The University of Western Australia
Professor Graeme Martin
Head of School
Contact details
| Address | School of Animal Biology The University of Western Australia (M092) 35 Stirling Highway CRAWLEY WA 6009 Australia |
|---|---|
| Phone | 6488 2237 |
| Fax | 6488 1029 |
| graeme.martin@uwa.edu.au | |
| Personal homepage | http://www.animals.uwa.edu.au/contact |
Biography
I was born in 1951 and grew up on sheep/cereal farm in Western Australia (WA). I graduated in Agricultural Science (Hons I) at the University of WA in 1975 and gained my doctorate in reproductive endocrinology in 1981. I then worked for two years at the INRA Station de Physiologie de la Reproduction at Nouzilly (France) and for three years at the Medical Research Council’s Reproductive Biology Unit in Edinburgh (UK). In 1986, I returned to Perth (WA) to take up a joint position as Lecturer in Animal Science (The University of WA) and Research Scientist (CSIRO Division of Animal Production). In 2001, I was promoted to Professor (Chair).
My research is on reproductive physiology, neuroendocrinology and behaviour in sheep and emus, and I also have small projects on rats, dogs, penguins and marsupials. The sheep research focuses on the influences of environmental factors on the reproductive system, with an emphasis on the brain mechanisms involved. The emu research covers a range of topics from basic reproductive and metabolic biology to reproductive technology. Work on rats and dogs is aimed at the development of new approaches to contraception. I have published 150 peer-reviewed papers and presented 180 conference papers. Much of my work has also been presented to the public via radio, television and newspapers. Of particular note here is the article by Ken Eastwood titled “Superbird” that appeared in Australian Geographic 58, 35-49 (2000).
I have served as the Head of the Animal Science Group in The Faculty of Agriculture, as Dean of the Faculty of Natural & Agricultural Sciences during its formation in 2002, and I am currently Deputy Chair of the Academic Board of the University.
My research is on reproductive physiology, neuroendocrinology and behaviour in sheep and emus, and I also have small projects on rats, dogs, penguins and marsupials. The sheep research focuses on the influences of environmental factors on the reproductive system, with an emphasis on the brain mechanisms involved. The emu research covers a range of topics from basic reproductive and metabolic biology to reproductive technology. Work on rats and dogs is aimed at the development of new approaches to contraception. I have published 150 peer-reviewed papers and presented 180 conference papers. Much of my work has also been presented to the public via radio, television and newspapers. Of particular note here is the article by Ken Eastwood titled “Superbird” that appeared in Australian Geographic 58, 35-49 (2000).
I have served as the Head of the Animal Science Group in The Faculty of Agriculture, as Dean of the Faculty of Natural & Agricultural Sciences during its formation in 2002, and I am currently Deputy Chair of the Academic Board of the University.
Key research
- We work mostly on reproductive physiology, neuroendocrinology and behaviour in sheep and emus, but also have small projects on rats, dogs, penguins and marsupials. Our sheep research focuses on the influences of environmental factors (especially nutrition and socio-sexual signals) on the reproductive system, with an emphasis on the brain mechanisms involved. Our emu research is designed to support the development of this sunrise industry in Australia and it covers a range of topics from basic reproductive and metabolic biology to reproductive technology. Work on rats and dogs is aimed at the development of new approaches to contraception. Much of our research is intended, in the long term, to help solve problems in animal industries or human medicine, although this pursuit has invariably been supported by basic research into endocrine, neuroendocrine and behavioural aspects of reproductive and metabolic physiology. I am particularly interested in the way that the central nervous system integrates a range of different types of information about the environment as it ‘formulates’ a reproductive strategy for the animal.
Major research interests
- Reproductive physiology and neurobiology
Qualifications
BSc(Agric) PhD W.Aust.
Publications
Rather than put a full list of publications here, I will provide 10 papers that highlight the achievements and current research interests of our laboratory. For the sake of efficiency, some of these will be invited reviews published in major journals.
Banchero, G.E., Perez Clariget, R., Bencini, R., Lindsay, D.R., Milton, J.T.B. & Martin, G.B. (2006). Endocrine and metabolic factors involved in the effect of nutrition on the production of colostrum in female sheep. Reproduction Nutrition Development 46, 447-460.
Blache, D., Zhang, Z. & Martin, G.B. (2006). Dynamic and integrative aspects of the regulation of reproduction by metabolic status in male sheep. Reproduction Nutrition Development 46, 379-390.
Delgadillo, J.A., Gelez, H., Ungerfeld, R., Hawken, P.A.R. & Martin, G.B. (2009). The ‘male effect’ in sheep and goats – revisiting the dogmas. Behavioural Brain Research 200, 304-314.
Hawken, P.A.R., Esmaili, T., Scanlan, V., Blache, D. & Martin, G.B. (2009). Can audio-visual or visual stimuli from a prospective mate stimulate a reproductive neuroendocrine response in sheep? Animal 3, 690-696.
Hawken, P.A.R., Jorre de St Jorre, T., Rodger, J., Esmaili, T., Blache, D. & Martin, G.B. (2009). Rapid induction of cell proliferation in the adult female ungulate brain (Ovis aries) associated with activation of the reproductive axis by exposure to unfamiliar males. Biology of Reproduction 80, 1146-1151.
Junaidi, A., Williamson, P.E., Cummins, J.M., Martin, G.B., Blackberry, M.A. & Trigg, T.E. (2003). The effect of a slow release implant containing the GnRH agonist Deslorelin on pituitary and testicular function in mature male dogs. Reproduction, Fertility and Development 15, 317-322.
Malecki, I.A., Rybnik, P.K. & Martin, G.B. (2008). Artificial insemination technology for ratites: a review. Australian Journal of Experimental Agriculture 48, 1284-1292.
Martin, G.B. & Kadokawa, H. (2006). “Clean, green and ethical” animal production. Case study: reproductive efficiency in small ruminants. Journal of Reproduction and Development 52, 145-152.
Martin, G.B., Rodger, J. & Blache, D. (2004). Nutritional and environmental effects on reproduction in small ruminants. Reproduction, Fertility and Development 16, 491-501.
Scaramuzzi, R.J. & Martin, G.B. (2008). The importance of interactions among nutrition, seasonality and socio-sexual factors in the development of hormone-free methods for controlling fertility. Reproduction in Domestic Animals 43 (Supplement 2), 129-136.
Viñoles, C., Meikle, A. & Martin, G.B. (2009). Short-term nutritional treatments grazing legumes or feeding concentrates increase prolificacy in Corriedale ewes. Animal Reproduction Science 113, 82-92.
Banchero, G.E., Perez Clariget, R., Bencini, R., Lindsay, D.R., Milton, J.T.B. & Martin, G.B. (2006). Endocrine and metabolic factors involved in the effect of nutrition on the production of colostrum in female sheep. Reproduction Nutrition Development 46, 447-460.
Blache, D., Zhang, Z. & Martin, G.B. (2006). Dynamic and integrative aspects of the regulation of reproduction by metabolic status in male sheep. Reproduction Nutrition Development 46, 379-390.
Delgadillo, J.A., Gelez, H., Ungerfeld, R., Hawken, P.A.R. & Martin, G.B. (2009). The ‘male effect’ in sheep and goats – revisiting the dogmas. Behavioural Brain Research 200, 304-314.
Hawken, P.A.R., Esmaili, T., Scanlan, V., Blache, D. & Martin, G.B. (2009). Can audio-visual or visual stimuli from a prospective mate stimulate a reproductive neuroendocrine response in sheep? Animal 3, 690-696.
Hawken, P.A.R., Jorre de St Jorre, T., Rodger, J., Esmaili, T., Blache, D. & Martin, G.B. (2009). Rapid induction of cell proliferation in the adult female ungulate brain (Ovis aries) associated with activation of the reproductive axis by exposure to unfamiliar males. Biology of Reproduction 80, 1146-1151.
Junaidi, A., Williamson, P.E., Cummins, J.M., Martin, G.B., Blackberry, M.A. & Trigg, T.E. (2003). The effect of a slow release implant containing the GnRH agonist Deslorelin on pituitary and testicular function in mature male dogs. Reproduction, Fertility and Development 15, 317-322.
Malecki, I.A., Rybnik, P.K. & Martin, G.B. (2008). Artificial insemination technology for ratites: a review. Australian Journal of Experimental Agriculture 48, 1284-1292.
Martin, G.B. & Kadokawa, H. (2006). “Clean, green and ethical” animal production. Case study: reproductive efficiency in small ruminants. Journal of Reproduction and Development 52, 145-152.
Martin, G.B., Rodger, J. & Blache, D. (2004). Nutritional and environmental effects on reproduction in small ruminants. Reproduction, Fertility and Development 16, 491-501.
Scaramuzzi, R.J. & Martin, G.B. (2008). The importance of interactions among nutrition, seasonality and socio-sexual factors in the development of hormone-free methods for controlling fertility. Reproduction in Domestic Animals 43 (Supplement 2), 129-136.
Viñoles, C., Meikle, A. & Martin, G.B. (2009). Short-term nutritional treatments grazing legumes or feeding concentrates increase prolificacy in Corriedale ewes. Animal Reproduction Science 113, 82-92.
Roles, responsibilities and expertise
1) Neurophysiological processes that underpin the induction of ovulation by male socio-sexual signals (especially pheromones). This includes neurogenesis, neuroendocrinology, learning and memory, interactions with nutrition, behaviour, the function of the corpus luteum.
2) Nutritional inputs into reproduction: ovulation rate, embryo survival, lactogenesis, sperm production (including testicular cell division and apoptosis).
2) Nutritional inputs into reproduction: ovulation rate, embryo survival, lactogenesis, sperm production (including testicular cell division and apoptosis).
Future research
Sheep industries around the world need a long-term vision with clear goals, and a research and development program that will lead to those goals. Our vision is based around gradual, but inevitable changes in the marketplace: the consumers are demanding products that are green, clean and more ethical. Effectively, for the sheep producers, this means moving into new practices – practices that do not involve chemical or hormonal treatments of animals, and practices that take into consideration the welfare of the animals. We can wait until these conditions are imposed on us, or we can begin to move towards them now.
Two aspects of this situation will be greatly advantageous for many of sheep producers:
1) Most of these green and ethical practices can actually improve productivity; all that is required is a little research and development so we can capture the maximum benefits;
2) Some genotypes (eg the Merino) are arguably ideal for these methods of management because they already show the characteristics that we need; again, all that is required is a little research and development so we can capture the maximum benefits.
Meat production effectively depends on reproduction. What we need is to be able to:
a) Control the season of lamb production – specifically, this means controlling the timing of breeding;
b) Maximise lamb turnoff – this means improving litter size and then ensuring that lamb survival is maximised;
c) Ensure that the above fits easily into a management system that often involves other enterprises on the same farm.
Two aspects of this situation will be greatly advantageous for many of sheep producers:
1) Most of these green and ethical practices can actually improve productivity; all that is required is a little research and development so we can capture the maximum benefits;
2) Some genotypes (eg the Merino) are arguably ideal for these methods of management because they already show the characteristics that we need; again, all that is required is a little research and development so we can capture the maximum benefits.
Meat production effectively depends on reproduction. What we need is to be able to:
a) Control the season of lamb production – specifically, this means controlling the timing of breeding;
b) Maximise lamb turnoff – this means improving litter size and then ensuring that lamb survival is maximised;
c) Ensure that the above fits easily into a management system that often involves other enterprises on the same farm.
Funding received
All of my work has been funded by competitive research grants (mostly Australian Research Council, National Health & Medical Research Council, Rural Research & Development Corporation) and has involved the training of students: 17 Honours, 5 Postgraduate Diplomas, 6 MSc and 19 PhDs. Excluding student scholarships, external grants total over Au$2.5 million.
Industrial relevance
Sheep industries around the world need a long-term vision with clear goals, and a research and development program that will lead to those goals. Our vision is based around gradual, but inevitable changes in the marketplace: the consumers are demanding products that are green, clean and more ethical. Effectively, for the sheep producers, this means moving into new practices – practices that do not involve chemical or hormonal treatments of animals, and practices that take into consideration the welfare of the animals. We can wait until these conditions are imposed on us, or we can begin to move towards them now.
Two aspects of this situation will be greatly advantageous for many of sheep producers:
1) Most of these green and ethical practices can actually improve productivity; all that is required is a little research and development so we can capture the maximum benefits;
2) Some genotypes (eg the Merino) are arguably ideal for these methods of management because they already show the characteristics that we need; again, all that is required is a little research and development so we can capture the maximum benefits.
Meat production effectively depends on reproduction. What we need is to be able to:
a) Control the season of lamb production – specifically, this means controlling the timing of breeding;
b) Maximise lamb turnoff – this means improving litter size and then ensuring that lamb survival is maximised;
c) Ensure that the above fits easily into a management system that often involves other enterprises on the same farm.
Two aspects of this situation will be greatly advantageous for many of sheep producers:
1) Most of these green and ethical practices can actually improve productivity; all that is required is a little research and development so we can capture the maximum benefits;
2) Some genotypes (eg the Merino) are arguably ideal for these methods of management because they already show the characteristics that we need; again, all that is required is a little research and development so we can capture the maximum benefits.
Meat production effectively depends on reproduction. What we need is to be able to:
a) Control the season of lamb production – specifically, this means controlling the timing of breeding;
b) Maximise lamb turnoff – this means improving litter size and then ensuring that lamb survival is maximised;
c) Ensure that the above fits easily into a management system that often involves other enterprises on the same farm.
Languages
English (Mother tongue), French (fluent), some Spanish
Memberships
Society for Reproductive Biology (Australia)
Endocrine Society of Australia
Endocrine Society (UK)
Society for Reproduction and Fertility (UK)
Australian Society for Animal Production
Austral Comparative Endocrinologists
Endocrine Society of Australia
Endocrine Society (UK)
Society for Reproduction and Fertility (UK)
Australian Society for Animal Production
Austral Comparative Endocrinologists
Honours and awards
1982 Overseas Study Award, Australian Meat Research Committee
1991 RJ Moir Medal, Australian Society for Animal Production
1992 75th Anniversary Award, The University of WA
1991 RJ Moir Medal, Australian Society for Animal Production
1992 75th Anniversary Award, The University of WA
Previous positions
1978-79
Tutor, Department of Animal Science & Production, Faculty of Agriculture, The University of Western Australia.
1980-81
Technician (Australian Meat Research Committee)
Department of Animal Science & Production, Faculty of Agriculture, The University of Western Australia.
1982-84
Research Fellow (Australian Meat Research Committee)
Station de Physiologie de la Reproduction, Institut Nationale de la Recherche Agronomique, France.
1984-86
Research Scientist
Reproductive Biology Unit, Medical Research Council, Edinburgh, UK.
1986-89
Joint Appointment
Lecturer, School of Agriculture (Animal Science), The University of Western Australia;
Research Scientist, CSIRO Division of Animal Production, Floreat Park, Western Australia.
1990-96
Joint Appointment
Senior Lecturer, Faculty of Agriculture (Animal Science), The University of Western Australia;
Senior Research Scientist, CSIRO Division of Animal Production, Floreat Park, Western Australia.
1996-2000
Associate Professor, Faculty of Agriculture (Animal Science), The University of Western Australia
Tutor, Department of Animal Science & Production, Faculty of Agriculture, The University of Western Australia.
1980-81
Technician (Australian Meat Research Committee)
Department of Animal Science & Production, Faculty of Agriculture, The University of Western Australia.
1982-84
Research Fellow (Australian Meat Research Committee)
Station de Physiologie de la Reproduction, Institut Nationale de la Recherche Agronomique, France.
1984-86
Research Scientist
Reproductive Biology Unit, Medical Research Council, Edinburgh, UK.
1986-89
Joint Appointment
Lecturer, School of Agriculture (Animal Science), The University of Western Australia;
Research Scientist, CSIRO Division of Animal Production, Floreat Park, Western Australia.
1990-96
Joint Appointment
Senior Lecturer, Faculty of Agriculture (Animal Science), The University of Western Australia;
Senior Research Scientist, CSIRO Division of Animal Production, Floreat Park, Western Australia.
1996-2000
Associate Professor, Faculty of Agriculture (Animal Science), The University of Western Australia
Teaching
I teach in a range of units that cover animal physiology, especially reproduction and endocrinology, as well as the principles and practice in the communication of science. I will only cover major subjects here.
1) Animal Science & Technology
This final-year course is self-paced and based on study guides that refer the students to relevant texts in the library. The students read these and answer questions in the study guide that provide them with a measure of the required depth of knowledge and understanding. Problems that arise are overcome in tutorials.
The academic objective is a thorough understanding of the regulation and integration of the major physiological systems in mammals, with particular emphasis on their impact and role in reproductive processes. The core study guides cover: the physiology and endocrinology of reproduction and lactation; environmental limitations to animal productivity; integration of neural and endocrine control systems; regulation of physiological processes. An important component of the unit is the management throughout the year of an experimental flock of sheep to investigate the biology and technology of reproduction, lactation and wool growth. In addition, the students choose from electives in a range of areas including animal fibre production, animal health and disease, aquaculture & fisheries, breeding objectives, dairy science and technology, management of animals in the rangelands, new animal industries, computer-simulated pig production, nutrient requirements and ration formulation, and impact of animal industries on the environment.
2) Ecosystem Processes
In this first year subject, we cover selected topics pertinent to contemporary issues in agriculture, animal science, horticulture and natural resource management, in Australia and overseas, with the aim of giving students a better insight into the purpose and strengths of their respective degrees. The specific objectives are to: allow students to appraise critically the strengths and weaknesses in their knowledge and learn ways to overcome the weaknesses; identify, access and evaluate information from a range of resources; express their ideas coherently and logically when working both independently and collaboratively (in teams) through assignments and practical sessions; demonstrate the use of mathematical, biological, chemical and economic principles in solving problems related to ecosystem processes. In addition, students are introduced to the scientific method of setting and testing hypotheses, and they are helped to communicate their comprehension and ideas.
This unit has six modules that vary in style and structure. In the first module, students are given professional instruction on how to work in groups and how to write and present assignments. Topics for modules include scientific investigation; genetic diversity; how grazing animals survive in times of shortage; native animals; aquatic systems; land processes and their management; and energy flows in resource management. The final module integrates economic principles into the scientific and management topics previously addressed in other modules.
3) Science & Its Communication
This concerns the principles of experimental science and the presentation of scientific results. It includes the relationship between ideas, objectives and hypotheses; developing the basis for an experiment; the methodology of science; the differences between science and knowledge and the consequences of these differences for the approach of scientists to experimentation and the design of experiments. Students learn about and practise communication through oral presentations of scientific material and through writing scientific reports. The written material includes the logical presentation of information and the clear presentation of numerical data. The unit is structured around the writing of a scientific article. In the tutorials, published and unpublished manuscripts are analysed and students prepare scientific articles from these.
1) Animal Science & Technology
This final-year course is self-paced and based on study guides that refer the students to relevant texts in the library. The students read these and answer questions in the study guide that provide them with a measure of the required depth of knowledge and understanding. Problems that arise are overcome in tutorials.
The academic objective is a thorough understanding of the regulation and integration of the major physiological systems in mammals, with particular emphasis on their impact and role in reproductive processes. The core study guides cover: the physiology and endocrinology of reproduction and lactation; environmental limitations to animal productivity; integration of neural and endocrine control systems; regulation of physiological processes. An important component of the unit is the management throughout the year of an experimental flock of sheep to investigate the biology and technology of reproduction, lactation and wool growth. In addition, the students choose from electives in a range of areas including animal fibre production, animal health and disease, aquaculture & fisheries, breeding objectives, dairy science and technology, management of animals in the rangelands, new animal industries, computer-simulated pig production, nutrient requirements and ration formulation, and impact of animal industries on the environment.
2) Ecosystem Processes
In this first year subject, we cover selected topics pertinent to contemporary issues in agriculture, animal science, horticulture and natural resource management, in Australia and overseas, with the aim of giving students a better insight into the purpose and strengths of their respective degrees. The specific objectives are to: allow students to appraise critically the strengths and weaknesses in their knowledge and learn ways to overcome the weaknesses; identify, access and evaluate information from a range of resources; express their ideas coherently and logically when working both independently and collaboratively (in teams) through assignments and practical sessions; demonstrate the use of mathematical, biological, chemical and economic principles in solving problems related to ecosystem processes. In addition, students are introduced to the scientific method of setting and testing hypotheses, and they are helped to communicate their comprehension and ideas.
This unit has six modules that vary in style and structure. In the first module, students are given professional instruction on how to work in groups and how to write and present assignments. Topics for modules include scientific investigation; genetic diversity; how grazing animals survive in times of shortage; native animals; aquatic systems; land processes and their management; and energy flows in resource management. The final module integrates economic principles into the scientific and management topics previously addressed in other modules.
3) Science & Its Communication
This concerns the principles of experimental science and the presentation of scientific results. It includes the relationship between ideas, objectives and hypotheses; developing the basis for an experiment; the methodology of science; the differences between science and knowledge and the consequences of these differences for the approach of scientists to experimentation and the design of experiments. Students learn about and practise communication through oral presentations of scientific material and through writing scientific reports. The written material includes the logical presentation of information and the clear presentation of numerical data. The unit is structured around the writing of a scientific article. In the tutorials, published and unpublished manuscripts are analysed and students prepare scientific articles from these.
New and noteworthy
Perhaps my most important discoveries include:
• Rapid (minutes) increase in LH pulse frequency in ewes induced by introduction of rams;
• Synergistic interactions between oestrogen and progesterone in the reduction of LH pulse frequency, and between oestrogen and inhibin in reduction of FSH secretion in females;
• Rapid (within hours) increase in the secretion of GnRH pulses in mature rams following an increase in food supply;
• Existence of mechanisms that control testicular function that are independent of the GnRH-gonadotrophin axis;
• Discovery that intracerebral insulin plays an key role in the control of reproductive activity;
• Demonstration that aromatisation of androgen to oestrogen in brain tissue plays an important role in gonadal feedback on GnRH activity, but not in the GnRH responses to changes in diet;
• Demonstration that brain orexin-A plays an important role in the control of GnRH activity;
• Demonstration of photoperiodic mechanisms that underpin seasonal changes in reproductive physiology and behaviour, appetite, feeding behaviour, and fat deposition in emus
• Demonstration of spontaneous cell proliferation occurs in the brain (dentate gyrus) of adult, female sheep, and that the rate of cell proliferation is doubled within a few hours of male introduction; this response is associated temporally with an increase in LH (and thus GnRH) pulse frequency (first dot-point above).
• Rapid (minutes) increase in LH pulse frequency in ewes induced by introduction of rams;
• Synergistic interactions between oestrogen and progesterone in the reduction of LH pulse frequency, and between oestrogen and inhibin in reduction of FSH secretion in females;
• Rapid (within hours) increase in the secretion of GnRH pulses in mature rams following an increase in food supply;
• Existence of mechanisms that control testicular function that are independent of the GnRH-gonadotrophin axis;
• Discovery that intracerebral insulin plays an key role in the control of reproductive activity;
• Demonstration that aromatisation of androgen to oestrogen in brain tissue plays an important role in gonadal feedback on GnRH activity, but not in the GnRH responses to changes in diet;
• Demonstration that brain orexin-A plays an important role in the control of GnRH activity;
• Demonstration of photoperiodic mechanisms that underpin seasonal changes in reproductive physiology and behaviour, appetite, feeding behaviour, and fat deposition in emus
• Demonstration of spontaneous cell proliferation occurs in the brain (dentate gyrus) of adult, female sheep, and that the rate of cell proliferation is doubled within a few hours of male introduction; this response is associated temporally with an increase in LH (and thus GnRH) pulse frequency (first dot-point above).
Current projects
TITLE: Male-induced neurogenesis and memory in the brain of female ungulates.
SUMMARY: When a female sheep meets an unfamiliar male, her brain immediately responds to his ‘socio-sexual’ stimuli and produce hormones that cause ovulation. At the same time, new cells are rapidly generated in an area in her brain that is associated with learning and memory. It seems that, in response to the male stimuli, the female’s cognitive brain centres form a memory to classify the male as ‘familiar', so that he is unable to induce her to ovulate again. In this project, we will test that idea and also whether the male signals are predominantly chemical (pheromones). We will also determine how the production of new cells is induced in the adult brain, and whether these cells need to persist for a female to remember the male as 'familiar'.
TITLE: Lambmax Australia (Meat & Livestock Australia) – The Maiden Ewe: perceptions, productivity and performance
SUMMARY: Maiden ewes are frequently not mated during the first year of their life thus reducing their potential lifetime performance and restricting the rate of genetic gain due to an extended generation interval. There are many reasons that farmers choose not to mate their maiden ewes including, but not restricted to, poor conception rates, reduced fecundity and fears of a negative impact on their future reproductive performance. Indeed, maiden ewes do typically show a poorer level of reproductive performance than sexually experienced, adult ewes but this is not necessarily as simple as the ewes being too young or light at mating. Instead, there are many facets to this depression in reproductive efficiency including age, onset of puberty, weight, body condition, season of birth and sexual experience. All of these factors contribute to characteristically lower conception rates and reduced litter size in those ewes that actually get pregnant. This phenomenon is further antagonised by poor maternal behaviour of young ewes resulting in elevated lamb mortality so that in essence, the poor reproductive performance of maiden ewes seriously compromises the potential lifetime productivity of ewes.
The current literature on the reproductive performance of maiden ewes is very confused and highly variable. Closer examination of the literature reveals that much of this confusion stems from lack of reporting or control of many confounding factors including breed, photoperiod, latitude, age, live weight, season of birth, use of male effect and whether the maidens reached puberty prior to the experiment. The current state of the literature combined with the attitudes of farmers towards maiden ewes make it impossible to develop on farm strategies for mating maiden ewes.
Potential solutions:
1. Baseline data
Monitor the natural time course of reproductive onset and activity in maiden ewes of target wool and meat breeds
Directly compare maiden performance to their mum’s – establish the extent of the disparity and thus the problem
Use this information to develop strategies to correct the disparity between adult and maiden ewes.
2. The male effect
Advance reproductive development (improve conception rates and/or fecundity)
Breed out of season (increase lifetime productivity & produce valuable lambs)
Pre-condition ewes to rams (learning element of sexual behaviour – improve conception rates)
3. Nutrition
Increase live weight at mating
Control condition score at mating
Focussed feeding (with or without male effect)
Nutritional drenches.
TITLE: Development of fertility technology for emu and ostrich farming (Rural Industries Research & Development Corporation)
SUMMARY: The aim is to use our ‘perivitelline techniques’ for quantitative assessment of fertility in emu and ostrich flocks, with a greater emphasis on ostrich, the least efficient breeder of the two. This is a first step towards diagnosis of the causes of reproductive wastage and the development of remedies. The major objectives are:
• Develop a sperm-egg interaction assay for assessment of sperm quality in emu and ostrich;
• Develop an objective method for diagnosis of reproductive wastage in emu and ostrich flocks;
• Develop methods for semen collection from male ostriches;
• Optimise in vitro sperm storage and sperm cryopreservation protocols for emu and ostrich.
SUMMARY: When a female sheep meets an unfamiliar male, her brain immediately responds to his ‘socio-sexual’ stimuli and produce hormones that cause ovulation. At the same time, new cells are rapidly generated in an area in her brain that is associated with learning and memory. It seems that, in response to the male stimuli, the female’s cognitive brain centres form a memory to classify the male as ‘familiar', so that he is unable to induce her to ovulate again. In this project, we will test that idea and also whether the male signals are predominantly chemical (pheromones). We will also determine how the production of new cells is induced in the adult brain, and whether these cells need to persist for a female to remember the male as 'familiar'.
TITLE: Lambmax Australia (Meat & Livestock Australia) – The Maiden Ewe: perceptions, productivity and performance
SUMMARY: Maiden ewes are frequently not mated during the first year of their life thus reducing their potential lifetime performance and restricting the rate of genetic gain due to an extended generation interval. There are many reasons that farmers choose not to mate their maiden ewes including, but not restricted to, poor conception rates, reduced fecundity and fears of a negative impact on their future reproductive performance. Indeed, maiden ewes do typically show a poorer level of reproductive performance than sexually experienced, adult ewes but this is not necessarily as simple as the ewes being too young or light at mating. Instead, there are many facets to this depression in reproductive efficiency including age, onset of puberty, weight, body condition, season of birth and sexual experience. All of these factors contribute to characteristically lower conception rates and reduced litter size in those ewes that actually get pregnant. This phenomenon is further antagonised by poor maternal behaviour of young ewes resulting in elevated lamb mortality so that in essence, the poor reproductive performance of maiden ewes seriously compromises the potential lifetime productivity of ewes.
The current literature on the reproductive performance of maiden ewes is very confused and highly variable. Closer examination of the literature reveals that much of this confusion stems from lack of reporting or control of many confounding factors including breed, photoperiod, latitude, age, live weight, season of birth, use of male effect and whether the maidens reached puberty prior to the experiment. The current state of the literature combined with the attitudes of farmers towards maiden ewes make it impossible to develop on farm strategies for mating maiden ewes.
Potential solutions:
1. Baseline data
Monitor the natural time course of reproductive onset and activity in maiden ewes of target wool and meat breeds
Directly compare maiden performance to their mum’s – establish the extent of the disparity and thus the problem
Use this information to develop strategies to correct the disparity between adult and maiden ewes.
2. The male effect
Advance reproductive development (improve conception rates and/or fecundity)
Breed out of season (increase lifetime productivity & produce valuable lambs)
Pre-condition ewes to rams (learning element of sexual behaviour – improve conception rates)
3. Nutrition
Increase live weight at mating
Control condition score at mating
Focussed feeding (with or without male effect)
Nutritional drenches.
TITLE: Development of fertility technology for emu and ostrich farming (Rural Industries Research & Development Corporation)
SUMMARY: The aim is to use our ‘perivitelline techniques’ for quantitative assessment of fertility in emu and ostrich flocks, with a greater emphasis on ostrich, the least efficient breeder of the two. This is a first step towards diagnosis of the causes of reproductive wastage and the development of remedies. The major objectives are:
• Develop a sperm-egg interaction assay for assessment of sperm quality in emu and ostrich;
• Develop an objective method for diagnosis of reproductive wastage in emu and ostrich flocks;
• Develop methods for semen collection from male ostriches;
• Optimise in vitro sperm storage and sperm cryopreservation protocols for emu and ostrich.
RFCD
270603
Research profile
