Forage gaps

Forage gaps typically occur in the summer and winter. They can be filled by feeding silage or hay, however, this will increase feed costs. Find out how to reduce the impact of a forage gap.

A forage gap is a gap in forage supply, such as when grass supply is below livestock feed demand.

This is different for every farm and from year to year, but generally follows the pattern shown in Figure 1.

Figure 1. Seasonal pattern of grass supply and livestock feed demand (kg DM/ha/day)

The graph illustrates how grass supply peaks sharply in spring and again modestly in early autumn, while livestock feed demand follows a smoother seasonal pattern, peaking in early summer and exceeding grass supply during winter and late summer.

If you know when your forage gaps will occur on your farm, you can plan ahead to reduce the impact of the forage gap by:

• Changing calving and lambing dates
• Selling livestock
• Using brassica and forage crops to fill gaps
• Tactical fertiliser applications
• Changing your grazing strategy
• Choosing different grass varieties

A good starting point is to consider:

• The total feed requirements for the stock on the farm
• How these feed requirements are met under the current system
• What opportunities brassica or forage crops offer
• How much feed is needed