Grazing swathed, small‐grain crops can reduce costs of overwintering beef cows (Bos taurus) by 40%. However, the late planting required to target mid‐September harvest may be associated with low yield and carrying capacity. The objective was to compare whole‐plant yield, nutritive value, and potential carrying capacity in relation to beef cow requirements for spring barley (Hordeum vulgare L.), oat (Avena sativa L.), and triticale (X Triticosecale Wittmack) when planted on seven weekly intervals (10 May–23 June) over 3 yr at Lacombe, AB; whole‐plant material was harvested at soft dough (barley and triticale) or milk stages (oat). Data were analyzed relative to planting date delay as an independent variable. Barley matured more rapidly than oat and triticale, with the latest planting date harvested on 27 August for barley, 8 September for oat and 25 September for triticale. Nutritive value for barley and triticale was unaffected by planting date, but neutral (NDF) and acid detergent fiber (ADF) concentrations increased quadratically with delay in planting for oat. In vitro true digestibility (IVTD) was lower for oat than barley and triticale. Yield declined linearly with planting delay for barley (35–39%), but increased (quadratically) as planting was delayed from late May to early June for oat (8%) and triticale (10%). Consequently, the potential carrying capacity for triticale was 1.6 and 1.8 times greater than barley and oat, respectively when planted for swathing in late August or early September.

We have measured peak plasma concentrations of lignocaine and bupivacaine after dual injection peribulbar block and investigated the influence of adrenaline and hyaluronidase. Twenty-four patients were allocated randomly to one of four groups: (I) local anaesthetic alone (lignocaine 10 mg ml-1-bupivacaine 3.75 mg ml-1); (II) local anaesthetic with adrenaline (5 micrograms ml-1); (III) local anaesthetic with hyaluronidase (75 iu ml-1); or (IV) local anaesthetic with adrenaline and hyaluronidase. Venous plasma concentrations of lignocaine and bupivacaine were measured in 24 patients using gas liquid chromatography before and at 5, 10, 15, 20, 25, 30, 45, 60, 90, 120, 180, 300 and 540 min after completion of the peribulbar injections. Main outcome measures were analysed using two-way analysis of variance. All patients, with one exception, received 10 ml of the local anaesthetic mixture. Overall peak plasma concentrations varied from 230 to 1910 micrograms ml-1 for lignocaine and from 160 to 1090 micrograms ml-1 for bupivacaine. Adrenaline significantly reduced peak plasma concentrations of lignocaine to 57% (P = 0.001) and bupivacaine to 61% (P = 0.004) compared with the nonadrenaline groups. Hyaluronidase had no significant effect on peak plasma concentrations of lignocaine and bupivacaine, which were 90% (P = 0.34) and 100% (P = 0.84) of the non-hyaluronidase groups. The area under the plasma concentration-time curves to 300 min (AUC300) behaved similarly. There was a reduction in AUC300 for lignocaine (P = 0.005) and bupivacaine (P = 0.011) in the adrenaline groups compared with the non-adrenaline groups, in contrast with no significant effects of hyaluronidase on AUC300 for lignocaine (P = 0.14) or bupivacaine (P = 0.53) compared with the non-hyaluronidase groups.

6,5,9,9 et7,5 et 10,9 et2O,4% inf6rieures. Bien qu'on ne connaisse pas l'ampleur de I'effet compensatoire, la meilleure qualit6 fourragbre des m6langes devrait compenser, du moins en partie, la l6gdre baisse de leur rendement de MS par rapport aux c6r6ales de printemps.

Grasses adapted to both hay and pasture are lacking in the prairie parkland. ‘Regar’ meadow bromegrass (Bromus riparius Rhem.), ‘Manchar’ smooth bromegrass (B. inermis Leyss.), S9044 (a smooth–meadow bromegrass cross), common meadow foxtail (Alopercurus pratensis L.), and ‘Kay’ orchardgrass (Dactylis glomerata L.) were evaluated for traits useful in dual purpose grass species at early (late May), late (late June), and regrowth (early September) harvests. Herbage, leaf, and stem nutritive value; mass; and leaf/stem ratio were determined. Differences among species were related more to herbage mass and morphology than to leaf and stem quality. Early harvest orchardgrass herbage mass was low at 55% of meadow foxtail (2.9 Mg ha−1). However, stem content of meadow foxtail represented 60% of early herbage mass, limiting its potential. Regrowth mass of meadow bromegrass, S9044, and orchardgrass exceeded 2.5 Mg ha−1, whereas smooth bromegrass and meadow foxtail were as low as 2.1 Mg ha−1. Regrowth leaf mass of the former species exceeded 1.9 Mg ha−1. Late herbage mass of smooth bromegrass was always greater than the other species. Leaf acid detergent fiber (ADF) of S9044 and smooth bromegrass was lower (range 189–242 g kg−1) than meadow bromegrass (range 217–284 g kg−1). By contrast, late and regrowth harvest stem ADF of meadow bromegrass was lower (range 237–360 g kg−1) than S9044 (range 257–366 g kg−1). Variation among Bromus types for late and regrowth yield, and leaf fiber may influence management strategies.

Soil carbon (C) and nitrogen (N) storage in grasslands is a function of litter and root mass production. Research on how annual grasses compare with perennials for above ground and below ground mass production, and contributions to the soil C pool under pasture management is scarce. The objective of this research was to evaluate grazing intensity effects on litter and root mass, C and N pools of perennial grasses, smooth bromegrass (Bromus inermis L.) and meadow bromegrass (Bromus riparius Rhem.), and the annual grass, winter triticale (X Triticosecale Wittmack). Litter mass and C pool for the perennial grasses were greater than those for triticale. Litter C and N pools generally decreased with increased grazing intensity. Root mass was greater for the perennial grasses than for triticale at all grazing intensities. Meadow bromegrass generally produced more root mass than smooth bromegrass. Root C and N pools for triticale were 31 and 27%, respectively, of that for the perennial grasses. Estimated total C contribution (roots and litter) to the resistant soil organic C pool was 1.5 times greater for light compared to heavy grazing. Total C (litter + root) contribution for perennial grasses was 2.7 times greater than that for triticale. Perennial grasses provided a larger litter base and root system that promote greater storage of C in the soil compared with triticale.