title: A mathematical optimisation model of a New Zealand dairy farm: The integrated dairy enterprise (IDEA) framework

authors: Doole, Graeme J.

subjects: dairy production

abstract: Optimisation models are a key tool for the analysis of emerging policies, price sets, and technologies within grazing systems. A detailed nonlinear optimisation model of a New Zealand dairy farming system is described. The framework is notable for its rich portrayal of pasture and cow biology that add substantial descriptive power to standard approaches. Key processes incorporated in the model include: (1) pasture growth and digestibility that differ with residual pasture mass and rotation length, (2) pasture utilisation that varies by stocking rate, and (3) different levels of intake regulation. Model output is shown to closely match data from a more detailed simulation model (deviations between 0 and 5 per cent) and survey data (deviations between 1 and 11 per cent), providing confidence in its predictive capacity. Use of the model is demonstrated in an empirical application investigating the relative profitability of production systems involving different amounts of imported feed under price variation. The case study indicates superior profitability associated with the use of a moderate level of imported supplement, with Operating Profit ($NZ ha-1) of 934, 926, 1186, 1314, and 1093 when imported feed makes up 0, 5, 10, 20 and 30 per cent of the diet, respectively. Stocking rate and milk production per cow increase by 35 and 29 per cent, respectively, as the proportion of imported feed increases from 0 to 30 per cent of the diet. Pasture utilisation increases with stocking rate. Accordingly, pasture eaten and nitrogen fertiliser application increase by 20 and 213 per cent, respectively, as the proportion of imported feed increases from 0 to 30 per cent of the diet.

text: A mathematical optimisation model of a New Zealand dairy farm: The integrated dairy enterprise (IDEA) framework Optimisation models are a key tool for the analysis of emerging policies, price sets, and technologies within grazing systems. A detailed nonlinear optimisation model of a New Zealand dairy farming system is described. The framework is notable for its rich portrayal of pasture and cow biology that add substantial descriptive power to standard approaches. Key processes incorporated in the model include: (1) pasture growth and digestibility that differ with residual pasture mass and rotation length, (2) pasture utilisation that varies by stocking rate, and (3) different levels of intake regulation. Model output is shown to closely match data from a more detailed simulation model (deviations between 0 and 5 per cent) and survey data (deviations between 1 and 11 per cent), providing confidence in its predictive capacity. Use of the model is demonstrated in an empirical application investigating the relative profitability of production systems involving different amounts of imported feed under price variation. The case study indicates superior profitability associated with the use of a moderate level of imported supplement, with Operating Profit ($NZ ha-1) of 934, 926, 1186, 1314, and 1093 when imported feed makes up 0, 5, 10, 20 and 30 per cent of the diet, respectively. Stocking rate and milk production per cow increase by 35 and 29 per cent, respectively, as the proportion of imported feed increases from 0 to 30 per cent of the diet. Pasture utilisation increases with stocking rate. Accordingly, pasture eaten and nitrogen fertiliser application increase by 20 and 213 per cent, respectively, as the proportion of imported feed increases from 0 to 30 per cent of the diet.

year: 2012-04

title: Using putative bovine embryonic stem cell-like cells for nuclear transfer cloning to determine their functional potential

authors: Appleby, Sarah Jane

subjects: cloning

abstract: The potential for cloning to improve dissemination of elite genetics has been a goal of livestock scientists for many years. However, efficiency of this technique has remained low compared to other in vitro embryo production methods. One hypothesised method to improve cloning efficiency is to use donor cells that require less reprogramming, as donor cells must be reprogrammed to an embryonic state in order to generate a whole embryo. Somatic cells are the most readily available cell type for donor cells, making them the most often used, but also the most differentiated. Embryonic stem cells (ESCs) are pluripotent cells, capable of generating all cell types. As ESCs are at a much lower differentiated state, they would be hypothesised to improve cloning efficiency. However, ESCs have only been derived from mice and rats. Using a novel culture method, bovine ESC-like cells (ePSCs) can be maintained for several weeks in vitro. The aim of this research was to evaluate the efficiency of using these bovine ePSCs in nuclear transfer (NT) cloning.

ePSC colonies were generated from in vitro produced blastocysts and arrested into mitosis with an overnight incubation with 500 nM nocodazole. A method was devised to isolate single cells, using serial treatment in dispase, pronase, and trituration in Ca-Mg-free dissociation media containing cytochalasin B. Arrested colonies were characterised for the degree of mitotic arrest, showing approximately 40% of the colony was arrested in mitosis, and the proportion of cells in DNA synthesis phase had significantly decreased. Cells expressing pluripotency genes SOX2 and NANOG were enriched in the central dome-shaped colony. Analysis of mitotic cells showed that 63% were also pluripotent. NT cloning was optimised for use with donor cells synchronised into mitosis. Pronase treated donor cells fused to metaphase II arrested cytoplasts in isoosmolar fusion buffer resulted in highest fusion rate. Comparison of artificial activation with ionomycin followed by DMAP, CHX, or anisomycin showed that ionomycin/DMAP activation produced the highest blastocyst development rate. Using these optimised conditions, cloning with ePSC donor cells resulted in a three-fold higher blastocyst development than with somatic cells. As donor cells were in metaphase, they contained double the normal amount of DNA. Therefore, it was important to assess the karyotype of blastocysts for normal ploidy. A bimodal distribution of chromosome spreads of around 60 and 120 chromosomes was observed, with higher chromosome numbers apparently restricted to trophoblast cells.

Further validation of blastocyst ploidy, characterisation of donor cells used for NT, and continued optimisation of protocols, through double cytoplast cloning or timing of gap between fusion and activation, is required before completing in vivo cloning trials. Embryo transfer trials will be the final step in addressing the long-term aim of this project: to demonstrate that elite bovine embryos can be converted into ePSCs and then ePSC derived animals.

text: Using putative bovine embryonic stem cell-like cells for nuclear transfer cloning to determine their functional potential The potential for cloning to improve dissemination of elite genetics has been a goal of livestock scientists for many years. However, efficiency of this technique has remained low compared to other in vitro embryo production methods. One hypothesised method to improve cloning efficiency is to use donor cells that require less reprogramming, as donor cells must be reprogrammed to an embryonic state in order to generate a whole embryo. Somatic cells are the most readily available cell type for donor cells, making them the most often used, but also the most differentiated. Embryonic stem cells (ESCs) are pluripotent cells, capable of generating all cell types. As ESCs are at a much lower differentiated state, they would be hypothesised to improve cloning efficiency. However, ESCs have only been derived from mice and rats. Using a novel culture method, bovine ESC-like cells (ePSCs) can be maintained for several weeks in vitro. The aim of this research was to evaluate the efficiency of using these bovine ePSCs in nuclear transfer (NT) cloning.

ePSC colonies were generated from in vitro produced blastocysts and arrested into mitosis with an overnight incubation with 500 nM nocodazole. A method was devised to isolate single cells, using serial treatment in dispase, pronase, and trituration in Ca-Mg-free dissociation media containing cytochalasin B. Arrested colonies were characterised for the degree of mitotic arrest, showing approximately 40% of the colony was arrested in mitosis, and the proportion of cells in DNA synthesis phase had significantly decreased. Cells expressing pluripotency genes SOX2 and NANOG were enriched in the central dome-shaped colony. Analysis of mitotic cells showed that 63% were also pluripotent. NT cloning was optimised for use with donor cells synchronised into mitosis. Pronase treated donor cells fused to metaphase II arrested cytoplasts in isoosmolar fusion buffer resulted in highest fusion rate. Comparison of artificial activation with ionomycin followed by DMAP, CHX, or anisomycin showed that ionomycin/DMAP activation produced the highest blastocyst development rate. Using these optimised conditions, cloning with ePSC donor cells resulted in a three-fold higher blastocyst development than with somatic cells. As donor cells were in metaphase, they contained double the normal amount of DNA. Therefore, it was important to assess the karyotype of blastocysts for normal ploidy. A bimodal distribution of chromosome spreads of around 60 and 120 chromosomes was observed, with higher chromosome numbers apparently restricted to trophoblast cells.

Further validation of blastocyst ploidy, characterisation of donor cells used for NT, and continued optimisation of protocols, through double cytoplast cloning or timing of gap between fusion and activation, is required before completing in vivo cloning trials. Embryo transfer trials will be the final step in addressing the long-term aim of this project: to demonstrate that elite bovine embryos can be converted into ePSCs and then ePSC derived animals.

year: 2015

title: A community psychology-based evaluation of the you good? You Good! program delivered by Jade speaks up educational trust in Aotearoa. Empowering tamariki emotional literacy, supporting mental health and encouraging well-being.

authors: Webbon, Abigail

abstract: This evaluation was completed for Jade Speaks Up (JSU) Educational Trust to provide feedback from school teachers and whānau who were involved in the You Good? You Good! (YG?YG!) program, delivered by JSU Educational Trust to schools across Aotearoa. The evaluation goal was to collate the narratives of participating school staff, whānau, and JSU Educational Trust trainers, contrasting experiences and perspectives to determine program effectiveness.
This program is for schools, management, and teachers who work with tamariki, to help teachers and students understand anxiety and develop skills and strategies to have self-agency. JSU Educational Trust developed YG?YG! in 2021, and in 2022 the YG?YG! pilot program was implemented.
This evaluation had three research objectives: 1) Identify and collate the experiences of school staff and other key stakeholders when implementing the YG?YG!, 2) Identify the strengths and barriers to inclusion for tamariki in schools where the program was delivered, and 3) Draw on the stakeholder narratives to assess the program's ability to achieve its goal: enable tamariki to be more agentic in responding to early signs of anxiety in themselves and others.
Information for this evaluation was collected from four sources: 1) Focus groups with JSU trainers, 2) Interviews with school staff, 3) Online surveys with school staff, 4) Archival supervision, and 5) Literature review. Data collected was interpreted through the use of thematic analysis, informed by Community Psychology principles, and the “Six C” framework, guided by He Awa Whiria.
Thematic analysis was completed by coding themes and categories from data sources. The findings from this empirical research engagement informed the analysis and discussion on program effectiveness. 
The findings and analysis found that forming a program design and approach informed with respect for the community’s needs and world-views can enable recognition, awareness and inclusion. A way for the program to begin to do so is to collaborate with communities.
Including researchers from a local community can enable empowerment, build social power, and create responses that promote the needs of the involved communities. The program can champion the field and those they work with by being accountable and enabling transparency.
The program can take an inclusive approach to sustaining its relationships, content relevance, and development for tamariki emotional well-being. The program can work on cultivating and empowering participants to be active partners, enabling the program to be shaped with equity in mind.
Key to program efficacy is acknowledging change and encompassing adaptation. The way to do this is to consider local health issues driven by who experience them, elevating the voice of the community.
Change and need cannot be determined without considering the voice of involved communities. By taking participants feedback, the program can create change for tamariki mental health, whilst acknowledging system and structural barriers, striving for community competence.
Importance lies within the work the program does to enable and support those affected by external factors. The program can acknowledge these challenges, and provide hope that community competence can be achieved.
To conclude, recommendations are presented for JSU Educational Trust to consider.

text: A community psychology-based evaluation of the you good? You Good! program delivered by Jade speaks up educational trust in Aotearoa. Empowering tamariki emotional literacy, supporting mental health and encouraging well-being. This evaluation was completed for Jade Speaks Up (JSU) Educational Trust to provide feedback from school teachers and whānau who were involved in the You Good? You Good! (YG?YG!) program, delivered by JSU Educational Trust to schools across Aotearoa. The evaluation goal was to collate the narratives of participating school staff, whānau, and JSU Educational Trust trainers, contrasting experiences and perspectives to determine program effectiveness.
This program is for schools, management, and teachers who work with tamariki, to help teachers and students understand anxiety and develop skills and strategies to have self-agency. JSU Educational Trust developed YG?YG! in 2021, and in 2022 the YG?YG! pilot program was implemented.
This evaluation had three research objectives: 1) Identify and collate the experiences of school staff and other key stakeholders when implementing the YG?YG!, 2) Identify the strengths and barriers to inclusion for tamariki in schools where the program was delivered, and 3) Draw on the stakeholder narratives to assess the program's ability to achieve its goal: enable tamariki to be more agentic in responding to early signs of anxiety in themselves and others.
Information for this evaluation was collected from four sources: 1) Focus groups with JSU trainers, 2) Interviews with school staff, 3) Online surveys with school staff, 4) Archival supervision, and 5) Literature review. Data collected was interpreted through the use of thematic analysis, informed by Community Psychology principles, and the “Six C” framework, guided by He Awa Whiria.
Thematic analysis was completed by coding themes and categories from data sources. The findings from this empirical research engagement informed the analysis and discussion on program effectiveness. 
The findings and analysis found that forming a program design and approach informed with respect for the community’s needs and world-views can enable recognition, awareness and inclusion. A way for the program to begin to do so is to collaborate with communities.
Including researchers from a local community can enable empowerment, build social power, and create responses that promote the needs of the involved communities. The program can champion the field and those they work with by being accountable and enabling transparency.
The program can take an inclusive approach to sustaining its relationships, content relevance, and development for tamariki emotional well-being. The program can work on cultivating and empowering participants to be active partners, enabling the program to be shaped with equity in mind.
Key to program efficacy is acknowledging change and encompassing adaptation. The way to do this is to consider local health issues driven by who experience them, elevating the voice of the community.
Change and need cannot be determined without considering the voice of involved communities. By taking participants feedback, the program can create change for tamariki mental health, whilst acknowledging system and structural barriers, striving for community competence.
Importance lies within the work the program does to enable and support those affected by external factors. The program can acknowledge these challenges, and provide hope that community competence can be achieved.
To conclude, recommendations are presented for JSU Educational Trust to consider.

year: 2024-11-14