No description available.

No description available.

No description available.

No description available.

With the increase in recent years of the popularity of outdoor pig production systems throughout the UK, it is important to address the welfare and production issues which arise from this method of farming. Outdoor sows are exposed to widely varying environmental conditions which affect their heat loss. Temperature, radiation, windspeed and precipitation are all important variables affecting heat loss, as is the sow's use of available shelter. It is currently unclear as to the amount of additional feed required to compensate for the adverse weather conditions likely to be encountered outside. Outdoor sows may also require additional energy for the potential increased degree of activity. In order to be able to predict heat loss under different meterological conditions a mathematical model is necessary. This study constructs such a model to determine the energy requirements of the outdoor sow, taking into account the variable insulation provided by subcutaneous fat and other tissues and the extent to which shelter can modify the effects of the environment. The effect of these factors is assessed using physical models of outdoor sows to estimate heat loss as a result of different environmental conditions. A behaviour study was carried out to assess the use of available shelter by outdoor sows. The mathematical model then allows an assessment to be made of the welfare implications of outdoor production systems.

The impact of three different culling regimes on a roe deer ( Capreolus capreolus) population in a Scottish commercial forest was investigated. For three years, two sites within the forest were unshot ('Unculled'). At two other sites, culling was maintained at pre-study levels ('Normal cull'), and on two further sites the deer were heavily culled ('Heavy cull'). Deer densities on the 'Unculled' sites increased while they were unshot, but on the others changes in deer densities were variable. The cull on the 'Heavy cull' sites often exceeded the deer density. However, deer numbers on the called sites never declined below approximately half the previous years' density, suggesting that the sites were rapidly recolonised. In the final study year, all sites were shot to obtain comparative data on age structure, reproductive performance and physiological indices (size, weight and condition) of the deer under the ceiling regimes. Weights of kids and male deer declined as the level of culling increased. The deer's diet also broadened with increased culling. The decline in weight was possibly due to the deer changing their foraging behaviour in response to the increased risk of being shot. Deer densities were calculated for the whole forest. These declined from 10.9 to 4.8 deer km-2, indicating the total cull exceeded the population's recruitment rate. There was no yearly variation in the reproductive performance or physiological indices, suggesting the total population was below the threshold when density-dependent effects began. There was significant variation in the density of deer between habitats. Deer numbers declined in all habitats during the study, with the greatest decline on Restock, attributable to its open nature, making deer more vulnerable there. There was significant variation in kid body weights and condition for deer living in different habitats. The different deer density and physiological indices between habitats were probably related to the decline in food availability with canopy-closure.

In this work peptide antigens [ESAT-6,p45 in water (1ml, 1mg/ml)] have been adsorbed onto 10mg inorganic substrates (hydroxyapatite (MHA P201;P120, CHA), polystyrene, calcium carbonate and glass microspheres) and in vitro release characteristics were determined. The aim of formulation was to enhance the interaction of peptides with antigen presenting cells and to achieve rapid peptide release from the carrier compartment system in a mildly acidic environment. Hydroxyapatite microparticle P201 has a greater surface area and thus has the largest peptide adsorption compared to the P120. CHA gave a further higher adsorption due to larger surface area than that available on microparticles. These particles were incorporated into the BOVIGAMTM assay to determine if they improve the sensitivity. After overnight incubation the blood plasma was removed and the amount of IFN-g in each plasma sample was estimated. CHA and MHA P201 gave a significantly higher immune response at low peptide concentration compared to the free peptide, thus indicating that these systems can be used to evaluate Tuberculosis (TB) amongst cattle using the BOVIGAMTM assay. Badgers are a source of TB and pass infection to cattle. At the moment vaccination against TB in badgers is via the parenteral route and requires a trained veterinary surgeon as well as catching the badgers. This process is expensive and time consuming; consequently an oral delivery system for delivery of BCG vaccines is easier and cheaper. The initial stage involved addition of various surfactants and suspending agents to disperse BCG and the second stage involved testing for BCG viability. Various copolymers of Eudragit were used as enteric coating systems to protect BCG against the acidic environment of the stomach (SGF, 0.1M HCl pH 1.2 at 37oC) while dissolving completely in the alkaline environment of the small intestine (SIF, IM PBS solution pH 7.4 at 37oC). Eudragit L100 dispersed in 2ml PBS solution and 0.9ml Tween 80 (0.1%w/v) gave the best results remaining intact in SGF loosing only approximately 10-15% of the initial weight and dissolving completely within 3 hours. BCG was incorporated within the matrix formulation adjusted to pH 7 at the initial formulation stage containing PBS solution and Tween 80. It gave viability of x106 cfu/ml at initial formulation stage, freezing and freeze-drying stages. After this stage the matrix was compressed at 4 tons for 3 mins and placed in SGF for 2 hours and then in SIF until dissolved. The BCG viability dropped to x106 cfu/ml. There is potential to develop it further for oral delivery of BCG vaccine.

The ruminant is less efficient at utilising dietary nitrogen (N) for growth than the non-ruminant. Some of this inefficiency may be due to differences in the timing of energy and N absorption following a meal. In the non-ruminant, both energy and amino acids are absorbed together, relatively rapidly following a meal. By contrast, the ruminant absorbs its nutrients asynchronously and this may lead to reduced post-prandial anabolic stimulus. A series of experiments were conducted in which the effects of different temporal patterns of posts ruminal nutrient supply on whole body and tissue metabolism were assessed. When energy and protein were supplied twice daily in three hour pulses, thus mimicking the non-ruminant, urea production was markedly reduced whilst tissue insulin exposure over the twelve hour infusion cycle was increased. This combination most likely indicates that net amino acid retention was increased by the synchronous infusion pattern. Infusion pattern does not influence protein synthesis in muscle, skin, gut or liver, however, and therefore the changes in whole body urea metabolism are most likely mediated through modulation of proteolytic systems. Maximising the capture of N in the post-prandial period may therefore be a means of increasing the efficiency of ruminant production systems.

Tannic acid was shown to increase weight loss, and total excretion of endogenous dry matter, nitrogen, uric acid, amino acids, energy and minerals (calcium, magnesium and phosphorus) in broilers. There was a positive linear correlation between the amount of tannic acid dosed, and the weight and endogenous losses. A variation in the excretion of individual amino acids and minerals in response to dosed tannic acid was also noted. The mechanisms of increased endogenous losses of the birds as influenced by tannic acid were investigated and discussed. Feeding gelatin and casein significantly reduced the adverse effects of tannic acid on weight and endogenous losses. There were also significant improvements in digestibility coefficients and metabolisable energy values of protein in tannic acid dosed birds when the amount of the protein increased. Although in birds not dosed with tannic acid, casein had a higher digestibility and metabolisable energy compared to gelatin, tannic acid dosed birds showed greater improvements in digestibility coefficients when receiving gelatin. The above contrast was possible because of the higher affinity of gelatin for tannic acid compared to the casein. Polyethylene glycol (PEG) was shown to alleviate the weight and endogenous losses of tannic acid dosed birds not receiving protein. Polyethlene glycol also reduce the endogenous losses as well as improved the digestibility coefficients and metabolisable energy values of tannic acid dosed birds when receiving the lower amounts of gelatin (6g) or casein (6 and 12g). However, the effect of PEG was less apparent in tannic acid dosed birds receiving the higher amounts of gelatin (12 and 18g) and casein (18g). In conclusion, the presence of tannins in poultry diets are likely to increase the endogenous losses of organic materials as well as minerals, but this is likely to depend on the type and amount of diet ingredients such as proteins and additives (eg. PEG).

No description available.