Recent analysis pointed towards visual imaging analysis (VIA), which yields pig body size measures and shape indices from two-dimensional visual images of living pigs, as a potential technique for estimating fat and lean content in pig carcasses (Doeschl et al., 2004). The present analysis further explored the potential of using VIA body size and shape indices as indicators of the proportion of lean and fat in various carcass joints, either alone or in combination with ultrasonic backfat depth of the live animal. Due to increasing interest in the shape of retail cuts in the meat industry, the association between VIA size measures and the dimensions of the longissimus dorsi and gluteobiceps muscles is also assessed.

Large variations in weight within groups of pigs at slaughter lead to either (1) inefficient use of resources as some pigs have to be retained for longer periods in finishing accommodation than others, or (2) large variation in carcass weights, which creates problems for processors. The aim of this study was to assess the effect of creating uniform weight groups at weaning at 4 weeks of age, or at the start of the finishing period at 10 weeks of age, on coefficient of variation in slaughter and carcass weight. The effect of these regrouping strategies on mean production performance during the growing and/or finishing periods was also assessed. In addition, the effect of regrouping pigs at the start of the finishing period on aggressive behaviour was assessed.

It is generally accepted that environmental enrichment improves the welfare of growing pigs through the provision of substrates for exploratory and manipulatory behaviour. EC Directive 2001/93 and The Welfare of Farmed Animals (England) (Amendment) Regulations 2003 state that pigs must have permanent access to materials to enable proper investigation and manipulation activities, and give as examples straw, hay, wood, sawdust, mushroom compost and peat. However, the use of particulate rooting materials in slatted systems can cause difficulties for slurry management and it is important to establish whether alternative enrichment forms, such as hanging objects, can be equally effective. The aim of this study was to assess the effects of environmental enrichment with either hanging manipulable toys or rootable substrates on the behaviour of finishing pigs in two contrasting housing systems.

Competition resulting in high social status and maintenance of that status within farmed pigs may have both welfare and economic consequences. Aggressive behaviours, associated with the establishment and maintenance of a dominance hierarchy, may cause poor welfare and skin damage reducing the value of pigs at slaughter. In order to investigate the impact of social status on welfare we first need to establish the status of individuals relative to their peers. In this paper we compare two alternative indicators of pig rank, namely: (i) aggressive interactions between individuals - the occurrence of aggressive behaviour from pig A to pig B is often assumed to imply social dominance of pig A over pig B; and (ii) the order in which pigs stand at the feeder - an advantage of attaining high social status in many populations is priority of access to food. Social rank of individuals based on observed aggressive behaviour can only be assigned once evidence for a linear or quasi-linear hierarchy has been established (Langbein and Puppe, 2004). In a population with a purely hierarchical structure we expect all triads of individuals to be transitive, that is A→B, B→C implies A→C. For observational studies it is unlikely that interactions between all individuals will be observed. Here we present a novel methodology by which we can assess the linearity of the dominance structure that is not affected by missing or null interactions between individuals. By conducting a census of all types of triad in a social network we can assess whether the subset of interactions observed provide evidence of a linear or quasi-linear hierarchy. Transitive triads provide evidence of linear hierarchy whilst intransitive triads, such as A→B, B→C, C→A, contradict the presence of a linear hierarchy.

Newly weaned pigs are at least partially protected against sub-clinical gastrointestinal disorders through the provision of in-feed antimicrobials. Possible associations with antibiotic resistance to life threatening bacterial infections in humans and environmental pollution will result in their ban. As a consequence, gut health and pig performance will be compromised. Current research is aimed at reducing, and eventually overcoming, such consequences through novel nutritional strategies. Effects of the latter on the consequences of sub-clinical infection may be assessed in an infection model, since the absence of in-feed antimicrobials does not always lead to gastrointestinal disorders, due to e.g. variation in infectious environmental conditions. A common gastrointestinal disorder is post-weaning colibacillosis (PWC), which is caused by enterotoxigenic E. coli (ETEC), and is associated with diarrhoea and reduced food intake, and hence reduced performance. Existing ETEC infection models, which have yielded variable results and employed relatively large infective doses of ETEC, have focused on clinical PWC (Madec et al., 2000). The objective of our experiment was to assess whether sub-clinical PWC can be induced through experimental infection with ETEC, and whether such sub-clinical PWC is sensitive to the level of infection used.

In the perspective of the complete ban of antibiotic growth promoters use in animal food by 2006, many alternatives have been studied. However, most of them are not yet technically and/or economically competitive with antibiotics. In this way, the incorporation of bovine colostrum in piglet diets has been studied. Bovine colostrum was chosen for its high concentration in growth promoting and anti-microbial peptides (Playford et al., 2000) and for its high availability. The aims of this study were to measure the efficiency of a bovine colostrum supplementation on growth performances of newly weaned piglets and to evaluate its effects on the digestive and immunological troubles involved by weaning (Pluske et al., 1997 and Vega-Lopez et al., 1995).

There is growing interest in the manipulation of dietary ingredients a means of reducing nitrogen excretion (NE) and ammonia (NH3) losses from pig production. Significant quantities of lactose may reach the hindgut of the older pig undigested, yielding a substrate for bacteria (Kim et al., 1978). It is hypothesised that increasing concentrations of lactose in finishing pig diets will alter NE patterns and reduce NH3-N emission.

The global area sown to genetically modified (GM) crops has increased rapidly from 1.7 million ha in 1996 to 67.7 million ha in 2003 (James, 2003). While GM crops have been shown to be substantially equivalent (e.g. Clarke and Ipharraguerre, 2000), the use of GM crops (e.g. maize grain) or components/products from them (e.g. soyabean meal) in livestock diets has raised a number of safety concerns including, the potential for transgenic DNA to transfer to animal-derived products intended for human consumption. Therefore, the aim was to determine the presence or absence of transgenic and endogenous plant DNA fragments in the blood, tissues and digesta of broilers consuming GM-based diets.

The potential antiparasitic effects of chicory (Cichorium intybus ) are currently investigated as an alternative means to control parasitism in organic sheep production systems. Previous studies showed that parasitised lambs grazing on parasite-clean chicory swards had improved growth and lower faecal egg counts (FEC) compared to those grazing on parasite-clean grass pastures (Athanasiadou et al, 2004). The objective of this experiment was to investigate whether chicory can have a role as a potential means to control parasitism in lactating ewes and their lambs grazing on previously parasite contaminated pastures.

The improvement of neonatal viability by maternal nutrition during gestation has been widely studied in numerous species. Recent investigations have explored the role of long chain omega-3 essential fatty acids (EFAs) in maternal diets during pregnancy. These are the major fatty acids, docosahexaenoic acid (DHA) in particular, in brain and nervous tissue, with specific roles in neural development and cognitive function. Studies in monogastric species have shown that supplementing maternal gestation diets with EFAs positively influences neonatal survival and growth (Rooke et al., 2001), but work in ruminant species is scarce. Previous investigations have predominantly used fish oil as the source of omega-3 EFAs but alternative, more sustainable, sources are desirable. To date, the effect of period of inclusion of EFAs in gestation diets has not been thoroughly explored. The period of rapid brain growth in the ovine foetus occurs between 10 and 6 weeks prior to birth (Turley et al., 1996). This study explored the effects of feeding an algal source of EFAs, with a high content of DHA, during different time periods on measures of lamb viability.

Sainfoin (Onobrychis viciifolia) is a Mediterranean forage rich in tannins, which has been shown to reduce the faecal excretion of nematode parasites in goats, when offered as hay supplement (Paolini et al, 2003). The use of conserved forages for parasite control may be preferred when either the climatic or agronomic conditions are not appropriate for the grazing of such forages. The aim of this experiment was to investigate whether the consumption of sainfoin hay could reduce the viability and fecundity of adult gastrointestinal parasites, when offered to parasitised sheep at different time points during the course of a parasitic challenge.

Zinc is an essential trace element necessary for the activity of numerous enzymes. Supplemental zinc is considered normal for ruminant livestock to ensure that requirements are met. Although zinc deficiency is not generally recognised in the UK, there is considerable evidence that this supplemental zinc is beneficial. The aim of this study was to investigate the effect of partially replacing zinc oxide with a zinc proteinate in the diet of ewes in late pregnancy and lactation on performance and health of ewes and lambs.

Trans- 10, cis- 12 conjugated linoleic acid (CLA), a biohydrogenation intermediate produced in the rumen, is a potent inhibitor of milk fat synthesis. Data from a number of studies where various doses of trans -10, cis -12 CLA have been abomasally infused demonstrate a curvilinear relationship between the percent reduction in milk fat yield and both the dose of trans- 10, cis- 12 CLA infused and the milk fat content of trans- 10, cis- 12 CLA. In addition to a reduction in milk fat output, under some circumstances an increase in milk yield and milk protein output are observed. To date, there has been no examination of the effects of trans- 10, cis- 12 CLA on milk fat synthesis in lactating sheep. The current study was therefore designed to determine if trans- 10, cis- 12 CLA would inhibit milk fat synthesis in lactating sheep. In order to test the effectiveness of trans- 10, cis- 12 CLA in inhibiting milk fat synthesis we used a lipid-encapsulated trans- 10, cis- 12 CLA supplement (LE-CLA) as a means to provide the trans- 10, cis- 12 CLA isomer post-ruminally.

Techniques to determine N availability and fermentation characteristics of protein in the hindgut of pigs are not available. The gas production technique (Cone et al., 1996) determines fermentation characteristics of OM and can also be used after pre-digestion of the samples with pepsin and pancreatic enzymes to determine fermentation characteristics of OM in the colon of pigs (Becker et al., 2003). The technique can be adapted to obtain gas production profiles reflecting the fermentation of protein (N availability). To achieve this, incubations have to be done with an excess of fast fermentable carbohydrates, in an N-free environment making N the limiting factor for microbial growth depending on the availability of N from the feed samples. The aim of this study was to investigate the possibilities to use the gas production technique to determine the fermentation characteristics of protein in the hindgut of pigs.

Lactic acid bacteria (LAB) consist of many genera, which contain numerous bacterial species. The LAB are Gram-positive, non-spore forming micro-organisms and typically give negative results to the catalase test (Stiles and Holzapfel, 1997). The current classification of LAB combines both phenotypic properties and genotypic examination. Phenotypic studies use the cell wall compositions (mainly for Bifidobacteria), protein fingerprinting which analyse the total soluble cytoplasmic proteins, and the patterns of certain isoenzymes. The gold-standard molecular method to identify LAB is DNA-DNA homology analysis, and molecular methods using specific genetic material patterns of LAB are increasingly being applied as an identification tool. The objective of this study was to develop potential specific oligonucleotide probes for the macro-array identification of LAB.

The purpose of this study was to determine whether litter origin had an effect upon the structure of the small intestine in newly weaned piglets. The gut of the newly weaned piglet undergoes significant structural changes such as a decrease in villus height and an increase in crypt depth following commercial weaning. Litter origin has been shown to influence piglet performance immediately post weaning (Slade and Miller, 1999) and to have a significant influence upon blood metabolite concentrations in the newborn piglet (Ilsley and Miller, 2003). Litter origin therefore may also influence the structure of the small intestine in the piglet, which in turn would affect the experimental sampling strategies used in trials investigating effects on gut structure. This study was carried out to test the null hypothesis that litter origin would not have an effect upon the structure of the small intestine in the newly weaned piglet.

The increase in the prevalence of post weaning diarrhoea in pigs due to the progressive ban of antibiotic use has necessitated the use of alternative management and nutritional strategies (Le Bellego and Noblet, 2001). During immunological stress, amino acids are redistributed away from protein production towards tissues involved in inflammation and immune response. This can disturb normal body processes, which can in turn induce specific amino acid requirements. Threonine utilization by the gut is higher than that of any other amino acid because it is involved in the synthesis of intestinal mucin. Mucin plays a key role in the defence of the mucosa, however it is indigestible. Thus, when the positive effects of an antimicrobial growth promoter are removed, increased levels of dietary threonine may benefit piglets due to additional reserves of threonine being present to compensate for the portion of dietary threonine that becomes unavailable due to the increased synthesis of intestinal mucin. The objective of the experiment was to investigate the interaction between threonine level and avilamycin inclusion on piglet performance and diet digestibility post weaning.

Pigs are able to synthesise their own ascorbic acid (AA), however a number of studies have shown benefits of supplementation. It is thought that additional ascorbic acid may be required in pig diets during periods of stress, infection or due to the increased demands for growth. The neonatal pig has an immature immune system and is also under physiological stress due to the rapid development of the gastrointestinal tract. The aim of this trial was to investigate effects of AA supplementation of sows in late pregnancy and lactation and oral drenching of piglets from birth to weaning on piglet performance and health during the suckling period.

The recent ban on animal protein sources as livestock feed has lead to an increased demand for alternative protein sources (Salgado et al., 2001). Soya protein has been suggested as a potential alternative to fishmeal in weaner diets in sustainable pig production systems. However, the digestion of soya products is known to be reduced by the presence of antinutritional factors such as protease inhibitors and lectins (Lallès, 1993). Several methods have been devised to refine soya thereby increasing ileal digestibility’s (Shon et al, 1994). Some of the refined products include isolate soy protein and soybean protein concentrate. The objective of this experiment was to compare the effect of replacing fishmeal (FO) with HP 300 a soya isolate product on growth performance of piglets from weaning to 28 days post weaning under commercial conditions.

The balance between cellular oxidants and antioxidants is important in the maintenance of cellular homeostasis and functionality. Vitamin C is a potent antioxidant with strong chelating properties, which enhances the absorption of ferric and non -heame iron from the gut (Fishman et al, 2000). However, vitamin C is unstable in the presence of alkali and is susceptible in the duodenum (Arrigoni, and De Tullio, 2002). This study tested the ability of a stable preparation of Vitamin C, Rovimix® Stay C® 35 (DSM Nutritional Products), to regulate iron uptake as measured by total iron binding capacity (T.I.B.C) and as an antioxidant as measured by total antioxidant status (TROLOX) in weaned piglets.