Current Progressive Dairy digital edition

Strategic use of annual forages

Mike Lamborn Published on 10 April 2013

Generally, a confined operator is at the mercy of high feed costs and must continually look at trimming other farm costs to maintain profitability. However, for the farmer who grazes all or part of his herd, increased forage production is a viable alternative.

For years, graziers have relied on the forage that their perennial pastures produce. Typically, perennial pastures start gathering valuable, storable nutrients at mid-fall and a noticeable decline in forage production occurs. By winter, they shut down almost completely and won’t provide any measurable feed until spring heralds a new growing season.



Traditionally, during this time of forage deficit, the feed cost for milk production is elevated because of near or full supplementation.

This is where the use of low-cost, high-value cool-season and warm-season annual forages can provide feed during the “shoulder” of the perennial growing season, when perennial pastures go into a productive decline.

This is certainly the case from fall to spring, but shoulders can also occur during the summer when hot, dry weather causes a decline.

As a rule, most annuals are established by sowing in a prepared seedbed (drilled or broadcast) or no-tilled in or broadcast on an existing pasture. Either way, there are certain guidelines to consider for achieving maximum productive potential.

Timing is critical for successful crop establishment and for determining the number of days it can be grazed. With cool-season small-grain cereals, which produce most of their forage production in fall through to early spring, it is imperative that these are sown early enough in late summer (sowing conditions allowing) to guarantee harvest of their growth potential.


This is equally important in both prepared seedbed and no-till situations. While recent trials have shown a 30 to 35 percent increase in yield in prepared seedbed over no-tilling, there are still productive benefits from no-tilling.

If no-tilling is the option, farmers need to resist trying to get the last grazing from the existing pasture if it means going over the sowing deadline.

Especially in the case of warm-season perennials such as common and coastal bermudagrass and bahiagrass, excess cover is far better low-clipped or scalped off and made into hay for dry cows.

Desiccation with either Paraquat or a sub-lethal dose of glyphosate can also be used to remove old pasture cover, but this process requires a forage length of five to six inches for successful translocation and thus must be mechanically removed.

When using the no-till option, farmers should consider cross-drilling, especially where small-grain cereals are being incorporated with annual ryegrass. Both seeds require a different sowing depth, and the crop is sown over almost double the given area, which generally gives a higher germination and plant survival rate.

One of the benefits of a prepared seedbed scenario is the opportunity for double cropping with both cool-season and warm-season annuals. The total potential yield of these two high-value annuals is very high.


A typical blend of turnips, winter rye, annual ryegrass and crimson clover sown in early fall will produce close to four tons of available dry matter per acre. Coupled with BMR sorghum-sudan sown in late spring, the total annual available dry matter produced from the acre in question is close to 7.5 tons.

Warm-season annual production can play a big part within a grazing platform when dry conditions and high temperatures force perennial pastures into the summer “slump.”

Just as cows need feed to produce milk, annual and perennial crops need fertilizer to produce forage. Assuming adequate levels of phosphorus and potassium are evident, nitrogen is the big player when it comes to producing optimum forage yields from annuals.

While the current cost of nitrogen is relatively high, the pros of applying this very important nutrient far outweigh the cons.

Generally speaking, cool-season annuals will require two applications of 50 units per acre – one in the fall and another in early spring. For warm-season annuals, the first application should be at sowing in a prepared seedbed and another halfway through the growth cycle. A wise move with both types of annuals is to test them for nitrates before starting to graze.

Effective grazing management of any forage, perennial or annual, is incredibly important to harvest the yield potential offered. Because annuals fill an important role in providing forage for the shoulders outside and within the grazing season, good grazing practices will go a long way.

Daily allocation is dependent on the available quantity of forage and the number of cows to be grazed. Experienced graziers use a pasture stick or rising plate meter to know how much forage is available.

This is akin to knowing how much grain is being fed in the parlor or how much is going in the mixer wagon. Being able to quantify a pre-grazing level and a post-grazing residual is absolutely paramount for proper allocation.

Managed intensive grazing with an electric fence is the best method to achieve this. The electric fence allows adequate daily allocation, achieves the required post-grazing residual and prohibits cows from grazing tender re-growth.

Of the two grazing levels, the post-grazing level is the most important because it sets the stage for recovery time (rotation length) and the number of recurring grazings.

Another smart move is to get a forage analysis done at the beginning and halfway through the grazing cycle and share this information with a nutritionist. An experienced nutritionist will use the information to effectively incorporate the forage into a balanced ration.

Once an annual forage program has been implemented, consideration needs to be given to matching the high-quality forage production to the seasonal peak nutrition needs of the lactating dairy cow.

In the U.S., fall and spring are the two major calving periods, and tight calving during these times is essential to get the maximum number of cows calved, transitioned and peaking when grazed forage is at its nutritional best.

Fall calving in the South works extremely well because the combination of high forage quality and cooler temperatures is favorable for economic milk production and for high conception rate.

Adding a warm-season grass such as crabgrass or other summer forage to a cool-season program fills the summer forage deficit and will maintain milk production until the cool-season program begins again. With this scenario, given mild winter conditions in the South, it is possible to effectively graze for 300-plus days.

Northern dairy farmers typically experience winter conditions that temporarily halt forage production and drive their herds into dry lots or barns for full supplementation. In this situation, spring calving is the better answer. A spring calving program will match high-value forage growth to the nutritional requirements required for peak milk production.

Summer calving for the grazing dairy farmer is not the best option. The primary reason is that in summer, high temperatures and humidity reduce grazed dry matter intake and reduce breeding activity and conception rate.

Recent research shows that grazed dry matter intake becomes measurably reduced when temperatures exceed 78ºF, and the higher the temperatures go, the greater the reduction in intake.

Because of differences in dairy operation locality, there will certainly be exceptions to the rule. However, certain management strategies can be implemented to create significant savings through an annual forage program. PD

Mike Lamborn
  • Mike Lamborn

  • Farm Consultant
  • DFA Grazing
  • Email Mike Lamborn