The post-weaning growth check of the piglet can be attributed to the inability of the animal to eat sufficient food in the initial post weaning period and hence grow at a maximum rate (Pluske et al., 1996). It is essential therefore to identify determinants of individual feed intake characteristics post weaning to improve piglet performance. A palatable creep-diet is often fed to piglets pre-weaning to increase performance and to allow piglets to become familiarised with solid feed sourced from a feeder. Bruininx (2002) et al., demonstrated using single spaced Feed Intake Recording Equipment (FIRE), that creep feed stimulates post-weaning feed intake and gain. In addition, Morgan et al. (2001) investigated feeding behaviour of piglets paired from creep or no creep backgrounds and concluded a learning effect which increased the feeding behaviour of the naïve piglet. The purpose of this experiment, therefore, was to investigate the effect of offering selected litters either creep feed or zero creep (naïve) pre-weaning on their latency to initiate feeding post weaning. It was hypothesised that learning behaviour between piglets may influence feeding initiation and so this experiment would also look at the effect of mixing piglets from the two lactation backgrounds.

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.

Due to the introduction of more stringent environmental controls through the implementation of current and impending environmental legislation, dietary crude protein (CP) levels for finishing pigs are an important area of research. Canh et al (1998) reported that nitrogen (N) excretion could be reduced through lowering CP levels and the aim of this study was to investigate the effect of decreasing CP levels of diets containing two levels of lysine (while maintaining the ideal protein balance through amino acid supplementation) on nutrient digestibility and N balance.

In commercial pig production, several diets are offered to pigs dependent on their age and/or weight. A common dietary regime includes at least four changes of diet from wean to finish but there is a lack of information in the literature regarding the optimum method of changing diet. A common practice is to abruptly change from one diet to the next, although an abrupt diet change has been reported to cause a disturbance in the gut flora resulting in diarrhoaea, especially in the post-weaning stage (Meyer et al 1974). The aim of the current study was to investigate the effect of changing diet in an abrupt, phased or free-choice manner on the performance of pigs from wean to finish.

The addition of ‘high quality’ complementary feedingstuffs to the diet of the post weaning pig can positively impact on growth and lean muscle deposition. The Maillard Reaction bonds amino acid and sugar molecules together, and is one of the major pathways in the chemical changes that occur in the cooking process. Cooking of feedingstuffs has been shown to improve the digestibility and nutritive value of a diet (Pickford et al, 1992). In this study, lysine (Lys), methionine (Met) and threonine (Thr) where chemically reacted with sugar molecules to give in vitro early Maillard Reaction Products (MRP). The aim of this study was to assess what effect the addition of a solution of these MRPs to a complementary feedingstuff (Matan XL) would have on overall diet digestibility and subsequent piglet performance.

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.

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.

A main aim of modern pig production is to reduce nitrogen excretion to the environment, capturing more of the dietary protein in saleable meat. One way to achieve this is to reduce dietary protein level but this is likely to increase fat deposition, especially in late-developing fat depots. Meat quality will also be affected and these effects will all be influenced by breed type. This study compared three nutritional strategies differing in dietary protein provision in terms of their effects on growth and fat deposition.

Gastrointestinal parasitism in lambs is usually manifested as a sub-clinical infection and causes significant losses in performance. Its control through the use of chemoprophylaxis is no longer sustainable due to the development of parasitic resistance to anthelminthics, but also due to environmental and consumer concerns. There is thus an urgent need to develop alternative, sustainable methods of controlling gastrointestinal parasitism. These include dietary supplementation of host with protein. The aim here is to develop a mathematical simulation model for the description of the joint effects of nutrition and host performance genotype on the outcome of sub-clinical challenge by gastrointestinal parasitism for growing lambs.

In recent years there has been an increased interest for breeding lambs resistant to gastrointestinal parasites due to the reduced efficacy of anthelminthics. Furthermore, protein supplementation alleviates the adverse effects of parasitism since more protein is available for the satisfaction of the competing body functions of growth and resistance to parasites. Therefore, differences in dietary protein might result in the expression of genotype x environment interaction. Additionally the estimates of genetic and phenotypic correlations obtained from populations kept under different nutritional conditions might differ with implications for the breeding programmes. The aim here is to explore the effect of dietary protein level on the estimates of genetic and phenotypic correlations of a population of growing lambs infected with gastrointestinal parasites using a simulation model.

Models that predict phenotypic responses from the interaction between genotypic descriptors and the environment are desirable both in the context of both animal production systems and evolutionary ecology. Nutrient availability is often related to the ability of a host to control an invading parasitic population and mounting an immune response is often associated with a nutritional cost. This cost is shown by the peripartuient break down of immunity (Houdijk et al., 2003) and reports of negative correlations between production and resistance traits (Rauw et al., 1998). The aim was to develop a model which is able to make predictions relating to the effects of resource allocation as determined by nutrition and genotype, on the course of microparasitic infection in farm animal hosts.

A primary infection of a parasite naïve animal has detrimental effects on intake (anorexia), which in turn results in impaired animal productivity. Recent studies have indicated that anorexia in nematode infected lambs is a direct consequence of the acquisition of immunity (Greer et al., 2005). In many models of disease, immune system activation results in elevated leptin levels and these have been associated with anorexia. However, whether the expression of acquired immunity following a secondary nematode infection results in elevated leptin levels and/or anorexia in growing lambs it is not known. In addition, it is not known whether the expression of acquired immunity differs between breeds that differ in production potential. The aim of the present study was to test the hypotheses a) that a secondary nematode infection results in increased leptin levels and anorexia in growing lambs and b) that lambs of a high production potential breed exhibit a higher degree of anorexia than lambs of a low production potential.

The consequence of sub-clinical gastrointestinal parasitism in farm animals, i.e. reduced food intake and growth, is often more pronounced in breeds with a high production potential compared with breeds with a low one (Houdijk et al., 2001). It cannot be excluded that such differences in disease resistance may arise from between-breed differences in genetic resistance to parasites rather than production potential per se, as within-breed selected farm animals with sufficiently different production potentials are not readily available. However, appropriately selected mouse lines are available (Bünger et al., 2001) to explore the hypothesis that selection for growth may reduce the animal’s capacity to cope with pathogens. We have recently shown in mice divergently selected for growth potential that in some lines, the absolute penalty of sub-clinical parasitism on high growth mice was higher than in their low growth counterparts (Houdijk and Bünger, 2006). Here, we test the hypothesis that this penalty on growth in one of these lines can be reduced through increased protein supply.

Expression of acquired immunity to gastrointestinal parasites usually breaks down during the periparturient period, which is characterised by an increased worm burden and nematode egg excretion. A possible nutritional basis of this phenomenon has been addressed in a rat model, as lactating rats exhibit a breakdown of immunity to the gastrointestinal nematode Nippostrongylus brasiliensis (Houdijk et al., 2005). Indeed, increasing protein supply and reducing protein demand at times of protein scarcity improved resistance to N. brasiliensis (Houdijk et al., 2005; Normanton et al., 2006) but did not affect associated local immune responses. The latter may have been due to the single sampling point used. Therefore, the objective of the current experiment was to assess temporal effects of increased protein supply on resistance and immune responses to N. brasiliensis in lactating rats.

The breakdown of acquired immunity during the periparturient period in the ewe can be reduced by metabolizable protein (MP) supplementation (Houdijk et al 2001). Recent evidence suggests that the development of immune response results in reduced food intake (anorexia) in many disease models (Materase et al, 2005). However, it is not known whether an immune response following the periparturient relaxation of immunity is associated with a reduction in food intake and whether this is affected by protein supplementation in parasitized ewes. In addition, differences in nutrient partitioning between sheep breeds that differ in production potential may affect the ability of the hosts to express immunity and this may be reflected by differences in their magnitude and/or duration of anorexia. The aim of the present study was to test the hypotheses that: a) nematode infection during the periparturient period results in anorexia and protein supplementation can effect the degree of anorexia in ewes, and b) ewes of a high production potential breed show higher breakdown of acquired immunity than ewes of a low production potential breed, and exhibit higher degree of anorexia.

Resistance to nematode parasites of sheep to broad spectrum anthelmintics is one of the main drivers in research on alternative solutions for parasite control. Previous work has shown clear differences between the Suffolk and Texel breeds in susceptibility to gastrointestinal nematode infection (Hanrahan & Crowley, 1999; Good, Hanrahan et al., 2006). The Suffolk being more susceptible to such parasitic infections has implications in the Irish industry where it plays a dominant role as both as a terminal sire and in the genetic makeup of the ewe population. Previous work has shown some beneficial anthelmintic effects following the administration of copper oxide wire particles (Bang, Familton et al., 2000; Knox, 2002). The aim of this study was to evaluate the potential of copper oxide wire particles (COWP) as an anthelmintic for lambs that were exposed to a natural nematode challenge postweaning.

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.

Lameness as a herd problem in dairy cattle typically presents as lesions of the claw horn (CHL); e.g. sole ulcer and white line disease, or as digital dermatitis (DD), an infection of the adjacent skin. The aetiology of these conditions is complex and over 100 potential hazards have been identified involving features of the environment, nutrition, phenotype and physiological state. Strategic plans for control of lameness need to be farm-specific and address the risks attached to these potential hazards on an individual basis. For purposes of analysis however, it is possible to allocate the multiplicity of hazards into functional categories: e.g. external forces acting on the foot, infection and hygiene, foot structure, systemic disorders. This paper examines associations between the severity of proximate risks ascribed to these hazard categories and the prevalence of lameness in first-calving heifers.

As a major health problem facing dairy farmers worldwide with substantial economic, production and welfare consequences, lameness has attracted much attention over the last two to three decades (Boelling, 1999). Lameness as a linear type trait is measured by locomotion scoring as there is a high genetic correlation between lameness and locomotion score. Studies have included locomotion (as a predictor of lameness) and have associated lameness with no effect, an increase and sometimes a decrease in milk production of cows. Several reasons have been given for these differences and the need still arises for estimates of the effect of lameness on milk yield in herds with current dairy management. The objective of this study was to quantify the effect of lameness on the daily milk yield (DMY) of dairy cows.

Sole lesions and lameness are significant problems for dairy cow production and welfare. Producers are increasingly incorporating non-Holstein genetics into the make-up of dairy herds for a number of reasons, particularly to promote improved fertility and health. However, much of the evidence that alternative breeds improve hoof health characteristics is anecdotal. The aim of the present study was to assess the effects of Holstein Friesian (HF) and Norwegian dairy cattle (N) genotypes on lameness parameters in dairy cattle within different production systems.