Tall Fescue Endophyte-Animal Relations: Cutting Edge Research and Implications

Many cattle producers in Kentucky manage tall fescue as their perennial forage base. Tall fescue has served cow-calf producers well because of its productivity and persistence with minimal management. Like most things, however, “you must take some bad with the good.” The agronomic traits we like so much about tall fescue can be attributed to a fungal endophyte that infects most fescue plants. Without the endophyte, the grass is no longer productive and tolerant of environmental stresses (dry weather, low fertility, and grazing). Unfortunately, the endophyte also produces ergot alkaloids that cause a toxicosis in cattle, which costs the U.S. Beef Industry approximately 1 billion dollars per year in lost production. Signs of toxicosis are: 1) severe heat stress in moderate to warm air temperatures, 2) maintaining rough hair coats during the summer, 3) fescue foot (loss of tail switches, ear tip, or gangrenous condition of the lower limbs), 4) poor weight gain of calves and poor body condition of cows. Ergot alkaloids cause constricted blood flow to peripheral tissues to incapacitate the animal’s ability to regulate body temperature. The alkaloids also reduce the amount of prolactin in blood circulation, which can reduce milk yields and are also thought to adversely affect other functions (hair coat growth, growth and development)

Stocking Decisions: They Make or Break You

Decisions on species and variety of forage to plant and manage are economically critical because it establishes the potential to meet a particular production goal. However, the stocking rate used to graze these forages is more critical because it ultimately determines if a targeted level of production is reached. Most cattlemen aim for a stocking rate that provides maximum economic return, but it should be emphasized that an economically optimum stocking rate is one that potentially provides sustained economic return. It is obvious that dollar return is not maximized if excessive heavy grazing results in costly pasture renovation, ranging from 15.00 to 120.00 dollars/acre. Therefore, the challenge is to set stocking rates that meet product goals, adjust stocking rates during adverse weather patterns, and follow pasture management practices that match the intensity that pastures are grazed (heavy grazing requires higher inputs of management!). This paper will discuss factors in setting stocking rates (species/varieties of forages, stocking rate effects on weight gain, climate and forage growth distribution), and having contingency plans for adjusting stocking rates in response to dry weather patterns

Forage Systems for Minimizing Hay and Concentrate Feed Needs

Cattlemen typically simplify their pasture management by relying on one or two forages that are well adapted and persist under their targeted levels of management and production. The 5.5 million acres of Kentucky-31 tall fescue in Kentucky is a strong indication how producers in the state rely on the cool-season perennial grass, sometimes in mixture with red or white clover, to meet their grazing needs. An advantage of this approach is that fertilization and grazing management is based on a single growth distribution and set of fertilizer needs. Disadvantages are that yield, growth distribution, and quality of forage may not meet targeted levels of cattle production, and that hay and costly concentrate supplements will be needed during lengthy periods of dormancy and inactive growth. Furthermore, dependence on endophyte-infected tall fescue as the sole pasture forage greatly increases vulnerabilities to fescue toxicosis, fescue foot, and fat necrosis, maladies caused by ergot alkaloids contained in endophyte-infected tall fescue

Grazing Management Options for Maintaining Optimum Pasture Composition and Utilization

Global demand for meat and dairy products will continue to increase over the 21st century, however, the global forage-based livestock industry will be challenged in meeting production goals with minimal impact of the environment. Sustainable production of grazing livestock will depend on the use of carefully planned grazing management strategies. Development of a grazing management plan involves making two decisions: determining the livestock density at which pastures are stocked and settling on the method used to graze the pastures. Stocking rate indirectly affects output per animal and per hectare through its direct effect on forage mass and pasture composition. A grazing method should be implemented to maintain the sustainability of a stocking rate that is set to meet a production goal. This review will emphasize the factors to consider in setting a stocking rate and in the selection and design of a grazing method that improves the sustainability of the stocking rate through optimum pasture utilization

What Fescue Toxicosis Is Really Doing Inside Your Animals

Eighty years have passed since Dr. F.N. Fergus collected seed of tall fescue from that hillside at the Suiter Farm in Menifee County that led to the commercial release of the cultivar ‘Kentucky 31’. Fescue provided an opportunity to replace the briar and weed patches that dominated the rocky hillsides of Kentucky with productive forage. Plantings of tall fescue were numerous in the state during the 1940s and 1950s, and its hardiness and adaptability resulted in the grass spreading over much of the middle and upper southeastern USA, eventually covering a region we now call the “fescue belt”. It did not take long before cattle producers complained of severe lameness and sloughing of hoofs, tails, and ear tips during cold weather, and poor weight gain and thriftiness during warm weather conditions. Reductions in calving rates and milk production were also of concern. Horse producers also identified serious issues with grazing pregnant mares (prolonged gestation, retained placentas, stillborns, and poor milk production) on Kentucky 31 tall fescue. Causes of the poor performance of cattle were not determined until researchers at the University of Georgia and Auburn University discovered in the early 1970’s that tall fescue was host to a fungal endophyte. Ergot alkaloids produced by the endophyte were soon identified as the causal factors of the symptoms of fescue toxicosis

Soy Hulls: More Than Just a Feed Supplement

There is approximately 35 million acres of tall fescue in the USA, with most of this acreage being utilized in hay meadows and grazed pastures in a region between the temperate northeast and subtropical southeast and commonly referred to as the Fescue Belt. Popularity of the grass is due to its productivity, persistence, and low cost of management. Unfortunately, a fungal endophyte that infects most plants of tall fescue produces ergot alkaloid toxins that cause a toxicosis in cattle and other grazing livestock. Fescue toxicosis may reduce reproductive performance of cow herds and weaning weights, and reduce post-weaning weight gain and overall thriftiness. Cattle inflicted with toxicosis have elevated body temperatures, maintain rough hair coats during the summer, and have reduced blood concentrations of prolactin (hormone required for milk production, and growth and development processes). Consequently, fescue toxicosis is estimated to cost the U.S. beef industry approximately 1 billion dollars each year

Promote Growth and Animal Health with Isoflavones in Red Clover and Other Legumes

The field of nutrition has continued to expand since the 18th century. We once thought that the only important components in foods and feeds were proteins, carbohydrates, fats and salts. Evidence was slowly pieced together to show that certain minor components were essential for life, and the vitamins were discovered. Like the doctors that first suspected vitamins were essential, some cattlemen have long noted advantages in animal performance and health on certain diets in ways that cannot be explained by a simple forage analysis. Today, we are learning the roles that phenolic plant secondary metabolites, sometimes called polyphenols, play in both human and animal nutrition. In particular, our USDA-ARS unit is conducting research on a group of polyphenols called isoflavones, which are found in clovers and other legumes. Isoflavones prevent damage by ultraviolet light in plants. They are also a chemical defense against infection by bacteria and fungi. It has long been recognized that isoflavones also have biological effects on animals that consume the plants. They are antioxidants and estrogens. The estrogenic effects of legumes, well known in ruminants, are due to isoflavones. Much of the early research on isoflavones in ruminant diets is about their negative effects on reproduction. However, new research is showing there are benefits to cattle that consume isoflavones. In this article, we will explore two recently discovered benefits of isoflavones: 1) improved dietary nitrogen efficiency, and 2) improved blood flow during fescue toxicosis

The interaction between policy and education using stroke as an example

This paper discusses the interaction between healthcare policy at the European, UK and Scottish levels and the funding of education that underpins specific health policy priorities. Stroke is used throughout to illustrate the relationship between a designated European and UK health priority and the translation of that priority into clinical delivery. The necessity to build a responsive and sustainable culture to address the healthcare education that underpins changing healthcare policies is emphasized

Sources of Error for Ultrasonic Measurements of Steer Compositional Traits in Grazing Studies

Real-time ultrasound technology has potential use for measuring compositional traits in grazing studies. Sources of error with this application must be identified for designing experiments with adequate precision to determine treatment effects. A study was conducted to evaluate breed type (Angus x Brahman, AB; Simmental x [Angus x Brahman], SAB; Simmental x [Brahman x Hereford], SBH), initial body weight, and initial ultrasonic measures as sources of experimental error in the analyses of external fat (EF) depths and longissimus dorsi (ribeye) areas (LDA). Steers were ultrasonically scanned at the initiation and conclusion of a grazing study that examined stocking rate effects on average daily gain (ADG) and body condition of steers grazing a mixture of rye (Secale cereale L.) and ryegrass (Lolium multiflorum L.). Breed type did not affect (P \u3e 0.10) final or increases in EF, and curvilinear trends of increased EF with increasing ADG (P \u3e 0.10) among the breed types over the range of ADG (0.03 kg d-1 to 1.62 kg d-1). The three breed types showed curvilinear increases in LDA as ADG increased, but the trends were different (P \u3c 0.05) for SBH than for the other two types. Final LDA and magnitude of increases in EF and LDA over the experimental period were influenced (P \u3c 0.05) by initial body weight. Results indicated that allotting cattle to pastures based on a combination of breed type and body weight should improve precision in detecting treatment effects