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Reproductive performance of a cohort of Standardbred mares under a commercial breeding system
Get PDFBackground: Despite being a large commercial breeding industry, there is little published data on the reproductive success of Standardbred mares.
Objectives: To quantify the reproductive performance of Standardbred mares under artificial breeding systems in a commercial setting and determine the incidence of early embryonic and other pre-partum losses.
Study design: Retrospective cohort study.
Methods: Data from four commercial farms were collected across four breeding years, and all mares were bred via artificial insemination. A total of 3995 mares contributed 7229 mare years. First-cycle pregnancy rate (FCPR) and end of season pregnancy rate (SPR) were analysed in mixed-effects logistic regression models. Time-to-conception interval was analysed in a Cox regression model.
Results: The mean FCPR was 61.4% (confidence interval [CI] 60.3%–62.6%), the mean end of SPR was 84.7% (CI 83.8–85.5%), the mean live foal rate (FR) was 73.1% (CI 72.1%–74.2%). Mares located on-farm were more probable to be pregnant in terms of both FCPR (odds ratio [OR] 1.168, CI 1.018–1.340, p = 0.026) and SPR (OR 2.026, CI 1.673–2.454, p < 0.001), mares inseminated with thawed–frozen semen were less probable to be pregnant in terms of FCPR (OR 0.598, CI 0.457–0.783, p < 0.001) and SPR (OR 0.479, CI 0.354–0.647, p < 0.001) compared with insemination with fresh-extended semen. Older mares (14 years and older) were less probable to be pregnant in terms of FCPR (OR 0.795, CI 0.688–0.919, p = 0.002) and SPR (0.435, CI 0.352–0.538, p < 0.001) compared with young mares (3- to 8-year old).
Main limitations: Retrospective data relied on accurate record keeping of stud farms and no mare-treatment or ovulation induction records were available. Live FRs relied mostly on annual foaling returns so fetal/foal deaths may be underrepresented.
Conclusion: This study provides substantial baseline data on reproductive performance for Standardbred mares managed under a commercial artificial breeding system
The emergence of plastic-free grocery shopping: Understanding opportunities for practice transformation
Get PDFDespite consumer concern for sustainability, avoiding plastic packaging, particularly in food shopping, is difficult due to its pervasiveness and usefulness. Yet achieving changes in consumer behaviour is an important part of environmental management approaches towards a circular economy and plastic reduction. This research explores how everyday food shopping practices might adapt and evolve to become more sustainable through consumers avoiding, reducing, or replacing plastic packaging in their grocery shopping. This qualitative research, based on eighteen semi-structured interviews with sustainably-oriented consumers, finds that plastic-free shopping practices are challenging for even committed practitioners. However, we illuminate four mechanisms representing ‘bright spots’ (i.e., points of optimism) that offer specific opportunities for environmental management. We define these as destabilisation, envisioning, emotional connection and adaptation. Destabilisation and envisioning help with recruitment of practitioners to plastic-free shopping, and emotional connection and adaptation help support practitioner loyalty and commitment. Further, consumer reflexivity and habituated sustainable-orientation supports practice recruitment, stabilisation and transition. We discuss the implications of our findings for environmental management approaches to ‘behaviour change’, focusing on the role of policy-makers, social marketers, retailers, and manufacturers in fostering competitive, stable plastic-free grocery shopping
Reducing nitrogen loss from cow urine patches: Strategies for pasture-based dairy systems : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
No full textIn dairy grazing systems, intensive farming practices with high nutrient inputs contribute to environmental pollution with nitrogen (N) loss from farmland, a key contributor to water quality degradation. The New Zealand dairy industry aims to reduce N leaching by 40-60% by 2030. Achieving this target may require transitioning from moderate to lower input systems and implementing mitigation strategies focused on managing high N sources, such as cow urine patches, to improve N use efficiency and reduce leaching risk. While cow urine patches present a primary source of N loss from pasture-based dairy farms, there is limited information on how the relationship between urine volume per urination event and urine patch area affect the N leaching risk. The aim of the thesis is to investigate this relationship and how grazing management strategies influence urine N load and plant N uptake following a regrowth period to mitigate N leaching risk. Additionally, it aims to develop a tool for predicting the impact of management strategies on N loss from urine patches.
A key finding of the literature review was that successful N mitigation requires tactical and operational knowledge of implementing mitigation strategies, which has slowed adoption due to uncertainty in implementation. Additionally, the review also identified mitigations centred around the transfer of N, specifically relating to the urine patch, urine N load, or plant N uptake, to improve N use efficiency within a farm system. The review identified a lack of decision support tools for farmers to tailor N mitigations to individual circumstances. One finding was the opportunity to provide tactical and operational tools, such as a urine patch model, to understand urine distribution variation and develop management strategies that target urine and urine patch characteristics to reduce leaching risk.
Using a modelling approach (Chapter 3), the aim was to determine if reducing N input alone could achieve the required N leaching reduction with minimal impact on farm operating profit, or if additional mitigation practices targeting N transfer from high N sources, such as cow urine patches, are needed to improve N use efficiency and reduce the risk of leaching. A two-year dairy farmlet study was conducted comparing two farm systems: moderate stocking rate (MSR, 3.9 cows/ha); and lower stocking rate (LSR, 2.9 cows/ha); with a benchmark, high-performing commercial demonstration farm (Lincoln University Dairy Farm [LUDF]; 3.4 cows/ha). Milk yield, pasture production, and quality data were collected, and modelled in FARMAX and OverseerFM to estimate the financial and environmental performance of each farm system. The LSR system produced the best environmental outcome across the two years (2018/19 and 2019/20), leaching an estimated 31% less N compared with MSR and LUDF, but at the cost of profitability. The average, annual milk solid production per ha was 28% less for LSR relative to MSR and LUDF. Correspondingly, the average annual operating profit per ha was 35% less for LSR compared with LUDF. A low N input system reduces production and operating profit to the extent that these mitigation strategies may not be adopted. Therefore, the next step was to target sources of high N input, such as cow urine patch areas, and improve N use efficiency from these areas to reduce the risk of leaching.
In Chapter 4, we investigated the effects of grazed pasture canopy characteristics (using plant species and height) on urine patch area. The experiment was conducted during autumn in Canterbury, New Zealand. Warm water was used to simulate urine events, ranging in volume from 1 to 8 L, onto either partially (Lenient, 6-15 cm) or fully (Hard, <6 cm) grazed perennial ryegrass and white clover or pure plantain pastures. A thermal digital camera and imaging software were used to calculate the wetted area of each urine event. When a mid-range volume (4 L) was poured onto lenient grazed pastures, plantain had a greater wetted area than perennial ryegrass/white clover pasture (0.30 m2 ± 0.11 m2 and 0.16 m2 ± 0.08 m2, respectively; mean ± standard deviation). However, the wetted area was similar for plantain and perennial ryegrass/white clover pasture under hard grazing (0.36 m2 ± 0.16 m2 and 0.31 m2 ± 0.13 m2, respectively). Irrespective of pasture treatments and grazing intensity, the relationship between water volume and wetted area was curvilinear, with no significant increase in wetted area for simulated urine events greater than 4 L. Our results indicated that both pasture treatments and grazing intensity (i.e., residual pasture canopy) affect urine patch area, which could have potential implications for the urine N load per urine patch. A limitation of this study was that sward surface height was measured at the paddock level rather than for each urine event simulated.
The first field experiment (Chapters 5 and 6) was split into two chapters to evaluate two objectives. The first objective was to investigate the effect of pre-graze pasture mass and time of pasture allocation, on total soil N levels from urine patches and subsequent N recovery from pasture following a regrowth period. The experimental design was a 2 x 2 x 2 factorial arrangement of treatments replicated twice within two experimental runs. The first factor corresponded to two levels of pasture mass using moderate to high mass (2226 or 2662 kg DM/ha respectively) to create lower herbage crude protein content in the high mass treatment. The second factor corresponded to time of allocation of pasture using morning or afternoon allocation. The third factor corresponded to time of urine deposition using anticipated peak (dawn) vs nadir (mid-morning) urinary N concentration and urine N load. A two-way interaction indicated larger urine patch areas for moderate mass at peak times (P 0.05) between peak and nadir times. High mass treatments showed better regrowth in both urine and non-urine patches. For non-urine patches, the herbage N yield was 18% lower for the moderate compared to the high mass pastures (P < 0.05). From this, we concluded that managing pasture mass can influence pasture recovery and nitrogen utilisation, with potential implications for reducing N leaching risk from dairy farms.
Chapter 6 aimed to investigate the relationship between volume per urination, urine patch area, and compressed pasture height. The objective of this chapter was to understand if pasture management practices can affect urine patch area and subsequent urine N load. Cows were fitted with acoustic urine sensors (AgResearch, New Zealand) on their hind legs. The sensors captured the timing, duration, volume per urination, and frequency of urination. Thermal digital imaging with an automated algorithm (AgResearch) was used to estimate urine patch area. Our findings revealed that compressed pasture height did not affect the urine volume and patch area relationship. The relationship was also weaker compared to the findings in Chapter 4. The results showed the importance of accurate urine volume measurement and the impact that measurement errors with different methodologies could have on the relationship with urine patch area. Further research with accurate measurements of volume per urination and corresponding patch area is needed to develop tools to model urine and urine patch characteristics and N leaching risk accurately before they can inform management strategies.
The second field experiment (Chapter 7) was carried out to collect additional data on the urine volume and patch area relationship. This study investigated the impact of pasture treatments and height on this relationship through simulated urination events. Conducted at Lincoln University Research Dairy Farm, the experiment utilised a 2 x 8 factorial design, comparing perennial ryegrass-white clover pasture with Italian ryegrass-plantain-red and white clover pasture across eight volume treatments (1-8 L). The study found no significant difference in urine patch area between pasture treatments. A curvilinear relationship between urine volume and patch area was identified (similar to that in Chapter 4), with a quadratic model (Urine patch area = 0.129 + 0.056v – 0.003v²) explaining 54.8% of the variance. Additionally, sward surface height significantly influenced urine patch area, with taller pastures reducing urine patch area, especially at higher urine volumes. This interaction was modelled (Urine patch area = 0.1259 + 0.09278v – 0.004742v² – 0.002363vh + 0.0001293v²h), explaining 70% of the variance.
In summary, effective strategies must combine reduced N inputs with mitigation practices targeting N transfer from high N sources, such as cow urine patches, to improve N use efficiency and reduce leaching risk. This thesis has shown that altering pasture mass or the timing of pasture allocation does not significantly influence urine patch area; instead, it was primarily affected by the time of urine deposition. Additionally, these grazing management practices do not enhance plant N uptake from urine patches. Management practices aimed at reducing urine N load at peak times might be more effective at reducing N leaching risk than grazing management. However, grazing management can increase N transfer during the regrowth phase from small urine events. By managing sward surface height when smaller urine events fall within the linear part of the volume and patch area relationship, the urine patch area can be increased at the time of deposition, improving urine N load distribution and plant N uptake. Ultimately, the urine patch model indicated that reducing daily N intake and increasing daily urine volume throughout the year can reduce N leaching by up to 14.5%
Developments and applications of electromagnetic tomography in process engineering
No full textIn the processing industry, monitoring, control, development and optimization are major performance improving activities. In this industry multiphase mixtures flow within enclosed domains such as process vessels or pipelines, with sometimes complex and harsh process conditions, such as high standards of hygiene or high temperatures and pressures, and require to be monitored and analysed for the purpose of continuous improvements in process control. Electromagnetic Tomography (EMT) is a promising tomographic technique which employs contactless non-invasive inductive sensing coils to evaluate the passive electromagnetic properties of what exists within a sensing domain. Although the potential applications of EMT are widespread throughout various industries such as the medical, environmental, geological and mining industries, this paper focuses on evaluating research focused on applications of this promising technique to the processing arena, with the purpose of identifying research gaps for future evaluation. Research in this area has been divided into two groups based on their purpose: developments in the technique with the purpose of enhancing its capabilities, and exploring the technique's various applications. As one of the more recent tomography techniques, EMT still has a lot of potential remaining to be discovered which would come about with further advancements in its hardware, i.e., sensor unit and excitation unit, and also with improvements in the data processing unit, i.e., data reconstruction. Combining different modalities, which would expand the capabilities of the resulting unit, is an interesting area with high potential, requiring further exploration. EMT remains to be studied in the future on countless other processes, unit operations and media and for several objectives. The application of EMT to other areas such as Food, Dairy, Pulp and paper processes also remain to be developed
The integration of control tools and attractants for optimising ground-based pest control : A thesis submitted in fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
No full textThe brushtail possum (Trichosurus vulpecula), a marsupial native to Australia, was widely introduced in New Zealand between 1890 and 1930 to support the booming fur industry in Australia. Before the settlement of humans in New Zealand, there were no terrestrial mammals other than bats; therefore, the local species evolved without mammalian predators. This isolation has profoundly affected native species like birds, invertebrates, and reptiles. Forty of the ninety-one land bird species are now extinct, and many others are in severe decline.
The government's initiative to eliminate New Zealand's predators (possums, rats, and mustelids) by 2050 has significantly expanded conservation control efforts in recent years. In New Zealand, predator control has been practised for a long time, but simple trapping has since developed into a thriving industry full of expertise, including species-specific attractants. The number of traps and bait stations needed to be set up, and the associated labour and expense would be significantly reduced if animals could be reliably drawn from a distance to a bait station or trap. Research presented in this thesis expands on previous studies with captive and wild animals, identifying the attractiveness of novel multi-sensory lures for possum control.
Audio lures are increasingly becoming a popular attractant for pest control in New Zealand as they can draw the animals' attention from further away and potentially become a long-lasting lure. 50% of possums were trapped at traps playing the aggressive possum audio in the winter 2022 trials; however, the attraction towards the aggressive possum audio was not reflected in the autumn 2023 trial replicate, as 57% of possums were trapped at the beep audio traps compared to the aggressive and distressed possum audio and the control. In a subsequent field trial, a newly developed audio-visual lure (AVL) device was evaluated, which emitted the aggressive possum audio. The results demonstrated that it effectively attracted possums to a live-capture cage trap, compared to an existing audio lure.
Visual lures are a tried-and-true attractant for possum control in New Zealand, with the flour blaze being a commonly used attractant. However, weather can easily impact flour blaze and may not last long in suboptimal conditions; therefore, identifying a long-lasting visual lure would be an advantage. A trial with captive animals compared a photoluminescent strip, white constant LED light, white flashing LED light and control (no visual lure). Whilst there was no significantly better visual lure overall, the constant LED light treatment had the most encounters (visits within 1 m of the trap).
While the lures were under development, Pest Free Banks Peninsula was given assistance for their upcoming control operations, focusing on collecting data on possum home ranges in these habitats. Understanding the size of these home ranges is crucial for optimal device spacing in line with the PFNZ2050 goal of elimination. Possums living in different habitats can have different home range sizes and population densities, especially for individuals living along/in the sea cliffs. Six GPS-collared possums deployed in Le Bons Bay, Banks Peninsula, were retrieved, identifying a significant degree of overlap between the individuals and small home range sizes (average of 2.65 ha) compared to other studies on Banks Peninsula (average of 6.2 ha). The results indicated that possums did not move far from resources or capture locations, and 100x100 m device spacing was sufficient.
Complementary research on captive hedgehogs identified the most attractive food-based lures being peanut butter, rabbit meat and salmon, which had significantly more activity than egg, huhu grub, mayonnaise, male hedgehog odour, female hedgehog odour and ferret odour. However, combining the most attractive food-based lures of rabbit meat with a predator (ferret) pheromone (scent) lure worked better when compared to the food-based options on their own (freeze-dried salmon and rabbit meat). Due to the positive results from the hedgehog combination lure trial, this methodology was then applied to free-ranging possums using the best performers from the earlier captive studies being combinations of audio (aggressive possum audio), visual (constant LED light) and scent lures (conspecific bedding material). Overall, there was no significant difference between the treatments; however, the combined audio-visual treatment had the most interactions (animals in traps) and encounters (visits within 1 m of the trap), and possums also spent more time in the encounter zone for audio-visual-scent lure sites.
In conclusion, these results indicate that combination lures have the potential to increase possum encounter and interaction rates around traps. The results also highlight the need for pest control managers to be flexible and choose lures that will be the most attractive to individuals at specific times of the year to ensure ongoing success. Adopting a strategic approach to lure selection can significantly enhance the effectiveness of pest control efforts and support the Predator Free 2050 goal
The impact of InsurTech on the firm performance and financial sustainability of insurance companies and Takaful operators in Malaysia : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
No full textOver the last decade or more, there has been substantial growth in digital innovation, especially in financial technology (FinTech). A subdimension of FinTech, insurance technology (InsurTech), was built to create solutions for the insurance sector based on the technological approach. InsurTech start-ups adopt a user-friendly approach, build a close relationship with insurance customers, and offer a service where the client is protected in all respects.
Malaysia’s digital economy grew at an exponential rate to RM66.22 billion in the first half of 2024, accounting for 22.6% of the country’s gross domestic product (GDP). According to a report from the World Economic Forum, Malaysia is at the forefront of adopting industry 4.0 technology, which includes robots. From insurers to advanced technology developers, leading multinational companies have relocated their Asia-Pacific “high-value, high-impact” central operating models to Kuala Lumpur, using Industry 4.0 technologies and the information and communications technology skill pool.
This study examines the impact of InsurTech on firm performance and the financial sustainability of insurance companies and takaful operators in Malaysia. Data from 51 registered insurance companies in Malaysia, with the sample spanning from 2008–when the FinTech movement gained popularity following the 2008 global financial crisis–to 2021. The sample period covers major financial issues, economic downturns and the Covid-19 pandemic. This study uses six indicators to measure the firm performance and financial sustainability, i.e. InsurTech, liquidity, financial efficiency, financial stability, solvency, and macroeconomics. This study uses a two-step system GMM analysis to examine the effect of InsurTech on performance indicators (return on assets, return on sales, insurance performance measurement and operating self-sufficiency), insurance characteristics, government interventions and the impact of the Covid-19 pandemic in Malaysia. This study runs the random effect/fixed effect models as a comparison.
The two-step system GMM results show that there is no relationship between financial stability and firm performance or between solvency and financial sustainability. In contrast, the results indicate that InsurTech, liquidity, and financial efficiency impact firm performance and the financial sustainability of Malaysia’s insurance companies and takaful operators. The empirical findings indicate that InsurTech companies and insurance characteristics adversely affect the insurance performance measurement and operating self-sufficiency of insurance companies and takaful operators in Malaysia, where takaful operators are more affected than insurance companies. InsurTech and tax incentives have no impact, but InsurTech and the Covid-19 pandemic negatively affect firm performance and the financial sustainability of insurance companies and takaful operators in Malaysia.
Through investment in technology, the insurance industry gains a profitable return by having InsurTech in the value chain, reducing manual operations costs and co-integrating with other financial industry players. The financial measurements and their relationships in this study contribute to the insurance industry's growth in Malaysia, with the adoption of advanced technology in insurance services that can improve profitability. Specifically, the study investigates the interactions between financial aspects to provide stakeholders, policymakers, and the insurance industry with a comprehensive understanding of financial and investment decisions
Return and volatility-managed portfolios: An investigation of China’s A-share market : A thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy at Lincoln University
No full textChina's A-share market is characterized by high volatility and a retail-dominated environment, which poses significant challenges for risk management. This study investigates the applicability and effectiveness of the Volatility Managed Portfolio (VMP) strategy in this market. The study begins by reviewing modern portfolio management theories, including single-factor and multi-factor models, and assesses their applicability and limitations in the context of China’s A-share market.
Using a large sample of historical trading data, the study constructs relevant risk factors and employs regression analysis to evaluate the performance of the VMP strategy. The strategy is further optimized to enhance its adaptability to different market conditions. The findings show that the VMP strategy improves risk-adjusted returns across various market phases and demonstrates strong risk control, especially in periods of high market volatility.
These findings provide empirical evidence for implementing such risk management strategies in volatile markets. This research not only contributes to the application of modern portfolio management theories in China's financial markets but also offers valuable insights for investors seeking to improve risk management in turbulent market environments. Future research could explore the integration of volatility management strategies with other investment approaches to further enhance investment performance and risk control
Enhancing resilience for New Zealand red meat producers by understanding the options, barriers and enablers to selling direct to the consumer
No full textNatural hazard events have significant impacts on rural communities through disruption to infrastructure and lifelines, production systems, and disruption to fast-moving agri-food chains. Selling direct-to-consumer (D2C), or farm to fork, is one way to help mitigate some of the risks arising from natural hazards, and maintain and potentially enhance, social, environmental and economic resilience. D2C sales may also add value, shorten the supply chain and increase the sustainability of the food system (Çakmakçı et al., 2023, FAO, 2022; Floriš et al., 2022). This project explores farmers’ perspectives on the barriers and enablers to selling red meat products D2C. The aim of the study, using a series of semi-structured interviews (N=14) with livestock farmers, is to understand how the interaction of farmers’ values and knowledge, and the NZ rules relating to food production, distribution and sales, shape outcomes for producers and strengthen rural resilience
Corporate culture and corporate reporting: A textual analysis
No full textThis study seeks to contribute to the existing literature by utilizing textual analysis to quantify the corporate culture of publicly traded U.S. firms from 2001 to 2021. The research aims to explore the implications of corporate culture on the quality of financial reporting and the quality of sustainability report which is measured by environmental, social, and governance (ESG) disclosure score. The findings reveal that organizations with a strong corporate culture—characterized by high index scores in five values including innovation, integrity, quality, respect, and teamwork—are less likely to engage in aggressive earnings management and tend to have significantly higher ESG disclosure scores. The study also highlights variations in the impact of different dimensions of corporate culture on earnings management and ESG disclosure scores. Overall, these insights emphasize the benefits of promoting a strong corporate culture to enhance the quality of corporate reporting
Conceptualising surface water-groundwater exchange in braided river systems
No full textBraided rivers can provide substantial recharge to regional aquifers, with flow exchange between surface water and groundwater occurring at a range of spatial and temporal scales. However, the difficulty in measuring and modelling these complex and dynamic river systems has hampered process understanding and the upscaling necessary to quantify these fluxes. This is due to an incomplete understanding of the hydrogeological structures that control river–groundwater exchange. In this paper, we present a new conceptualisation of subsurface processes in braided rivers based on observations of the main losing reaches of three braided rivers in Aotearoa / New Zealand.
The conceptual model is based on a range of data, including lidar, bathymetry, coring, particle size distribution, groundwater level and temperature monitoring, radon-222, electrical-resistivity tomography and fibre-optic cables. The combined results indicate that sediments within the recently active river braidplain are distinctive, with sediments that are poorly consolidated and better sorted compared with adjacent deposits from the historical braidplain that become successively consolidated and intermixed with flood silt deposits due to overbank flow.
A distinct sedimentary unconformity, combined with the presence of geomorphologically distinct lateral boundaries, suggests that a “braidplain aquifer” forms within the active river braidplain through the process of sediment mobilisation during flood events.
This braidplain aquifer concept introduces a shallow storage reservoir to the river system, which is distinct from the regional aquifer system, and mediates the exchange of flow between individual river channels and the regional aquifer. The implication of the new concept is that surface water–groundwater exchange occurs at two spatial scales: the first is hyporheic and parafluvial exchange between the river and braidplain aquifer; the second is exchange between the braidplain aquifer and regional aquifer system. Exchange at both scales is influenced by the state of hydraulic connection between the respective water bodies. This conceptualisation acknowledges braided rivers as whole “river systems”, consisting of channels and a gravel aquifer reservoir.
This work has important implications for understanding how changes in river management (e.g. surface water extraction, bank training and gravel extraction) and morphology may impact groundwater recharge (and potentially flow, temperature attenuation and ecological resilience) under dry conditions