Variation in circulating Cortisol is often used as an indicator of stress in farm animals. In this study the variation in baseline salivary Cortisol of farrowing and lactating sows was examined, to assess their physiological response to three different farrowing systems. It was part of a larger project examining alternative farrowing systems.

Three farrowing systems in neighbouring rooms were compared. In two systems the sows were loose-housed and could move freely: five strawed pens (2.5m x 1.5m) with farrowing rail (Pen), and five crates modified to allow the sows to walk through (Free Crate). Sows had access via a passageway to a transponder-controlled feeder and a north facing outside area with two water drinkers.

There has been much debate on the causes of stereotypy, but the motivational bases of these abnormal behaviours have yet to be fully understood. In the case of oral stereotypies in sows, there is evidence that the motivation to perform feeding behaviour may be involved. Restrictively-fed sows are highly food-motivated for large periods of the day. It has been shown that high-fed gilts perform stereotypies at a lower rate than low-fed gilts indicating that the level of feeding is important (Terlouw et al., 1991). Oral stereotypies in sows occur largely within a specific time after the daily food ration has been consumed. In sows housed in barren pens stereotypy is expressed as excessive drinking or chewing bars or chains, while sows housed on straw will nose and chew the bedding excessively in the same time period after feeding (Burbidge et al, 1993). The behaviour patterns are similar to those used in normal food-searching behaviour, but occur in the absence of reward. It has been suggested that oral stereotypy is the result of the appetitive phase of foraging entering a closed loop of repetition as the normal goal, attainment of more food, cannot be achieved (Hughes & Duncan, 1988). Two experiments were designed to examine the behavioural response to size and frequency of food rewards and they represent the first in a series of experiments which investigate the bases of stereotypies.

Growing pigs spend considerable time orally manipulating their environment, which can include their pen-mates. In certain situations this leads to problems such as tail-biting. It is unclear if this active behaviour represents foraging or exploratory motivation, a problem exacerbated by the possibility that both share certain behavioural elements. The aim of this experiment was to distinguish appetitive foraging (extrinsic exploration) from intrinsic exploration by manipulating both feeding motivation and the content of the external environment. The objective was to discover which behavioural elements are common to either behavioural category. This would allow hypotheses to be proposed concerning the causation of oral-manipulation of the environment and inappropriate stimuli such as pen-mates, and furthermore to control for the effects of intrinsic exploration in continuing experiments concerning foraging behaviour.

Many finishing pigs have little experience of handling, especially during the final management stage before slaughter. Earlier work (Weeding et al 1993) suggested that certain farms, producing pigs which were more difficult-to-handle than others, had a tendency towards dark, firm and dry meat (DFD). The effect of routine movement on behaviour during pre-slaughter handling and subsequent meat quality was evaluated using groups of finishing pigs.

Forty pens of pigs (17-19 pigs per pen) from two similar, fully-slatted finishing houses were involved. When pigs reached 16 weeks of age, pens were randomly allocated to treatment or control. Pigs in control pens were not moved before transport to the abattoir.

Non-starch polysaccharides (NSP) which have been linked to antinutritional activity through elevated viscosity of intestinal contents may be found in greater amounts in certain regions of the cereal grain specifically the endosperm cell wall (Forrest & Wainwright 1977; Mulder, Hotten et al 1991).

The current series of experiments was designed to investigate whether different levels of barley fractions contained within standard diets would influence the viscosity of broiler digesta and to examine the NSP content of the fractions and digesta supernatants.

Modem feed processing techniques, designed to reduce the microbial burden of compounded animal feedstuffs, subject feed ingredients to high temperatures and pressures. Certain feed components are labile under these conditions and may be destroyed or undergo chemical modification during processing reducing their availability. A number of vitamins, added as supplements to diets, are known to be sensitive to aggressive processing methods. Vitamin A is particularly sensitive to oxidation and losses are increased in the presence of high humidity and temperature. A study was carried out to examine the effects of two processing technologies, the Anaerobic Pasturisation Conditioner (APC) and the Expander (EX), upon the content and bioavailability of vitamin A in poultry diets.

In studies of animal growth it is often necessary to assess whole body composition or organ size prior to and during the course of a particular treatment. Nuclear Magnetic Resonance (NMR) offers the possibility to achieve these measurements on the same animal and in a non-invasive fashion. The use of NMR in attaining body images, referred to as Magnetic Resonance Imaging (MRI), has developed as the imaging method of choice for humans, due to its excellent soft tissue contrast and use of nonionizing radiation. The use of NMR in animal studies has been limited, which is probably related to the availability of suitable facilities and the cost of using them. However, several research groups have applied it to determining fat and water content of tissue samples and intact animals (Mitchell et al., 1991; Scollan et al., 1993). The aim of this study was to evaluate the use of MRI to determine the size (volume) and shape of the Pectoralis muscle (Pectoralis major and minor) in broiler chickens, non-invasively and in vivo.

To date commercial broiler breeders have focused primarily on increasing early growth rate in selection programmes aimed at improving overall production efficiency. In commercial programmes, early growth rate is simplified to a single body weight measure taken at a fixed age during the growth phase approaching common slaughter weights. Most recent selection studies report heritabilities from experimental populations that are at best, synthesised from crossing modern broiler material from several different sources (Leenstra et al, 1986; Wang et al, 1991). Therefore, such populations are likely to exhibit greater heterozygosity than many commercial lines which have undergone many generations of intense selection in closed populations. This paper reports heritabilities estimated using both least squares and derivative-free maximum likelihood techniques for data from a commercial breeder dam line which has remained closed since its inception in 1975.

Increased lamb production during the 1980's stimulated interest in winter indoor finishing systems, traditionally all-concentrate. Recent research has been directed towards the supplementation of a silage-based ration as an option to reduce costs. The objective of this experiment is to compare the utilisation of metabolisable energy (ME) from silage and concentrate for carcass gain and to determine the effect of ME source on carcass quality.

Seventy-eight Blackface wether lambs (mean initial live weight 29.3 kg) were housed in late October and offered silage for two weeks prior to allocation to treatments.

Methane production by ruminant animals is an important anthropogenic source of methane to the atmosphere and is considered an important source to more accurately estimate and to control. It has been known for some time that, in ruminants, diet type and composition can influence methane production, yet there is little quantitative information for contemporary diets used in the UK. Attempts to predict methane production from either diet chemical composition or digestibility have not been successful (Moss and Givens, 1990; Johnson et al., 1991). In order to estimate more accurately the amount of methane produced by a ruminant on a given diet, it is essential to establish whether there are interactions of various substrates with forage and to relate this to the rumen environment. Previous work showing interactions has used mainly hay-based diets (Blaxter and Wainman, 1964); as grass silage is now the major forage in the UK, work with this forage was undertaken.

Unlike most of Spain, Galicia's temperate, humid climate supports year-round grass growth, with a moderate summer drought. Local lamb markets demand lean, light carcases (10-12kg) produced from lambs grazing whilst still with the ewe. Grazing systems studies with the native Gallego breed, Flores (1992) established optimum grazing heights as 8.0 cm for individual lamb liveweight gain (LWG) and 5.5 cm for LWG/hectare but no data were recorded on the carcase yield. The objective of this trial was to test whether optimum individual LWG and carcase yield is obtained under these systems.

A number of abnormal activities had been observed in a group of 30 lambs (R lambs; 10 Shetland (SH),10 Scottish Blackface (SB) and 10 Welsh Mountain (WM), half females and half entire males), on a restricted allowance (about mature maintenance intake and 0.5 of ad libitum intake), of a high quality pelleted diet (Diet A; 200g/kg crude protein, HMJ/kg ME). The lambs had been individually housed since 8 weeks of age, in pens (2m x lm), made up of metal barred gates with wooden slatted floors. Abnormal oral activities included some that caused obvious husbandry problems, such as wool-biting and slat chewing, and others which caused no overt damage, but may nevertheless be associated with impaired welfare (Cooper and Nicol 1993), such as bar-biting and repetitive licking. In a preliminary observation at 22 weeks of age, lambs only ate in the hour following food presentation (Fig 1), after which all of the allowance had been eaten, and abnormal oral activities were recorded in 30% of scans. Similar repetitive activities, described as “stereotypies” have been associated with food restriction in dry sows (Appleby and Lawrence 1987). In a series of observations, we investigated the effect of increasing weight and nutrient value of the lamb's diet on the incidence of oral stereotypies, whilst minimising any influence on the ongoing feed trial.

The Chernobyl nuclear power station accident in April 1986, resulted in widespread deposition of radionuclides across Europe and the Former Soviet Union. The radionuclides 1-131, Cs-134 and Cs-137 are of particular concern as a potential health hazard due to their accumulation in the plant-animal-human food chain.

Due to the long half life of Cs-137 (30 years), contaminated regions will take several years to return to evels prior to the accident.

We have shown previously (Cooper and Kyriazakis, 1993) that lambs offered a choice between a low energy density (ED) food and a high ED food, do not solely consume the high ED food, as it would have been expected from an optimal foraging perspective. It is proposed that the lambs offered this choice have to balance the benefits of consuming a high ED food (high growth rate) against the metabolic costs incurred, which may be excessive disturbances to the rumen environment, such as a low rumen pH and an increased osmolality (this has been shown to be the case in the diet selection of sheep between concentrates and hay in an experiment by Engku Azahan and Forbes (1992)). The aim of this experiment was to test which of these two rumen conditions have an influence upon diet selections made by sheep offered foods of different ED.

The 1991 reform of the EC Common Agricultural Policy was designed to be acceptable to a successful GATT agreement with EC bureaucrats having an understanding of the GATT objectives, with the start of the recent GATT round beginning in 1986. Hence, the objective of both pieces of legislation is similar - to encourage free trade by reducing support of product prices through removing import quotas, export subsidies etc. As a consequence CAP has transferred open ended support for product price to a support of limited numbers of production units through cow and sheep quotas. It is therefore expected that product prices will fall closer to world market prices, particularly for products in surplus in the EC such as beef. Precise market specifications will therefore impinge directly on producers in terms of price and encourage the development of specific production systems to meet these specific markets, eg ultra light Mediterranean market.

Productivity in livestock systems is closely correlated with gross efficiency. Improving efficiency by increasing productivity is an honourable pursuit since it minimises waste; not least the waste of animals through disease, infertility or simply the inability to provide food in excess of maintenance. By this (limited) definition the limits to productivity in any system are defined only by the quality of feed available and the genetic and physiological capacity of the animal to convert it into food for man. However, the approach to the limit is asymptotic, i.e. subject to the law of diminishing returns. Until recently most Animal Science has been directed towards marginal improvements in productivity but we now recognise the need to broaden our objectives to include quality of life criteria, such as environmental protection and animal welfare. My remit is to consider how to incorporate a proper concern for animal welfare into the assessment of limits to productivity,or more precisely, the cost/benefit analysis of marginal responses to increased intensity of production.

The success of the poultry industry since the end of the Second World War has been based very considerably upon the introduction of increasingly productive strains of birds. This has been achieved by intensive selection for productive characteristics such as growth rate, meat yield and egg productivity. However this emphasis on production attributes seems to have resulted in birds that have pronounced weaknesses in other characteristics that become manifest in a range of metabolic disorders. The severity and impact of these disorders is such that there needs to be a re-evaluation of the basis for continued genetic development of poultry stock.

The main metabolic disorders affecting modern poultry are those involving skeletal and cardiac systems. There are three main types of skeletal disorder: bone growth abnormality in meat poultry, bone fragility in laying hens and cartilage disorders in heavy breeding birds. The main cardiac disorders are ascites and sudden death syndrome.

The gastrointestinal tract is a major organ of the immune system. Gut associated lymphatic tissue (GALT) contains approximately 40% of mature lymphocytes and represents a significant part of gut mass. GALT consists of a complex of immune cells found in discrete organs e.g. Peyer's patches and mesenteric lymph nodes, as well as dispersed within the lamina propria and the epithelium. Both B cells and the two main subsets of T cells, CD4(helper/inducer) and CD8 (suppressor/cytotoxic) are found. This significant involvement of the immune system in the gut should not be a surprise, given that the gut represents a major site of interaction with the ‘outside world’ and therefore represents a major challenge to homeostasis, specifically from infectious disease.

The gut also has a fundamental dilemma, it must respond vigorously with a protective response against any pathogens presented at its mucosal surface, yet sustain digestive and absorptive function of dietary non-harmful antigens. On occasion it gets it wrong, resulting in damaging hypersensitivity reactions e.g. Coeliac Disease, milk intolerance in children, food allergies and diarrhoea in the postweaned pig and the pre-ruminant calf. It is these inappropriate immunological responses that can prove to be a constraint on animal production, specifically on the use of legumous protein sources for animal feeds.

Ruminant production systems can have a negative effect on the environment within three main areas 1) loss of nutrients to aquatic environment, 2) loss of nutrient to the aerial environment and 3) contribution to the global increase in temperature (green house effect).

In Denmark area 1) is considered as a very serious problem in particular NO3-leaching from the agricultural land. Within area 2) the loss of NH3 from ruminant production is considered as a major problem. Concerning the green house effect (area 3)) the loss of N20, C02 and CH4 are considered as a problem in connection to ruminant production.

Pollution problems caused by monogastrics occur primarily because of the high numbers of pigs and poultry either in a given area or on individual intensive units. There is a total of approximately 7.6M pigs and 162M poultry which have a total excreta output of about 9.4M tonnes from pigs and 4.6M tonnes from poultry. This is equivalent to a total nitrogen content of approximately 76 and 112 thousand tonnes and a total phosphate content of 47 and 96 thousand tonnes for pigs and poultry respectively. These levels of nitrogen and phosphate are based on chemical analyses of large numbers of slurry and manure samples as spread.