Fall Weed Control in Pastures

Fall Weed Control in Pastures

Fall is not generally the right time to control many pasture weeds.  However, some perennial weeds are effectively controlled by fall herbicide applications.  Fall is a good time to treat for weeds such as cogongrass, blackberries, dewberries, biennial thistles, and Chinese Tallow trees.

Cogongrass

cogongrass flowering

Cogongrass flowering

Cogongrass is an invasive warm season perennial grass.  It spreads by rhizomes and seed in north Florida.  It can quickly spread from roadsides or forest areas into pastures.  Established areas of cogongrass can have massive root systems making them difficult to control.  Eradication of cogongrass infestations often take 3 or more years of twice a year treatments.  Currently, only products with the active ingredients glyphosate and imazapyr are effective against cogongrass.  Spring and fall treatments of either glyphosate, imazapyr or a combination of the two should be applied until the infestation is eradicated. Both of these herbicides are non-selective and will likely result in bare ground in treated areas.  These areas are not going to produce adequate forage for animals so owners should consider this in their grazing management plan.  For more information on cogongrass and treatment plans, please read the following UF/IFAS publication: Cogongrass (Imperata cylindrica) Biology, Ecology, and Management in Florida Grazing Lands

Blackberries and Dewberries

blackberry plants

Blackberries grow upright and have hard, tough thorns.

Blackberry and dewberry control in pastures is difficult to achieve.  The first step is identification of the plant.  Blackberries grow upright while dewberries have a low vine-like growth habit.  Dewberries have slender thorns and red hairs on the stem while blackberries have hard, tough thorns and no hairs.  Blackberries grow up to 3-6 feet tall, however, dewberries rarely reach over 2 feet in height.  Also, the seeds of dewberries are harder and much larger than that of blackberries.

dewberry plants

Dewberries have slender thorns and red hairs on the stem and are low growing and somewhat vine-like.

For blackberries, effective broad spectrum herbicides include:  Pasturegard HL (triclopyr + fluroxypyr), or Remedy Ultra (triclopyr ester).  You can either apply these herbicides in the spring when the plants are blooming, or in the fall.  Fall applications are more effective.

For dewberries, use Pasturegard HL (2pt/acre) but only expect 60-70% control.

Remember to wait at least 6 weeks after applying the herbicide before mowing.  For more information on blackberries and dewberries in pastures, please read the following UF/IFAS publication:  Blackberry and Dewberry: Biology and Control

Biennial Thistles

first year thistle plant

First year thistles, in the rosette stage, are easiest to control.

Most thistles in Florida are biennial, meaning they live for two years.  Thistles begin as a rosette and remain in this stage for the first year.  In year two, the thistle sends up a stalk and flowers, produces seeds and dies.  Thistles bolt (send up the stalk) January through July and flower from April through August.  Each plant can produce up to 4,000 seeds. The key to controlling thistles is to keep the plant from flowering and producing seeds.

Thistles in the rosette stage are the most susceptible to herbicides but are hardest to see in the field since they lay flat on the ground.  Once the thistles bolt, they are harder to kill with herbicides.  Effective herbicides for thistles during the rosette stage include 2,4-D, triclopyr, GrazonNext HL, PastureGard HL and Weedmaster.  For more information on thistle control in pastures, please read the following UF/IFAS publication:  Thistle Control in Pastures

Chinese Tallow Trees (Popcorn Trees)

chinese tallow seedling

Chinese Tallow seedlings can be treated by foliar applications of triclopyr ester.

Chinese Tallow, also known as the Popcorn Tree, was introduced in the US over 200 years ago.  They are prolific invaders of natural areas, pastures, wetlands, and yards.  Mature trees can be cut down with a chain saw and the stump promptly treated with an herbicide with the active ingredient, triclopyr amine.  You should try to make the final cut as low to the ground as possible.  You can use a paint brush to apply the herbicide to the stump.  A basal bark application of triclopyr ester plus a penetrant oil can be used on smaller trees.  Treat the trunk to a height of 12 to 15 inches from the ground, thoroughly wetting it on all sides with the herbicide mixture.  Basal bark treatments are only effective on saplings and seedlings less than 6 inches in stem diameter.  Sometimes suckers may sprout from remaining roots.  A foliar application can be used on these sprouts from July to October, before onset of fall color. For more information on Chinese Tallow, please read the following UF/IFAS publication:  Natural Area Weeds: Chinese Tallow

For more information on pasture weed control, use the following publication link:  Weed Management in Pastures and Rangeland

Precision Feeding After a Challenging Hay Season

Precision Feeding After a Challenging Hay Season

Just like soil sampling before purchasing fertilizer, hay should be sampled and sent to a lab for evaluation before purchasing supplemental feeds. As Dr. Jennifer Tucker from UGA often says, “Don’t guess, forage test!” Credit: Doug Mayo, UF/IFAS

The summer of 2018 has been very challenging for hay production.  The combination of frequent rainfall, and heavy downpours have prevented timely harvest, and also diminished the quality of the hay produced.  The days are getting shorter, grass growth has slowed, so it is time to start planning for cool-season supplementation. Because of the rainy summer, many producers will have to feed at least some lower quality hay this year.  Since hay serves as the base for the winter feeding program on most operations, it will be even more critical this year to balance low quality hay with adequate supplemental feeds.  This conundrum has many producers asking, “What is the best way to do that?”

In the modern area of precision agriculture, many crop farms have implemented the technique of precision fertilization.  Using grid soil sampling, GPS maps can be generated with variable rate fertilization zones.  Once the maps are paired with high-tech application equipment that responds to the data, crop farmers can fertilize more efficiently than ever before.  While most livestock producers are familiar with high-tech genetic and breeding technologies, many farms are not utilizing the available technology for what I call “Precision Feeding.”  Whether you produce your own hay, or buy it from a local farm or supply dealer, you should have your hay tested for nutritional quality.  As Dr. Jennifer Tucker, UGA Beef Specialist,  often says, “Don’t guess.  Forage test!”  Once you know how good or bad your hay is, you can precisely determine the type and amount of supplement needed to balance the nutritional needs of the animals you are feeding.

Forage Sampling

So where do you begin this process of fine-tuning your winter nutrition program?  The first step is to sample each cutting or purchased lot of hay to determine the nutritional quality.  Contact your local county agent to get some help with thisA number of the agents in the Florida Panhandle have forage probes at their office, or can get one to use from a nearby county.  If you want to purchase your own equipment, there are a number of different companies that sell forage sampling probes.  The one I use, was ordered from Nasco and fits on the end of a 1/2″ cordless drill.  The combined cost of the forage probe ($130) and a heavy duty 1/2″ cordless drill is around $350.

Forage Sample Equipment

To send in a forage sample to a lab for analysis you need a 1/2″ cordless drill, forage probe, and a submission form from the lab of choice. Credit: Doug Mayo, UF/IFAS

To submit a hay sample to a lab for testing, you will need to fill a 1-quart Ziploc bag with ground hay from probing 7-10 random hay bales from each cutting or purchased lots. Samples of hay from the exterior of a bale will not provide an adequate representation of the hay you will be feeding.   You also don’t want to sample only a single bale.  Just as with soil testing, you want to try to get a representative sample from each cutting by taking core samples from bales produced from different parts of the field.  If you purchased the hay to be tested, just randomly sample from as many different bales as possible from each load.

Forage Testing

There are a number of both commercial and university forage laboratories that can be used to provide a summary of the nutritional quality of your hay.  The main things you need to know are the moisture content or dry matter (%DM), crude protein (CP), and the energy level reported as total digestible nutrients (TDN).  The University of Florida has a forage testing lab at the  Range Cattle Research and Education Center in Central Florida, that provides a basic test for $7/sample:  UF Forage Test Submission Form.  You can also send in hay samples through the Southeast Hay Contest that are analyzed by the University of Georgia’s Forage Lab:  SE Hay Contest Entry Form.  For $22 you get the forage analysis, a nitrate level test, and may win recognition at the Sun Belt Ag Expo as one of the top forage producers in the region.  The entry deadline is the third week in September each year.  If you want to use a commercial service, you can also submit samples to Waters Ag Lab in Camilla, GA:  Waters Feed Test Submission Form.  No matter which lab you select, the goal is find out what level of protein and energy is provided by the hay, so you can calculate the level of supplemental feed needed to complement it.

Forage Analysis Results

Most all forage labs provide sample analysis results in two formats:  as-sampled and dry-matter.  The as-sampled column would be useful for actual ration formulation of a total mixed ration.  In general though, you should focus on the dry-matter columns for comparisons between forages, and for basic supplementation calculations.  Moisture levels of forages are rarely identical, so removing the moisture gives a more accurate comparison.  For basic supplementation program development, you would use the highlighted dry-matter protein and energy values.  If you want to know more about the other information provided in a forage test, Understanding Your Forage Test Report is an article that was published a while back that more completely explains what each of the reported values represent in a standard forage test lab report.

sample hay test rport
The forage analysis report above is fairly typical quality for average quality Bahia or low quality Bermudagrass hay that was more mature because of frequent summer rains.  If you were going to feed this hay to lactating cows, or growing animals you would expect those animals to be deficient in both protein and energy.  These numbers mean very little, however, without also knowing the nutrient requirements of the animals you are feeding.

Decision Aids for Supplement Calculations

There are a number of commercial software options for livestock ration balancing, as well as private nutrition consultants that provide very precise calculations for complete ration balancing.  For feedlots and dairy operations, having very precise mixing recipes is essential.  For most cow-calf operations, however, determining the right amounts of supplements to provide is not that complicated.  Since you typically feed hay free-choice, all you really need to know is whether the hay is adequate or deficient in protein and energy.  Once you know that, a simple spreadsheet can be used to provide a good estimate of the type and amount of supplement required to maintain body weight.  Dr. Nicolas DiLorenzo, UF/IFAS Beef Specialist recently developed a very simple spread sheet called the UF HAY BALANCER that can be used to help cattle producers make decisions on supplement choices for mature cows on a free-choice hay diet.  The University of Georgia also has a decision aid spreadsheet called the UGA BASIC BALANCER  that is a little more complex, but it can be used to compare supplements for brood cows, bulls, heifers, and stockers, as well as providing some feedstuff cost comparisons.  Both of these are Microsoft Excel spreadsheets that come with information pre-loaded for use.  Commodity prices do fluctuate, so you may need to update the prices in the feed list provided.

Putting it All Together

In closing, I wanted to share an example of the end results of this process to demonstrate how the UF Hay Balancer can be used to help cattle producers become more precise with feeding supplements to compliment the hay they produce or purchase.  For this example lets assume that you must purchase hay to feed 25 cows for 30 days that will be in their 2nd month, or peak lactation.  This would be the time of most concern, because if you don’t supply adequate nutrition for these cows they will lose weight, reduce milk production, delay cycling and calve later for the following season. The following is a comparison of two types of hay at different prices, and a comparison of different supplement options.  You can purchase 850 pound Bahia hay for $43 per bale or 1,000 pound Bermudagrass bales for $67 per bale (based on Alabama Weekly Hay Report).  Which would be the best to purchase?

A comparison of two types of hay and the supplements needed to maintain cows at peak lactation. Source UF Hay Balancer, Alabama Weekly Hay Report and Alabama Weekly Feedstuff/Production Cost Report.

As you can see from this summary, this was not a simple scenario to answer.  The end result of this exercise was that even though the bahiagrass hay was lower in quality, the cheaper price compensated for the lack of quality.  The Bahia hay required a supplement that offered both protein and energy such as whole cottonseed, that can be purchased from local cotton gins, to balance the diet for these cows.  The Bermudagrass hay provided adequate protein, so an energy supplement such as corn or molasses was all that required for a balanced diet.  However, using 4 pounds/head/day of whole cottonseed, a rancher could feed his or her herd for 30 days cheaper with Bahia hay than with Bermudagrass hay, even though the supplement costs were $45 lower. If you had worked through this scenario with hay you have grown yourself, with similar production costs, the Bermudagrass hay would have been the better option.

If you would like assistance with forage testing, or balancing cattle herd supplementation, contact your local county extension agent.  They can help you develop a precision feeding program for your herd.

Dr. Ann Blount Named 2018 Woman of the Year in Agriculture

Dr. Ann Blount Named 2018 Woman of the Year in Agriculture

Ann Blount UF/IFAS Forage Breeder

Ann Blount, UF/IFAS Forage Specialist talks to cattle producers about the Legend oat variety that her team developed with rust resistance and increased yield. Credit: Doug Mayo, UF/IFAS

On September 19th, Commissioner of Agriculture Adam Putnam announced that Dr. Ann Blount has been named the 2018 Woman of the Year in Agriculture. Dr. Blount has dedicated her career to researching and implementing innovative techniques to improve fall forage production in Florida’s southern coastal areas. The award, now in its 34th year, recognizes women who have made outstanding contributions to Florida agriculture.

I’m honored to recognize Dr. Blount as the 2018 Woman of the Year in Agriculture. Throughout her career, Dr. Blount’s extensive research and techniques have incorporated Florida’s unique natural resources to bolster our agriculture industry,” said Commissioner Adam H. Putnam.

Dr. Blount earned a Bachelor of Science in Crop Ecology from Texas A&M University. She continued her education at the University of Florida, where she earned her master’s degree and Ph.D. in Plant Breeding and Genetics. Dr. Blount has since spearheaded research of breeding efforts on physiological aspects of fall forage, specifically: developing improved bahiagrass, evaluating new perennial peanut varieties, and enhancing small grains and ryegrasses.

Dr. Blount joined the University of Florida, Institute of Food and Agricultural Sciences in 1988, and she currently serves as an extension specialist and professor of forage breeding and genetics for the UF/IFAS North Florida Research and Education Center in Quincy. Dr. Blount uses a hand-on approach to train new and veteran agents to implement innovative foraging and help landowners test new livestock forages and wildlife blends to assess potential use on their properties.

Dr. Blount has made significant contributions to the agriculture industry, such as six plant patents and plant variety protections, as well as 76 cultivars and germplasm releases and forages. She has also written several educational publications, including: two book chapters, 198 refereed articles, 385 non-refereed articles, 22 national and international proceedings, 124 abstracts and 28 refereed Extension articles. Dr. Blount’s impressive forage breeding program and UF/IFAS Extension activities have improved the production and efficiency of thousands of acres of Florida’s forage varieties.

Ann Blount, UF/IFAS Forage Specialist developed a Pensacola cultivar called UF Riata that has les daylength sensitivity, so it has a longer growing season than other Bahia varieties. Photo credit: Marisol Amador, UF/IFAS

The Woman of the Year in Agriculture award is sponsored by the Florida Department of Agriculture and Consumer Services and the Florida State Fair Authority. The award will be presented to Dr. Blount during the 2019 Florida State Fair, in Tampa.

Editors Note:  Dr. Blount has invested the last 30 years of her life educating livestock producers, county extension agents, and researchers about forage varieties and and forage management. Use the following email link if you would like to send her congratulations on this tremendous honor:  Ann Blount, UF/IFAS Forage Specialist.

Pest Identification is Essential and Sometimes Surprising

Pest Identification is Essential and Sometimes Surprising

Throughout my 22 year history as an Extension Agent, I have been the first responder for all sorts of strange things farmers, ranchers, and landowners encounter.  This is one of the critical roles county agents play all over the country.  If you see something odd or unusual, whether it is a new weed, insect or disease, your county agent should be one of the first people you contact to get information.  It is very possible that if you find something you have never seen before, others may not have not seen it either.  County agents are connected to a vast network of experts and identification labs that can help figure out what those strange new things are. Because of the ports, huge numbers of visitors, and tropical storms, new pests and diseases show up in Florida on a regular basis.  It is very important to have new pests identified, before they have the opportunity to spread.

Most of the time the plants, bugs, and diseases agents have identified by experts are harmful in some way to the crops we grow.  Whether it is toxic weeds in pastures, insects feeding on plants, or diseases in crops, the first thing you need to know is, “What is it?” Once the issue is identified, most of the time there are some type of control options available.  Sometimes, however, things are not at all what you expect.  Such was the case this summer as four types of plant pests were identified that turned out to be harmless, and in some cases were actually beneficial.

Specimen #1

Aschersonia aleyrodis on Satsuma is a fungus that feeds on whitefly nymphs. Photo credit: Doug Mayo, UF/IFAS

A citrus grower thought that his satsuma trees were under serious attack.  White flies were already an issue as noted by the sooty mold growing on the leaves, and then this terrible scale that he had never seen was all over the undersides of the leaves of the trees.  While from a distance this looks much like a harmful scale insect, it turned out to be a beneficial fungus that destroys whitefly nymphs!

Dr. Xavier Martini, UF/IFAS Entomologist in Quincy shared the following information:

What you have is not scale, it is citrus whitefly nymphs that have been attacked by an entomopathogenic fungi called Aschersonia aleyrodis. It is very good to have this fungus, because it helps control the whitefly population.

You can read about this in the Featured Creature article entitled: Citrus WhiteflyScroll down to the section called: Parasitic fungi for more details.

Aschersonia aleyrodis fungus on the underside of a satsuma leaf looks terrible, but it was actually making a bad situation better by reducing the whitefly population on young satsuma trees. Photo credit: Doug Mayo, UF/IFAS.

Specimen #2

The beneficial fungus Beauveria bassiana is a natural enemy of kudzu bugs on soybeans. Photo credit: Doug Mayo, UF/IFAS.

A soybean grower saw something he had never noticed before.  A white mold was growing in spots all over the stems of soybean plants in a field.  This is where you have to be careful.  Soybeans can get white mold, which is caused by the fungus Sclerotinia sclerotiorum.  If you do a google search for Soybean white mold, you will find pictures that look somewhat similar.  Upon closer inspection, at the NFREC Plant Pathology Lab, in Quincy,  the fungus was actually Beauveria bassiana which is a biological control of kudzu bugs.  The white spots in the photos are actually dead or dying kudzu bugs, and the fungus was growing on the insects, not the soybean stalks.  You can read more about this beneficial fungus at: Kudzu bugs’ decline is attributed to two factors.

The white spots are beneficial fungus Beauveria bassiana that are attacking kudzu bugs not the soybean stalks. Photo credit: Doug Mayo, UF/IFAS

Specimen #3

Slime mold found growing on a centipede lawn. Photo credit: Doug Mayo, UF/IFAS

A landowner noticed this really strange growth on her centipede lawn.  It looks hideous and destructive.  In truth, it was a relatively harmless plasmodial slime mold, named Fuligo septica.

Larry Williams, UF/IFAS Okaloosa Horticulture Agent shared the following information:

Slime molds mostly function as saprophytes, feeding on and breaking down organic matter. It should not cause any permanent problems or major damage to the lawn. One such slime mold is commonly referred to as “dog vomit” slime mold.

Here is a link to an article on slime molds that pop up on lawns, in mulch, and damp areas under trees with high organic matter: Those Mysterious Molds

Slime mold growing on the moist organic matter in a Jackson County Lawn. Photo credit: Doug Mayo, UF/IFAS.

Oklahoma State University’s diagnostic labs had gotten so may calls from concerned homeowners that they developed a YouTube video on slime molds:

Specimen 4

Harmless slime mold growing on centipede lawn after multiple rainy days. Photo credit: Doug Mayo

A similar scenario was seen on a centipede lawn at a county building in Jackson County.  This slime mold is commonly found on lawns and pasture grasses during extended rainy periods in Florida. While it looks like a serious disease, it is really just another plasmodium species that feeds on decaying organic matter.  As with the large slime mold in specimen 3, what you are seeing is actually the spore masses that will generate more slime molds when conditions are favorable again for growth.  You can knock these off with a garden hose, if you want to, but they disappear almost as fast as they form.  No real harm is done to the grass that is just serving as a platform for slime mold reproduction.

Read more about it in this article written by Matt Orwatt, UF/IFAS Washington Horticulture Agent: Frequent Rains Induce Slime Mold in Panhandle Lawns

Summary

Most of the time, when you see something that does not look normal it is a bad thing, such as weeds, fungal diseases, or damaging insects. But before you spend money on a control, it is really important to have a positive identification of the pest.  Not everything unusual is harmful.  Modern pesticides have become very target specific, so it is vital to first find out what this new thing is before you spend money trying to control it.  So the next time you see something alarming or strange in your crop, pasture, or landscape, contact your local county agent, so you can find out for certain what you are dealing with, and get some science-based advice on a plan of action, if one is needed.

2018 Sunbelt Ag Expo Offers Innovation, Technology, & Education – October 16-18

2018 Sunbelt Ag Expo Offers Innovation, Technology, & Education – October 16-18

 

When you visit the Sunbelt Ag Expo in October, make sure you visit the UF/IFAS Barn to visit with members of the Panhandle Ag Team about services available from the Extension Service for farmers, and enjoy some free orange juice and peanuts while you are there.

Becca Turner, Sunbelt Ag Expo

The Sunbelt Agricultural Exposition will celebrate its 41st Anniversary show October 16-18, 2018. Over 1,200 exhibitors will display and demonstrate products and welcome thousands of visitors to the 100 acre show site.

Crowned as North America’s Premier Farm Show ® and the largest Farm Show in America with field demonstrations, the Sunbelt Ag Expo brings together all segments of agribusiness including farmers, educators, policy-makers, ag-enthusiasts and families.  All attending the show will see the latest innovation and technology that the agriculture industry has to offer.

Education is the key component of the show with over 300 seminars and demonstrations offered over the 3-day event.  These seminars and demonstrations are taught in exhibit areas for beef, dairy, poultry, forestry, pond management, equine and cattle management.  Farmers and ranchers attending gain beneficial knowledge on the latest in cutting edge techniques from industry leaders and university specialists.  The Expo works with 21 different education sponsors to host a strong seminar and demo schedule.  These education sponsors include major universities and colleges with six of these having permanent exhibit buildings on-site.   New this year, the Expo will feature Youth Educational Challenges for 6th-12th graders as a competitive and fun opportunity for students to demonstrate their knowledge in six different content areas.

The Hoss Tools Sustainable Living Center focuses on topics for the specialty gardener. If you are interested in learning how to garden year round, visit this section.  Greg Key, owner of Hoss Tools will offer a bounty of information on gardening tips, tools and more in the demonstration garden.

A crowd pleaser is the 600-acre research farm’s field demonstrations. These demos showcase harvesting and tillage equipment for cotton, peanuts, corn, soybeans and hay. As in the past, cotton will be harvested during the show!  In addition, hay demos will include all facets of hay harvesting from cutting to baling and will provide visitors the opportunity to see 80 different types of hay harvesting equipment run in a true farm setting.

Expo is honored to have Kentucky as the 2018 Spotlight State. The Kentucky Spotlight State Committee has put together an all-encompassing exhibit themed “Kentucky Start to finish: Pioneering Innovation.”  The exhibit will also feature a special section on Agricultural Safety, including seminars and demonstrations.

There’s never a dull moment during the 3-day show and attendees will find there is something for the entire family.  There is a daily rolling Antique Tractor Parade, the American Grand Finals Stock Dog Trials (the largest field of competition in recent Expo history), and even a Cow Milking Contest. Add in rural lifestyle fun, truck, tractor and ATV test drives, and the venue is perfect for rural enthusiasts.

Chip Blalock, Show Director, says, “The Sunbelt Expo is an unbelievable showcase of rural living blanketed with agriculture’s newest ideas and technologies. Its 3-days of fun, education and dreaming about agriculture’s future as we team together to feed, clothe and house a growing population around the world.”

The Sunbelt Ag Expo is open Tuesday through Thursday, October 16-18, from 8:30 AM to 5:00 (T,W) and 4:00 (Th).  Admission at the gate is $10 per person per day. Advanced and discount tickets can be purchased online.  The Show site is four miles southeast of Moultrie, GA on Hwy 133. For more information, go to the show website at www.sunbeltexpo.com.

Managing Carbohydrates from Grazed Pastures for Horses with Metabolic Disorders

Managing Carbohydrates from Grazed Pastures for Horses with Metabolic Disorders

Florida pasture grasses contain lower sugar content than in other parts of the country.  Even so, pasture access might need to be limited to help control calorie intake. Limiting grazing time may cause some horses to overeat when they are turned out, so consider using a grazing muzzle or feeding horses some hay before turnout to slow intake. Photo Credit: Amy Parker

Marcelo Wallau, Lori Warren, Carissa Wickens, Jose Dubeux and Doug Mayo, UF/IFAS Extension

As extension specialists, we are often asked about nonstructural carbohydrates (NSC) in forages and the potential risks grazing poses to insulin-resistant horses. Numerous blog posts and reports have been written on the topic, alarming horse owners everywhere. However, for horses managed on pastures in Florida, is over-consumption of NSC actually a problem?

Nonstructural carbohydrates are a form of energy reserve in plants, and include simple sugars, fructan and starch. The major source of NSC in a horse’s diet is usually from grains, which range from 60 to 85% starch, and commercial concentrate feeds, frequently containing molasses and other ingredients to increase palatability. In forages, the concentration of NSC depends on plant type, management, and season of the year, typically highest in the spring and fall when growth is slow and seedheads are present. Temperate climate forages (e.g. orchard, timothy, or our cool-season species here in Florida, such as oats, ryegrass and clovers) tend to have more NSC (around 16%) than our warm summer grasses (around 8%), such as bahiagrass and bermudagrass.

Several factors are known to contribute to the development of metabolic disorders in horses, including genetics (Morgans, Arabians, ponies, and Spanish breeds are most affected), overfeeding (of anything, not just grain), overweight/obese animals (those prone to being “easy keepers”), and lack of exercise. The most common metabolic disorders are Cushing’s Disease (pituitary pars intermedia dysfunction) usually associated with aging, and equine metabolic syndrome (resulting from the genetic and management factors described above). What they share in common is insulin resistance (similar to, but not exactly like Type 2 diabetes in humans), making them susceptible to secondary diseases such as laminitis or founder. These horses tend to be more sensitive to sugar, starch, and fructan in the diet. Not all horses have these problems. In fact, the frequency of laminitis in horses is low, ranging from 2 to 5% (Kane et al., 2000) and normally is related to horses which have a predisposition, either genetic or acquired from sub-optimal management practices.

For horses with metabolic disease or a history of laminitis, feeding diets with less than 10% NSC is recommended. Reducing NSC in the diet can be accomplished by cutting back on grain consumption and any other sort of treat containing high sugar levels. For lush pastures containing cool-season forages, there may be a need for limiting pasture access and timing turnout to occur in the period from late night to early morning when sugar and fructan levels in the grass will be at their lowest. For pastures containing Florida’s warm-season forages, NSC is less of a problem, but pasture access might need to be limited to help control calorie intake. Note that limiting grazing time may cause some horses to overeat when they are turned out, so consider using a grazing muzzle or feeding horses some hay before turnout to slow intake. These approaches combined with monitoring horses’ body condition and weight will allow owners and farm managers to safely utilize forages in feeding horses diagnosed with metabolic disorders.

Although the incidence of insulin-resistance is relatively low, many people worry about the health of their horses housed on pasture. What is important, however, is to provide a balanced diet which is in accordance with the category and use of the animal: growing, lactating and active horses (working or athlete) need a more nutrient dense diet to meet their requirements, while most leisure horses’ nutrient requirements can be met primarily by forages and a vitamin-mineral supplement. Nevertheless, the low NSC content of most forages in Florida represent a low risk, even for horses with pre-disposition for metabolic disorders

 

The following are some additional references and suggestions for further reading on this topic:

  • Kronfeld DS, Harris PA. 2003. Equine grain-associated disorders (EGAD). Compendium on continuing education for the practising veterinarian. 25:974–83.
  • Lameness and laminitis in U.S. horses. 2000. USDA: APHIS: VA, CEAH, National Animal Health Monitoring System. Fort Collins,CO. Contract No.:N318.0400.
  • Kane AJ, Traub-Dargatz J, Losinger WC, Garber LP. 2000. The occurrence and causes of lameness and laminitis in the U.S. horse population. San Antonio TX: Proceedings of the 46th AAEP; Nov 26–29; p.277–280.
  • Longland, A.C., and B.M. Byrd. 2006. Pasture Nonstructural Carbohydrates and Equine Laminitis. J. Nutr. 136(7): 2099S–2102S
  • Wickens, C. 2016. Monitoring Body Condition in Horses: Helpful Smart Phone Apps for Horse Owners.