Screwworm Outbreak and the Use of Insect-Parasite Control Products

The current screwworm outbreak can likely be contained and pushed back to Panama through sterile fly releases, much like the successful eradication effort of the 1960s. That program remains one of the most effective biological control efforts ever carried out. While today’s infestation differs in several ways, the same approach should still lead to successful control.

One important change since the earlier infestation problem is the availability of more effective anthelmintics and insecticides for treating and perhaps preventing infected animals. In the past, “worm dope” worked mainly by direct contact with the worm and often required repeated applications. Today, treatment is generally closer to a single application followed by careful observation. The greater challenge is finding and identifying infected animals in the first place.

These modern products should be used carefully, because overuse may ultimately cause more long-term damage than the screwworm itself. Excessive mass preventive treatment can drive parasite resistance and leave livestock and wildlife more vulnerable to internal parasites, flies, lice, ticks, and other pests. Over time, parasites can become harder to control, while animals may lose some of their natural genetic resistance to infection-infestation. This risk applies not only to screwworms, but also to many other parasites and insect pests.

Adding feed-grade ivermectin and other very effective products to a wildlife-livestock feeding program may seem like an easy solution. Some argue that wildlife value justifies the cost, but over time this practice could create a net loss for both wildlife and livestock operations.

The time has passed for trying to “kill all the bad guys”—insects, bacteria, nematodes, viruses, and others—at the expense of beneficial organisms. In fact, when studied closely many of the ‘bad guys’ have a place in Natures realm of treasures. (When referring to Nature with a capital N, I am referring to the Lord’s work.) Many grazers have found that routine worming of cattle and sheep, along with treatments for flies, grubs, and lice, is not always needed or even necessary within an effective controlled grazing program. Avoiding unnecessary treatments can improve soil and animal health while helping restore the natural biota that once characterized the New World and its rangelands. Not to mention the cost savings of not applying those added controls, thinking through and applying the ‘whole’ to the ranching program is essential.

Management decisions should be based not only on current conditions, but also on long-term consequences.

THE BETTER IT GETS, THE FASTER IT GETS BETTER

Recently controlled White Brush – Mesquite. Southwest Bristle Grass response has been amazing. Hard to visualize from picture, but livestock and wildlife will have a difficult time getting to it as it is tucked tightly within the dead ‘it is hoped’ white brush. How long it will take for dead white brush to deteriorate is subject to observation.

Livestock Management Is Essential to Rangeland Improvement

For producers and rangeland managers pursuing healthier rangelands and a profitable ranching operation, livestock can be one of the most valuable reclamation tools available. The impact livestock create on the land remains as important today as the influence once provided by large herds of ungulates, such as buffalo, elk, antelope, and deer, before humans became more dominant in the landscape. Recognizing that many degraded rangelands result from the loss of concentrated animal impact followed by adequate rest and recovery is essential to beginning the restoration process.

Controlled livestock use creates beneficial disturbance on rangeland, followed by planned rest and recovery before animals return to the area. This approach has proven effective for improving land health while supporting the rancher’s economic viability. Without making grazing management a consistent foundation before applying other reclamation practices, the cycle of degradation is unlikely to be broken without repeated use of costly tools such as brush management, seeding, and erosion-control measures. These tools may still be needed to accelerate improvement, but sound grazing management is what makes long-term reclamation effective.

The Better it Gets, The Faster it Gets Better

Eastern Gama 24 days after grazing. Take note of the Johnson Grass at bottom of picture it was grazed less than the EG and still is much smaller than the regrown EG.

From Dawn’s Early Light to Twilight’s Last Gleaming

As our nation approaches its 250th birthday, every citizen should reflect on the extraordinary blessings we have been given: our Constitution, our people, and our natural resources. Those who care for the land carry a profound responsibility to steward the Lord’s carefully created rangelands and support nature’s ongoing work of maintaining balance. Thanks to our Constitution, each land steward has the freedom to decide how to participate in preserving this work for future generations.

We have learned much about rangelands through universities, government resources, and, importantly, the experience of land managers themselves. Understanding how to help nature reach its full potential means working with natural processes, asking why conditions exist, and considering more than manipulating the land to a preconceived state. By seeking those answers and taking proactive steps to support nature’s work, land stewards can strengthen both the health of the land and the success of their operations. Healthy rangelands relate closely with healthy pocketbooks.

The age-old issue of: Are we working toward the sunset or ending of an era, or the beginning of a new age even more productive than the past? Whether politically or at the level of the individual rangeland manager, let’s go with the latter.

                            THE BETTER IT GETS, THE FASTER IT GETS BETTER

Dawns Early Light

Twilights Last Gleaming

Grass Growth and Rangeland Recovery: Scientific Insights and Management Practices

Understanding how a grass plant grows and reproduces can be a very complex (scientific) learning process. The below link will offer interesting, yet tedious reading (For us simple ranchmen) that some grass managers might find productive in their understanding of ‘why’ some grazing-management programs are more effective than others.

One of the highlights from the article is: “Perennial grasses can produce by both buds and seed, although more than 99 percent of new tiller growth comes from the bud bank. Seed life spans are short-lived and do not extend beyond 1 year. However, buds are long-lived and have a potential life that may exceed 5 years. Since bud life varies among grass species, current research efforts are focused on determining which species have the longer living buds. Vegetative buds respond quickly to environmental changes like rain, fire, and grazing.” It should be added that disturbance of the grass plant, including grazing, trampling, mechanical, fire and even the destruction of moribund grass plants caused by desert termites’ can all effect the simulation of new growth nodes. (Nature has developed numerous recovery process over millennia)

While I disagree with the statement that the seed life span is only one-year. It has been my experience that given the opportunity, seed can survive for an extremely long time and when given the opportunity (an effective graze-rest program) dormmate seed can provide excellent rangeland recovery. Albeit over an extended period. (Numerous years of application of that effective management program.)

A second highlight emphasized by the article is: “Current research has shown that perennial grasses reproduce by vegetative processes through asexual reproduction. Seed contribution to maintain an established grassland is less than 1 percent of the total reproductive effort.”

What can be gleaned form this article is that grazing-management programs should be designed to enhance bud simulation of the grass plant, seeding will take care of itself over time. (Patience is key here)

 It is all about stimulating growth buds to promote rangeland recovery and after stimulation giving the plant the opportunity (REST) to reach its genetic potential.

Photo shows a formerly erosive site that has almost total recovery form loss of soil. Vine Mesquite Grass is an excellent plant to quickly cover bare areas, especially when extra rain water is provided from runoff. After it is established, runoff is slowed to the point of putting the water into the ground. Greatly enhancing soil health.

THE BETTER IT GETS, THE FASTER IT GETS BETTER

Recovery after an extended dry spell is an exciting event.

After approaching four years of extended drought and having exhausted all drought management options, total liquidation of the livestock was imminent. Thankfully the rains began to fall in mid-April, not large amounts .87” the largest rain event, but consistent small rains continuing from April to the current date. Along with relatively cool spring temperature’s, excellent growth and recovery of the rangeland has been achieved. (Seldom does this combination of rains and cool temps occur even during high rainfall times.) Past graze-rest adaptive grazing is paying excellent benefits as the photo below shows.

Big Blue (Center of picture) and Indian Grass (Upper center, just above Big Blue) are showing excellent recovery even though grazed to the ground during the dry spell. Some would say to never graze that short and I would concur, but under extended drought conditions that seems to occur often. Obviously, the root systems of both plants were healthy enough to recover quickly under those extenuating circumstances. Perhaps the rocky terrain helped, as the livestock could not graze so close as to ‘grub’ the roots below the surface. Of important note Sideoats, Texas Cup, Green Sprangle Top and Silver Bluestem are doing well, but they were not grazed to the ground as the highly palatable Indian and Big Blue were.

The Better It Gets, The Fast It Gets Better

Rangeland Drought Comparison: 1950s vs Current Situation

A veteran producer recently asked me: Is the current drought worse than the one in the 1950’s? My quick response was that we hadn’t seen anything yet. As in the early ‘50s drought, the rain gauge at the Bobs Creek headquarters (My home) had an average rainfall of just under 6” per year for a four-year period and the drought lasted from 6 to 7 years depending on the area.

Then it occurred to me that the rangeland was in much better condition prior to the ‘50s drought than it is today. Remember the story of a long-time rancher telling me when I was in my 20’s (late 1970’s) that: “With each passing dry spell one can never run as many livestock as he could prior to that dry spell.” Loss of grazing capacity has dwindled from documented grazing of 100 plus animal units per section in 1880 to 15 -10 and even less animals per section today on the same rangeland. With that loss of grass density, root structure in the soil (sod if you will) loss of topsoil due to erosion, soil health decline and density of brush cover increase. The limited moisture that has fallen during this dry period has considerably less opportunity to produce new growth providing all of the benefits healthy growing plants provide. (5.49” for the year at his point in 2024 at my house)

So perhaps on rangelands that are not under an effective grazing management program this drought is possibly worse than the 1950’s event. Many to the north and east of my area have had a tremendous rainfall year and recovered well, but even in those areas I suspect it is noticeable which operations have practiced a good grazing management program prior to and during the dry conditions before the rains came.

Just a few miles to the west of me it is obvious that the desert is steadily encroaching to the east and without a dramatic change in grazing technique this trend will continue. The knowledge is out there, and the time is here to do something about it.

The photo below is of some native-unseeded Switch grass that has survived from many years of abuse (heavy brush and very forbidding-rough terrain has protected these surviving plants) and under the current Graze-Rest-Graze-Rest program is making a strong recovery even without a direct water source. (Most consider Switch grass to be dependent on a close source of water, springs-sub irrigated-intermittent standing water.) Think back to the beginning of the cattle industry in West Texas when Switch grass and other tall grasses were healthy and numerous, this ‘little’ dry spell would have a much different affect and would have little consequence to the long-range health of the plants with a healthy rangeland in place before the droughts beginning.

The Better it Gets the Faster it gets Better

Rainfall and Grazing Management are Both Essential

Adequate rainfall is critical to any grazing program. The following photos depict this with great emphasis. All taken within a few days of each other, spanning some 30 miles east to west. All three places have essentially the same grazing program, long rest (250 to 300 days) short graze period determined by number of pastures within the grazing unit from 23 in the latter picture to 12 pastures in the first picture. Certainly not mob grazing, but a single herd grazing program adapted to the managers goals and overall management plan. The only difference in the grazing units is primarily the annual rainfall, which within the 30 miles is dramatic. The extended drought of three years going into the fourth, has delt the management team many serious decisions, that at many times have felt very wrong, but essential within the long-term plan of both the rangeland health and economic health of the ranching operation.

It is obvious that the first place pictured has recovered very well from the drought conditions that were prevalent just a couple of months ago. That rapid recovery is, no doubt, the result of the dedicated-on-going grazing management program. When looking at the second picture the limited rainfall this year is showing great promise, as the fresh growth shows numerous surviving grass plants that with ‘a little’ more rainfall can quickly move the rangeland condition forward to a fully recovered state. Going a bit further west, the third picture shows a struggling rangeland. Yes, it is probably grazed too short for most managers eyes but still has good litter cover and remaining plants that will recover quickly once the rains come in larger volume. An old-time rancher once told me that “With each passing dry spell (drought) one can never run as much livestock as he could prior to that dry spell. He was correct until it was figured out that grazing management, utilizing a well-planned and initiated graze-rest-graze-rest program was essential. Now recovery after drought does not have to be so devastating.

Sure, hope the predictions of the upcoming La Nina event aren’t as severe as predicted, otherwise the grazing units of the last two pictures will be temporarily abandoned until adequate rains do come. Of course, here is proof that El Nino doesn’t always produce rain. As I like to say, “It depends on where you are standing.”

THE BETTER IT GETS, THE FASTER IT GETS BETTER

Effective Rainfall

The small rainfall events throughout the year are many times of too little volume to have a positive effect on the rangeland, but how small is that amount?

There are numerous factors that have a direct bearing on whether rainfall will be effective in promoting growth of plants. Quantity of rain, temperature, humidity, wind, and timing of the next rainfall event are all critical to the effectiveness of the Lord’s gift of moisture. The rancher-manager has no influence or control of any of those factors, thus he should not lose any sleep from worrying over those things. (Yet most all of us do so.) However, he does have control over a key factor, that being the health and cover of the soil he is managing. Or perhaps more simply stated, rangeland health. When the rangeland is healthy those small rainfall events become a valuable part of the ecosystem’s ability to move forward. Sustaining the rancher until the next rain.

The exciting thing is there are many ways of achieving the desired rangeland health, arguably some more effective than others and the type grazing program chosen is critical. It is up to the manager to evaluate goals, both long term and short term, in selecting the type and intensity of the grazing program. Within the more brittle-dryer environments achieving that healthy rangeland is dependent on grazing and rest as they are key ingredients to that successful program. Those two factors are controlled by animal impact and recovery from that impact. Leave out either one of those two and the grazing program and rangeland health improvement will most likely be an undesirable result.

The photo below is an excellent example of achieving the healthy rangeland goal and what can happen without an effective grazing program, but remember it takes time to accomplish. Those wishing for instant success will be disappointed.

It is up to the rancher to determine how he wants his rangeland to look.

Drought is Taking its Toll.

Drought is affecting even the mesquites. This photo appears to be a bad spray job from the past but has never been sprayed and certainly will not be this year. The trees are very stressed from lack of moisture for the last two years. The rangeland grasses are a depressing sight, as the desert termites have finished off the bulk of the old moribund plants. (It is my opinion that termites seldom attack healthy grass plants, only those that are decaying from age and lack of use.) A good chance of rain shows to be in the forecast late this week, sure hope it is a GOOD PREDICTION. Photo was taken May 4, 2023

The next photo was taken yesterday May 6 and shows how the creek bottom is struggling to green up and is actually growing some forage. Note the upper portion of the creek is very dry. This is an awesome statement as to the effectiveness of a productive graze rest program over the last several years. The bottoms of the creeks and washes are the first to recover from continuous grazing and begins the process of recovery from erosion of our precious soil, even during a drought.

THE BETTER IT GETS THE FASTER IT GETS BETTER, BUT ADEQUATE RAINFALL IS ALWAYS A KEY INGREDIENT REGARDLESS OF THE GRAZING PROGRAM.

Effective Rainfall

As the ongoing dry spell continues over a wide area. The question of ‘How much rain does it take to be effective?’ becomes an even more relative issue than during higher rainfall periods. The answer lies within numerous ‘What ifs?’ most of which the rangeland manager has no control over. Humidity, wind, cloud cover, temperature and length of time until the next rain event are all things that the manager has no control over and can’t do anything to change. But the most important of all variables that the manager does have control over are the health of the plants on the ground, the density of those plants and the amount of litter covering the ground. (Litter being, dead plant material that has fallen on the soil and is in a state of decay.)

Some managers would say ‘It is dry and has been for a long time, there is no way I can improve on those things.’ Preparation for the ongoing drought began during the last good growing conditions and continues even during the dry spell, by proper grazing rate and giving adequate recovery time for those plants by removing the animals from the pasture for predetermined periods of time. This preparation does not happen by chance alone, it takes planning and diligence of initiation. Then replanning after observing livestock, plant recovery, economic conditions, and rainfall, this is called ‘proper grazing management’. When this ‘plan’ is put in place density of cover -over time- will approach 100% coverage, healthy root systems provide healthy soils that retain moisture and ground litter covers the soil lessoning the evaporation rate caused by all of those variables that the manager has no control over.

The current drought is hurting good managers and poor managers alike. Those that have prepared for current conditions are faring much better than others, even to the point of growing a little forage where good ground cover-healthy soils are prevalent.

THE BETTER IT GETS, THE FASTER IT GETS BETTER

Take note that this photo is along a formerly erosive creek bank. Recovery of creek areas is one of the first places an effective grazing program influences.