ANIMAL WELFARE AND ECONOMIC OPTIMISATION OF FARROWING SYSTEMS

Livestock Production/Industries, alternative housing systems, animal welfare, economic optimisation, farrowing systems, pig,

The social organization of Scottish Blackface sheep

This thesis describes the social organization of a home range group of Scottish Blackface sheep occupying an area known as the Howlet in the Pentland Hills, Midlothian, Scotland. Evidence to support the contention that these sheep constitute a home range group is presented. The home range occupied by the group was found to be at a minimum in winter (the winter range) and at a maximum in summer (the summer range). Using cluster analysis on individuals' location data it was shown that in autumn and winter there was little individual variation in home range behaviour in comparison to summer. Variability in home range size showed a similar trend. Ewes in summer could occupy home ranges differing by as much as 40 ha. It was further illustrated that in winter ewes showed increased gregariousness, forming large sub -groups and being readily influenced by the movements of other sheep, whilst in summer the converse was true. It was concluded that these seasonal variations in social organization occurred largely in response to ecological changes; in winter a reduction in the variability in the quality of the hill swards and the worsening weather; in summer the increase in the dispersion of resources through the growth of the widley distributed Agrostis-Festuca swards. The presence of a lamb in summer would seem to satisfy the ewe's proximal motivation to group, thus allowing her greater flexibilty of movement between Agrostis-Festuca swards.In contrast to the findings of previous workers, the ewe-daughter bond was found to be of little significance beyond 7 to 8 months. Around this age ewe-lambs formed peer groups that during their first winter moved independently of other group members. In their second summer ewe-lambs became integrated into the larger social group. Early experience was found to be important in determining summer home range patterns of individual ewe-lambs. The cohesion of the home range group seemed to result from the animals' preference for an area and their motivation to form sub-groups; specific bonds between individuals were not of importance in this respect.Social organization was shown to negate supposed advantages of feedblocks, fed as a supplement to the group during winter. Ewe -lambs did not follow older ewes to the feedblock; 2 and 3 year old ewes did not compete successfully with older ewes when feeding at the block; further the feedblocks apparently decreased the size of ewes home ranges, which it seems must have led to the overuse of the lower parts, and conversely underuse of upper parts of the range.The results are discussed in relation to literature on wild, feral and domestic sheep. It is concluded that whilst in general terms the social behaviour of domestic sheep remains close in form to that found in feral and wild populations, that there remain unresolved questions over the function of aspects of social behaviour in domestic ungulates. It is argued that that a better understanding of the effects of domestication on, for example, anti -predator behaviour in domestic sheep would help in the construction of a theoretical framework for the study of the ethology of farm animals

Ionisation effects for laser-plasma interactions by particle-in-cell code

The particle-in-cell code EPOCH was extended to include field and collisional ionisation for use in simulating initially neutral or partially-ionised targets in laser-plasma inter- actions. The means by which particles ionise in the the field of an intense laser was described and physical models were included to determine the instantaneous ionisa- tion rate at particles within the simulation domain for multiphoton, tunnelling, barrier- suppression and electron-impact ionisation. The algorithms used to implement these models were presented and demonstrated to produce the correct ionisation statistics. A scheme allowing for modelling small amounts of ionisation for an arbitrarily low number of superparticles was also presented for comparison and it was shown that for sufficient simulation time the two schemes converge. The three major mechanisms of ionisation in laser-plasma interactions were described as being ionisation-induced defocussing, fast shuttering and ionisation injection. Simulations for these three effects were presented and shown to be in good agreement with theory and experiment. For fast-shuttering, plasma mirrors were simulated using the pulse profile for the Astra Gemini laser at the Central Laser Facility. Rapid switch-on and the theoretical maximum for contrast ratio was observed. For ionisation injection, simulations for laser wakefield acceleration in a helium gas were performed and the accelerated electron population was shown to be greatly increased through use of a 1% nitrogen dopant consistent with the experimental results of McGuffey et al. A study of the laser filamentation instability due to SRS backscatter at the relativistically corrected quarter critical surface (RCQCS) was per- formed in collaboration with C.S. Brady and T.D. Arber at the University of Warwick [1]. It was found that for hydrogen and plastic the instability was unaffected by the in- clusion of ionisation. Further study with argon revealed a attening of the RCQCS and it was demonstrated that for a material with multiple ionisation levels ionising strongly near the self-focussed intensities at the RCQCS, rapid ionisation caused an inversion of the RCQCS that suppressed the filamentation instability

Happy or healthy?:How members of the public prioritise farm animal health and natural behaviours

The importance given to minimising health issues and promoting natural behaviours is a polarising issue within farm animal welfare. It is predominantly thought that members of the public prioritise animals being able to behave naturally over other aspects of farm animal welfare, such as addressing health issues. However, public perspectives may be more multi-dimensional than is generally thought, with the importance given to these different elements of welfare dependent on the situation and state of the animals in question. To examine this, a factorial survey using vignettes, which experimentally manipulated the different levels of health (high health vs. low health) and natural behaviour provision (high behaviour vs. low behaviour), was completed by a sample (n = 810) representative of the UK population (on age, gender, ethnicity). Contrary to the predominant view, this study found animal health had the greatest effect on participants' judgements, explaining more of the variance in their assessments of animal welfare than any other factor. However, findings also indicated that participants considered animal welfare to be most positive when both health issues are minimised and natural behaviours are promoted. Attitudes to natural behaviours also varied more between participants, with females, individuals who do not (regularly) eat meat and those with a greater belief in animal mind giving greater priority to natural behaviours. In the context of public and private welfare standards seeking to meet public expectations, this study provides important insights into how public perspectives of animal welfare are more nuanced than previously thought, influenced by the context of the animal, the aspect of welfare in question and personal characteristics