Tall fescue (Festuca arundinacea (Schreb) Darbysh.) has the potential to become a useful component of irrigated dairy pastures in northern Victoria owing to its high dry matter (DM) production compared with perennial ryegrass. However, tall fescue is not widely grown because its grazing management is perceived as difficult. In October 2010, a tall fescue–white clover pasture was established and irrigated. In September 2011, six grazing-management treatments were imposed over 3 years, involving grazing: at 1-leaf stage; at 2-leaf stage (1.5-leaf stage during spring); at 3-leaf stage (2.5-leaf stage during spring); at intervals based upon days between grazings ranging from 15 days in October–December to 60 days in winter; at intervals as above except for 21 days in October–December; and at intervals approximating that of a well-managed perennial-ryegrass-based pasture . Measurements included pre- and post-grazing pasture mass, nutritive characteristics, botanical composition and plant frequency.

Pasture consumption from the treatment grazed at the 3-leaf stage was >3.5 t DM ha^–1 year^–1 (30%) greater than from the three most frequently grazed treatments. However, crude protein content was 1–3% DM units lower when grazed at the 3-leaf stage compared with the two most frequently grazed treatments. There was no effect on estimated metabolisable energy or neutral detergent fibre contents of the pasture on offer. Differences in pasture composition between the pastures grazed at the 3-leaf stage and those most frequently grazed emerged over time and were most conspicuous in the third year, with a greater plant frequency (79% v. 66%) and tall fescue content (61% v. 40% DM) and lower weed content (14% v. 28% DM).

From the study, a grazing regime for tall fescue based on the 3-leaf stage appears promising because it produced the most DM over the experiment. A disadvantage of this regime was the need for an extra mowing each year. The practicality of this approach to grazing tall fescue needs to be tested at the whole-farm level.

Practical and reliable measurement of pasture intake by individual animals will enable improved precision in livestock and pasture management, provide input data for prediction and simulation models, and allow animals to be ranked on grazing efficiency for genetic improvement. In this study, we assessed whether pasture intake of individual grazing cattle could be estimated from time spent exhibiting behaviours as determined from data generated by on-animal sensor devices. Variation in pasture intake was created by providing Angus steers (n = 10, mean ± s.d. liveweight 650 ± 77 kg) with differing amounts of concentrate supplementation during grazing within individual ryegrass plots (≤0.22 ha). Pasture dry matter intake (DMI) for the steers was estimated from the slope (kg DM day^–1) of the regression of total pasture DM per plot on intake over an 11-day period. Pasture DM in each plot, commencing with ≤2 t DM ha^–1, was determined by using repeatedly calibrated pasture height and electronic rising plate meters. The amounts of time spent grazing, ruminating, walking and resting were determined for the 10 steers by using data from collar-mounted, inertial measurement units and a previously developed, highly accurate, behaviour classification model. An initial pasture intake algorithm was established for time spent grazing: pasture DMI (kg day^–1) = –4.13   2.325 × hours spent grazing (P = 0.010, r² = 0.53, RSD = 1.65 kg DM day^–1). Intake algorithms require further development, validation and refinement under varying pasture conditions by using sensor devices to determine specific pasture intake behaviours coupled with established methods for measuring pasture characteristics and grazing intake and selectivity.

A key goal of temperate pasture management is to optimise nutritive value and production. The influence of individual components such as irrigation, nitrogen (N) fertiliser, and grazing interval and intensity has been well researched, yet conjecture remains regarding practices that optimise pasture nutritive value, largely because interactions between inputs and grazing management have not been quantified. A 2-year, split-split-plot experiment was undertaken to investigate these interactions in a perennial ryegrass (Lolium perenne L.) dominant pasture at Elliott, Tasmania. Irrigation treatments (rainfed or irrigated) were main plots and defoliation intervals (leaf regrowth stage: 1-, 2- or 3-leaf) were subplots. Defoliation intensity (defoliation height: 30, 55 or 80 mm) and N fertiliser (0, 1.5 or 3.0 kg N/ha.day) were crossed within sub-subplots. Herbage samples were collected from each plot four times during the experiment and analysed for concentrations (% dry matter, DM) of neutral detergent fibre (NDF), acid detergent fibre (ADF) and crude protein (CP). Metabolisable energy (ME) concentration (MJ/kg DM) was estimated from these values. ME concentration decreased as defoliation height and interval increased for all time points except during winter. Crude protein concentration increased with increasing N fertiliser applications in the plots defoliated at the 1-leaf stage, but only as N applications increased from 1.5 to 3.0 kg N/ha.day for the plots defoliated at the 2- and 3-leaf stages. As N application rates increased from 0 to 1.5 kg N/ha.day, plots defoliated at the 3-leaf stage had greater increases in NDF concentration than plots defoliated at the 1-leaf stage, except during spring. As defoliation height and interval increased, ADF concentration increased in both spring and summer. Although defoliating at frequent intervals (1-leaf stage) and lower heights (30 mm) produced pasture of marginally higher nutritional value, these benefits are mitigated by the previously established, negative consequences of lower pasture yield and poor pasture persistence. Consequently, grazing management that maximises pasture productivity and persistence (i.e. defoliation between the 2- and 3-leaf regrowth stages to a height of 55 mm) should be applied to perennial ryegrass pastures irrespective of input management.

This study examined whether the productivity and persistence of mixed pastures that included subterranean clover (Trifolium subterraneum L.), lucerne (Medicago sativa L.), and/or phalaris (Phalaris aquatica L.) were improved if species were spatially separated rather than being sown together in each drill row. The study also compared the productivity and persistence of subterranean clover with alternative annual legume species biserrula (Biserrula pelecinus L.) and strand medic (Medicago littoralis Rhode ex Loisel). Twelve pasture treatments were sown in replicated field experiments at five locations across the medium-rainfall region of south-western New South Wales in 2012 and monitored for 3 years. Pastures that included lucerne, phalaris and subterranean clover were generally more productive than pastures with only one or two of those species, regardless of sowing configuration. Averaged across sites, subterranean clover regeneration in year 3 was 29% higher and total cumulative biomass 13% higher where subterranean clover was sown in a 1 : 1 configuration with lucerne than where the species were mixed together in every drill row. There were fewer consistent benefits of alternative spatial configurations on swards containing phalaris with subterranean clover or with lucerne. Results of the present study appeared to be highly site-specific, or season-dependent, and therefore alternative spatial configurations cannot be recommended as a universal strategy at this time. More research is required to understand the factors driving the responses to alternative spatial configurations observed in the present study.

Neither biserrula nor strand medic was superior to subterranean clover in a 3-year pasture phase with lucerne, despite abundant rhizobia compatible with all species at all sites. The density of subterranean clover in year 3 was 29% and 41% higher than of biserrula and strand medic, respectively. A narrow choice of adapted cultivars as well as excessive levels of hard seed for the legumes used in phased pastures with lucerne are suggested as contributing to the inferior performance of the alternative legumes species tested in the study.

Grazing management has been identified as a means of increasing livestock production and improving the composition of perennial pastures. The benefits of intensive rotational grazing have been the subject of much debate, but few studies have evaluated contrasting management of intensive rotational systems. A grazing management experiment was established on a pasture with cocksfoot (Dactylis glomerata L., varieties Porto and Kara) as the dominant species, to investigate different stocking rates, paddock numbers and rotation speeds, and a flexible treatment that adjusted grazing time, rest periods and stock numbers for optimal pasture utilisation. Data were collected on pasture composition and diet quality assessed by using faecal analysis, animal weight changes and pasture characteristics. Animal production per hectare was greatest for fast rotations (56 days’ rest) at high stocking rates (HStR, 13.6 dry sheep equivalents (DSE) ha^–1), but continuous grazing (CG) was equally productive. Although flexible grazing based on the 3–4-leaf stage was proposed as the best balance between pasture production and quality, this treatment had lower stocking rates (9.2 DSE ha^–1) and was not as productive. No treatment negatively affected pasture composition over the 4-year period. Area of bare ground was highest for the HStR CG treatment; however, the 30-paddock rotations were able to limit bare ground at the same stocking rate. The results indicated that intensive rotational grazing could be effectively managed by using green herbage allowance. In spring, green herbage allowance needed to be 1–1.5 kg green dry matter (DM) DSE^–1 day^–1, which increased to 5 kg green DM DSE^–1 day^–1 as the quality of green DM decreased, to allow selective grazing to enhance diet quality.

Perennial cereals may offer a novel forage source in mixed farming enterprises while improving the sustainability of grain farming. There has been limited analysis of the quality of this forage type and its likely value to mixed grazing/cropping farming systems. This study evaluated the biomass and grain production of four wheat × wheatgrass hybrid experimental lines under four simulated grazing regimes; nil defoliation (grain only; D₀), defoliate once (D₁), defoliate twice (D₂) and defoliate twice followed by a simulated hay cut (D₃), and compared performance to a winter wheat, Wedgetail, and the perennial grass Thinopyrum intermedium. Early biomass production of the perennial entries was significantly less than Wedgetail (P = 0.01). Grain yield from Wedgetail was generally higher (P < 0.001) than all other lines. As defoliation frequency increased, the comparative difference in grain yield between Wedgetail and the hybrid entries decreased, with lines OK7211542 and 11955 exceeding the grain yield of Wedgetail in the D₃ treatment. Cumulative annual biomass production of the hybrid lines exceeded that of Wedgetail, though the seasonal production differed markedly. Generally there was limited decline in perennial plant population between April and December in both years of the experiment. Defoliation had little impact on perennial plant survival; however, none of the hybrids could sustain a significant plant population beyond the second summer of the experiment. Yield declines of the hybrid entries was due to increasing plant mortality, rather than a predisposed yield limitation of the germplasm, as all hybrid entries either maintained or increased their grain yield on a per plant basis. In contrast, the perennial grass maintained a constant population for the duration of the experiment. Dry matter digestibility and energy content of all forages tested were high, averaging 80.2% and 13.3 MJ ME/kg DM, respectively. Crude protein was higher (P < 0.001) in Th. intermedium and the hybrid entries with 62% and 25% more crude protein than Wedgetail, respectively. All cereals had very high potassium : sodium and low calcium : phosphorus ratios, which indicated the need to provide mineral supplements to grazing animals to maintain growth rates and manage animal health disorders, similar to conventional grazing cereals. This paper discusses the role perennial cereals could play in a sustainable expansion of the cropping zone in south-eastern Australia.

Rainfed farms in south-eastern Australia often combine annual cropping and perennial pasture phases with grazing sheep enterprises. Such diversity serves in managing diseases, pests and plant nutrition while stabilising income in the face of wide, uncorrelated variations in international commodity prices and local weather over time. We use an actuarial accounting approach to capture the above contexts to render financial risk profiles in the form of distributions of decadal cash balances for a representative 1000-ha farm at Coolamon (34°50′ S, 147°12′ E) in New South Wales, Australia. For the soil and weather conditions at this location we pose the question of which approach is better when establishing the perennial pasture lucerne (Medicago sativa L.): sowing with the final crop of the cropping phase, or sowing alone following the final crop? It is less expensive to sow lucerne with the final crop, which can provide useful income from the sale of grain, but this practice can reduce pasture quantity and quality in poorer years. Although many years of field research have confirmed that sowing lucerne alone is the most reliable way to establish a pasture in this area, and years of extension messages to this effect have gone out to farmers, they often persist in sowing lucerne with their final cereal crops. For this region, counting all costs, we show that sowing lucerne alone can reduce farm financial risk (i.e. probability of negative decadal cash balances) at stocking rates >10 dry sheep equivalents (DSE)/ha, compared with the practice of sowing lucerne with a cover crop. Establishing lucerne alone allows the farmer the option to profitably run higher stocking rates for higher median decadal cash margins without additional financial risk. At low stocking rates (i.e. 5 DSE/ha), there appears to be no financial advantage of either establishment approach. We consider the level of equity, background farm debt and overhead costs to demonstrate how these also affect risk-profile positions of the two sowing options. For a farm that is deeply in debt, we cannot suggest either approach to establishing lucerne will lead to substantially better financial outcomes.

Extreme climatic events such as heat waves, extreme rainfall and prolonged dry periods are a significant challenge to the productivity and profitability of dairy systems. Despite projections of more frequent extreme events, increasing temperatures and reduced precipitation, studies on the impact of these extreme climatic events on pasture-based dairy systems remain uncommon. The Intergovernmental Panel on Climate Change has estimated Australia to be one of the most negatively impacted regions with additional studies estimating Australian production losses of around 16% in the agricultural sector and 9–19% between the present and 2050 in the south-eastern dairy regions of Australia due to climate change.

Here we review the literature on the impact of climate change on pasture-based dairy systems with particular focus on extreme climatic events. We provide an insight into current methods for assessing and quantifying heat stress highlighting the impacts on pastures and animals including the associated potential productivity losses and conclude by outlining potential adaptation strategies for improving the resilience of the whole-farm systems to climate change. Adapting milking routines, calving systems and the introduction of heat stress tolerant dairy cow breeds are some proposed strategies. Changes in pasture production would also include alternative pasture species better adapted to climate extremes such as heat waves and prolonged periods of water deficit. In order to develop effective adaptation strategies we also need to focus on issues such as water availability, animal health and associated energy costs.