NZSAP - Travel Report - Susanne Meier

Travel Report

Susanne Meier (Dexcel Limited)

New Zealand Society of Animal Production - Animal Science Award
Travel Report 2002. 24th October 2002
Travel Report by Susanne Meier (Dexcel Limited)

1. Purpose.
cow pic The purpose of the current travel was to attend the 6th International Symposium on Reproduction in Domestic Ruminants, Crieff, Scotland. I presented 2 posters during this meeting from recent work carried out in New Zealand: 1). 'Effect of mono propylene glycol on plasma metabolites and glucose release in pasture-fed lactating cows', and 2). 'Progesterone release, in relation to the luteinising hormone surge at ovulation, in two strains of Holstein-Friesian cows, fed two different diets'.

As the symposium consisted of 4 days of invited speakers, the aim was to not only present the research being carried out in New Zealand, but also receive feedback and network with as many people as possible while at the Symposium. During this period I also visited the Nottingham University, Animal Science Campus at Sutton-Bonington and Roslin Institute, outside of Edinburgh, Scotland.

2. Itinerary.
Arrived in London, 5th August

Drive to Nottingham, 6th August, with Dr Lucia Chagas (Dexcel)

Visit the Animal Science Campus of Nottingham University, at Sutton-Bonington, 7th August

Visit researchers at Roslin Institute, outside Edinburgh, 12th July
Travel to Crieff and attended the Symposium from the 13th to the 17th July

Departed from Edinburgh, 18th August 2002

3. List of important contacts.

Visit to Nottingham University (Sutton-Bonington Campus)

Spent the day talking to various people or interest. These included Drs Melisa Royal, George Mann, Phil Gainsworthy, John Brameld, and Prof. Bob Webb. Gave a seminar in the afternoon on Reproduction research at Dexcel.

Dr Brameld, research interests are predominantly the study of interactions between hormones and nutrients in the regulation of growth, development and metabolism of skeletal muscle and adipose tissue. These studies fall into 3 areas: Investigations into the mechanisms by which specific nutrients influence the growth hormone-insulin like growth factor (GH-IGF) axis. Although he uses the pig as the model system for study, they are interested in the interactions between various hormones (insulin, thyroid hormones, glucocorticoids and growth hormone) and specific nutrients (glucose and individual amino acids) in the regulation of expression of growth hormone receptor (GHR) and IGF-I mRNA in cultured pig hepatocytes. This work is being extended to identify the mechanisms for these effects of nutrients (gene transcription, mRNA stability or translation). These effects are tissue specific and therefore studies into the regulation of these same genes in other tissues (muscle and fat) are planned.

The regulation of energy partitioning and the balance between storage and use (fat or glucose) is important both in terms of farm animals providing food and also humans in terms of developing obesity and the various co-morbidity’s associated with obesity (insulin resistance, hypertension, etc). The GH-IGF axis appears to play a role in regulating energy partitioning (usage v storage) dependent upon whether nutrients are plentiful or scarce. Research investigating the effects of nutrition/fasting on circulating GH and tissue GHR expression and their subsequent effects on fat and glucose metabolism is underway.

We are similarly interested in what controls energy partitioning and energy balance in lactating dairy cows, with particular interest in the GH-IGF axis, adiposisity and ovarian-uterine function Therefore it was thought that speaking to Dr Brameld could lead to future collaboration as we have similar interests.

Dr Garnsworthy main area of interest lies in the nutrition of dairy cows and trying to maximise the efficiency of feed utilization for milk production without compromising reproductive performance.

Another area of interest is the effect of nutrition on fertility in dairy cows and beef heifers. Diets designed to increase blood insulin concentrations have led to earlier resumption of cyclic activity and improved conception rates in postpartum dairy cows. In beef heifers, although pregnancy rates are increased by a high-insulin diet, very high concentrations of insulin may be detrimental to embryo development. We are currently investigating the effects of individual dietary components on plasma insulin in dairy cows, so that we can develop models to predict the implications of different feeding strategies for reproduction.

Dr Gainsworthy and his group are also investigating the use of alkanes for measuring food intake of cows fed under group conditions. Alkanes are inert waxes found naturally in plants and have been used for predicting intake in grazing sheep and cows. They have developed a near-infrared spectroscopy tehcnique that provides accurate measurements of food intake from faecal samples. This technology may be adapted for the analysis of alkanes in New Zealand.

Dr Royal is actively researching in the decline in fertility of dairy cows. In the UK black and white dairy cattle has declined severely over the last 20 years to a current level of 39% pregnancy rate to first service. In addition, it is now clear that substantial, unfavourable genetic correlations (rG) exist between fertility and milk yield, the major selection criterion in dairy cattle breeding goals. The ultimate aim of the dairy industry is to operate an economically efficient production system but this is dependant on high reproductive efficiency. Thus, the need to halt and reverse this decline in infertility is imperative. Dr Royal's interest is looking at fertility as a quantitative trait, therefore any variation observed (phenotypic) is comprised of both genetic and environmental variation. In fact the coefficient of genetic variation present in many fertility traits is of a similar magnitude to that present in production traits. This means there is a potential to make long-term improvements in fertility genetically and also through improved management and nutrition.

Dr George Mann, current research interests are focus heavily on dairy cow fertility and in particular, how the ovarian hormone progesterone influences early embryo development. Principal research approach involves in vivo studies at the whole animal level supported by further in vitro investigation. The overall aim of this research is to gain a greater understanding of early pregnancy failure in order to develop approaches with which to combat this ever-increasing problem. This is of particular interest to myself. Other main areas of research including; understanding the processes controlling domestic animal performance, particularly reproduction., endocrine management of dairy cow infertility, regulation of luteinisation and progesterone secretion in the bovine corpus luteum, nutritional influences on reproductive function, monitoring reproductive function in beef suckler cows by milk progesterone analysis, the use of near infrared spectroscopy in on line milk progesterone measurement, steroid hormones in the uterine endometrium, and the effects of bovine viral diarrhoea on reproduction.

Professor Bob Webb, formally from the Roslin Institute (Edinburgh), is now a Professor in Animal Production, at the University of Nottingham (Sutton-Bonington). Prof. Webb still collaborates closely with former colleagues at the Roslin Institute. His main areas of research aim to understand the processes controlling domestic animal performance, particularly reproduction. The strategic aim is to understand the genetic control of variation in ovulation rate and the mechanisms controlling follicular growth, oocyte quality and embryo survival. Using an integrated approach to investigate the key mechanisms at the molecular and cellular levels and in the whole animal. For example, specific areas of research include:

(i) The regulation of the expression of gonadotrophin receptors, growth factors, growth factor receptors and growth factor binding protein genes in developing follicles.
(ii) The isolation and purification of novel gonadal proteins.
(iii) Investigation into the peptides and growth factors involved in the inter- and intra-ovarian control of follicular growth and oocyte maturation. As well as providing a greater understanding of reproduction in domestic species this work has also led to benefits to human medicine, including the development of ovarian tissue banking.

Additional areas include ongoing work includes the synchronisation of follicle growth, for more precise oestrous synchronisation and improved superovulatory responses, and the identification of the factors influencing oocyte quality, for increased embryo survival. The resulting improvements in artificial insemination and embryo transfer, coupled with the newer technologies of genome and linkage mapping, should ensure a more rapid rate of genetic gain. In collaboration with the Roslin Institute this group is investigating the effect of nutrition and milk yield on oocyte maturation and early embryonic development in dairy cattle. The objective of this work is to determine the specific nutrients that have direct effects on the reproductive system, namely follicle growth, oocyte quality and embryo survival in dairy cattle. This will then enable us to formulate diets for improved reproduction, rather than just for increased milk production. The overall objective is to move from empiricism to prediction by determining the principles underlying the dietary effects on fertility.

Visit to Roslin Institute (Edinburgh)

Visited Roslin Institute, home of Dolly. Talked to Drs David Armstrong and Jin Gong, who work in the reproduction-nutrition area. Their main areas of interest include examing the regulation of ovarian function in cattle. The work of the ovarian physiology group addresses the problems associated with cattle reproduction by investigating basic mechanism controlling ovarian function. The research is principally directed at understanding intra-ovarian regulatory processes that control follicle growth and corpus luteum development and regression. A key component of the work is how nutritionally induced changes in metabolic hormones interact with these intra-ovarian mechanisms.

As an example of the research areas of this group, they have shown that nutritional induced changes in the concentration of metabolic hormones regulate expression of genes encoding components of the ovarian insulin-like growth factor system. This in turn regulates the sensitivity of follicle to gonadotrophins, which are the main drivers of ovarian follicle growth. These observations highlight the need to understand the basic mechanisms regulating folliculogenesis in cattle in order to control follicle growth and maximise the yield of developmentally competent oocytes. Recently, short-term changes in the plane of nutrition have been shown to provide a non-invasive procedure for manipulating bovine follicle growth. Again, understanding the mechanisms through which nutrition regulates ovarian function will underpin the development of technologies designed to improve cattle fertility

6th International Symposium on Domestic Ruminant Reproduction

The symposium covered a wide range of topics, with symposia starting with an overview of ruminant reproductive problems; gamete-somatic cell interactions; reproductive technology; prenatal programming, ovary-uterine-embryo interactions; neuroendocrine interactions, genes controlling reproductive performance, nutrition-reproduction interactions, and the use of ruminant models for human clinical medicine. The last session was a celebration of Prof. David Baird, a renowned reproductive biologist with a very illustrious career.

The symposium attracted guest speakers' form around the globe, all experts in their respective fields. The symposium attracted over 90 posters, and was attended by over 150 scientists. This provided opportunities to discuss ideas and work with different researchers.

Some of the highlights for me included meeting Professor Baird, it is interesting that his work is now more closely aligned with human reproductive health and contraceptive research. Of the presentations, there were a number of presentations that were of particular interest to the work that I undertake at Dexcel. These included the session on Ovary-uterine-embryo interactions which included presentations on Follicle-luteal transition by Dr Joy Pate; Follicle health and subsequent CL/embryo development by Dr Claire Wathes; Embryo-uterus interactions by Dr Mike Roberts and Uterine-follicle interactions by Prof. Thatcher. Other presentations of interest included that by Dr Lorraine Young on the developing embryo and fetus, the session on neuroendocrine interactions which covered stress, leptin and the hypo-pituitary ovarian axis. The nutrition-reproduction session was particularly interesting with talks by Dr Kevin Sinclair on the early embryo; Dr David Armstrong on Female fertility and Dr Matt Lucy on post-partum fertility.

4. Description of findings relevant to New Zealand animal production and animal science.

Findings relevant to New Zealand animal production and animal science were that many researchers are carrying out research in related research fields. Being able to meet and become aquatinted with these researchers is hoped to lead to collaborations and continuing relationships whereby we are able to contribute strengths and knowledge, in areas others that are lacking. It is hoped that this type of networking and collaboration will advance the research outcomes.

The symposium was of scientific interest as it brought together experts from around the globe to one meeting. The meeting highlighted the advancements that genomic and proteomic approaches may have on reproductive research and some of the difficulties associated with these areas.

Although a large amount of research is not carried out under the New Zealand Dairy production system, a lot of the work being carried out focussed at examining the poor fertility in cows can be related back to the New Zealand situations. Data from research examining embryo-uterine interactions can be transferred. This is also true for the work that is examining the nutrition-reproduction interactions, particular the GH-IGF-insulin axis, an area that is of interest to the research carried out by the group at Dexcel.

The work currently being carried out with the strain trial and the poster presented on progesterone concentrations in 2 strains of cows, is examining why higher producing cows tend to have reduced fertility. These areas of common research indicate that we are all looking at similar problems and therefore we can work together to make larger advances, then when we work alone.

Once the presented papers are published in the next supplement in Reproduction, this text will be the background reading on these areas for researchers.

5. Summary of overall expenditure, and where and how the NZSAP Award funds were expended.

The money awarded from the NZSAP Animal Science Award was $2000. The total amount was used to cover some of the costs of the airfare from Auckland to London, and travel expenses from London to Edinburgh.

6. Summary of the report

The purpose of the current travel was to attend the 6th International Symposium on Reproduction in Domestic Ruminants, Crieff, Scotland. I presented 2 posters during this meeting from recent work carried out in New Zealand: 1). 'Effect of mono propylene glycol on plasma metabolites and glucose release in pasture-fed lactating cows', and 2). 'Progesterone release, in relation to the luteinising hormone surge at ovulation, in two strains of Holstein-Friesian cows, fed two different diets'.

As the symposium consisted of 4 days of invited speakers, the aim was to not only present the research being carried out in New Zealand, but also receive feedback and network with as many people as possible while at the Symposium. During this period I also visited and Roslin Institute, outside of Edinburgh, Scotland.

At the Nottingham University, Animal Science Campus at Sutton-Bonington, I visited a number of different researchers; all of who work in areas that are of interest to groups and myself in Dexcel. These included Drs Melissa Royal, George Mann, Phil Gainsworthy, John Brameld, and Prof. Bob Webb. In the afternoon, I presented a seminar on they type of Reproductive research carried out by Dexcel.

At the Roslin Institute I visited Drs Armstrong and Gong, researchers who work in the area of nutrition-reproduction interactions. They are interested in how nutritional induced changes in the concentration of metabolic hormones regulate expression of genes encoding components of the ovarian insulin-like growth factor system. This in turn regulates the sensitivity of follicle to gonadotrophins, which are the main drivers of ovarian follicle growth

This trip was a great opportunity to network and meet people. I greatly appreciated and thank the New Zealand Society of Animal Production for their support.

Susanne Meier 24/10/2002