Few perennial legumes have dependable long‐term productivity under grazing in the northern USA. Our objective was to determine the effects of frequent clipping and sheep(Ovis spp.) grazing on forage yield and quality of kura clover (Trifolium ambiguum. Bieb.), a rhizomatous perennial legume. Clipping and grazing trials were initiated on a 5‐yr‐old stand of ‘Rhizo’ kura clover on a Waukegan silt loam and conducted for 3 yr. Total season yield (mean of 8.6 Mg ha‐1) was unaffected by clipping frequency until the third year, when five and six cuttings per season produced 80 and 70% as much forage, respectively, as either three or four cuttings. In the second and third years of sheep grazing treatments, kura clover rotationally stocked with 14‐d rest periods produced 28 and 16% less forage, respectively, than that under rotational stocking with 28‐d rest periods. In contrast to total season forage yield, spring yield following 3 yr of clipping and grazing did not differ among clipping frequency increased from three to six cuttings per year, (Missing Data.) (CP) and in vitro digestible dry matter (IVDDM) concentrations increased from 222 to 254 and from 854 to 880 g kg ‘1 DM, respectively, and neutral‐detergent fiber (NDF) concentration decreased from 326 to 295 g kg‐1 DM. Forage was of high quality, because leaf concentration always exceeded 850 g kg‐1 of forage dry matter. Established kura clover is tolerant of frequent and close defoliation and warrants pasture use because of its long‐term productivity and high forage quality.

Kura clover (Trifolium ambiguum M. Bieb.) is a rhizomatous perennial legume that has not been adequately evaluated in the USA under grazing. Our objective was to compare kura clover and birdsfoot trefoil (Lotus corniculatus L.) persistence and productivity when seeded in monoculture and in a binary mixture and grazed by lambs. A controlled, high herbage allowance (mean of 7.4% of lamb body weight in forage dry matter per day) was applied for 4 yr to pastures on a Waukegan silt loam (fine‐silty over sandy, mixed, mesic Typic Hapludoll). Initial seeded legume composition of monocultures was >95%, while the composition of the kura clover‐birdsfoot trefoil mixture was initially 10 and 90%, respectively. By the fourth year of grazing, the kura clover monoculture and mixture had >99% kura clover, while the birdsfoot trefoil monoculture had only 20% birdsfoot trefoil (80% broadleaf weeds). At the initiation of grazing, kura clover had 20% greater leafiness and higher forage quality than birdsfoot trefoil. Animal days per hectare and liveweight gain per hectare were initially similar for the legume monocultures and mixtures, but by the fourth year were 105% and 86% greater, respectively, for the kura clover dominated mixture and the kura clover monoculture than for the birdsfoot trefoil monoculture. Average daily lamb gain was similar (4‐yr mean of 199 g per lamb) for the treatments each year. Seeding with birdsfoot trefoil did not reduce the incidence of lamb bloat (6%) that occurred on kura clover pastures when kura clover comprised 20% or more of the mixture. Kura clover has potential as a pasture legume in the northern USA because of its excellent persistence, ability to spread, and high forage quality. Additional evaluation of animal performance under lower herbage allowance and on determination of kura clover compatibility with grasses in mixtures is warranted.

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Total basic alkaloid concentration of reed canarygrass (Phalaris arundinacea L.) is negatively correlated with palatability (selection when a choice is offered) of the grass to ruminant animals. The significance of these alkaloids to ruminants not offered a choice of pasture forage remained unknown. Our objectives were to determine whether alkaloid concentration and alkaloid type differences among reed canarygrass genotypes affect animal performance, grass intake, and health of grazing sheep and cattle. Replicated pastures representing two primary alkaloid types (gramine vs. tryptamine‐carboline) and two alkaloid concentrations were primarily established from eight clones of reed canarygrass. During 1973 and 1974, these pastures were grazed by lambs and during 1975, by steers. Total alkaloid concentration of the grass was highly negatively associated with average daily gains by lambs and steers (r= —0.91, —0.90, and —0.91 for 1973, 1974, and 1975, respectively). Alkaloid concentration was highly negatively correlated with an estimate of voluntary intake (r = −0.85) by lambs not offered a choice of reed canarygrass genotypes, but alkaloid concentration was not usually overtly associated with voluntary intake by steers. Animals had more diarrhea when grazing high‐alkaloid plants and when grazing tryptamine‐carboline‐containing compared to gramine‐containing plants. This physiological upset may have been a major contributor to reduced animal gains. Breeding or managing reed canarygrass cultivars for lower alkaloid concentration per se, and breeding for tryptamine‐carboline‐free (gramine‐containing) cultivars, should provide pasture that has improved animal performance potential. “Phalaris staggers” or “sudden death” were not incited in sheep or cattle grazing exclusively reed canarygrass that had very high indole alkaloid concentrations. This indicated that these disorders, thought to be caused by indole alkaloids in animals grazing Phalaris species, are very likely not caused by indole alkaloids alone. We have conclusively demonstrated that palatability differences and their associated alkaloid concentration differences among reed canarygrass genotypes have a substantial biological significance for grazing lambs and steers.

Heifers (Bos taurus) may exhibit severe photosensitization and low gains when they consume ‘Monarch’ cicer milkvetch (Astragalus deer L.). We wanted to determine whether grazing lambs (Ovis aries) also would display these problems when they consumed Monarch cicer milkvetch compared to ‘120’ alfalfa (Medicago sativa L.), ‘Norcen’ birdsfoot trefoil (Lotus corniculatus L.), or ‘Arlington’ red clover (Trifolium pratense L.). A controlled, light grazing pressure (5 to 6% of body weight in leaf‐plus‐flower tissue dry matter per day) was used in pastures that had a Waukegan silt loam (flne‐silty over sandy, mixed, mesic Typic Hapludoll) soil. Lambs confined to the least palatable legume (cicer milkvetch) gained as well as or better than those confined to each of the other three species, even though animals often exhibited photosensitization exclusively on cicer milkvetch. Mean average daily gains during the 3 yr were 215, 228, 217, and 224 g Iamb‐' for alfalfa, birdsfoot trefoil, red clover, and cicer milkvetch, respectively. Even though red clover was leafier and had superior digestibility of stems and total forage, it usually did not promote different animal gains. Bloat of lambs occurred infrequently and only on alfalfa. Lamb product per hectare was influenced more by legume carrying capacity than by daily gains. The first‐year carrying capacity advantage of red clover progressively declined until it was lowest during the third year. We conclude that legume nutritive value variation had no consistent significance for lamb performance, and that earlier intake and gain problems by cattle that grazed cicer milkvetch were not repeatable with lambs. The excellent long‐term pasture persistence, carrying capacity, nutritive value, and lamb gains attributable to cicer milkvetch indicate that more research and breeding improvement are merited with this species even though it can cause photosensitization. Poorer persistence, but excellent initial carrying capacity, nutritive value, and lamb gains from red clover and birdsfoot trefoil indicate that breeding specifically to develop longer stand life would greatly enhance their pasture potential.