Got Bermudagrass Pastures? Need Spring Forage?

Two weeks ago, most of North Carolina experienced enough cool weather for our warm season pastures to go into dormancy.  This means pastures with perennial grasses like Bermudagrass or Bahiagrass will produce little to no forage until late April or May so it’s time to pull out the hay rings, hay huts, corner feeders!   Horse owners who have the luxury to stack hay to the rafters of their barn will probably have enough to get through winter but those who cannot store large amounts could be hard-pressed to find a decent supply come February.  Some hay producers scaled back on their fertility due to the ballooning cost of fertilizer.  Less fertilizer means lower overall hay yield so there is potential for a limited supply.  The best way to curb our reliance on hay, is to consider overseeding our pastures with winter annuals.  These are forage species that are planted in the fall (ideally September through October) to help compensate for the winter/spring slump that we experience with Bermuda and Bahiagrass pastures.  Winter annuals are a one-shot deal which means come May and June they mature and die.  When planning a winter annual overseed, there are a few things to take into consideration before pulling the trigger.  

Species Selection:

There are several types of forage species on the market so it’s good select the ones that fit both the horse and horse owner’s needs.  Make sure the species you select is frost/cold tolerant.  Grasses such as ryegrass, cereal rye, triticale, and winter oats are some of the most commonly winter annual grasses utilized for horse pastures.   

Site preparation:

Ideally, we recommend soil sampling your pastures before planting any type of forage.  The reports from the soil analysis give us a fertilizer and liming recommendation to bring essential nutrients and soil pH up to acceptable levels.  Considering we are on the later end of the planting window for winter annuals and soil testing is a 2-3 week turn around, I would recommend using a previous report if there was one taken within the last three years and work with your County Extension Agent to come up with a fertility plan “prescription”.  A winter overseed will need some form of starter fertilizer in the fall and then more in early spring as growth increases with warmer temperatures.  Splitting fertilizer applications allows the forage to utilize nutrients more efficiently which leads to thick, lush stands for your horse to graze.  Alternative fertilizers such as poultry litter, and manure are great sources of nutrients and are inexpensive compared to our commercial fertilizers.  The drawback with manures is they are harder to handle and apply without proper equipment.  

Note: Some winter annuals such as annual ryegrass can compete with bermudagrass during green-up in April and May so it is recommended that you devote only a portion of your pastures to a winter annual overseed.

Establishment:

To establish any winter annual forage in warm season pastures, we need to get any excess bermudagrass or bahiagrass growth out of the way.  The best way to do this is through mowing or grazing down grass down to two inches.  Again, since time is of the essence, a mower is going to be quicker than a grazing animal.  After pastures are clipped/grazed down, it’s time to plant your seed. 

There are generally two methods for planting.  First is using a no-till grain drill.  Although this is the best method to overseed your pasture, no-till drills require some horsepower and must be pulled by a tractor.  Several County Soil and Water District offices rent no-till drills for a reasonable fee. If you do not have access to a large tractor or no-till drill, the next option is broadcasting with a spreader followed by dragging with a chain harrow or piece of chain-link fence with weights.  This will help work the seed closer to the soil and increase germination.  For cereal rye, oats, or triticale the recommended seeding rate is 100-120 pounds per acre and for annual ryegrass you should plant 20-30 pounds per acre.  If you are broadcasting, we recommend planting the high rate to increase your chances of establishing a good stand.  If mixing two or more species, reduce the seeding rate of each by 50 percent.  For example, if you want to plant oats and rye together, plant 50-60 pounds of each.

Grazing Management:

Depending on weather conditions, winter annual overseeded in pastures can be slow to establish. Generally, rye, oats and triticale are not ready to graze until February. Ryegrass develops much slower and is usually not ready to graze until mid-March. Start grazing when plants reach 6 to 8 inches and stop grazing before plants reach 3 inches to keep from damaging stands! Winter annuals benefit from rotational grazing systems. Dividing pastures into smaller paddocks and rotationally grazing allows your forage to rest and recover before the animal returns.  This increases forage utilization and lowers the chances of overgrazing.  With adequate fertility and moisture, these winter annuals can produce 2-3 tons of dry matter per acre.   

Overseeding bermudagrass pastures with winter annuals can help compensate for the winter slump in forage production and provide your animal with nutritious feed in the spring.  If you are planning to overseed your pastures for spring grazing, the window is closing quickly!  If you have any questions about pasture management please contact your local Extension office. 

Teff Hay for Horses

 Teff is a warm-season annual grass originally developed and grown in Ethiopia as a grain. Although it’s been suggested to have lower palatability than some other more common grasses, in recent years it has become popular among horse owners in the U.S. looking to reduce the amount of sugar in their horses’ diets.

There is a bit of research looking at the use of teff hay in diets where low sugar, low starch forages are warranted or required and forage intake restrictions are recommended.

Staniar et al 2010: These authors report non-structural carbohydrate (NSC) contents for teff of 5.4% in the ‘boot’ stage and 8.4% in the ‘late heading stage’ of plant maturity. Both really low NSC levels and well below the 10 – 12% threshold considered safe for laminitic/ID/EMS/PPID horses. Variation in NSC levels between samples was also minimal.

Horses in this study ate 1.5% to 1.8% of their bodyweight in teff hay, with the lower intakes being on the more mature hay. Again, this is a good thing as horses on restricted diets are unlikely to eat this hay as fast as more palatable hays like alfalfa, so they should eat for longer periods of time for lower calorie intake.

McCown et al 2012: Reported that when fed to horses unaccustomed to teff and given a choice of either teff and alfalfa or teff and timothy, their intake of teff is lower than their intake of alfalfa (no surprise there) and timothy. BUT, when given access to only teff, intake was about the same as timothy hay. So they don’t relish teff hay, but they are also less likely to overeat it if they are overweight to begin with.

Askins et al 2017: These authors report that horses given free access to teff hay consumed 1.5% of their bodyweight per day which equated to 86% of maintenance calorie requirements. So the finding of lower intake on teff continues.

This study also reports that resting glucose and insulin levels did not change over 10 days while the horses were fed teff. To keep this in context however, ryegrass hay (which can be higher in NSCs) was fed as the control hay in this study and glucose and insulin levels also remained the same on this hay. Unfortunately the NSC content of the hays was not reported.

DeBoer et al 2017: In another recent study, these authors report that cool season perennial grasses had a significantly higher NSC content than teff pasture in summer and fall/autumn, however actual NSC content was not reported.

This research also looked at differences in plasma glucose levels in horses grazing either alfalfa, cool season grasses or teff and found that differences were minimal. However, we know that insulin resistant horses can maintain normal glucose levels, they just need a lot more insulin to achieve this.

DeBoer et al 2018: Authors report that horses grazing teff had significantly lower peak insulin levels when compared to horses grazing cool season grasses in fall/autumn… despite NSC levels not being significantly different between the grasses (the cool season grasses had numerically higher NSC values but when variation was taken into account they were not significantly different). It is worth noting here however that teff was not recorded with an NSC above 10% at any time point where the cool season grasses did reach 12.6% NSC in summer.

Overall, from the research available, teff appears to be suitable for horses who need either a calorie restricted and/or NSC restricted diet. However, if you are going to use teff hay for a metabolically challenged horse, it is still wise to test it to confirm NSC levels.

Adapted from an article by Nerida McGilchrist.