Program 1 - Animal Welfare Methodology
The community generally accepts the role of the scientific method to solve problems. However, there is considerable uncertainty within science on the concept of animal welfare. Scientists differ in their views on how animal welfare should be measured or judged, with three prominent concepts of animal welfare in the literature: the welfare of animals is judged on the basis of (1) how well the animal is performing from a biological functioning perspective; (2) affective states, such as suffering, pain and other feelings or emotions; and (3) the expression of normal or ‘natural’ behaviours.
In this program, we undertake projects to further our understanding of the relationships between these concepts and methodologies.
Novel peptide mediates the inhibitory effects of stress on female reproduction
Investigators: A. Tilbrook, I. Clarke and P. Hemsworth
Students: C. Ralph, M. Papargiris and C. Keating
Funding: ARC Discovery
Stress inhibits reproduction in females but the specific mechanisms driving this inhibition are unknown. This project offers a novel approach to elucidating stress-induced inhibitors of reproduction. A novel peptide, gonadototropin inhibitory hormone (GnIH), which is present in the brain, is proposed to be the principle protagonist in mediating the inhibitory effects of stress on sexual behaviour and secretion of reproductive hormones in the female. This project will determine the impact of stress on the synthesis and secretion of GnIH and will quantify the effects of GnIH in mediating the inhibitory effects of stress on reproduction in females.
In the first year we showed that stress did not influence the level of mRNA of GnIH in the hypothalamus and we established a working GnIH radioimmunoassay. We also showed that GnIH administered centrally did not influence the secretion of lutienizing hormone in ovariectomized ewes. It was also reaffirmed that the stress hormone cortisol inhibits sexual receptivity but not sexual motivation or the ability of females to attract males. Further, we established that the mechanism of action of cortisol to inhibit receptivity does not involve disruption of the oestradial signal to induce oestrus.
We plan to generate data to assist in the mechanisms by which stress inhibits sexual motivation and sexual attractivity including the role of GnIH and other relevant neuropeptides.
We have published three journal articles to date and have presented data at national and international laboratories. We have submitted an abstract to the International Congress of Neuroendocrinology. To date, publications and presentation of data at international laboratories has generated substantial debate to the point where requests to collaborated internationally have been forthcoming.
Validating the use of proximity loggers in measuring feeder visits, displacements and social interactions in pigs in competitive feeding situations
Investigators: P. Hemsworth, E. Jongman and R. Morrison
Students: M. Rice
Funding: Australian Pork Limited
High levels of aggression which occur when mixing sows has prompted a large amount of research into the optimal housing, group size and space allowance to reduce aggression. Recently APL funded a research project examining the behavioural characteristics of individual sows which may predict aggression in groups.
When working with a large number of animals behavioural studies can be time consuming, and sometimes impossible to do with videos (eg. large space allowances, and large group sizes often make video observations more complicated and tracking individual animals becomes very difficult).
The use of proximity loggers may provide an opportunity to overcome these limitations, however they have not been used within this setting. This project will enable a greater understanding of the full potential of the proximity logger in this setting and secondly validate a methodology for measuring displacements from feeders which could later be tested as a predictive test of aggression.
Objectives
- To examine the practicability of using proximity loggers with intensively group housed pigs
- To investigate the accuracy of the proximity logger in determining displacements of pigs from feeders and by whom
- To examine the repeatability of these displacement observations over time.
Usefulness of preference for resources and biological functioning to assess animal welfare
Investigators: A. Tilbrook, P. Hemsworth and C. Lee
Students:
Funding: Australian Pork Limited
Animal welfare (AW) elicits a range of views within the community, which lead to marked attitudes to AW issues. Welfare groups lobbying specific animal industries/ practices indicate the strength and implications of these views.
Science has a critical role in underpinning our decisions on animal use and attendant conditions and compromises. Biologists have the responsibility of establishing the facts on how animals biologically respond to various practices, whether they relate to farming, laboratory or general community uses of animals. Gaining a consensus on the welfare implications of a specific animal use would appear to be an easier task to achieve amongst scientists than within the general community. However, conflicts have arisen in science around the definition of AW and the methodology used to assess AW varies amongst scientists.
Differing definitions of AW provoke debate on AW assessment and standards. This unease with the definition exists both within science and more broadly when decisions on acceptable welfare standards are being made by individuals or the community. This is a limitation, since an important step in developing defensible policies on animal care and use is to assemble factual information on the animal's biological responses to the particular system or treatment.
While there is limited evidence that deprivation of highly preferred resources results in biological dysfunction, research utilizing well-accepted stress models is required to understand the relationships between these concepts and methodologies. Particularly, research is required to examine the effects of deprivation of these resources on the animal’s behaviour, physiology, health and fitness.
Therefore, the general objective of this project is to improve our understanding of the relationship between these two main methodologies of AW by testing the hypothesis that deprivation of highly preferred resources results in biological dysfunction. This fundamental research may assist in reducing the interpretative differences in AW science.
Objectives
- To determine the relationships between the two main approaches to welfare assessment, the functioning approach and the preference approach. A sound understanding of these two methodologies is essential in the validation of welfare research methodology to establish welfare standards and develop tools to measure welfare in the field.
