greatest skills of pasture management and is critical to maximise pasture eaten and feed quality. A temporary pasture surplus, if not managed, allows ryegrass to grow to form stem and seed head, resulting in lower pasture quality.

Pasture management in late spring is based around providing high quality feed to the cows. Grazing residuals drives pasture quality and when growth exceeds demand, residuals will rise unless this surplus is managed.

Surplus management is all about anticipation. To get surplus management right requires weekly pasture assessment to predict feed surpluses before they happen.

• Why identify early?

  Identifying pasture surplus early allows better management of a surplus, including decisions around rotation length, removal of supplements and the number of paddocks to shut up. It also provides time to organise a contractor and therefore better control silage quality.

  It is critical to anticipate in advance the length of the closed period and associated risks. These include:

  • shutting up too much area for too long and restricting future milk production (higher risk with higher stocking rates)
  • managing silage quality. After the pasture has passed target grazing residuals, the quality will decline at an average rate of 0.3 MJME/kg DM for each week of closure. Try to harvest silage within 42 days of the last grazing.

  For information see the surplus management page.

  Pasture silage

  Pasture silage is an important source of supplementary feed on New Zealand dairy farms.
  The better the silage’s quality, the higher the milksolids (MS) production and body
  condition score (BCS) gain in cows.
  Key points:

  • Pasture cut for silage must be of high quality.
  • Grazing residuals should be 1500-1600kg DM on paddocks to be closed for silage.
  • Silage paddocks should be closed for no longer than six to seven weeks.
  • Cutting, packing and covering the stack must be done quickly to reduce spoilage losses. Some inoculants can improve the fermentation process.
  • Take care to minimise losses both at the stack and in the paddock/feed pad.

  Further information

  • Grass silage
  • Pasture silage - maximising the return on your investment (Technical Series September 2016)

• Making the right decisions with spring pasture

  There are many factors that contribute to growing good pasture in spring.

  Good-clover ryegrass mix

  Good clover-ryegrass mix is vital for productive pastures. 

  • The core elements of productive pastures are best met by mixtures of ryegrass and white clover.
  • When clover comprises between 10 and 40 percent of total dry matter (DM) in summer, there are gains in DM of between 1.4 and 3.4 t DM/ha per year.
  • Yield gains come mostly in summer, when extra feed grown has high economic value.
  • White clover generally requires higher levels of soil nutrients than ryegrass – especially phosphorus, potassium, sulphur and sometimes magnesium and molybdenum.
  • Excessive focus on nitrogen (N) fertiliser and failure to meet the soil nutrient requirements of white clover in recent years have inhibited clover growth and compromised pasture productivity. 

  For more information, read the September 2016 Tech Series article ‘Good clover-ryegrass mix – vital for a productive pasture.’

  Maintaining good quality pasture through grazing management

  Spring grazing management influences the amount and quality of pasture grown later in the season.

  • Pasture quality is optimised when pastures are grazed between the 2 and 3-leaf stage of regrowth, and grazed to residuals of 3.5-4cm (or 7-8 clicks on RPM).
  • Good pasture management in spring increases tillering in perennial ryegrass.

  For more information, read Making the right decisions with spring grazing (Technical Series September 2016).

• Spring (September to November)

  Pasture response relevant to ryegrass persistence

  Frequent grazing favours ryegrass tiller initiation by:

  • Preventing shading. Light encourages initiation of tillers from buds at the base of the plant
  • Preventing establishment of weeds
  • Reducing stem elongation as some tillers become seed heads.

  Good management: improved persistence

  Consistent post-grazing residuals, with grazing timed between the two to three leaf stage.

  Bad management: reduced persistence

  • Lax or under-grazing.
  • Silage and hay crops too long. More than 4000kg DM/ha
  • Insufficient (less than 26 days) recovery time after cutting silage and hay
  • Repeated grazing before the two leaf stage
  • Pre-grazing levels regularly above 3000kg DM/ha.

  Recommended rotation length

  16 - 26 days. Graze closer to the three leaf stage (26 days) if higher growth rates are required to meet cow demand.

  Recommended grazing residuals

  Note: grazing residuals are expressed as height in clicks, as measured by the rising plate meter based on the winter formula.

  Target is seven clicks (1500kg DM). Achieve consistent grazing height at each grazing event. If fewer than seven clicks (1500kg DM), feed supplement to maintain herd intake. If more than nine clicks (1750kg DM), mow to a lower height after grazing.

• Transition: spring to summer (November and December)

  Pasture response relevant to ryegrass persistence

  • Development of reproductive tillers and flowering peaks
  • Rates of tiller death and replacement peaks
  • Soil seedbank: summer-active grass weed seeds germinate and establish in pastures. 

  Good management: improved persistence

  • N fertiliser applied at 30kg N/ha after each grazing. This helps development of new tillers and reduces tiller population decline during summer
  • Where a summer moisture deficit is likely, a lower grazing frequency is needed to allow for slower leaf development. A gradual reduction in grazing area per day is needed. Achieve this without lowering the 
    grazing residual
  • Grazing area offered per day on January 1: approximately 80 percent of the area offered on November 1. Change from a 20 to a 30 day rotation
  • Supplements fed if changing rotation lowers grazing residual below seven clicks. Alternatively, de-stock.

  Bad management: reduced persistence

  • Grazing residuals more than the consistent level previously determined in the spring
  • This can elevate growing points, potentially exposing them to grazing at the next grazing.
  • Reduced height of grazing residual compared with spring indicates underfeeding occurring and a threat to the growing points of existing and developing tillers
  • Grazing to a lower residual than the previous grazing.

  Recommended rotation length

  Shift from 20 towards 30 days.

  Recommended grazing residuals

  Note: grazing residuals are expressed as height in clicks, as measured by the rising plate meter based on the winter formula.

  • No more than eight clicks (1600kg DM) on the rising plate meter. Target is seven clicks (1500kg DM).
  • Achievement of consistent grazing height at each grazing is important
  • If fewer than seven clicks (1500kg DM), feed supplements to maintain herd intake.