A NIMERSTY OF ARKANSAS Agriculture and Natural Resources DIVISION OF AGRICULTURE Cooperative Extension Service FSA2140 "Friendly"Endophyte-Infected Tall Fescue for Livestock Production Jlohn A Jenninas Introduction Cattle suffering from fescue toxicosis retain rough hair coats Specialist-Forages cool (Figure 1),exhibit heat stress during e nsas warm periods(Figure 2)and suffer Charles P.West and much of the southeastern U.S. s of ear tips and d tail switches Professor.Department Tall fescue is widely grown throughout (Figure 3). of Crop,Soil and Arkansas because of its persistence, Environmental Sciences ent an ed at ase or ong growing e in this region is $50 million annually in Arkansas Steven M.Jones infected with that produces livestock Extension Horse Specialist toxins called ergot alkaloids.This fungus tolerance and stand Kentucky-31 Cons umption of toxic dep body and milk production in cows and weaning weights in calves.These problems are collectively called Grazing tures or consu Arkansas Is toxic E+tall fescue hay decreases forage intake Our Campus lowers average daily gain Figure 1.Rough hair coats on cattle grazing toxic endophyte-infected tall fescue. nited State and County Governments Cooperatin
Agriculture and Natural Resources FSA2140 “Friendly” Endophyte-Infected Tall Fescue for Livestock Production John A. Jennings Introduction Extension Livestock Specialist - Forages Tall fescue is the major coolseason perennial forage in Arkansas Charles P. West and much of the southeastern U.S. Professor, Department Tall fescue is widely grown throughout of Crop, Soil and Arkansas because of its persistence, Environmental Sciences ease of management and long growing season. Most tall fescue in this region is Steven M. Jones infected with a fungus Extension Horse that produces livestock toxins called ergot Specialist alkaloids. This fungus (endophyte) lives within the tall fescue plant, improving its drought tolerance and stand persistence on poor soils. Therefore, there is still widespread use of toxic tall fescue in Arkansas, consisting mainly of the variety Kentucky-31. Consumption of toxic endophyte-infected (E+) tall fescue depresses body condition, reproduction and milk production in cows and weaning weights in calves. These problems are collectively called “fescue toxicosis.” Grazing toxic E+ tall fescue pastures or consuming Arkansas Is toxic E+ tall fescue hay Our Campus decreases forage intake, lowers average daily gain and alters hormone concentrations in cattle and Visit our web site at: other livestock species. http://www.uaex.edu Cattle suffering from fescue toxicosis retain rough hair coats (Figure 1), exhibit heat stress during warm periods (Figure 2) and suffer losses of ear tips and tail switches during cool periods (Figure 3). Losses in cattle production due to fescue toxicosis have been estimated at $50 million annually in Arkansas. Figure 1. Rough hair coats on cattle grazing toxic endophyte-infected tall fescue. University of Arkansas, United States Department of Agriculture, and County Governments Cooperating
Fpi2S6ndnganeeadopayeniectedtaltescue Egpnne6caelhi6e8oncatiegrazing1oac Management Options for Combating Fescue Toxicosis tall fesng cl ers or otn appropriate.however.when pasture terrain or other Sodseeding and Supplementation factors make renovation with a non-toxic forage impractical. Some of the management techniques promoted Research indicates that mineral supplem ntation d。 eping tal corrects mineral deficiency(not toxicity)problems on toxic E+tall fe of s not correc th here sses may antioxidant vitamins,vasodilating vitamins, Table 1.Effects of white clover on steer growth performance in toxic endophyte-infected tall fescue pastures Toxic Endo Forage Steer average daily Clover% Clover% gain,Ib Grass alone 0 0.79 0 2.03 Grass+Regal white clover 147 0to 2 1.96 Grass+Durana white clover 35t054 2.55 35t053 3.21 Source:J.H.Bouton.2002.29th Annual Conference Proceedings.Arkansas Forage and Grassland Council
Figure 2. Cattle on toxic endophyte-infected tall fescue pasture standing in a pond. Management Options for Combating Fescue Toxicosis Sodseeding and Supplementation Some of the management techniques promoted in the past to address the problem of fescue toxicosis included keeping tall fescue seedheads clipped, reducing late spring nitrogen fertilization, sodseeding toxic tall fescue pastures with legumes or other grasses and supplementing livestock with non-toxic hay. While there is value in implementing these practices, significant production losses may Figure 3. Missing tail switches on cattle grazing toxic endophyte-infected tall fescue. still occur as long as toxic E+ tall fescue is included in the diet (Table 1). Sodseeding clovers or other forages into a toxic E+ tall fescue pasture may be appropriate, however, when pasture terrain or other factors make renovation with a non-toxic forage impractical. Research indicates that mineral supplementation corrects mineral deficiency (not toxicity) problems on toxic E+ tall fescue pastures. However, mineral supplementation does not correct the negative impacts of fescue toxicosis on animal growth performance. Studies have evaluated the use of antioxidant vitamins, vasodilating vitamins, Table 1. Effects of white clover on steer growth performance in toxic endophyte-infected tall fescue pastures Forage Toxic Endophyte-Infected Tall Fescue Endophyte-Free Tall Fescue Clover % Steer average daily gain, lb Clover % Steer average daily gain, lb Grass alone 0 0.79 0 2.03 Grass + Regal white clover 5 to 7 1.47 0 to 2 1.96 Grass + Durana white clover 35 to 54 2.55 35 to 53 3.21 Source: J. H. Bouton. 2002. 29th Annual Conference Proceedings. Arkansas Forage and Grassland Council
on,iron sulfate,selenium,bentonite, The University of Arkansas has also been active Tate ions.antibiotics and owth implants for ltingcn liveto e,Laf ette.IN) ArkPlus is derived from the HiMag tall fescue Endophyte-Free Tall Fescue reached commercial stages. Endophyte-free Although F-tall fes Friendly Tall Fescue performance over toxic tall fescue,endophyte Research Results removal results in reduced see ing vigor and lower Plant Persistence plant pers fescue pastures relative to toxic tall fescue pastures. Unlike toxic E+tall fescue,E-tall fescue can be easily overgrazed and will not tolerate poor st and of Je managemen E+tall fescue to be nearly twice that of Jesup E tall fescue.Three years into a grazing tolerance Research at the University of Tennessee h a mix of E.and study cond by the Univ ue rates have and exceeded Jesun E.tall fescue moderate to high stocking rates increase the These res pr e aplant pants in the pasture.In other sare however ong-term Arkansas needs further evaluation.The d which friendly endophytes improve stand persis- "Friendly"Endophyte-Infected Tall Fescue med or Until rec Preliminary data from south Arkansas suggest tha made between either good plant persistence and friendly endophytes enhance drought tolerance of poor animal performance(toxic E+tall fescue)or tall fescue in pastures. ood d poor plant persis Cow-Calf Performance E+tall fescue hit the market.Friendly E+tall fes cue is also referred to as"novel"or"non-toxic"E+ Two factors that dramatically impact the tall fe tall fesc ergot a the plant wea ing ill i f that tages of toxic E+tall fescue with the animal perfor. be marketed within a given calving season or vear mance advantages of E-tall fescue. Lower pregnancy rates,calving rates and calf wean infected with the MaxQTM endophyte ng we ights have b ers grazing versu in both the jesun and ge ia-5 varieties E-tall fescue Madi on,GA)was the first Cows and heifers must be in proper body den ondition mance.In a competition with bermudagrass and under heavy trials were assigned to either toxic E+or MaxQTME+tall astern as tle studies have been consistent and promising. pasturesover theme
activated carbon, iron sulfate, selenium, bentonite, fat, zeolite, hydrated sodium calcium aluminosilicate, drugs, toxin binders, modified yeast cell wall preparations, antibiotics and growth implants for alleviating fescue toxicosis in livestock. None of these products have been found to eliminate all fescue toxicosis problems without adverse side effects. Endophyte-Free Tall Fescue Endophyte-free (E-) tall fescue was initially tapped as a “silver bullet” for fescue toxicosis. Although E- tall fescue improves animal performance over toxic tall fescue, endophyte removal results in reduced seedling vigor and lower plant persistence. Many researchers and producers have observed accelerated stand losses in E- tall fescue pastures relative to toxic tall fescue pastures. Unlike toxic E+ tall fescue, E- tall fescue can be easily overgrazed and will not tolerate poor management. Research at the University of Tennessee indicated that in pastures with a mix of E- and toxic E+ tall fescue, low stocking rates have little or no effect on pasture endophyte infection rate, yet moderate to high stocking rates increase the percentage of E+ plants in the pasture. In other words, E- plants did not stand up to grazing pressure as well as E+ tall fescue plants. “Friendly” Endophyte-Infected Tall Fescue Until recently, producing and utilizing tall fescue was a double-edged sword. A choice had to be made between either good plant persistence and poor animal performance (toxic E+ tall fescue) or good animal performance and poor plant persistence (E- tall fescue). This changed when “friendly” E+ tall fescue hit the market. Friendly E+ tall fescue is also referred to as “novel” or “non-toxic” E+ tall fescue. It contains endophytes that do not produce the ergot alkaloid livestock toxins. Friendly E+ tall fescue combines the plant persistence advantages of toxic E+ tall fescue with the animal performance advantages of E- tall fescue. Tall fescue infected with the MaxQ™ endophyte in both the Jesup and Georgia-5 varieties (Pennington Seed, Inc., Madison, GA) was the first commercially available friendly E+ tall fescue. MaxQ™ E+ tall fescue has been evaluated under demanding management conditions (i.e., in competition with bermudagrass and under heavy stocking rates) in multiple university research trials across the southeastern United States. Both plant persistence and livestock (beef cattle, dairy cattle, sheep and horse) performance results from these studies have been consistent and promising. The University of Arkansas has also been active in friendly E+ tall fescue research, and seed from the Arkansas program is marketed as ArkPlus brand tall fescue (FFR Cooperative, Lafayette, IN). ArkPlus is derived from the HiMag tall fescue variety. Research trials are ongoing across the region examining livestock and plant performance of MaxQ™ and ArkPlus E+ tall fescue as well as other friendly E+ tall fescues that have not yet reached commercial stages. Friendly Tall Fescue Research Results Plant Persistence Extensive testing in Georgia over five years (including some of the hottest and driest years on record) has shown stand survival of Jesup MaxQ™ E+ tall fescue to be nearly twice that of Jesup Etall fescue. Three years into a grazing tolerance study conducted by the University of Kentucky, stand survival of Jesup MaxQ™ E+ tall fescue was statistically similar to Jesup toxic E+ tall fescue and exceeded Jesup E- tall fescue. These results are promising; however, long-term stand survival of friendly E+ tall fescue pastures in Arkansas needs further evaluation. The degree to which friendly endophytes improve stand persistence during drought is yet unknown. Arkansas research trials in Fayetteville were performed on deep, moist soil very suitable for tall fescue. Preliminary data from south Arkansas suggest that friendly endophytes enhance drought tolerance of tall fescue in pastures. Cow-Calf Performance Two factors that dramatically impact the profitability of a cow-calf operation are calving rate and weaning weight. Improvement to these production factors will increase the pounds of calf that can be marketed within a given calving season or year. Lower pregnancy rates, calving rates and calf weaning weights have been observed in many research efforts in cows and heifers grazing toxic E+ versus E- tall fescue. Cows and heifers must be in proper body condition for optimal reproductive performance. In a trial at the University of Georgia, Angus and Angus x Hereford cows of similar body condition were assigned to either toxic E+ or MaxQ™ E+ tall fescue pastures at calving. Cows grazing toxic E+ tall fescue gained only half as much body condition from calving to weaning as cattle grazing MaxQ™ E+ tall fescue in adjacent pastures over the same
pastures.Whstures eights were compared mortality and produce weak and dysmature foals. ntage over Very low levels of toxic E+tall fescr y66 pounds over the three- problems in the mare.Severe Their heifer counterparts had a weaning weight reproductive performance can be seen with as little tal fescue in a scue pastures ther Stocker Cattle Performance eeliutetroe Research shows able if broodmares are allowed to tha catt that average daily or m nitored closely during late on for udder Arkansas and Missouri researchers observed rough development and relaxation in the yulva and hair coats,elevated respiration rates and elevated the tail head.L attle graz g may t cue immediately after birth.Commercial milk replacers MaxE+tall fescue has also been evaluated or nurse animals may be needed if agalactia or low against toxic E+and E-tall fescue in several mil a prob of in Treatment f ids may Grazing behavior studies at the University of Use of oral Equidone(domperidone)therapy Georgia indicate that cattle grazir 10 days prior Toaling is anoth more decade nro vided evidence that Equidone(domperi probably an attempt to dissipate body heat).take done)is safe and effective for the prevention and fewer bites and chews and have lower forage intake reatment of escue toxicosis in he tall fescu Consult a eterina sing te y sh tall 500 kg(1100 lb)of body weight starting 10 days fescue have elevated body temperatures during prior to the anticipated foaling date up to foaling. On farms with a 80 I pe E+ ere m ares reidone to 15 to 25 days prior to the anticipated foaling date. Horse Production Tovic E tall foseue has lo case,mares should be dosed with domperidone twice all classes of horses but the most dramatic effects daily for clas es of horses at idr an ght minit and prolonged but c geldings.Reduced g wth rate in yearlings has also been documented.Toxic E+tall fescue causes 品e h din do mperidone gastrointe tina depre serum prolactin age. 、the milk test used to ntrat h 0 predict foaling and potential leaking of milk and gestation.premature placental separations orred oss of colostrum. bagging,"foaling difficulty or dystocia,increased placental retention and placental thickening (which toxic E+tall fescue have emphasized removing
period. Average daily gain was also three times higher in cows grazing the MaxQ™ E+ pastures over the toxic E+ tall fescue pastures. When adjusted 205-day weaning weights were compared, steer calves raised on MaxQ™ E+ pastures had a weaning weight advantage over calves raised on toxic E+ tall fescue pastures that averaged approximately 66 pounds over the three-year study period. Their heifer counterparts had a weaning weight advantage of approximately 44 pounds over heifer calves raised on toxic E+ tall fescue pastures. Stocker Cattle Performance Research shows that average daily gains are higher in cattle stocked on E- or friendly E+ tall fescue than on toxic E+ tall fescue (Table 2). Arkansas and Missouri researchers observed rough hair coats, elevated respiration rates and elevated rectal temperatures in cattle grazing toxic E+ tall fescue compared to cattle grazing ArkPlus or E- tall fescue. Stocker cattle growth performance on MaxQ™ E+ tall fescue has also been evaluated against toxic E+ and E- tall fescue in several research trials throughout the southeastern U.S. with consistent results. Grazing behavior studies at the University of Georgia indicate that cattle grazing toxic E+ tall fescue spend more time idling (neither grazing nor ruminating), more time standing instead of lying (probably an attempt to dissipate body heat), take fewer bites and chews and have lower forage intake than cattle grazing E- or MaxQ™ E+ tall fescue. Results from the Georgia stocker cattle research trials also show that cattle grazing toxic E+ tall fescue have elevated body temperatures during warm periods and depressed body temperatures during cool periods, while cattle grazing MaxQ™ E+ or E- tall fescue have body temperatures closer to normal values. Horse Production Toxic E+ tall fescue has long been taboo for use as horse pasture or hay. Toxic E+ tall fescue affects all classes of horses, but the most dramatic effects are seen in pregnant mares. Other classes of horses exhibit an increased risk of laminitis, and prolonged exposure may result in weight loss for inactive geldings. Reduced growth rate in yearlings has also been documented. Toxic E+ tall fescue causes pregnant mares to have depressed serum prolactin and progestin concentrations. The absence or reduction of these hormones results in prolonged gestation, premature placental separations or “red bagging,” foaling difficulty or dystocia, increased placental retention and placental thickening (which makes it difficult for the foal to break through the bag). Many mares also have agalactia or low milk production, low IgG levels in colostrum (important for proper immune function), increased foal mortality and produce weak and dysmature foals. Very low levels of toxic E+ tall fescue can cause problems in the mare. Severe effects on equine reproductive performance can be seen with as little as 10 percent or less of toxic E+ tall fescue in a forage stand. Therefore, inclusion of clovers or other forages in a toxic E+ tall fescue pasture does not effectively dilute toxicosis effects in broodmares. Expect trouble if broodmares are allowed to graze toxic E+ tall fescue. These mares need to be monitored closely during late gestation for udder development and relaxation in the vulva and muscles around the tail head. Low or absent milk production is likely, and rebreeding may be difficult. Be prepared to administer colostrum to the foal immediately after birth. Commercial milk replacers or nurse animals may be needed if agalactia or low milk production is a problem. Treatment for septicemia and infusion of intravenous fluids may also be necessary. Use of oral Equidone® (domperidone) therapy for 10 days prior to foaling is another option. Clemson University studies spanning the last decade provided evidence that Equidone® (domperidone) is safe and effective for the prevention and treatment of fescue toxicosis in horses. Consult a veterinarian for dosing recommendations. Typically, domperidone is administered at a rate of 5 cc per 500 kg (1100 lb) of body weight starting 10 days prior to the anticipated foaling date up to foaling. On farms with a history of severe fescue toxicosis or where mares remain on toxic E+ tall fescue up to foaling, domperidone treatment may be needed up to 15 to 25 days prior to the anticipated foaling date. Domperidone can also be used to bring agalactic mares into milk or increase milk production in low milking mares as a result of fescue toxicosis. In this case, mares should be dosed with domperidone twice daily for two days followed by once daily administration for an additional three days. Cost of domperidone treatment may vary, but count on paying at least $10 per day. Since domperidone stimulates gut motility, it should not be used in horses with suspected or known gastrointestinal blockage. In addition, domperidone may cause a false positive on the milk calcium test used to predict foaling and potential leaking of milk and loss of colostrum. Past recommendations for horse production on toxic E+ tall fescue have emphasized removing
Table 2.Stocker cattle average daily gains grazing tall fescue Study Location Tall Fescue Endophyte Average Daily and Duration Cattle Cultivar Status Gain,Ib Reference steers HiMag 4(ArkPlus) 1.43 West et al. 2-year study 1.36 Endophyte-free 1.55 Kentucky-31 Toxic endophyte 0.93 infected Calhoun,GA Angus x Kentuckv-31 AR542 (MaxOTM) 1.61 Parish et al. (Northwest Georgia Hereford SERAIEG-8 Branch Station): steers and Endophyte-free 1.57 Proceedings 3-year study heifers heegopnte 1.08 Eatonton.GA Hereford Georgia-5 AR542(MaxQTM) 2.09 steers Jesup AB542 (MaxOTM 1.72 Proceedings 3-year study Endophyte-free 2.14 Toxic endophyte 0.68 infected Winnsboro,LA steers Jesup AR542 (MaxQTM) 2.5 Ais0n.2002 Macon Ridge SERAIEG-8 Research Station): Georgia-5 AR542(MaxQTM) 2.4 Proceedings 2-year study Endophyte-free 2.6 Toxic endophyte 1.7 infected Mount Vernon.MO: steers HiMag 4 (ArkPlus) 121 West et al. 2-year study Endophyte-free 1.21 Kentucky-31 Toxic endophyte 0.55 infected Raymond,MS steers Jesup AR542(MaxQTM) 0.87 Macoon et al. (Central Mississippi 2002 search and Georgia-5 AR542(MaxQTM 0.91 SERAIEG-8 1-year study enter) Proceedings Kentucky-31 Endophyte-free 0.94 Grand Junction.TN Angus Kentucky-31 AR542 (MaxQTM 1.62 Waller et al. (Ames Plantation): steers 2001 Uniy of 3-year study Endophyte-free 1.64 Tennessee Annual Dept. Toxic endophyte 1.06 Rep. infected
Table 2. Stocker cattle average daily gains grazing tall fescue Study Location Tall Fescue Endophyte Average Daily and Duration Cattle Cultivar Status Gain, lb Reference Fayetteville, AR; 2-year study steers HiMag 4 (ArkPlus) 1.43 West et al. 9 1.36 Endophyte-free 1.55 Kentucky-31 Toxic endophyteinfected 0.93 Calhoun, GA Angus x Kentucky-31 AR542 (MaxQ™) 1.61 Parish et al. (Northwest Georgia Branch Station); Hereford steers and SERAIEG-8 Endophyte-free 1.57 Proceedings 3-year study heifers Toxic endophyte- 1.08 infected Eatonton, GA Hereford Georgia-5 AR542 (MaxQ™) 2.09 Parish et al. (Central Georgia Branch Station); steers SERAIEG-8 Jesup AR542 (MaxQ™) 1.72 Proceedings 3-year study Endophyte-free 2.14 Toxic endophyte- 0.68 infected Winnsboro, LA (Macon Ridge Research Station); steers Jesup AR542 (MaxQ™) 2.5 Alison. 2002. SERAIEG-8 Georgia-5 AR542 (MaxQ™) 2.4 Proceedings 2-year study Endophyte-free 2.6 Toxic endophyte- 1.7 infected Mount Vernon, MO; 2-year study steers HiMag 4 (ArkPlus) 1.21 West et al. Endophyte-free 1.21 Kentucky-31 Toxic endophyteinfected 0.55 Raymond, MS (Central Mississippi Research and steers Jesup AR542 (MaxQ™) 0.87 Macoon et al. 2002. Georgia-5 AR542 (MaxQ™) 0.91 SERAIEG-8 Extension Center), 1-year study Proceedings Kentucky-31 Endophyte-free 0.94 Grand Junction, TN Angus Kentucky-31 AR542 (MaxQ™) 1.62 Waller et al. (Ames Plantation); steers 2001. Univ. of 3-year study Endophyte-free 1.64 Tennessee Annual Dept. Toxic endophyte- 1.06 Rep. infected