Effects of red clover isoflavones on tall fescue seed fermentation and microbial populations in vitro.

Negative impacts of endophyte-infected Lolium arundinaceum (Darbyshire) (tall fescue) are responsible for over $2 billion in losses to livestock producers annually. While the influence of endophyte-infected tall fescue has been studied for decades, mitigation methods have not been clearly elucidated. Isoflavones found in Trifolium pratense (red clover) have been the subject of recent research regarding tall fescue toxicosis mitigation. Therefore, the aim of this study was to determine the effect of ergovaline and red clover isoflavones on rumen microbial populations, fiber degradation, and volatile fatty acids (VFA) in an in vitro system. Using a dose of 1.10 mg × L-1, endophyte-infected or endophyte-free tall fescue seed was added to ANKOM fiber bags with or without 2.19 mg of isoflavones in the form of a control, powder, or pulverized tablet, resulting in a 2 × 3 factorial arrangements of treatments. Measurements of pH, VFA, bacterial taxa, as well as the disappearance of neutral detergent fiber (aNDF), acid detergent fiber (ADF), and crude protein (CP) were taken after 48 h of incubation. aNDF disappearance values were significantly altered by seed type (P = 0.003) and isoflavone treatment (P = 0.005), and ADF disappearance values were significantly different in a seed × isoflavone treatment interaction (P ≤ 0.05). A seed × isoflavone treatment interaction was also observed with respect to CP disappearance (P ≤ 0.05). Eighteen bacterial taxa were significantly altered by seed × isoflavone treatment interaction groups (P ≤ 0.05), eight bacterial taxa were increased by isoflavones (P ≤ 0.05), and ten bacterial taxa were altered by seed type (P ≤ 0.05). Due to the beneficial effect of isoflavones on tall fescue seed fiber degradation, these compounds may be viable options for mitigating fescue toxicosis. Further research should be conducted to determine physiological implications as well as microbiological changes in vivo.

[Medication overuse headache]. / Abuzusnaia golovnaia bol'.

Rebound headache (RH) is a chronic daily headache which occurs when analgesics, triptans, ergotamines are taken frequently (more than 15 days/month for more than 3 months) to relieve headaches. The prevalence of RH is 1 to 4% in the general population. RH commonly occurs in patients with migraine and tension-type headache. The deficit of central sensitization and psychological factors play an important role in initiating and maintaining of RH. Treatment of noofen for 2 months is effective in 75% of patients with RH.

Preference for tannin-containing supplements by sheep consuming endophyte-infected tall fescue hay.

Tannins may bind to alkaloids in endophyte-infected (E+) tall fescue and attenuate fescue toxicosis. To test this hypothesis, thirty-two 4-mo-old lambs were randomly assigned to 4 treatments (8 lambs/treatment) in a 2 by 2 factorial design that included a basal diet of tall fescue hay [E+ or endophyte-free (E-)] supplemented with (TS) or without (CS) bioactive Quebracho tannins. The concentration of ergovaline in E+ fed in 2 successive phases was 65 ± 21 µg/kg (Phase 1) and 128 ± 4 µg/kg (Phase 2). After exposure to hays and supplements, all lambs were offered choices between TS and CS and between E+ and E- hays. During Phase 1, lambs offered E+ consumed more hay than lambs offered E- (P = 0.03). Lambs on E+/TS displayed the greatest intake of hay and the least intake of TS (P < 0.05). During Phase 2, when the concentration of ergovaline increased, lambs offered E+ consumed less hay than lambs fed E- (P < 0.0001). Lambs on E+/CS consumed less hay than lambs on E-/CS (P = 0.02), but hay intake by lambs on E-/TS and E+/TS did not differ (P = 0.96). Lambs preferred CS to TS during preference tests (P < 0.0001) and lambs on E+/TS ingested the least amounts of supplement TS and the greatest amounts of supplement CS (P = 0.001). Lambs offered E+ displayed greater body temperatures than lambs offered E- in both phases (P < 0.05). When offered a choice among the 3 hays, lambs previously exposed to E+ preferred E+ (low content of ergovaline) > E- > E+ (greater content of ergovaline; P < 0.001). Thus, decreased concentrations of ergovaline increased rectal temperatures, and affected intake of and preference for tannins and fescue hay. Quebracho tannins did not attenuate the effects of E+ on body temperature and feed intake. Ingestion of E+ reduced intake of quebracho tannins, suggesting that alkaloids in E+ antagonized ingestion of condensed tannins.

Use of different levels of ground endophyte-infected tall fescue seed during heat stress to separate characteristics of fescue toxicosis.

Studies of fescue toxicosis using whole seed diets show reduced feed intake and thermoregulatory ability, but much of the seed passes undigested through the animal. Cattle were fed ground tall fescue seed at different levels to potentially facilitate digestion and absorption of toxins and identify toxin sensitivity for major characteristics of the condition [i.e., hyperthermia, reduced feed intake (FI), reduced blood prolactin]. Steers (n = 18; 350 kg BW) were housed in the Brody Climatology Laboratory at thermoneutrality (TN; 19°C) and randomly assigned to daily diet treatments with either ground endophyte-infected [E+; low and high doses at 20 and 40 µg ergovaline/(kg BW/d), respectively] or endophyte-free [E-; control at 0 µg ergovaline/(kg BW/d)] tall fescue seed. After 12 d at TN, animals received 2 d of transition to heat stress (HS; 36°C daytime, 25°C nighttime) and maintained for 14 more days. Cattle were fed twice daily at 0800 and 1600 h, with water ad libitum. Feed intake was measured at 0700 h, with skin and rectal temperatures, and respiration rate at 0600, 1100, 1600, and 2100 h. Blood was sampled on selected days for prolactin and leptin determinations. Steers fed ground E+ diet decreased (P ≤ 0.0001) FI below controls at TN, with no dose effect. Maximum FI reduction with E+ treatment was 25% at TN, with an additional 46% decrease during HS (P ≤ 0.05). By the end of HS, E+ FI increased (P > 0.05) to that of E-, suggesting recovery. Prolactin was reduced (P ≤ 0.05) in high E+ cattle below controls at study end. Leptin blood concentrations were unaffected by E+ treatment (P > 0.05) but was reduced (P ≤ 0.05) by the end of HS. Pattern of rectal temperature response to HS showed a more rapid initial increase and decline for both E+ groups compared with controls (P ≤ 0.05). Skin temperature was the only variable that identified E+ dose differences. Although there were no treatment differences at TN, skin temperature was lower (P ≤ 0.05) for high E+ steers compared with controls during HS when air temperature was reduced each day. In general, FI was more responsive to E+ toxins than body temperature or blood prolactin, declining even at TN and exhibiting dynamic activity during HS. Although body temperature response to E+ toxins appears to stabilize during HS, this is misleading as rapid change in air temperature exposes effects on skin temperature.

Changes in concentrations of lysergol in urine and prolactin in plasma, rectal temperature and respiration rate in sheep selected for resistance or susceptibility to ryegrass staggers and fed ergovaline.

AIM: To determine the effects of feeding ryegrass seed containing ergovaline to sheep selected for resistance or susceptibility to ryegrass staggers on concentration of lysergol (a metabolite of ergovaline) in urine, prolactin in plasma, rectal temperature and respiration rate. METHODS: Two experiments were carried out using 12 Romney crossbred ewe lambs aged 9 months, comprising animals resistant (n=4), susceptible (n=4) or outcross (n=4) to ryegrass staggers. In Experiment 1, sheep were given either a single (Part A) or six (Part B) feed (s) of endophyte-infected seed containing ergovaline at 30 mg/kg dry matter (DM), at 42 µg ergovaline/kg bodyweight (BW), to simulate acute and chronic exposure to ergovaline, respectively. The concentration and excretion of lysergol in urine and concentration of prolactin in plasma were measured over 3 and 12 days, for Parts A and B respectively. In Experiment 2, after a recovery period of 7 days, the same sheep were fed with ergovaline at 67 µg/kg of BW for 7 days. Soon after the seventh feed the sheep were moved to a hothouse at 36.5°C and 60% humidity, and 3 h later their rectal temperatures and respiration rates were measured. RESULTS: The concentration of lysergol and excretion in urine increased to a peak between 6 and 9 h after exposure to ergovaline whereas the concentration of prolactin in plasma was markedly reduced. Differences in concentration and rate of excretion of lysergol in urine between animals resistant, outcross and susceptible to ryegrass staggers were not significant (p>0.1). The animals resistant to ryegrass staggers had a lower rectal temperature (p<0.05) and a faster respiration rate than the outcross and susceptible groups when exposed to high ambient temperature and high humidity. CONCLUSIONS: This study showed that excretion of lysergol in urine increased with each exposure of sheep to ergovaline. Animals genetically resistant to ryegrass staggers exhibited a lower rectal temperature and a faster respiration rate than those susceptible, demonstrating the possible cross resistance of sheep to ergovaline in a population originally selected for resistance to ryegrass staggers. Hence potential exists to select animals resistant to ryegrass staggers that are also resistant to ergovaline.

Hemodynamics are altered in the caudal artery of beef heifers fed different ergot alkaloid concentrations.

Doppler ultrasonography was used to compare blood flow characteristics in the caudal artery of heifers fed diets with endophyte (Neotyphodium coenophialum) noninfected (E-, 0 microg of ergovaline/g of DM), a 1:1 mixture of endophyte-infected and E- (E+E-; 0.39 microg of ergovaline/g of DM), or endophyte-infected (E+, 0.79 microg of ergovaline/g of DM) tall fescue (Lolium arundinaceum) seed. Eighteen crossbred (Angus x Brangus) heifers [345 +/- 19 kg (SD)] were assigned to individual pens and fed chopped alfalfa hay plus a concentrate that contained E- tall fescue seed for 7 d during an adjustment period. A 9-d experimental period followed with feeding treatments of chopped alfalfa hay plus a concentrate with E+, E-, or E+E- seed being assigned randomly to pens. Doppler ultrasound measurements (caudal artery luminal area, peak systolic velocity, end diastolic velocity, mean velocity, heart rate, and flow rate) and serum prolactin were monitored during the adjustment (3 baseline measures) and during the experimental period (7 measures). Statistical analyses compared proportionate differences between baseline and responses at 3, 27, 51, 75, 171, and 195 h from initial feeding of the experimental diets. Serum prolactin concentrations for E+ and E+E- diets were less (P < 0.001) than baseline concentrations beginning at 27 and 51 h, respectively, from initial feeding of the diets. Although baseline measures were taken when ambient temperatures were likely below thermoneutrality, caudal artery luminal cross-sectional area in E+ heifers had declined (P = 0.004) from baseline by 27 h and remained less (P < 0.02) until 195 h, and caudal artery luminal area declined (P = 0.004) in E+E- heifers from baseline by 51 h and remained less (P < 0.07) until 171 h. Blood flow rate was slower than the baseline rate at 51 h for E+ (P = 0.058) and E+E- (P = 0.02 heifers, but blood flow remained slower in E+E- heifers for 48 h, whereas it remained slower in E+ heifers for 96 h. Adjustments in artery luminal area and blood rate with the 3 diets appeared to parallel the increases in ambient temperature. Heifers fed a diet containing a larger amount of ergot alkaloids had less of a response to ambient temperature than heifers consuming the diet with less or no ergot alkaloids.

Emergency treatment of migraine.

During the past few years, several surveys have highlighted the high prevalence of migraine amongst the general French population and the large healthcare burden associated with suboptimal treatment. Since it opened, the Centre d'Urgences Céphalées (EHC) has treated more than 55 000 patients, the majority of whom were suffering from migraine. Expert diagnosis of the type and causes of the headache, followed by immediate medication, allows patient stabilization. Detailed assessments can then determine the most appropriate treatment for each patient to improve outcomes and reduce the necessity for further emergency admissions. Triptans are generally recommended, and for those patients who currently have ineffective migraine control with one triptan, individual evaluation allows prescription of an alternative triptan which will better suit their needs. Follow-up is crucial to ensure that treatment remains optimal and that patient expectations are being met. Although a minority of patients with severe headache will continue to require repeated emergency treatment, more than 90% of patients seen at the EHC can be successfully managed with this combination of accurate diagnosis, effective treatment and individualized follow-up care.

[Treatment and prophylaxis of an acute migraine attack]. / Wie scharf müssen Sie gegen die Migräne schiessen? Eisbeutel und ASS, oder Triptan und eine Prophylaxe.

The treatment of migraine takes into consideration the intensity of the headache and the accompanying symptoms. The goal is to reduce the headache intensity, to relieve nausea and vomiting and to restore the ability to function in the daily routine. For drug treatment, there are now highly effective serotonin agonists available in addition to the older ergotamine preparations. A problem with all migraine analgesics is that in long lasting migraine attacks, the headache can recur as the pharmacological effect of the medication wears off. Through nonmedicinal and medicinal prophylactic measures, the frequency and intensity of the migraine attacks can be reduced. Keeping a headache diary for documentation is essential.

Toxicokinetics of ergovaline in the horse after an intravenous administration.

The toxicokinetics of ergovaline (an ergopeptine mycotoxin present in some grasses infected with endophytic fungus of the genus Neotyphodium) were studied after intravenous administration of a single dose of 15 microg/kg bwt in four gelding horses. Plasma ergovaline concentrations were measured by high performance liquid chromatography, and the kinetic data were described by a three-compartment model. The elimination half-life and the total clearance of ergovaline were found to be 56.83 +/- 13.48 min and 0.020 +/- 0.004 L/min x kg, respectively. According to the toxicological data previously reported in the horse, and in spite of the very low dose administered, clinical signs were observed, including excessive coolness of the ears and the nose, excessive sweating and prostration.

[Headaches caused by abuse of symptomatic anti-migraine and analgesic treatment]. / Céphalées induites par abus des traitements symptomatiques antalgiques et antimigraineux.

These daily or near-daily headaches result from the chronic overuse of all immediate relief antimigraine drugs: ergotamine, analgesics, and/or more recently triptans. Like for much chronic daily headaches, the International Headache Society diagnostic criteria for drug abuse headaches are difficult to apply. Generally, patients confuse primary headaches (usually migraines) with interparoxysmal tension-type headaches called "rebound headaches". Psychosocial factors may play a role. Insidiously, a compulsive automedication results, often in anticipation of headache. This headache syndrome resists symptomatic and prophylactic treatment. These headaches are frequent, very disabling and socioeconomically costly. They are still largely underdiagnosed. Drug-induced headaches may be restricted to those patients who are already headache sufferers. The pathogenesis is not clearly understood: it may involve a deficience of inhibitory pain modulation, a hyperactivation of nociceptive facilitatory systems, and the peripheral and central effects of the incriminating drugs. The withdrawal of all offending analgesic drugs and a multimodality approach are indispensable, but the therapeutic protocoles are actually very heterogeneous and poorly estimated. Non-drug means could be very helpful. Effective education of headache sufferers and regular follow-up are essential to avoid relapses. Prognosis factors have been evoked, but may not be significant for the long term outcome. The rate successfull of is actually estimated at 60 p. cent at five years. The benefits of an adequate management encourage early recognation of drug-induced headaches. This article has in view to take stock of the literature at the end of 1999, and to help physicians become mora aware of this problem and develp a more preventive attitude.

[Profile of the migrainous patients according to drug intakes]. / Perfil de los pacientes migrañosos según el consumo de fármacos habituales.

Migraine headache is a common, recurrent and often incapacitating disorder resulting in a substantial loss of work days and productivity, significant consumption of medicines, and considerable economic cost. We performed this study in order to determine the characteristic features of migrainous patients with regular or frequent intake of ergotamine preparations and non steroidal anti-inflammatory drugs (NSAIDs) and the existence of significant differences between both groups. 186 patients were included in the study, 36.6% suffering from migraine without aura and 63.4% from migraine with aura. 24.7% were males and 75.3% females. Mean age of the sample was 35.6 +/- 12.9 years. With regard to medication used for immediate relief of headache, 74.7% patients reported an intake of analgesics and 25.3% ergotamine preparations. In patients with analgesic intake the mean age was significantly lower than in patients with ergotamine for treatment of migraine. When clinic features of these two headache groups were examined, the duration of migraine attacks in the analgesic group was significantly higher (p = 0.0014) than in the ergotamine group, and the severity of migraine was lower (p < 0.05) than in this group. Among associated symptoms, nausea and vomiting were significantly less frequent (p = 0.024) in the analgesic group than in the group of patients with ergotamine intake.

Influence of alkaloid concentration of tall fescue straw on the nutrition, physiology, and subsequent performance of beef steers.

Two experiments were conducted to evaluate digestion, performance, and physiological responses to Acremonium coenophialum-infected tall fescue straw offered to vary ergovaline concentrations. In Exp. 1, 16 Hereford x Angus ruminally cannulated steers (370 +/- 12 kg BW, mean +/- SE) were blocked by age and BW and, within block, randomly assigned to one of four treatments containing graded concentrations of ergovaline in the diet: 1) 0 ppb, 2) 158 ppb, 3) 317 ppb, and 4) 475 ppb. Alkaloid concentrations were produced using various mixtures of two varieties of tall fescue straw that had similar genetic and phenotypic characteristics but differed in degree of endophyte incidence and associated concentrations of alkaloids. In the 36-d digestion study, feed intake, apparent DMD, and total tract NDF digestion were not influenced by alkaloid concentration (P > .10). Differences were observed with digesta kinetics; specifically indigestible ADF (IADF) fill and outflow decreased linearly with increasing alkaloid concentration (P < .10). These differences, however, may be attributed to differences in IADF concentration of the diets. Physiological variables (heart rates, respiration rates, and rectal, ear, and tailhead skin surface temperatures) were not influenced by alkaloid concentration (P > .10). Concentration of serum prolactin measured weekly tended (P < .10) to decrease with increasing alkaloid concentration of the diet. At the conclusion of the study, each steer was injected with 100 micrograms of thyrotropin-releasing hormone (TRH). All steers responded to the TRH challenge (P < .10); however, responses did not differ (P > .10) between alkaloid concentrations of the basal diet (P > .10).(ABSTRACT TRUNCATED AT 250 WORDS)

Office management of benign headache. The science and the art.

Headache management requires a comprehensive strategy that includes accurate diagnosis, reassurance and education of the patient, nonpharmacologic methods of preventing attacks, and appropriate use of prophylactic and abortive medications. Personal input from the physician and judicious selection of headache medications are crucial. Implementation of such a strategy gives patients greater ability to control and cope with their headaches.

The effects of endophyte-infected tall fescue consumption and use of a dopamine antagonist on intake, digestibility, body temperature, and blood constituents in sheep.

Two experiments were conducted with lambs that consumed endophyte-infected (Acremonium coenophialum) tall fescue diets under elevated temperature and humidity and supplemented with the dopamine antagonist metoclopramide (M). In Exp. 1, 12 ruminally cannulated wethers (average weight 49 kg) were allotted by weight to either an endophyte-free diet (E-) or endophyte-infected diet (E+; 1,170 ppb of ergovaline), or E+ supplemented with M (15 mg/kg of lamb BW; E+M). Ad libitum DM intake and digestibility were lower (P < .05) for E+ than for E- diet. Supplementation of E+ with M increased (P < .05) DM intake by 27.6% but did not change DM digestibility. Body temperature increased (P < .05) when lambs consumed E+ and was further increased when M was supplemented. For Exp. 2, 19 wether lambs (average weight 24 kg) were allotted to treatments to evaluate the effects of endophyte consumption (0 vs 2,430 ppb of ergovaline) and supplementation with M (0 vs 20 mg/kg BW). An interaction (P < .05) of main effects was measured for DM intake. Lambs that consumed E+M consumed more DM than did lambs fed only E+, but lambs offered the E- diet and supplemented with M did not increase DM consumption. Diet DM digestibility was not different among treatments. Skin vaporization decreased (P < .05) due to E+ consumption and M supplementation. The concentration of prolactin in plasma was decreased (P < .05) by consumption of E+ (8 vs 136 ng/mL) and did not increase due to M supplementation.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of endophyte-infected tall fescue consumption on diet utilization and thermal regulation in cattle.

Two experiments were conducted to determine the effects of endophyte fungus (Acremonium coenophialum) ingestion in tall fescue diets and environmental temperature on heat dissipation and diet utilization by cattle. In Exp. 1, 12 Angus heifers (average weight 244 kg) were allotted by weight to either an endophyte-free (E-) or endophyte-infected (E+; 381 ppb of ergovaline) diet. Environmental temperature varied between 22 and 32 degrees C. Voluntary DM and water intakes were similar (P > .10) among treatments. Rectal temperatures and concentrations of prolactin in plasma were lower (P < .05) after ingestion of the E+ diet. Plasma triiodothyronine, thyroxine, and cortisol concentrations were not affected by diet. In Exp. 2, 24 Holstein steers (average weight 114 kg) were allotted by weight to either E- or E+ (285 ppb of ergovaline) and one of two environmental temperatures (22 or 32 degrees C). At 32 degrees C, feed intake was reduced by 22%, and water consumption was increased by 62% compared with steers housed at 22 degrees C. Consumption of E+ reduced feed intake by 10% but did not influence water consumption. Plasma concentration of prolactin was decreased (P < .05) within 48 h after consumption of E+. Rectal temperatures increased in response to both environmental temperature (P < .05) and E+ consumption (P = .06). Digestibilities of DM and OM for E+ were 9% lower (P < .05) than for E-.(ABSTRACT TRUNCATED AT 250 WORDS)

Propuesta para sistematizar el tratamiento de la migraña / A proposal to normatize the treatment of migraine

Los autores analizan la posibilidad de implementar una sistematización en el tratamiento de la migrañas. Proponen como medicación preventiva a los siguientes fármacos: 1)Bloqueadores de canales cálcicos tales como flunarizina y nimodipina. 2)Antagonistas beta-adrenorreceptores como el propanol, metoprolol y atenolol. 3)Antagonistas de los receptores 5HT2 como el pizotifeno, metisergida y ciproheptadina. 4)Agentes serotoninérgicos como son la amitriptilina y la imipramina. 5)Estimulantes de los receptores alfa tales como la clonidina de buena acción sobre el aura. Para el tratamiento de las crisis, analizan diferentes fármacos antimigrañosos como los alcaloides ergóticos (tartratos de ergotamina y dihidroergotamina) y la nueva droga sumatripan agonista de los receptores 5HT1D. Se menciona también a los analgésicos y antinauseosos, como los agentes antiinflamatorios no esteroides y la domperidona y se deja para casos excepcionales a las drogas opiodes. Se aclara que éste es sólo un esquema general que abrirá una interesante controversia entre los expertos

Propuesta para sistematizar el tratamiento de la migraña / A proposal to normatize the treatment of migraine

Los autores analizan la posibilidad de implementar una sistematización en el tratamiento de la migrañas. Proponen como medicación preventiva a los siguientes fármacos: 1)Bloqueadores de canales cálcicos tales como flunarizina y nimodipina. 2)Antagonistas beta-adrenorreceptores como el propanol, metoprolol y atenolol. 3)Antagonistas de los receptores 5HT2 como el pizotifeno, metisergida y ciproheptadina. 4)Agentes serotoninérgicos como son la amitriptilina y la imipramina. 5)Estimulantes de los receptores alfa tales como la clonidina de buena acción sobre el aura. Para el tratamiento de las crisis, analizan diferentes fármacos antimigrañosos como los alcaloides ergóticos (tartratos de ergotamina y dihidroergotamina) y la nueva droga sumatripan agonista de los receptores 5HT1D. Se menciona también a los analgésicos y antinauseosos, como los agentes antiinflamatorios no esteroides y la domperidona y se deja para casos excepcionales a las drogas opiodes. Se aclara que éste es sólo un esquema general que abrirá una interesante controversia entre los expertos

Performance, forage utilization, and ergovaline consumption by beef cows grazing endophyte fungus-infected tall fescue, endophyte fungus-free tall fescue, or orchardgrass pastures.

Two 120-d trials (May to September, 1988 and 1989) determined the effects of grazing tall fescue (two varieties) or orchardgrass on forage intake and performance by beef cows. Each summer, 48 cow-calf pairs grazed endophyte-infected Kentucky-31 tall fescue (KY-31), endophyte-free Mozark tall fescue (MOZARK), or Hallmark orchardgrass (OG) pastures (16 pairs/treatment). Forage OM intakes and digestibilities were determined during June and August each year. Cow and calf BW and milk production were determined every 28 d. During June of both years, OM intakes did not differ (P greater than .10) among treatments. During August of 1988, intakes were 18% lower (P less than .05) by KY-31 cows (1.6% of BW) than by MOZARK or OG cows (average 1.95% of BW); however, no differences (P greater than .10) were measured in August of 1989. Estimates of ergovaline consumption during June from KY-31 were between 4.2 (1988) and 6.0 mg/d (1989), whereas August estimates were between 1.1 (1988) and 2.8 mg/d (1989). Ergovaline in MOZARK estrusa was below detection limits, except in August of 1989. Cows that grazed KY-31 lost three times (P less than .01) more BW than cows that grazed MOZARK or OG (42 vs 9 and 13 kg, respectively). Milk production by KY-31 cows was 25% lower (P less than .01) than that by cows that grazed MOZARK or OG (6.0 vs average of 8.0 kg/d). Similarly, slower (P less than .01) calf gains were noted for KY-31 than for MOZARK or OG (.72 vs .89 and .88 kg/d, respectively). Cows grazing KY-31 experienced accelerated BW loss and reduced milk production and weaned lighter calves than did cows grazing MOZARK or OG. Decreased performance was not explained by consistently reduced forage intakes; hence, altered nutrient utilization was suspected.