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Multispecies swards, comprised of different plant functional groups have comparable production potential to high N input L. perenne swards at reduced N when legumes are included. However, information on the appropriate management of multispecies swards is limited. The effect of differing management practices on the herbage dry‐matter (DM) production and botanical composition of different sward types was investigated using a 3 × 2 × 2 factorial design plot experiment. The experiment consisted of three sward types: L. perenne‐only receiving (LP; 250 kg N ha−1 a−1); L. perenne‐Trifolium repens (LP‐TR); multispecies sward containing L. perenne, Phleum pratense, Trifolium repens, Trifolium pratense, Plantago lanceolata and Cichorium intybus (MSS). LP‐TR and MSS received 90 kg N ha−1 a−1. Harvesting of plot herbage took place every 21 or 28 days to a defoliation height of 4 or 6 cm, over two growing seasons (March to November 2020 and 2021 inclusive). Annual herbage produced by both LP and LP‐TR was not significantly affected by defoliation frequency. However, MSS produced 1923 kg DM ha−1 a−1 more herbage when harvested less frequently. Unsown species contributed significantly less to the herbage DM of MSS compared to LP and LP‐TR and remained similar in 2020 and 2021, whereas the contribution of unsown species to herbage DM increased in LP and LP‐TR from 2020 to 2021, with noxious species more associated with LP and LP‐TR than MSS. Results demonstrate the role of multispecies swards in improving the sustainability of grass‐based agricultural systems in an environment of reduced fertilizer inputs. [ABSTRACT FROM AUTHOR]

Keywords: Clover; grass; legumes; forage; alfalfa; herbicide resistance; buttercup; chicory; proximal hyperspectral sensing EN Clover grass legumes forage alfalfa herbicide resistance buttercup chicory proximal hyperspectral sensing 249 251 3 05/17/22 20220801 NES 220801 In this special issue of NZJA, we have collected papers that focus on new science in the discipline of plant sciences. Ranunculus acris control in dairy pasture - a comparison of herbicides, plant growth promoters, a bioherbicide and pregraze mowing. Clover, grass, legumes, forage, alfalfa, herbicide resistance, buttercup, chicory, proximal hyperspectral sensing Continuing the legume theme, Gerard et al. ([7]) present an interesting data set comparing yields of eight perennial clover cultivars under field conditions over two years. [Extracted from the article]

Perennial ryegrass (Lolium perenne L.) is cultivated in many countries for its high yield and good quality forage. Its cultivars have specific functional traits, such as phenology, growth habit and rate, which affect the competitiveness and productivity of mixtures. The cultivation of new cultivars of perennial ryegrass or mixtures of cultivars in swards is one of the complementary measures to improve the condition of swards. The study was aimed to determine the productivity potential of three newer, less investigated Lithuanian perennial ryegrass (Lolium perenne L.) cultivars 'Elena DS', 'Raminta', 'Verseka', and cultivar mixtures in single-species swards and in mixtures with legumes - white and red clover. The experiment was set up in the central part of Lithuania in the Nemoral climate zone. Mineral fertilisers were not used for the mixtures with legumes, singlespecies crops were fertilised with N150 kg ha-1 yr-1. Over the two experimental years, the average dry matter yield of perennial ryegrass was 8.00 t ha-1 for the 'Elena DS', 7.4 t ha-1 for 'Verseka', 6.9 t ha-1 for 'Raminta' and 7.4 t ha-1 for the cultivar mixture. In the 1st year of sward use, the productivity of the perennial ryegrass cultivars did not differ significantly. In the 2nd year, the productivity of 'Elena DS' was significantly higher compared with that of the other cultivars cultivated in single-species crops. The influence of functional traits of the cultivars was significant in the first year of cultivation and persisted in single-species swards but not in mixtures from the second year onwards. The plants of the cultivar 'Elena DS' allowed the development of clover in the mixture, resulting in an increase in herbage productivity and crude protein content. The results of the experiment suggest that a mixture of perennial ryegrass cultivars can be used in swards, as a similar dry matter yield was recorded compared to a single-cultivar swards. However, the benefits of swards may vary from season to season, and more research is needed to assess the impact of a mixture of cultivars on grass productivity and quality with ageing of swards and accumulation in different environmental conditions. [ABSTRACT FROM AUTHOR]

This experiment investigated the feasibility of using herb-clover mixes to enable early weaning of lambs at ∼60 days of age. Over two years, twin lambs weighing more than 16 kg were allocated to three treatments: ryegrass pastures until 90 days-of-age, herb-clover mix until 90 days-of-age or weaned at ∼60 days of age onto herb-clover mix. In 2014, lambs offered the herb-clover mix, weaned at 60 or 90 days, were heavier at 90 days than lambs grazing on pasture with their dams. In 2015, lambs that weaned early onto the herb-clover mix were lighter at the same age as lambs that remained with their dam, but they still achieved a commercial weight. Ewes weaned early were heavier at weaning than ewes suckling lambs on ryegrass pasture in both years. Under some conditions, early weaning of lambs onto a herb-clover mix can be an effective alternative to conventional weaning on ryegrass pasture. [ABSTRACT FROM AUTHOR]

• Red clover inclusion to a grass sward improved pre-weaning lamb performance. • Clover or herb inclusion to a grass sward improved post-weaning lamb performance. • Days to slaughter was reduced by grazing binary sward types. • Ewe performance was largely similar across all sward types studied. Ireland's competitive advantage in sheepmeat production is based on the efficient and cost effective production and utilisation of pasture. The objective of this study was to assess the influence of binary mixtures of perennial ryegrass (Lolium perenne L.) plus a companion forage on ewe and lamb performance at pasture. Five sward mixtures were compared, namely; i) perennial ryegrass (Lolium perenne L.;PRG), ii) PRG plus white clover (Trifolium repens L.;PRG + WC), iii) PRG plus red clover (Trifolium pratense L.;PRG + RC), iv) PRG plus plantain (Plantago lanceolate L.;PRG + Plan) and v) PRG plus chicory (Chicorium intybus L.;PRG + Chic). Five farmlets with one sward treatment assigned to each were established which 23 ewes plus their lambs grazed from March to December for the years 2018 to 2021 inclusive. Farmlets were rotationally grazed, stocked at 11.5 ewes/ha and received 130 kg nitrogen/ha/year. Lambs were weaned on average at 15 weeks of age. Post-weaning a leader-follower grazing system was implemented with lambs grazing ahead of the ewes. Post weaning, lambs were weighed fortnightly and drafted at a live weight of 42 kg in June and increasing by 1 kg per month thereafter to produce a target carcass weight of 20 kg. Results show that lamb lifetime average daily gain (ADG) was greater for lambs grazing all binary sward mixtures relative to grazing PRG. Relative to PRG, lamb lifetime ADG was increased by between 17 g/day (PRG + Plan; P < 0.01) to 31 g/day (PRG + RC, and PRG + Chic; P < 0.001) and subsequently the number of days required to reach slaughter (DTS) was reduced by between 15.8 days (PRG + Plan; P < 0.01) to 28.6 days (PRG + RC; P < 0.001) with the addition of a companion forage. As a result of lower DTS, the average total number of anthelmintic treatments administered per lamb was significantly reduced for lambs grazing on all of the binary sward mixtures relative to PRG (P < 0.001). Scanned litter size and ewe milk yield were similar across all sward types as were ewe body weight (BW) and body condition score (BCS) from mating up until 6 weeks post-lambing (P > 0.05). Of the ewes retained from one production year to the next, those grazing PRG + WC, PRG + RC and PRG + Plan had a greater BW than those grazing PRG at the second mating event (P < 0.05), whilst, PRG + RC, PRG + Plan and PRG + Chic ewes had a greater BCS than PRG ewes (P < 0.05). These results suggest the suitability of binary sward mixtures under an intensive sheep grazing system to improve ewe and lamb performance at pasture. [ABSTRACT FROM AUTHOR]

• Multispecies increased forage intake and milk production of dairy cows. • Urinary N% was 20% lower when cows consumed multispecies. • Cows offered clover forages had a higher N intake and lower N use efficiency. • Perennial ryegrass resulted in the highest milk and N use efficiency. The objective of this experiment was to assess the impact of forage type on the DMI and milk production of mid-late lactation dairy cows. Perennial ryegrass (Lolium perenne) (PRG), PRG and white clover (Trilfolium repens) (PRGWC) and multispecies forage containing PRG, timothy (Phleum pratense), WC, red clover (Trifolium pratense), chicory (Cichorium intybus), and plantain (Plantago lanceolata) (MULTI), were compared using 24 cows in a three-period Latin square changeover design experiment. Cows were acclimatized to dietary treatments for 14 days, before entering a 21-day sampling period. Animals were housed indoors throughout the experiment, with access to forage treatments via computerized feeding boxes that recorded daily forage fresh weight intake and feeding behavior. Forage was harvested using a zero-grazer and feed boxes filled throughout the day. Forage dry matter was determined daily and forage DMI subsequently calculated. Milk yield (MY) was recorded daily, with milk composition (fat, protein, lactose) measured weekly. Once per sampling period, blood and rumen samples were collected. The partitioning of dietary nitrogen into milk, feces and urine was assessed for 6-days in each sampling period. Data was analyzed in SAS using PROC MIXED and checked for normality using UNIVARIATE. Forage botanical composition changed from period 1 to period 2 and 3, leading to significant differences in chemical composition between periods. Despite this, dry matter intake was consistently higher (P <0.05) for MULTI (20.14 kg DM) and PRGWC (18.30 kg DM) compared to PRG (17.06 kg DM). Offering cows MULTI increased daily MY (21.20 kg/d; P <0.001) compared to PRG (20.28 kg/d) and PRGWC (20.19 kg/d). Cows offered PRG made fewer visits to the feed box (P <0.001) and had a reduced meal size (kg/visit) (P <0.001) compared to PRGWC and MULTI. Offering cows MULTI reduced UN concentration (%) by 20% compared to either PRG or PRGWC. Perennial ryegrass resulted in higher dietary nitrogen use efficiency (NUE) compared to PRGWC or MULTI, though this effect was not consistent between periods. These results show that multispecies forages can increase milk production when offered to cows housed indoors. However, despite MULTI resulting in a lower UN concentration, cows offered PRG had a higher dietary NUE, likely due to a lower N intake. [ABSTRACT FROM AUTHOR]

Decreasing reliance on fertiliser Nitrogen (N) is key to enhancing the sustainability of pasture-based agricultural systems. This study assesses the effect of sward type on annual and seasonal herbage dry-matter (DM) production potential, sown species and unsown species contribution to herbage DM under an intensive dairy-calf to beef system. Three sward types were investigated in a farmlet experiment: Lolium perenne (LP; 205 kg N ha-1 a-1); L. perenne-Trifolium repens (LP-TR); multispecies sward consisting of L. perenne, Phleum pratense, T. repens, Trifolium pratense, Cichorium intybus and Plantago lanceolata (MSS). L. perenne-T. repens and MSS each received 92 kg N ha-1 a-1. Herbage samples were collected for DM production and botanical composition determination at each grazing. Further quadrat sampling was undertaken on three occasions per grazing season (early-, mid- and late-season), to enumerate the unsown species composition of swards and changes in bare ground. Over the course of the two-year study, LP, LP-TR and MSS produced annual herbage DM yields of 9950, 10,650 and 12,600 kg DM ha-1 a-1 respectively, despite reducing fertiliser N application to LP-TR and MSS by 55% compared to LP. The average proportional contribution of grass species to MSS' herbage DM remained constant, the clover content of MSS increased, while the herb content decreased from 2020 to 2021. Seasonally, the proportional contribution of L. perenne and P. lanceolata to MSS' herbage DM declined as the grazing season progressed, the contribution of T. repens and T. pratense increased and that of P. pratense and C. intybus remained similar. In LP-TR, T. repens ' proportional contribution to herbage DM increased from 2020 to 2021, while L. perenne 's proportional contribution declined. Seasonally, the proportional contribution of L. perenne to the herbage DM of LP-TR declined as the grazing season progressed, while the proportion of T. repens ' increased. The contribution of dead plant material to herbage DM increased across all swards in the second year but did not differ between sward types. Sward type did not affect the proportional contribution of unsown species by functional group to herbage DM. These results demonstrate that under a relatively-intensive beef grazing system, MSS receiving reduced N compared to LP monocultures, and the same N compared to LP-TR swards, produce more herbage DM, and do not have a greater weed (unsown species) burden. Overall, our findings demonstrate the potential of MSS to 'produce more while using less', a key requirement of sustainable grazing systems. • The performance of a six species multispecies sward (MSS) was tested for two years. • The performance of MSS was compared to that of a perennial ryegrass monoculture (LP) and LP-white clover mixture (LP-TR). • MSS demonstrate potential for higher DM production from lower N inputs compared with LP. • MSS swards did not show signs of increased unsown species to LP despite a lack of herbicide application. • Legumes persist well, however herbs do not under an intensive, rotationally grazed dairy calf to beef system. [ABSTRACT FROM AUTHOR]

• Multispecies had a higher dry matter degradability than grass/grass-clover forages. • Rumen pH was below 6.0 for longer when cows consumed multispecies. • Perennial ryegrass-white clover resulted in higher rumen ammonia throughout the day. • Multispecies can support milk production but may result in lower milk fat. An experiment was conducted to compare the rumen fermentation and degradability of three forage treatments. A perennial ryegrass (PRG; Lolium perenne), perennial ryegrass and white clover (Trifolium pratense) (PRGWC) and multispecies forage (MULTI), containing two grass species; perennial ryegrass and timothy (Phleum pratense); two clover species; white clover and red clover (Trifolium repens); and two herb species; chicory (Cichorium intybus) and plantain (Plantago lanceolata), were compared. Six rumen fistulated lactating dairy cows were used in a replicated 3 × 3 Latin square experiment consisting of 3 periods lasting 21-days. Cows were allowed ad libitum access to fresh forage and offered 2.71 kg DM concentrate each day. During days 1 – 14 of each period, cows were acclimatized to dietary treatments before entering a 7 – day sampling period. Indwelling rumen pH probes were inserted into the rumen of each cow on day 15 and 16. Rumen fluid samples were taken on day 18 every 2 h for rumen volatile fatty acid and ammonia nitrogen (NH 3 N) analysis. Forage dry matter (DM) and crude protein (CP) degradability was assessed via in sacco incubation beginning on day 19 of each period. Treatment had no effect on dry matter intake (DMI) or milk yield. There was no difference in mean rumen pH between treatments. The rumen pH of cows offered MULTI was below pH 6.0 for a higher percentage of time than the other treatments, however the concentration of acetic acid in the rumen of cows was similar between treatments. Effective degradability (ED) of DM was higher (P = 0.003) for MULTI (0.77) compared to PRG (0.68) and PRGWC (0.66). The soluble CP fraction of MULTI and PRGWC was significantly lower than that of PRG (P = 0.007), though PRGWC had the highest rumen ammonia concentration of all treatments (P = 0.002). MULTI had the highest ED and rate of DM degradation in the rumen, and lowest soluble CP of all treatments. Multispecies forages can support milk production in lactating dairy cows; however, care must be taken to ensure adequate dietary NDF due to the low fiber concentration and highly degradable nature of the forage. [ABSTRACT FROM AUTHOR]

Over a three year period the performance of lambs being finished on three sward treatments were compared. The three treatments included (i) ‘Grass-clover mixture’; perennial ryegrass ( Lolium perenne L.) and white clover ( Trifolium repens ) (ii) ‘Plantain-clover mixture’; plantain ( Plantago lanceolata ), white clover and red clover ( Trifolium pratense ) (iii) ‘Chicory-plantain-clover mixture’; plantain, chicory ( Cichorium intybus L.), white- and red-clover. Each year was divided into five grazing periods namely; winter, early spring, late-spring, summer and autumn with only the Grass-clover mixture being utilised in the winter due to the growth profile and management requirements of the herb species. Over the three year period, a total of 3353 kg live weight per ha was produced on the Grass-clover mixture, which was less (P < 0.05) than the 3838 kg/ha produced with the Plantain-clover mixture or 3768 kg/ha on the Chicory-plantain-clover mixture. Similarly over the three year period, 1270 kg of carcass weight gain per ha was produced on the Grass-clover mixture, which was less (P < 0.05) than the 1706 kg/ha produced with the Plantain-clover mixture or 1732 kg/ha with the Chicory-plantain-clover. This indicates that farmers aimed at lamb finishing can have some confidence that when utilising these herb-clovers mixtures they can increase lamb and meat productivity for at least three years. [ABSTRACT FROM AUTHOR]

In dairy systems, grass–clover swards are fertilized with on–farm cattle slurry as a basic dressing and often supplemented with mineral fertilizer throughout the season. Uncertainty remains on consequences for N input from atmospheric N 2 -fixation by grassland legumes. The aim of this study was to examine the N response of slurry versus mineral N fertilization on clover dynamics, the proportion of N derived from the atmosphere (%Ndfa) and the quantitative N 2 -fixation (qBNF) using the 15N isotope dilution method. This was done in an on farm setting at two sites in two years with increasing rates of N fertilizer (0–480 kg available N ha-1) either of mineral N only or combined with application of cattle slurry. The leys were at one site composed a 2–species mixture of white clover (Trifolium repens L.) and ryegrass (Lolium perenne L.) and at the other site of a 4–species mixture of white clover, red clover (Trifolium pretense L.), festulolium (Festulolium braunii) and ryegrass. Species dynamics were significantly affected by fertilizer rate in the 2–species sward and by fertilizer rate and type in the 4–species sward. Reduction of the clover proportion in response to fertilization was due to a clover yield decrease (2–species sward) or a grass yield increase (4–species sward). In the 4–species sward, in treatments with mineral N only %Ndfa decreased markedly with N rate, whereas the corresponding slurry + mineral N treatments did not. Thus, apart from fertilization with mineral N only at one site the general picture was a relatively high (>80%) %Ndfa over the season when the N level was below 200–300 kg available N ha-1. The qBNF of the harvested biomass in sward without fertilization reached 193–216 kg N ha-1 in the 2–species sward and 203–286 kg N ha-1 in the 4–species sward. Clover persisted at high fertilization rates, but qBNF was reduced to 16–79 kg N ha-1 and 58–163 kg N ha-1 in 2– and 4–species swards, respectively. Interestingly, in the 4–species sward amended with slurry + mineral N, qBNF was high and independent of fertilization rate. We conclude that response of clover dynamics to N fertilization differed with fertilizer type and level – slurry have lower effect whereas the effect of mineral N only on N 2 -fixation is less predictable. • N response of grass–clover leys was investigated as affected by mineral N or slurry. • Dry matter yield and grass fraction increased as expected with N level. • Leys at two sites showed two patterns of N 2 -fixation activity response to fertilizer type. • Slurry in combination with mineral N sustained high N 2 -fixation until 240 kg N ha-1. • Clover N 2 -fixation response to mineral N only was less predictable among sites. [ABSTRACT FROM AUTHOR]

Simple Summary: The present study simulated the effects of different dairy cow diets based on local feeding strategies on enteric methane (CH4) emissions and surpluses of crude protein (CP) in small-scale dairy systems (SSDS). Our study evaluated five scenarios of supplementation (S): without supplementation (control diet), meaning no supplements were provided, only pasture (S1); pasture supplemented with 4.5 kg dry matter (DM)/cow/day of commercial concentrate (CC) (S2); supplemented with 200 g DM/kg per milk produced of CC (S3); supplemented with ground maize grains and wet distiller brewery grains (S4); and S4 plus maize silage (S5). In addition, two pasture managements (cut-and-carry versus grazing) and two varieties of legumes (red clover vs. white clover) were considered. The results suggest that methane emissions and large nitrogen surpluses in the diet are affected by the type of supplementation given to cows, in addition to the management and chemical composition of the pastures offered. In SSDS, it is possible to formulate diets with local inputs to reduce excess nutrients and dependence on external inputs, increasing feed efficiency and reducing costs (excess of CP in the diet) and CH4 emissions. In cattle, greenhouse gas (GHG) emissions and nutrient balance are influenced by factors such as diet composition, intake, and digestibility. This study evaluated CH4 emissions and surpluses of crude protein, using five simulated scenarios of supplementation in small-scale dairy systems (SSDS). In addition, two pasture managements (cut-and-carry versus grazing) and two varieties of legumes (red clover vs. white clover) were considered. The diets were tested considering similar milk yield and chemical composition; CH4 emission was estimated using Tier-2 methodology from the Intergovernmental Panel on Climate Change (IPCC), and the data were analyzed in a completely randomized 5 × 2 × 2 factorial design. Differences (p < 0.05) were found in predicted CH4 emissions per kg of milk produced (g kg−1 FCM 3.5%). The lowest predicted CH4 emissions were found for S3 and S4 as well as for pastures containing white clover. Lower dietary surpluses of CP (p < 0.05) were observed for the control diet (1320 g CP/d), followed by S5 (1793 g CP/d), compared with S2 (2175 g CP/d), as well as in cut-and-carry management with red clover. A significant correlation (p < 0.001) was observed between dry matter intake and CH4 emissions (g−1 and per kg of milk produced). It is concluded that the environmental impact of formulating diets from local inputs (S3 and S4) can be reduced by making them more efficient in terms of methane kg−1 of milk in SSDS. [ABSTRACT FROM AUTHOR]

Simple Summary: Diverse pastures based on combinations of the forage herb species plantain and chicory with red clover and white clover, provide superior annual feeding value to finish lambs in temperate regions, compared to the traditionally used perennial ryegrass and white clover pastures. The success of herb-clover diverse pastures is dependent on maintaining the relative abundance of each species in the mix over time. The selective grazing by lambs on herb-clover mixes was compared with their selection on perennial ryegrass and white clover pasture, by using randomly tagged individual plants, to determine if selective grazing changed the relative abundance of any of the herb or clover species. Variations in the selection of the forage species over the seasons of the year were observed, but best practice grazing management was shown to maintain the relative abundance of species in herb-clover pastures required for superior lamb live weight gains. Plantain (Plantago lanceolata) and chicory (Cichorium intybus) are now widely used in combination with clover species to provide greater annual lamb live weight gains than perennial ryegrass and white clover pasture. Reported selective grazing of the species in herb-clover mixes could potentially detrimentally change the relative abundance of species and decrease lamb production. Lambs were offered three herbage treatments: Pasture (perennial ryegrass and white clover) mix, plantain (plantain, red clover and white clover) mix and a chicory (chicory, plantain, red clover and white clover) mix in each of four seasons for two years. The experiment was a randomized complete block design with three replicates with 18–30 lambs per treatment replicate depending on the season. Lambs were rotationally grazed and fed ad libitum. Selection by the lambs of individually tagged plants within the pasture treatments was observed for three days on two occasions per season. Red clover was the most selected species on day 1, but by day 3 there was no difference in the selection of the species (p < 0.05). Plantain and chicory in the plantain and chicory mixes were selected less on day 1 in autumn relative to the other seasons (p < 0.05). It was concluded that three days of grazing before moving lambs maintained the relative abundance of species in the herb-clover mixes. [ABSTRACT FROM AUTHOR]

Simple Summary: Exposure of lambs to herbage-based diets prior to weaning may facilitate the development of the rumen which may subsequently increase animal performance after early weaning. The aim of this study was to estimate the effects of varying durations of exposure of lambs to a herb–clover mix containing chicory, plantain, red clover, and white clover prior to early weaning (at ~45 days of age) on their subsequent growth and rumen development at conventional weaning age. Prolonged exposure of lambs to the herb–clover mix prior to early weaning had no impact on lamb growth or rumen development, suggesting that using this management option will not improve performance of lambs after early weaning. Twin sets of lambs were randomly allocated to one of six treatments: (1) lambs born and managed on ryegrass–clover-based pasture until conventional weaning approximately at 99 days of age (Grass–GrassCW); (2) lambs born on ryegrass–clover-based pasture and early weaned onto a herb–clover mix at ~45 days of age (Grass–HerbEW); (3) lambs born on ryegrass–clover-based pasture, transferred with their dam onto a herb–clover mix at ~45 days of age until conventional weaning (Grass–HerbCW); (4) lambs born on ryegrass–clover-based pasture, transferred with their dam onto a herb–clover mix at ~15 days of age and early weaned onto a herb–clover mix at ~45 days of age (Grass–HerbD15EW); (5) lambs born and managed on herb–clover mix until conventional weaning (Herb–HerbCW); (6) lambs born on herb–clover mix and weaned early onto a herb–clover mix at ~45 days of age (Herb–HerbEW). In both years, Herb–HerbCW lambs had greater (p < 0.05) growth rates than lambs in other treatments. The liveweight gains and rumen papillae development of Herb–HerbEW, Grass–HerbD15EW and Grass–HerbEW lambs did not differ (p > 0.05). The weight of the empty digestive tract components at either early weaning or conventional weaning did not differ (p > 0.05) between treatments. Exposing early-weaned lambs to the herb mix for a prolonged period, prior to early weaning, does not improve their subsequent growth. [ABSTRACT FROM AUTHOR]