title: How Nutritional and Genetic Factors affect New Zealand Goat Milk Composition

authors: Huitema, Nadine Aly

subjects: Goat

abstract: Demand for goat milk produced in New Zealand (NZ) is rapidly growing, particularly in expanding Asian markets. The aim of this study was to investigate how genetic and nutritional factors influence milk composition of NZ dairy goats. Little is known about these two factors in dairy goats, especially when compared to extensive research conducted in the area on dairy cows. Therefore in an attempt to improve goat milk production and composition, one important gene and three common nutritional supplements were investigated as part of this study.

The gene CSN1S1 was chosen for genetic analysis as it is highly polymorphic and can produce a range of effects on milk composition. 126 dairy goats were genotyped and 100 of these were aligned to herd-test and fatty acid data. Key findings include (a) ‘medium’ and ‘low’ CSN1S1 variants are the most common in the NZ dairy goat population, (b) CSN1S1 genotype significantly influences milk protein content, (c) in some circumstances CSN1S1 genotype can affect milk yield and fat content (d) CSN1S1 genotype has no effect on somatic cell count or the kilograms yielded of fat and protein or milk solids and (e) CSN1S1 genotypes produce small differences in two fatty acids (C10:0 and C18:3n3).  
Due to their increasing popularity as alternative animal feeds, palm kernel extract (PKE), biscuit waste (BW) and yeast nutritional factors were investigated. PKE significantly increased C12:0 and C14:0 fatty acids which were reduced to control-farm levels following removal of the supplement in the next season. BW had no clear effects on milk fatty acid composition while yeast supplementation had no effect on any aspect of milk composition. Significant seasonal effects were observed for some fatty acids.

Overall this research has shown that milk produced from NZ dairy goats has the potential to be modified through genetic and dietary means. Genetic factors such as CSN1S1 and nutritional supplements, especially PKE can alter milk composition. The healthfulness of goat milk can therefore be optimised to better suit the nutritional needs of the consumer.

text: How Nutritional and Genetic Factors affect New Zealand Goat Milk Composition Demand for goat milk produced in New Zealand (NZ) is rapidly growing, particularly in expanding Asian markets. The aim of this study was to investigate how genetic and nutritional factors influence milk composition of NZ dairy goats. Little is known about these two factors in dairy goats, especially when compared to extensive research conducted in the area on dairy cows. Therefore in an attempt to improve goat milk production and composition, one important gene and three common nutritional supplements were investigated as part of this study.

The gene CSN1S1 was chosen for genetic analysis as it is highly polymorphic and can produce a range of effects on milk composition. 126 dairy goats were genotyped and 100 of these were aligned to herd-test and fatty acid data. Key findings include (a) ‘medium’ and ‘low’ CSN1S1 variants are the most common in the NZ dairy goat population, (b) CSN1S1 genotype significantly influences milk protein content, (c) in some circumstances CSN1S1 genotype can affect milk yield and fat content (d) CSN1S1 genotype has no effect on somatic cell count or the kilograms yielded of fat and protein or milk solids and (e) CSN1S1 genotypes produce small differences in two fatty acids (C10:0 and C18:3n3).  
Due to their increasing popularity as alternative animal feeds, palm kernel extract (PKE), biscuit waste (BW) and yeast nutritional factors were investigated. PKE significantly increased C12:0 and C14:0 fatty acids which were reduced to control-farm levels following removal of the supplement in the next season. BW had no clear effects on milk fatty acid composition while yeast supplementation had no effect on any aspect of milk composition. Significant seasonal effects were observed for some fatty acids.

Overall this research has shown that milk produced from NZ dairy goats has the potential to be modified through genetic and dietary means. Genetic factors such as CSN1S1 and nutritional supplements, especially PKE can alter milk composition. The healthfulness of goat milk can therefore be optimised to better suit the nutritional needs of the consumer.

year: 2012

title: A continuum model for the dynamics of the phase transition from slow-wave sleep to REM sleep

authors: Sleigh, James W.

subjects: SWS

abstract: Previous studies have shown that activated cortical states (awake and rapid eye-movement (REM) sleep), are associated with increased cholinergic input into the cerebral cortex. However, the mechanisms that underlie the detailed dynamics of the cortical transition from slow-wave to REM sleep have not been quantitatively modeled. How does the sequence of abrupt changes in the cortical dynamics (as detected in the electrocorticogram) result from the more gradual change in subcortical cholinergic input? We compare the output from a continuum model of cortical neuronal dynamics with experimentally-derived rat electrocorticogram data. The output from the computer model was consistent with experimental observations. In slow-wave sleep, 0.5–2-Hz oscillations arise from the cortex jumping between “up” and “down” states on the stationary-state manifold. As cholinergic input increases, the upper state undergoes a bifurcation to an 8-Hz oscillation. The coexistence of both oscillations is similar to that found in the intermediate stage of sleep of the rat. Further cholinergic input moves the trajectory to a point where the lower part of the manifold in not available, and thus the slow oscillation abruptly ceases (REM sleep). The model provides a natural basis to explain neuromodulator-induced changes in cortical activity, and indicates that a cortical phase change, rather than a brainstem “flip-flop”, may describe the transition from slow-wave sleep to REM.

text: A continuum model for the dynamics of the phase transition from slow-wave sleep to REM sleep Previous studies have shown that activated cortical states (awake and rapid eye-movement (REM) sleep), are associated with increased cholinergic input into the cerebral cortex. However, the mechanisms that underlie the detailed dynamics of the cortical transition from slow-wave to REM sleep have not been quantitatively modeled. How does the sequence of abrupt changes in the cortical dynamics (as detected in the electrocorticogram) result from the more gradual change in subcortical cholinergic input? We compare the output from a continuum model of cortical neuronal dynamics with experimentally-derived rat electrocorticogram data. The output from the computer model was consistent with experimental observations. In slow-wave sleep, 0.5–2-Hz oscillations arise from the cortex jumping between “up” and “down” states on the stationary-state manifold. As cholinergic input increases, the upper state undergoes a bifurcation to an 8-Hz oscillation. The coexistence of both oscillations is similar to that found in the intermediate stage of sleep of the rat. Further cholinergic input moves the trajectory to a point where the lower part of the manifold in not available, and thus the slow oscillation abruptly ceases (REM sleep). The model provides a natural basis to explain neuromodulator-induced changes in cortical activity, and indicates that a cortical phase change, rather than a brainstem “flip-flop”, may describe the transition from slow-wave sleep to REM.

year: 2010

title: Culturally-Oriented Environmental Identity Transitions: Migrant Indian Teachers in Aotearoa New Zealand Early Childhood Education

authors: Rathore, Devika

abstract: An increasingly multicultural Aotearoa New Zealand early childhood education (ECE) landscape that includes a growing number of migrant teachers forms the context for my doctoral study. In this country, respect for the natural world and kaitiakitanga are integral to the ECE bicultural curriculum framework Te Whāriki (Ministry of Education [MoE], 2017) which is grounded in Indigenous Māori worldviews that acknowledge strong spiritual connections to land and place. The natural environment is considered an integral part of the national identity and early childhood has been recognised as an important stage when Environmental and Sustainability Education should begin.   

Within the context of this superdiverse nation, a significant number of migrant teachers transfer their cultural and environmental knowledge, practice, and identity as they transition into the Aotearoa New Zealand context. This thesis explored migrant Indian teachers’ understandings of their culturally-oriented and negotiated environmental identities. I was keen to examine if the environment might hold different meanings and places in their home (Indian) and host (Aotearoa New Zealand) cultural systems.   

Through this study, insights were gained into migrant Indian teachers’ perceptions of the influence of cultural identity on their environmental identities in Aotearoa New Zealand ECE. A sociocultural theoretical perspective informed this study, drawing primarily on Sauvé’s (2009) model of personal and social development of the self in relation to other humans and the environment. Primary data for this interpretivist study were gathered through in-depth interviews with nine Indian ECE teacher participants. Interviews with their ECE setting managers/head teachers were conducted to support and supplement the teachers’ practices and experiences. The audio-recorded interview data were transcribed and examined using thematic analysis. Observations of teacher participants’ workplaces were used to provide a contextual profile for each of the nine Indian teachers. I also obtained a small number of assessment documents in the form of Learning Stories which the teachers had prepared, to analyse them for cultural and environmental themes and experiences.   

Indian teacher participants’ perceptions of their own culturally-oriented environmental identities highlighted the significance of teachers’ own early childhood environmental experiences and home cultural context influences on their environmental identities. Teacher participants’ perceptions shed light on their cultural and environmental identity transitions and acculturation process. These teachers brought their cultural and environmental identities from their home cultural context and used their cultural lens to interpret the connections between the host cultural context and environmental worldviews.   

The Indian teacher participants perceived close connections between their cultural and environmental identities. At the same time, they recognised cross-cultural connections between their culturally-oriented environmental identities and tikanga Māori (Māori ways of doing including practices, customs and rituals) and te ao Māori (the Māori world). These perceived connections were most evident through the significance of Indian philosophies of spirituality, relationships, belonging, and cultural recognition and exchange in their specific ECE contexts. These connections facilitated teachers’ cultural and environmental identity transitions and had a positive impact on their cultural and environmental teaching practices when supported within the ECE setting and by management/leadership.   

Cultural and environmental transitions for this steadily growing group of migrant teachers require further investigation to facilitate their cultural and environmental participation and acculturation into the Aotearoa New Zealand ECE context. In these ways, the existing cultural, environmental, and sustainability connections within ECE could be strengthened to foster children’s culturally-oriented environmental identities.

text: Culturally-Oriented Environmental Identity Transitions: Migrant Indian Teachers in Aotearoa New Zealand Early Childhood Education An increasingly multicultural Aotearoa New Zealand early childhood education (ECE) landscape that includes a growing number of migrant teachers forms the context for my doctoral study. In this country, respect for the natural world and kaitiakitanga are integral to the ECE bicultural curriculum framework Te Whāriki (Ministry of Education [MoE], 2017) which is grounded in Indigenous Māori worldviews that acknowledge strong spiritual connections to land and place. The natural environment is considered an integral part of the national identity and early childhood has been recognised as an important stage when Environmental and Sustainability Education should begin.   

Within the context of this superdiverse nation, a significant number of migrant teachers transfer their cultural and environmental knowledge, practice, and identity as they transition into the Aotearoa New Zealand context. This thesis explored migrant Indian teachers’ understandings of their culturally-oriented and negotiated environmental identities. I was keen to examine if the environment might hold different meanings and places in their home (Indian) and host (Aotearoa New Zealand) cultural systems.   

Through this study, insights were gained into migrant Indian teachers’ perceptions of the influence of cultural identity on their environmental identities in Aotearoa New Zealand ECE. A sociocultural theoretical perspective informed this study, drawing primarily on Sauvé’s (2009) model of personal and social development of the self in relation to other humans and the environment. Primary data for this interpretivist study were gathered through in-depth interviews with nine Indian ECE teacher participants. Interviews with their ECE setting managers/head teachers were conducted to support and supplement the teachers’ practices and experiences. The audio-recorded interview data were transcribed and examined using thematic analysis. Observations of teacher participants’ workplaces were used to provide a contextual profile for each of the nine Indian teachers. I also obtained a small number of assessment documents in the form of Learning Stories which the teachers had prepared, to analyse them for cultural and environmental themes and experiences.   

Indian teacher participants’ perceptions of their own culturally-oriented environmental identities highlighted the significance of teachers’ own early childhood environmental experiences and home cultural context influences on their environmental identities. Teacher participants’ perceptions shed light on their cultural and environmental identity transitions and acculturation process. These teachers brought their cultural and environmental identities from their home cultural context and used their cultural lens to interpret the connections between the host cultural context and environmental worldviews.   

The Indian teacher participants perceived close connections between their cultural and environmental identities. At the same time, they recognised cross-cultural connections between their culturally-oriented environmental identities and tikanga Māori (Māori ways of doing including practices, customs and rituals) and te ao Māori (the Māori world). These perceived connections were most evident through the significance of Indian philosophies of spirituality, relationships, belonging, and cultural recognition and exchange in their specific ECE contexts. These connections facilitated teachers’ cultural and environmental identity transitions and had a positive impact on their cultural and environmental teaching practices when supported within the ECE setting and by management/leadership.   

Cultural and environmental transitions for this steadily growing group of migrant teachers require further investigation to facilitate their cultural and environmental participation and acculturation into the Aotearoa New Zealand ECE context. In these ways, the existing cultural, environmental, and sustainability connections within ECE could be strengthened to foster children’s culturally-oriented environmental identities.

year: 2024