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An innovation systems approach involving agribusiness representatives, researchers and farmers identified that damage caused by grass grub (Costelytra giveni) was a key factor contributing to areas of reduced yield within high-producing pastures. Using a recognised yield mapping technique, areas of ‘Low’ and ‘High’ pasture height were identified in different paddocks over 3 years; ‘Low’ areas had significantly higher numbers of grass grub larvae than ‘High’ areas. Pasture production was measured for the ‘Low’ and ‘High’ pasture height areas, and the difference was calculated to be 6800 kg DM/ha for 2018/19. This difference persisted after grass grub larvae were no longer active. Farm systems modelling analysis estimated this ‘yield gap’ led to a $650/ha/year difference in profit. A survey of farmer perceptions of grass grub damage on 23 central Canterbury dairy farms estimated 19% of pastures were affected by grass grub, with 11% of the area in those paddocks being damaged. Econometric modelling showed differences in farmer perceptions of grass grub damage. Data from the survey and the pasture measurements were combined with the farm systems modelling results to estimate a $1,870,000/year regional-scale impact of the ‘yield gap’. An integrated pest management approach is suggested to control grass grub damage.

Models for infestations of Californian thistle (Cirsium arvense) and variegated thistle (Silybum marianum) were used to modify fortnightly pasture growth forecasts using Agricultural Production Systems simulator software using climate and soil data from a single farm (Tangihanga Station) over four aspects and three slope classes. Modelling using Farmax software was used to estimate profitability using the current farm enterprises with or without either the Californian or variegated thistles. Modelled pasture production, based on field observations of thistle infestation, was similar to estimates using animal intake (from Farmax). Californian thistle reduced pasture production in summer and autumn, while variegated thistle reduced autumn, winter and spring pasture growth. Californian thistle had a much greater overall presence (20%) than variegated thistle (9%). Both types of thistle reduced the potential to finish lambs in summer and reduced ewe wintering numbers, while the presence of Californian thistles also reduced over-wintering cattle numbers, by reducing summer-autumn pasture accumulation. Cost of control for Californian thistle ($233/ha) over two years was higher than for variegated thistle ($184/ha) over four years. Net profitability was reduced by 24% ($87/ha) by the presence of Californian thistle, and by 37% ($135/ha) by the presence of variegated thistle.

© 2017 Elsevier Ltd Crops and livestock play a synergistic role in global food production and farmer livelihoods. Increasingly, however, crops and livestock are produced in isolation, particularly in farms operating at the commercial scale. It has been suggested that re-integrating crop and livestock systems at the field and farm level could help reduce the pollution associated with modern agricultural production and increase yields. Despite this potential, there has been no systematic review to assess remaining knowledge gaps in both the social and ecological dimensions of integrated crop and livestock systems (ICLS), particularly within commercial agricultural systems. Based on a multi-disciplinary workshop of international experts and additional literature review, we assess the current knowledge and remaining uncertainties about large-scale, commercial ICLS and identify the source of remaining knowledge gaps to establish priorities for future research. We find that much is understood about nutrient flows, soil quality, crop performance, and animal weight gain in commercial ICLS, but there is little knowledge about its spatial extent, animal behavior or welfare in ICLS, or the tradeoffs between biodiversity, pest and disease control, greenhouse gas (GHG) mitigation, and drought and heat tolerance in ICLS. There is some evidence regarding the economic outcomes in commercial ICLS and supply chain and policy barriers to adoption, but little understanding of broader social outcomes or cultural factors influencing adoption. Many of these knowledge gaps arise from a basic lack of data at both the field and system scales, which undermines both statistical analysis and modeling efforts. Future priorities for the international community of researchers investigating the tradeoffs and scalability of ICLS include: methods standardization to better facilitate international collaborations and comparisons, continued social organization for better data utilization and collaboration, meta-analyses to answer key questions from existing data, the establishment of long term experiments and surveys in key regions, a portal for citizen science, and more engagement with ICLS farmers.

Context Since COVID-19 (SARS-CoV-2) was first identified in the human population, it has had immediate and significant effects on peoples' health and the worldwide economy. In the absence of a vaccine, control of the virus involved limiting its spread through restrictions in the movement of people, goods and services. This has led to unprecedented impacts on labour availability, provision of goods and services, value chains, and markets. Objective Against the backdrop of COVID-19 control measures, this article summarises quantitative and qualitative assessments of the impacts, adaptations, and opportunities to increase the resilience of the agricultural systems in Australia and New Zealand. Methods Using both survey and interview methodologies, we describe the various agri-food systems and the impacts of the COVID-19 control measures across different industries, and discuss the results applying a resilience framework. Results As essential services, all agricultural activities except for fibre production have been permitted to continue during quarantine periods but have been exposed to the major flow-on effects of movement control. We found that, to June 2020, the impacts of the COVID-19 control measures on the agri-food sectors in both Australia and New Zealand have been relatively small and that this has been due to the high levels of resilience in the agricultural systems and the people running them. Conclusions We consider agri-food systems to be comprised of multiple subsystems with varying vulnerability to external influences. Agri-food systems were resilient to June 2020 at least, and that resilience was achieved via one or more subsystems that were able to compensate for the more vulnerable subsystems. We contrast the resilience of industries that have high plasticity (that can have a flow of material that can safely vary in time) to more rigid industries that are dependent on a steady flow of material with little or no storage. Ultimately both types of industries were resilient, but they achieved that resilience via compensating subsystems. High plasticity industries relied on their production and processing subsystem; rigid industries engaged their institutional subsystem to achieve the same end. The social and cultural subsystem was important across all industries. Significance It is not yet clear if the current resilience mechanisms can persist under the continued onslaught of the virus. We indicate the need to capture longer term effects and analysis during the more sustained effects of the virus and through a recovery period. We anticipate a follow-up study in 2022.

Although the link between agriculture and diffuse water pollution has been understood for decades, there is still a need to implement effective measures to address this issue. In countries with light-touch regulation, such as New Zealand and Australia, most efforts to promote environmental management practices have relied on voluntary initiatives such as participatory research and extension programmes; the success of which is largely dependent on farmers’ willingness and ability to adopt these practices. Increased understanding of the factors influencing farmer decision-making in this area would aid the promotion of effective advisory services. This study provides insights from 52 qualitative interviews with farmers and from observations of nine farmer meetings and field days. We qualitatively identify factors that influence farmer decision-making regarding the voluntary uptake of water quality practices and develop a typology for categorising farmers according to the factors that influence their decision-making. We find that in light-touch regulated countries certainty around policy and also around the effectiveness of practices is essential, particularly for farmers who delay action until compelled to act due to succession or regulation. The contribution of this paper is threefold: (i) it identifies factors influencing decision-making around the uptake of water quality practices in a light-touch regulated country; (ii) it develops a typology of different farmer types; and (iii) it provides recommendations on policy approaches for countries with light-touch regulation, which has potential relevance for any countries facing changes regarding their agricultural policy, such as post-Brexit policy in the UK.

Between 2011 and 2016, small-scale farm trials were run across three dairy regions of New Zealand (Waikato, Canterbury, Otago) to compare the performance of typical regional farm systems with farm systems implementing a combination of mitigation options most suitable to the region. The trials ran for at least three consecutive years with detailed recording of milk production and input costs. Nitrate leaching per hectare of the milking platform (where lactating cows are kept) was estimated using either measurements (suction cups), models, or soil mineral nitrogen measurements. Post-trial, detailed farm information was used in the New Zealand greenhouse gas inventory methodology to calculate the emissions from all sources, dairy platform, dairy support land used for wintering non-lactating cows (where applicable) and replacement stock, and imported supplements. Nitrate leaching was also estimated for the support land and growing of supplements imported from off-farm using the same methods as for the platform. Operating profit (NZ$/ha/year), nitrate leaching (kg N/ha/year), and greenhouse gas emissions (t CO2-equivalent/ha/year) were all expressed per hectare of milking platform to enable comparisons across regions. Nitrate leaching mitigations adopted in lower-input (less purchased feed and nitrogen fertiliser) farm systems reduced leaching by 22 to 30 per cent, and greenhouse gas emissions by between nine and 24 per cent. The exception was the wintering barn system in Otago, where nitrate leaching was reduced by 45 per cent, but greenhouse gas emissions were unchanged due to greater manure storage and handling. Important drivers of a lower environmental footprint are reducing nitrogen fertiliser and purchased feed. Their effect is to reduce feed flow through the herd and drive down both greenhouse gas emissions and nitrate leaching. Emission reductions in the lower-input systems of Waikato and Canterbury came at an average loss of profit of approximately NZ$100/t CO2-equivalent (three to five per cent of industry-average profit per hectare).

Wintering cows on forage crops leads to urine being excreted onto wet, compacted soils, which can result in significant emissions of nitrous oxide (N2O). A field trial was conducted to determine the N2O emission factor (EF3; proportion of urine-N lost as N2O-N) for dairy cows wintered on a kale forage crop on a poorly drained soil. Urine was collected from non-lactating dairy cows on a forage kale diet and applied at 550 kg N ha−1 to artificially compacted soil to simulate trampling and non-compacted soil in a kale field. Cumulative N2O losses over four months were 7.38 and 2.64 kg N2O-N ha−1 from urine applied to, respectively, compacted and non-compacted soil. The corresponding EF3 values 0.75% and 0.30%, respectively, differed (P = .003) due to compaction. Combining our results with previous studies, where brassica-fed livestock urine was applied to soils supporting a forage brassica crop, suggested a significant relationship between soil water-filled pore space (WFPS) and brassica-derived urin...

Collaborative approaches are becoming more common to help agriculture and rural communities navigate the range of complex issues they face. This article outlines the Exploring Futures Platform (EFP) process and critiques two case studies. EFP was developed for pastoral agriculture communities to help participants jointly define challenges and explore joint management of solutions for the future. EFP was designed to ensure successful integration of systems thinking and is built on transformational engagement, inclusion of diverse of views, delivery of real-time local data, building a system understanding, future focus, reflection and action. Lessons from the case studies using the EFP were to consider how researchers shape the discussion, make participants’ and researchers’ roles clear, ensure expectations of data and analysis presented are managed highlight the value of detailed case-studies identify the mandate for action from participants, build upon local knowledge, linking into local networks, and ens...

In grazed pastures, nitrous oxide (N2O), a powerful greenhouse gas and an ozone depletion substance, is mostly emitted from animal excreta, particularly animal urine-N returned to the soil during grazing. We conducted a series of four field lysimeter and plot experiments to assess the potential of using gibberellic acid (GA) and/or alternative pastures or forage crops to mitigate N2O emissions from outdoor dairy farming systems. Pasture and forage plants assessed in the experiments included Italian ryegrass (Lolium multiflorum L.), lucerne (Medicago sativa L.), diverse pastures (including plantain (Plantago lanceolata L.), chicory (Cichorium intybus L.), perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.)), fodder beet (Beta vulgaris L.), kale (Brassica oleracea L.), as well as the standard perennial ryegrass and white clover (RG/WC) pastures. N2O was determined using a standard static chamber method in the field either on top of lysimeters or field plots. The results showed that the application of GA to urine-treated lysimeters with Italian ryegrass, lucerne or RG/WC pastures did not result in lower N2O emissions. However, the use of diverse pastures which included plantain with a lower urine-N loading rate at about 500 kg N ha−1 significantly decreased N2O emissions by 46 % compared with standard RG/WC with a urine-N loading rate at 700 kg N ha−1. However, when urine-N was applied at the same rates (at 500 or 700 kg N ha−1), the N2O emissions were similar between the diverse and the standard RG/WC pastures. This would indicate that it is the N-loading rate in the urine from the different pastures that determines the N2O emissions from different pastures or forages, rather than the plants per se. The N2O emissions from cow urine from fodder beet were 39 % lower than from kale with the same urine-N application rate (300 kg N ha−1). These results suggest that N2O emissions can potentially be reduced by incorporating diverse pastures and fodder beet into the grazed pasture farm system. Further studies on possible mechanisms for the lower N2O emissions from the different pastures or forages would be useful.

Agricultural systems in New Zealand, as elsewhere in the world, are subject to increasing environmental (and associated social) pressures, for example, around water quality and greenhouse gas emissions. Whilst novel, knowledge-based, alternative land use systems, exist that could relieve these pressures, the challenge facing New Zealand is how to achieve a timely transition to these systems at any meaningful scale. This paper considers the factors that are important to land managers in determining whether or not to change their land use system when the development of an irrigation scheme provides an opportunity for transformative change. A multicriteria decision-making framework using the analytical hierarchy process is used to assess the factors influencing decision makers who are shareholders in the Central Plains Water Scheme in the South Island of New Zealand. As expected, financial factors generally were weighted above other factors in terms of importance. Social, environmental and market factors were rated similarly, whilst regulatory and knowledge factors appeared generally less important. In addition to profitability, the study identified the desire of land managers to simplify complex agricultural systems, their need for scale, their concerns over knowledge competition, their willingness to collaborate and the challenge brought about by &lsquo, cultural path dependency&rsquo, as being important. This suggests that if novel systems can be developed that better meet these needs and concerns as well as addressing the wider environmental and social challenges, then there may be a greater chance of engendering a land use transition.

The nutritive value of pasture is an important determinant of the performance of grazing livestock. Proximal sensing of in situ pasture is a potential technique for rapid prediction of nutritive value. In this study, multispectral radiometry was used to obtain pasture spectral reflectance during different seasons (autumn, spring and summer) in 2009–2010 from commercial farms throughout New Zealand. The analytical data set (n = 420) was analysed to develop season-specific and combined models for predicting pasture nutritive-value parameters. The predicted parameters included crude protein (CP), acid detergent fibre (ADF), neutral detergent fibre (NDF), ash, lignin, lipid, metabolizable energy (ME) and organic matter digestibility (OMD) using a partial least squares regression analysis. The calibration models were tested by internal and external validation. The results suggested that the global models can predict the pasture nutritive value parameters (CP, ADF, NDF, lignin, ME and OMD) with moderate accuracy (0·64 � r 2 � 0·70) while ash and lipid are poorly predicted (0·33 � r 2 � 0·40). However, the seasonspecific models improved the prediction accuracy, in autumn (0·73 � r 2 � 0·83) for CP, ADF, NDF and lignin; in spring (0·61 � r 2 � 0·78) for CP and ash; in summer (0·77 � r 2 � 0·80) for CP and ash, indi

Multi-spectral remote sensing of green vegetation provides an opportunity for assessing biophysical and biochemical properties. This technique could play a crucial role in pasture management by providing the means to evaluate pasture quality in situ. In this study, the potential of a 16-channel multi-spectral radiometer (MSR) for predicting pasture quality, crude protein (CP), acid detergent fibre (ADF), neutral detergent fibre (NDF), ash, dietary cation–anion difference (DCAD), lignin, lipid, metabolisable energy (ME) and organic matter digestibility (OMD) was evaluated. In situ canopy spectral reflectance was acquired from mixed pastures, under commercial farm conditions in New Zealand. The multi-spectral data were evaluated by single wavelength, linear and non-linear renormalized difference vegetation index (RDVI), and stepwise multiple linear regression (SMLR) models. The selected non-linear, exponential fit, RDVI index models described (0.65 ≤ r2 ≤ 0.85) of the variation of pasture quality components (CP, DCAD, ME and OMD), while CP, ash, DCAD, lipid, ME and OMD were estimated with moderate accuracy (0.60 ≤ r2 ≤ 0.80) by the SMLR model. The remaining pasture quality components ADF, NDF and lignin were poorly explained (0.40 ≤ r2 ≤ 0.58) by the models. This experiment concluded that the MSR has potential to rapidly estimate pasture quality in the field using non-destructive sampling.

A study was conducted to explore the potential use of a hand-held (proximal) hyperspectral sensor equipped with a canopy pasture probe to assess a number of pasture quality parameters: crude protein (CP), acid detergent fibre (ADF), neutral detergent fibre (NDF), ash, dietary cation–anion difference (DCAD), lignin, lipid, metabolisable energy (ME) and organic matter digestibility (OMD) during the autumn season 2009. Partial least squares regression was used to develop a relationship between each of these pasture quality parameters and spectral reflectance acquired in the 500–2 400 nm range. Overall, satisfactory results were produced with high coefficients of determination (R 2), Nash–Sutcliffe efficiency (NSE) and ratio prediction to deviation (RPD). High accuracy (low root mean square error-RMSE values) for pasture quality parameters such as CP, ADF, NDF, ash, DCAD, lignin, ME and OMD was achieved; although lipid was poorly predicted. These results suggest that in situ canopy reflectance can be used to predict the pasture quality in a timely fashion so as to assist farmers in their decision making.

There is a growing interest in forage mixtures (Diverse pasture; e.g. containing grasses, legumes and herbs), especially those with a greater tolerance of dry conditions and a decreased nitrogen (N) content (reducing N losses), compared with ryegrass (Lolium perenne L and Lolium multiflorum L)/white clover (Trifolium repens L) pastures (RyeWC), which dominate New Zealand pastoral systems for dairy production. However, the effect of alternative forages on enteric methane (CH4) emissions is not known. The objective of the present trial was to compare CH4 emissions and milk production from dairy cows grazing either mature RyeWC or mature Diverse pasture (both approximately with pasture mass of 5600 kg DM/ha). The Diverse mixture comprised ryegrass, white clover, lucerne (Medicago sativa L), chicory (Cichorium intybus L) and plantain (Plantago lanceolata L). Milk production, measured from cows commencing at ~162 days of lactation, was less when cows grazed RyeWC than Diverse pastures (15.4 vs 16.7 kg/day; P < 0.001), whereas CH4 production (g/day) was similar for the respective treatments (411 g/day; P = 0.16). Milk composition was not affected by diet and CH4 intensity was similar for both diets (22 g/kg fat- and protein-corrected milk; P = 0.31). Methane yield [g/kg predicted dry matter intake (DMI)] averaged 22.6 and 24.9 for cows grazing RyeWC and Diverse pastures, respectively (P = 0.006). In conclusion, although the CH4 yield was greater when Diverse pasture was grazed, relative to RyeWC, there were no differences in emissions intensity or total CH4 emissions.

Optical remote sensing tools are being used in a number of agricultural applications by recording an object’s transmission of electromagnetic energy from reflecting and radiating surfaces. This unique spectral information is used to characterize the features of green vegetation. With the development of proximal sensing tools, vegetation or crop health can be determined and monitored in real-time. This information provides an opportunity for precise management of input resources to optimise plant growth and reduce the potential for an adverse environmental effect. Pasture management is of major importance in New Zealand. This paper describes the operation of multispectral (Crop Circle™ and CROPSCAN™) and hyper spectral sensors (ASD Field Spec® Pro) to explore the pasture quality and quantity. The ability to manage these factors is an important component in grazing, livestock management, and a key driver of animal performance and productivity. The results indicate that these sensors have the potential to assess vegetation characteristics.

The financial and environmental performance of a typical dairy and sheep/beef farm under contrasting inputs and systems were modelled to test associations between productivity, profitability, nitrogen (N) leaching and green house gas (GHG) emissions. GHG emissions and N leaching were found to be closely correlated (R2 > 0.90) but the correlation between these two emissions items and production and/or profit was less so, suggesting that systems that are both profitable and have a modest emissions output should be possible. The reasons why farmers have not already adopted these systems are complex but could include any of: requirement of higher level of managerial skill, incompatibility with farm soil type or contour, increased risk and capital cost to convert to the new system. Any system that involves improvements in animal efficiency is associated with a reduction in emissions per kg of saleable product. Keywords: productivity, profit, N leaching, GHG emissions, modelling

An important challenge facing the New Zealand (NZ) dairy industry is development of production systems that can maintain or increase production and profitability, while reducing impacts on receiving environments including water and air. Using research &lsquo, farmlets&rsquo, in Waikato, Canterbury, and Otago (32&ndash, 200 animals per herd), we assessed if system changes aimed at reducing nitrate leaching can also reduce total greenhouse gas (GHG) emissions (methane and nitrous oxide) and emissions intensity (kg GHG per unit of product) by comparing current and potential &lsquo, improved&rsquo, dairy systems. Annual average GHG emissions for each system were estimated for three or four years using calculations based on the New Zealand Agricultural Inventory Methodology, but included key farmlet-specific emission factors determined from regional experiments. Total annual GHG footprints ranged between 10,800 kg and 20,600 kg CO2e/ha, with emissions strongly related to the amount of feed eaten. Methane (CH4) represented 75% to 84% of the total GHG footprint across all modelled systems, with enteric CH4 from lactating cows grazing pasture being the major source. Excreta deposition onto paddocks was the largest source of nitrous oxide (N2O) emissions, representing 7&ndash, 12% of the total GHG footprint for all systems. When total emissions were represented on an intensity basis, &lsquo, systems are predicted to generally result in lower emissions intensity. The &lsquo, systems had lower GHG footprints than the &lsquo, current&rsquo, system, except for one of the &lsquo, systems in Canterbury, which had a higher stocking rate. The lower feed supplies and associated lower stocking rates of the &lsquo, systems were the key drivers of lower total GHG emissions in all three regions. &lsquo, Improved&rsquo, systems designed to reduced N leaching generally also reduced GHG emissions.

Accurate estimation of pasture mass is essential for managing farm systems for top performance. The C-DAX Rapid Pasturemeter has the potential to provide fast, accurate estimates of pasture mass. However, the Pasturemeter has been calibrated for 'typical' temperate dairy pastures and its suitability for use on kikuyu (Pennisetum clandestinium)-based pastures in Northland, is unknown. This study determined the accuracy of the technology for estimation of pasture mass on kikuyu/ryegrass-based dairy pasture on the Northland Agricultural Research Farm at Dargaville, New Zealand. Keywords: pasture mass estimation, kikuyu, Northland, dairy, calibration

A dynamic model for nematode parasites in lambs which links their adult parasite burden with liveweight gain was extended to investigate alternate grazing with cattle to provide relatively larval-free pasture for finishing lambs. Liveweight performance of weaned lambs was tracked fortnightly under rotational grazing using three cattle:sheep ratios, with three initial parasite burdens and two initial infective larval densities on pasture. Lambs were removed from grazing at 37 kg or if they failed to gain weight during the preceding fortnight. An 80%:20% cattle:sheep ratio reduced larval pasture contamination by 75% but did not affect parasitic burden and total lamb liveweight gain compared with an all-lamb treatment. For low and moderate initial parasitic burdens in the 80%:20% cattle:sheep ratio, 25% of lambs reached 37 kg and 100% gained weight until week 18. This simulation indicated that in organic lamb finishing systems, alternate grazing with cattle provides substantial benefit but only when the initial parasite burden was low or moderate. Keywords: modelling, parasites, liveweight gain, alternate grazing

This work was undertaken to determine whether measurement of preference 30 min after alternative hays are offered to lactating dairy cows adequately predicts preference over a 3-day period and to determine the influence of the concentrations of water-soluble carbon (WSC) and neutral detergent fibre (NDF) of hays on preference. Eleven test hays were chosen to provide an NDF concentration of between 45% and 60% and a WSC concentration of between 10% and 30%. The test hays were each offered to lactating dairy cows as an alternative choice, with two control hays with NDF concentrations of 49% and 54%. A replicated Latin-square design was used to determine the preference of cows for the test hays, using three cows for each test hay versus control-hay comparison. Preference measured 30 min after hays were offered to cows was highly correlated with measures of preference made after 24 h and again for the same measures on the third day of the hays being offered. However, preference measures with the two different control hays were not well related, thus indicating that preference values are control-hay specific. Total hay intake was unchanged with the low-NDF control hay but declined with increasing NDF concentration of the test hays with the higher-NDF control hay. WSC did not influence preference at any one level of NDF of the test hays when the control hay had a low NDF concentration, but there was a small rise in preference at each NDF level when the control hay had a higher NDF concentration. This may have been a result of a contribution of WSC to digestibility as much as to taste response. With the low-NDF control hay, drivers of preference were the NDF concentration and the digestibility of the hay, but with the higher-NDF control hay, the drivers were the NDF concentration and fibre characteristics (shear and potential fibre digestibility). Calculation of the NDF concentration of the total hay consumed, test plus control hays, suggested that a change in drivers of selection is likely at the point where the NDF concentration of the test hay equals that of the control hay. Unless models identifying selection drivers handle non-linear data, misleading results may be obtained.

Recognition is increasingly given to the need of improving agricultural production and efficiency to meet growing global food demand, while minimising environmental impacts. Livestock forms an important component of global food production and is a significant contributor to anthropogenic greenhouse-gas (GHG) emissions. As such, livestock production systems (LPS) are coming under increasing pressure to lower their emissions. In developed countries, LPS have been gradually reducing their emissions per unit of product (emissions intensity; EI) over time through improvements in production efficiency. However, the global challenge of reducing net emissions (NE) from livestock requires that the rate of decline in EI surpasses the productivity increases required to satisfy global food demand. Mechanistic and dynamic whole farm-system models can be used to estimate farm-gate GHG emissions and to quantify the likely changes in farm NE, EI, farm productivity and farm profitability as a result of applying various mitigation strategies. Such models are also used to understand the complex interactions at the farm-system level and to account for how component mitigation strategies perform within the complexity of these interactions, which is often overlooked when GHG mitigation research is performed only at the component level. The results of such analyses can be used in extension activities and to encourage adoption, increase awareness and in assisting policy makers. The present paper reviews how whole farm-system modelling has been used to assess GHG mitigation strategies, and the importance of understanding metrics and allocation approaches when assessing GHG emissions from LPS.

The role of cholecystokinin (CCK) in modulating feed intake depression in parasite-infected lambs was investigated using CCK receptor antagonists (L364–718 and loxiglumide). Four experiments were carried out using ewe lambs infected with 4000 Trichostrongylus colubriformis larvae/d or non-infected controls (n 8, live weight 25 kg). Animals were fed daily on a nutritionally complete pelleted diet and had free access to water. In the first experiment, infected and non-infected animals were injected subcutaneously with CCK antagonist (100 μg L364–718) or carrier alone as a single dose. In the second experiment, CCK antagonist (loxiglumide: 0, 5, 10 or 20mg/kg live weight) was injected into a jugular vein immediately before feeding. In the third experiment, animals were infused continuously with the CCK antagonist (loxiglumide; 10mg/kg per h) for 10 min before feeding and for the first 2 h of feeding. In the final experiment, lambs were fitted with an indwelling cerebral ventricular cannula and infused with a CCK antagonist (loxiglumide, 162μg/min), CCK agonist (CCK-8, 2.5 pmol/min), loxiglumide plus CCK-8 or sterile saline solution alone via the cannula for 30 min before feeding and for the first 60 min of feeding. In all the experiments short-term feed intake was recorded at 10 and 15 min intervals for the first and second hours of feeding respectively, then at hourly intervals for the remainder of the 8 h recording period. Peripheral injection with L364–718 or loxiglumide did not elevate feed intake in either the infected or non-infected animals. However, feed intake was increased (P < 0.05) in the short term by central infusion of loxiglumide, this effect being greater in the infected animals and apparently due to an elevation in intake during the second hour of feeding. CCK-8 depressed short term feed intake only in the infected animals (P < 0.05). Total daily feed consumption was not influenced by any of the pharmacological agents. The results indicate an involvement of central CCK receptors in regulation of feed intake depression following gastrointestinal parasitism of sheep and the possibility of a similar role in non-infected sheep. They do not support the singular importance of a peripheral action of CCK in determining satiety.Cholecystokinin: Loxiglumide: Feed intake: Gastrointestinal parasites

Fodder beet (Beta vulgaris L.) has a very high readily fermentable carbohydrate concentration, which could affect rumen fermentation and reduce enteric methane (CH4) emissions. The objective of the current study was to estimate CH4 emissions from dry dairy cows grazing either fodder beet supplemented with perennial ryegrass (Lolium perenne L.)-dominated pasture silage (6 kg DM/cow/day; FB+Sil) or forage kale (Brassica oleracea L.) supplemented with barley (Hordeum vulgare L.) straw (3 kg DM/cow/day; kale+Str; dry cows, Experiment 1), and from dairy cows in early lactation grazing perennial ryegrass-dominated pasture alone (pasture) or supplemented with fodder beet bulbs (3 kg DM/cow/day; past+FB; lactating cows; Experiment 2). Methane measurements were performed using GreenFeed units (C-Lock Inc., Rapid City, SD, USA) for 40 days in August–September 2015 (Experiment 1) and for 22 days in November–December 2015 (Experiment 2), from 45 and 31 Holstein–Friesian × Jersey dairy cows in Experiments 1 and 2, respectively. Dry cows grazing FB+Sil in Experiment 1 produced 18% less CH4 (g/day) and had 28% lower CH4 yield (g/kg DM intake; P < 0.001) than did cows grazing kale+Str. Lactating cows grazing past+FB in Experiment 2 produced 18% less CH4 and had 16% lower CH4 intensity (g/kg fat and protein-corrected milk production; P < 0.01) than did cows grazing pasture alone, while milk production and composition were similar for the two groups. In conclusion, feeding fodder beet at ~50% and 20% of the diet of dry and lactating dairy cows in pastoral systems can mitigate CH4 emissions.

We hypothesised that the preference of sheep among a wide range of annual legumes at successive stages of plant phenology would be related to laboratory measurements of the chemical composition of the forage. We tested this by examining the relative preferences of sheep among 20 genotypes of annual plants at three phenological stages of plant growth using the Chesson–Manly selection index. Plant material was collected for laboratory analyses at each phenological stage and samples were analysed for nitrogen, sulfur, neutral detergent fibre, acid detergent fibre, in vitro digestibility and water soluble carbohydrates. Sheep differed in relative preference among the plant genotypes within and between each of the three phenological stages. Vegetative characteristics that were correlated with relative preference also differed with plant phenology. Measured characteristics of the plant material explained an increasing proportion of the variance in relative preference with successive phenological stages (4.8, 51.1 and 60.9% at the vegetative, reproductive and senesced stages; P < 0.001). The relative preference of the sheep depended on the overall quality of the vegetation. When the quality of the vegetation was high, relative preference did not correlate well with measured nutritive characteristics. However, when the vegetation was of low quality, sheep selected plants with characteristics associated with higher nutritive value. We conclude that sheep adopt different foraging strategies in response to changing vegetation characteristics and increase their preference for plants that increase their intake of digestible dry matter as the sward matures.

Grazing saltbush reduces productivity in sheep mostly because the high salt intake decreases feed intake and challenges the metabolism of the animal. However, little is known of the effect of salt load on the endocrine control systems that regulate voluntary feed intake and metabolism. Plasma concentrations of leptin, insulin and cortisol and blood glucose were monitored in wethers fed for 2 weeks with either a control diet (adequate salt) fed ad libitum, a high salt diet (20% of dry matter) fed ad libitum or a group fed the control diet with an intake restricted to that of the high salt ad libitum group (control pair-fed). High salt intakes reduced voluntary feed intake within 1 day and circulating concentrations of insulin and glucose within 2 weeks. Liveweight and leptin concentrations were not specifically affected by the high intake of salt but decreased in response to the decrease in intake. Cortisol secretion was not affected. Although salt intake had a specific effect on insulin and glucose (over and above the effect of reduced feed intake alone), the reduction in insulin would be expected to increase rather than decrease appetite and feed intake. Therefore, insulin, leptin and cortisol do not appear to play major roles in the control of feed intake in sheep consuming high levels of salt.

Salinity is a problem facing many crop and livestock producers in southern Australia. One management option is to revegetate with salt-tolerant plants suitable for animal production. These plants are often halophytic shrubs containing up to 30% ash, predominantly as sodium, potassium, or chloride. This experiment examines the consequences of a high intake of sodium and potassium separately or together on feed intake, digestibility, liveweight change, and wool growth. Twelve groups of 6 weaner wethers were allocated to treatments according to a balanced 3 × 4 factorial design with 3 levels of added potassium (0, 0.38, and 0.77 mol/kg DM equivalent to 0, 15, and 30 g/kg DM) and 4 levels of added sodium (0, 0.87, 2.18, and 3.48 mol/kg DM, equivalent to 0, 20, 50, and 80 g/kg DM) as the chloride salts. The treatment diets were fed to sheep for 6 weeks. Increasing sodium in the diet significantly decreased feed intake, digestibility, liveweight gain, and wool growth either as a main effect or through an interaction with potassium. Organic matter intake was reduced from 1.35 kg at the lowest levels of sodium and potassium to 0.67 kg at the highest levels. Comparing the same 2 groups, liveweight gain was reduced from 144 to 0 g/day, organic matter digestibility from 59.1% to 57.3%, and wool growth from 1.21 to 1.04 mg/cm2.day. The response surfaces indicate that production was depressed even at the lower levels of sodium, whereas high potassium depressed intake, digestibility, and liveweight gain at high levels of sodium only. The interaction between sodium and potassium was always negative at high levels of sodium, indicating that manipulation of the proportions of the 2 elements is unlikely to provide benefits for animal production when total salt levels are high. Although wool growth was depressed at high sodium and potassium, the efficiency of wool growth increased from 10.0 to 15.4 g/kg organic matter intake when the lowest and highest levels of the sodium and potassium were compared. This result may present significant opportunities for the use of saline land to grow fine wool.

This work examines nutritive value and preference by sheep of 2 saltbush species, river saltbush (Atriplex amnicola) and old man saltbush (Atriplex nummularia). Both species are woody perennials that are native to Australia and used in commercial grazing systems. The hypothesis for this study was that sheep will graze saltbushes with higher nutritive value and lower secondary compounds in preference to bushes with lower nutritive value and higher secondary compounds. This was expected to be found both within and between the old man and river saltbush species. To test the hypothesis, 10-month-old Merino ewes grazed a 10-ha plot containing a mixture of old man and river saltbush in approximately equal proportions. Within the plot, and prior to grazing, 20 bushes of each species were pegged for identification and samples of edible plant material collected for analysis. Each week during the grazing period the bushes were photographed for assessment of preference. Sheep preferred river saltbush to old man saltbush and also showed some preferences for specific bushes within each species. Differences in digestibility of dry matter and organic matter, crude protein, ash, oxalates, and nitrates were not clearly associated with differences in preference. Although the reasons for preferences were not demonstrated, the analysis of the plant material did indicate that the content of total ash and oxalates was at levels likely to depress voluntary feed intake.

The aim of the present study was to determine whether leptin might play a role in the gonadotrophic response of mature merino rams to changes in the level of nutrition in rams fed ad libitum. Recombinant bovine leptin was infused intracerebroventricularly and voluntary food intake (VFI) and luteinizing hormone (LH) pulse frequency were measured. In Experiment 1, rams (n = 5) were infused for 24 h per day for 5 days with vehicle or with leptin (0.04, 0.4 and 4.0g h –1 ). All doses decreased both VFI and LH pulse frequency. In Experiment 2, rams were infused for 24 h per day for 5 days with vehicle (n = 10) or leptin (4 g h –1; n= 5); a sub-group of 5 controls was pair-fed to the leptin-infused group to control for effects of changes in feed intake. LH pulse frequency was reduced equally in both the leptin-infused and pair-fed groups. Leptin did not affect other systems controlled by the hypothalamic–pituitary axis. Thus, rather than stimulate LH secretion, intracerebral leptin specifically inhibits it by reducing food intake, so it is unlikely that effects of nutrition on the reproductive axis in mature rams involves leptin as a single blood-borne signal. A range of nutritional or metabolic inputs may be needed, and perhaps interconnections between neural centres that control appetite and reproduction.

A growing body of work aims to understand the impacts of climate change on agriculture as well as farmer’s perceptions of climate change and their likeliness to adopt adapting and mitigating behaviors. Despite this, little work has considered how intention to adopt differs from actual adoption of climate change practices in agriculture. Applying the Theory of Planned Behavior we aim to assess whether different factors affect intended versus actual adoption of climate behaviors among farmers in New Zealand. Data were collected through mixed methods (37 interviews and a telephone survey of 490 farmers) in two regions of New Zealand 2010–2012. Through multiple regression models we test hypotheses related to the Theory of Planned Behavior around the role of attitudes, subjective norms, and perceived capacity in affecting intended and actual adoption. Results suggest that there are different drivers of intended and actual adoption of climate change practices. Climate change attitudes and belief is only associated with intended not actual adoption. We find no evidence that subjective norms (climate change policy support) significantly influence either intention or actual adoption. Only perceived capacity and self-efficacy were important predictors of both intended and actual adoption. These results suggest a disconnect between intended and actual behavior change and that using data about intention as a guiding factor for program and policy design may not be prudent. Furthermore, fostering perceived capacity and self-efficacy for individuals may be crucial for encouraging both intended and actual adoption of climate adapting and mitigating behaviors.