Outdoor farrowing system account for 27% of breeding sows in England, and it is therefore important to understand the factors affecting their production efficiency. Piglet mortality is a significant economic and welfare issue, with farrowing and preweaning losses in commercial oudoor herds currently averaging 19% of all pigs born. Since sophisticated environmental and human interventions at the time of farrowing are infeasible in these systems, risk factors may differ in importance from those seen in indoor systems. A better understanding of the risk factors for different causes of mortality will help to design strategies to minimise losses.

In the UK, markets for ‘welfare friendly’ meat have increased the use of more extensive, deep-bedded straw housing. Straw yard housing may increase physiological development at slaughter (Salmon & Edwards, 2007), with many confounded potential causal factors including increased space allowance, natural lighting/photoperiod, straw availability, increased activity levels and reduced social stress. Physiological development at slaughter is a key issue in the success of heavy pig production utilising entire boars, since greater maturity may increase adverse behaviours, therefore decreasing pig welfare, and increase risk of carcass taint. The objectives of this research were to investigate whether straw supplementation, in the absence of confounded space and lighting effects, influenced physiological development and associated undesirable effects in entire boars and gilts grown from 60kg to 120kg slaughter weight.

The immediate postweaning period in pigs is often characterised by a reduced and variable food intake, digestive disorders and poor growth and development. Historically such effects were reduced by the use of in-feed antibiotic growth promoters (AGPs), copper sulphate and zinc oxide to enhance the efficiency of feed conversion and hence maximise nutrient capture. However from January 2006 the routine use of in-feed AGPs was banned and, due to concern over environmental pollution, levels of inclusion of heavy metals are limited by regulation and likely to be further reduced in the future. Weaning pigs at a later age has been suggested as an approach to reduce the potentially negative effects of the AGP ban on the national herd. The objective of the AGEWEAN programme of research was to investigate the effects of weaning age (4, 6 and 8 weeks) in both an indoor and outdoor lactation environment on the biological and economic efficiency of production where diets contain no AGPs and lower levels of copper (<25ppm added) and zinc (<100ppm added).

Recent estimates of total pre-weaning piglet mortality range between 16-19% (MLC 2006). With environmental modification using the farrowing crate reaching its potential to decrease mortality, as well as raising serious welfare concerns, a different approach to effectively address piglet survival is needed. Genetic breeding programmes implemented in alternative farrowing systems could prove a viable option.

Weaning pigs from the sow at an older age, when their digestive systems are more mature, has been suggested as an approach to reduce the potentially negative effect of the in-feed antibiotic growth promoter (AGP) ban on the national pig herd. Whilst this approach has been shown to improve feed intake and piglet growth rate during the early postweaning period (Edge et al. 2006) it is also important to consider how changes in weaning age may influence sow productivity and longevity in the herd. The AGEWEAN programme of research followed 570 gilts whose piglets were weaned at either 4, 6 or 8 weeks of age through four successive parities; reproductive performance, litter data and the timing and reasons for any sow being culled from the herd were recorded.

The ease with which posture changing occurs in pigs has welfare relevance since the duration of lying down and standing up behaviour may indicate the adequacy of floor type to give security of movement, and/or the mobility of animals after resting on floors differing in comfort. Standing and lying behaviours consist of a predictable sequence of movements, with stages between movements when the animal can pause in a relatively stable transition state. In sows, it has been suggested that the duration of one or more of these stages might be sensitive to both animal and environmental factors (Marchant and Broom, 1996); however whether this is the case in finishing pigs is less certain. The aim of this study was therefore to evaluate behaviours indicative of both the physical comfort of different types of floors and security of movement in finishing pigs.

Slaughter weight in UK pig production is increasing annually, with an associated increase in age at slaughter. This increases risk of reaching sexual maturity and a reduction in carcass quality and production efficiency. In entire boars, puberty is associated with increased aggression levels and the production of hormones causing carcass taint. Management systems and production practices may affect these risks. Thomas et al (1979) found that extensive housing and management systems increased the risk of pigs reaching puberty. In previous Scandinavian research, Fredriksen et al (2005) found that maintaining stable litter groups reduced aggression and mounting behaviour, and gave a lower propensity for carcass taint at slaughter. To date, there is a lack of research examining the effects of these factors on physiological development and aggression under UK conditions. This study explored the effect of stable litter grouping and housing system on performance, aggression and physiological maturity in entire males and gilts over the 60kg-130kg weight range.

The periparturient rise in nematode eggs at lambing is a crucial part of the epidemiology of nematode infections as it allows a large number of infective larvae to be present in the pastures when the lamb is young and most immunologically naïve. With a rapidly rising level of anthelmintic resistance and increasing public concern over drug residues remaining in animal products, it is necessary to achieve more long-term, sustainable nematode control programmes. Some plant products could provide alternatives or adjuncts to conventional control with anthelmintics and ease the selection pressure for anthelmintic resistance. The polyunsaturated fatty acid, docosahexaenoic acid (DHA), which can be produced in high concentrations by some marine algae, has been shown to modify immune response in many species and decrease the production of proinflammatory cytokines (Calder, 2001). This action could reduce inflammation in the gut in response to parasite infestation and reduce the extent of associated hypophagia. The objective of this study was to investigate the long term effects of providing an algal DHA dietary supplement in late pregnancy, on the periparturient rise and the resulting effects on the infection levels and production consequences for their lambs.

The UK dairy industry currently suffers huge losses due to declining fertility. Although fertility in the sheep industry is good overall, the use of multiple ovulation and embryo transfer techniques would benefit from improved conception and embryo survival rates. Studies suggest that omega-3 supplementation may bring about a reduction in the secretion of prostaglandin F2α (PGF2α), which would favour the maintenance of the corpora lutea (CL) and hence, a successful pregnancy. Feeding fish meal to dairy cows has been found to improve pregnancy rates by 10% (Burke et al., 1997). Using sheep as a model, this study aimed to evaluate whether reproductive performance in ruminants is improved by feeding an algal source of omega-3 fatty acids, particularly docosahexaenoic acid (DHA, C22:6 n-3). The study was also structured to determine whether prostaglandin production is affected by supplementing diets with omega-3.

As nutrient density requirement decreases with increasing age, finishing pig diets may oversupply nutrients. This can result in excess protein, including the amino acid tryptophan, reaching the large intestine where it can be metabolised by the microbial flora providing a substrate for bacterial skatole production. Skatole can give rise to carcass taint. The use of non-starch polysaccharides (NSP), has been proposed to reduce the levels of production and absorption of skatole. One type of NSP, short chain fructo-oligosaccharides (scFOS), has shown to influence the microbial population and reduce skatole production in vivo (Xu et al. 2002). It is thought the reduction in skatole production is due to an increased requirement for amino acids for bacterial cell protein synthesis, combined with changed microbial biota and pH which shifts the microbial metabolism of tryptophan toward indole production. This study explored the effect of a dietary inclusion of scFOS on the production of skatole and performance of a commercial UK genotype taken to heavier slaughter weight.

Whilst many of the on-farm factors identified as enhancing pigmeat meat eating quality are already standard commercial practice, variability in quality is still a problem whose reasons are poorly understood. Particular uncertainty exists about the effect on eating quality of increasing slaughter weight, a current development which facilitates reduced cost of production by spreading carcass overhead costs between more kg of saleable meat. However, this strategy means that pigs will be older at slaughter, which carries uncertainties about the risk of increased toughness and boar taint. In targeting a market for branded pigmeat of high eating quality, there may also be beneficial strategies for adoption in carcass selection and post-slaughter management. These questions were addressed as part of a research project on the improvement of meat eating quality in the Scottish red meat sector.

There are many studies that show that breed, gender, age and feeding regime influence animal growth rate, meat yield and composition. These factors, together with slaughter and post-slaughter conditions, are thought to influence tenderness and flavour attributes of meat (Thompson, 2002)). Low variability is highly desirable and processes such as ‘A blueprint for improved consistent quality lamb’ (MLC, 1999) in the UK have attempted to improve the level and consistency of lamb eating quality. The purpose of this trial was to test whether the adoption of several key enhanced on–farm and in-abattoir practices led to improved eating quality throughout the lamb production season, especially for heavier, lean carcasses.

There is a need to identify finishing systems for pigs that meet the requirements of both pig producers and society. These require that a system is economically efficient, but also takes due account of animal welfare, food safety and environmental considerations. As part of an integrated investigation, this study assessed the health and welfare implications of giving pigs either dry or liquid feed when housed in either fully-slatted or straw-based accommodation.

Although feeding pigs ad libitum is known to result in increased tenderness (e.g. MLC, 1989), there would be benefits in reduced cost of production if this could be obtained without the concomitant reduction in feed efficiency and carcass leanness. The ad libitum effect on tenderness could be due to higher lean tissue growth rate (LTGR) and associated increased protein turnover and muscle enzyme activity, but other factors may also contribute, such as reduced feeding stress compared to restricted feeding. The aim of this trial was to assess the eating quality of pork from pigs reared in a range of housing and nutritional treatments, designed to give a wide variation in LTGR.

Public concern about the welfare of farm animals has resulted in an increasing body of legislation regulating livestock production systems. In 2003, the UK implemented two new EU Directives on Pig Welfare (Directives 2001/93/EC and 2001/99/EC), and issued revised Welfare Codes for Pigs. New Council of Europe Recommendations are also at the consultation stage. The welfare issues highlighted for current consideration within the pig sector include space allowance and floor type, environmental enrichment, tail docking, weaning age and the use of the farrowing crate. With present scientific and practical knowledge, not all of these issues have a simple resolution. From an industry perspective, the major welfare issue is the level of endemic disease and, in particular, the dramatic influence of PMWS. There are also concerns regarding potential conflicts between the different policy objectives of animal welfare, environmental protection, food safety, staff health and safety, and financial sustainability that will need to be resolved.

The feeding of high fibre diets to sows prior to ovulation has been shown to have beneficial effects on embryo viability, leading to a possible increase in piglet litter size. This trial was conducted to look at the effect of feeding sows a high fibre diet from mid lactation until breeding on subsequent litter size on a commercially run farm. The sows used were either Large White or Large White x Landrace in genotype and ranged from parity 1 to 7. The sows were allocated to receive either a cereal-based control diet (C), or a high fibre diet (HF) of similar specification but containing unmolassed sugar beet pulp (USBP) at a 20% inclusion rate during lactation and 40% from weaning to oestrus. The diets were fed from day 11 of lactation until oestrus. The sows were inseminated at oestrus and then fed a standard gestation diet until farrowing. The trial was conducted over a 3-month period and in total 198 sows received the HF diet with the rest of the sows over the 3-month period acting as controls (496) on the cereal-based diet. The effect of the diet on total litter size and the number of piglets born alive per sow was analysed in a general linear model (Minitab release 12.1). The combined results for both breed types showed that sows fed the HF diet had a significantly higher number of piglets born (12.37 ± 0.27 versus 11.41 ± 0.26, P<0.01) and a higher number of piglets born alive (11.47 ± 0.26 versus 10.85± 0.26, P<0.01) compared to 130 control fed sows matched for farrowing week. The difference in piglet litter size was still apparent when all the control sows farrowing over the 3 month trial period were included in the statistical analysis, with values of 12.47 ± 0.27 versus 11.79 ± 0.15 (P<0.05) for total number of piglets born and 11.77 ± 0.26 versus 11.16 ± 0.14 (P<0.05) for the number of piglets born alive for the HF and control diet respectively. Based on the results from this trial and previous studies, feeding a diet with a high content of USBP during late lactation and prior to insemination can increase the total number of piglets in the litter and the number of piglets born alive. This effect is less marked in crossbred sows with high baseline performance.

The objective of this experiment was to measure the effects of preand postnatal supplementation of sows with an algal source of docosahexaenoic acid (DHA) on the pre and post–weaning performance of their piglets. The experiment was of 2 x 2 factorial design, with DHA supplementation of the sow diet (3g DHA/kg feed) during the last 4 weeks of pregnancy and/or 4 weeks of lactation. There was a significant positive effect (P<0.05) of lactation DHA on weaning weight. Piglets from sows which had received DHA supplement in gestation were heavier throughout the post–weaning period than controls (P<0.05), as were piglets whose mothers received DHA in lactation (P<0.05). When age and weight at weaning were used as covariates in the model, the liveweight gain in week 1 and over the whole 26 day post–weaning period were significantly greater (P<0.05) for piglets from sows which had received DHA supplement in gestation. It is concluded that DHA supplementation of sow diets can improve piglet performance.

The intake of immunoglobulin G (IgG) by sucking piglets from colostrum was estimated over the first 24 h of sucking by the weigh-suck-weigh technique using experimentally determined correction factors for metabolic and urinary losses and was related to appearance of IgG in piglet plasma. Colostrum immunoglobulin G (IgG) concentrations declined rapidly from 61 mg/ml at the start of sucking to 9·0 mg/ml after 24 h sucking. IgG was first detected in piglet plasma after 4 h sucking, increased to a maximum after 12 to 16 h sucking and thereafter declined. In piglets allowed to suck from birth, there was no significant relationship between estimated IgG intake and plasma IgG concentration suggesting that IgG intake did not limit acquisition of IgG by the piglet. When sucking was delayed by 8 or 12 h, colostrum intakes by piglets were not different from piglets allowed immediate access to the udder but IgG intakes were significantly (P < 0·001) decreased. Total plasma IgG (g/kg live weight) did not decline significantly as a result of delayed sucking. In conclusion, under the experimental conditions employed, the appearance of IgG in piglet plasma was limited by factors other than by colostrum IgG intake.

Nose rings have been proven to reduce the occurrence of paddock rooting behaviour, however, the practice has been questioned on ethical grounds. The aim of this experiment was to identify a suitable alternative. Previous attempts to reduce paddock damage by dietary means have succeeded in redirecting rooting behaviour (Bornett et al., 2002) or at reducing the overall frequency of paddock rooting behaviour (Braund et al., 1998) but neither succeeded in reducing paddock damage. It is hypothesised that whilst the experiment of Bornett et al. (2002) fulfilled the sow’s desire to forage, and the experiment of Braund et al. (1998) fulfilled the sow’s need to feel satiated; neither fulfilled both criteria simultaneously. In this experiment, both of these needs were considered and it was therefore hypothesised that paddock damage would be reduced.