Toughness is a determinant of meat quality and a common cause of unacceptability in meat products. Although calpain proteases are believed to be involved in meat tenderisation by post mortem (PM) degradation of proteins within muscle (Sensky et al., 2001), other proteolytic systems are likely to contribute to the process (Sentandreu et al., 2002). Caspases are proteases involved in protein degradation in apoptosis and are activated early in pathological events associated with hypoxia/ischaemia, not dissimilar to the hypoxic conditions in muscle after slaughter. Caspases cleave a number of proteins which are targeted by calpains during post mortem proteolysis and also degrade the calpain-specific inhibitor calpastatin. The caspase system has a hierarchy of initiating isoforms (such as caspases 8, 9 and 12) which activate effector caspases (such as 3 and 7) that cleave specific substrates. Our hypothesis is that caspase activity may contribute to early post mortem proteolysis and tenderisation, similar to the calpain system. The objective of this study was to investigate the relationship between changes in caspase activity during post mortem conditioning and shear force in pork.

The proportion of beef cattle originating from the suckler herd is projected to decrease, relative to the proportion from the dairy herd. Sinclair et al., (2001) found no difference between eating quality of Holstein and Charolais when hung tenderstretch. Most genotype comparisons in relation to meat quality have used the longissimus dorsi muscle and very few have considered more than one particular post slaughter process (ie hanging technique, aging period). The present study was undertaken to investigate the effect of genotype and post slaughter processing (hanging technique and aging time) on the eating quality of a range of hindquarter muscles.

Unpredictable variations in meat toughness in the British pig herd remain a concern to the meat industry. Whilst genetics is clearly important, 50% of this variability can be accredited to environmental factors, such as stress. At slaughter the levels of calpastatin (encoded by the CAST gene), a specific inhibitor protein that regulates the calpain proteinases largely responsible for postmortem tenderization, are strongly related to meat toughness. Down-regulation of CAST expression in the days before slaughter therefore provide a practical opportunity to reduce toughness. There are at least three CAST gene promoters (1xa, 1xb and 1u) containing transcription factor motifs sensitive to β-adrenergic stimulation, which can be induced by physiological stress (Parr et al., 2004). The 1u promoter is the predominant form in porcine muscle and the resulting CAST mRNA transcripts are increased in animals treated with the β-agonist clenbuterol (Sensky et al., 2004) or in cells treated with the analogue dibutyryl cAMP (db cAMP) (Sensky et al., 2005). In this study, the functionality of the 1u promoter is further dissected by truncation studies and mutation of potential cAMP responsive elements (CRE).

Recent data on meat quality indicates that dairy genotypes produce more tender meat than beef genotypes. The relationships between carcass parameters and instrumental measures of meat quality depend on the method of hanging (Lively et al., 2005). The present study was undertaken to evaluate the impact of some carcass parameters on meat eating quality of two genotypes when two carcass hanging methods are used.

Legumes are important constituents of ruminant diets and are a vital part of low input and organic systems. Previous studies have established the high intake characteristics and animal production potential of red clover silage. Studies with milk produced from cows fed on red clover silage was noted to have higher levels of polyunsaturated fatty acids (PUFA) but had a reduced shelf life which could be ameliorated by feeding additional vitamin E (Al-Mabruk et al., 2004). This study considered the effects of incremental inclusion of red clover silage in the diet of beef cattle on the fatty acid composition of the m. longissimus dorsi and meat quality.

The potential of Raman spectroscopy for the analysis of fats and oils has been recognised for some decades. The main advantages of the technique are that no sample preparation is required (allowing in situ or on-line studies) and that it can be applied to any physical state including gases, liquids, gels, amorphous solids and crystals. The power of Raman spectroscopy to discriminate between cooking oils has previously been demonstrated. Beattie et al (2004a) demonstrated the use of Raman spectroscopy for the characterisation of lipids in model systems and also in clarified butterfat (Beattie et al 2004b). The aim of this paper was to determine whether Raman spectroscopy could discriminate between the adipose tissue from different species and which characteristics of the lipids (i.e chain length , unsaturation) contributed to the discriminating functions.

The immediate postweaning period in pigs is often characterised by a reduced and variable food intake and poor growth and development, reducing lifetime performance. At present the effects of the postweaning growth check are reduced by the use of 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 is to be banned and, due to concern over environmental pollution, levels of inclusion of heavy metals are likely to be further reduced. 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 potential negative effect of the AGP ban on the national herd. The objective of the AGEWEAN programme of research is to investigate the effects of weaning age (4, 6 and 8 weeks) in both an indoor and outdoor lactation environment on biological and economic efficiency of a production system where diets contain no AGPs and lower levels of copper (<25ppm added) and zinc (<100ppm added).

Oilseed rape is a protein crop that can be readily grown under UK conditions and has a good amino acid profile relative to other plant protein sources. Its use in diets for young pigs has been limited by concerns about its content of anti-nutritive factors, especially glucosinolate compounds, although these have been progressively reduced by plant breeders (Gill and Taylor, 1989). The whole seed contains a high level of digestible oil, making it an excellent energy source for piglets provided that the oil is made available by milling or heat treatment to rupture the seed coat. The forthcoming ban on use of in-feed anti-microbial growth promoters has renewed interest in rapeseed use because glucosinolate compounds can have antimicrobial effects (Fenwick and Heany, 1983), and because weaning age may be increased in future to reduce risk of health problems. In this circumstance, where regular intake of solid feed is established during lactation, the sensitivity to dietary rapeseed in the post weaning stage may be less critical. This experiment therefore evaluated the response in performance and health indicators of piglets weaned at different ages to diets with different rapeseed inclusion levels.

In-feed antimicrobial growth promoters (AGPs) have long been used as means of protection against enteric disorders such as post-weaning colibacillosis (PWC), a diarrhoeal disease of newly weaned pigs resulting from the colonisation and proliferation of enterotoxigenic E. coli (ETEC) in the small intestine. One of the strategies to enable the British pig industry to remain competitive in the global market whilst complying with the imminent removal of AGPs may be to increase weaning age and change the level of crude protein in the diet. If weaning age is increased, sensitivity to PWC may be reduced and pigs be better able to cope with higher levels of protein in the diet, which have been associated with an increased risk of PWC (Prohászka and Baron, 1980). The objective of the current experiment was to investigate the effects of experimental challenge, weaning age and dietary protein supply post-weaning on the health and performance of pigs in the absence of AGPs.

Post weaning piglet performance is often associated with a growth check (LeDividich and Seve, 2000) which is a key concern to the pig industry. The ban of in-feed antimicrobial growth promoters (AGPs) has increased this concern. Sodium butyrate (NaB) has been shown to reduce intestinal inflammation and stimulate enterocyte growth in humans (Ogawa et al., 2003) and thus appears to be a possible alternative to AGPs in diets for weaned pigs. Zinc oxide (ZnO) is normally added to weaner diets to control post weaning diarrhoea. The objective of this experiment was to compare varying levels of dietary supplementation of NaB both with and without ZnO to determine whether NaB can improve piglet performance alone or in combination with ZnO.

Wheat is a major component of piglet diets, representing a significant source of energy. Nutritional value of wheat can be influenced by genetic and environmental factors (Wiseman and Inborr, 1990). Previous work examining the effect of wheat cultivar on pig performance has failed to show a clear relationship with digestibility (Lewis et al., 1999), although selection of which wheats to evaluate has invariably been unstructured. The aim of the current study was to investigate the effect of wheat endosperm texture, in wheats which were closely related, on nutritional value for the newly weaned piglet.

The removal of in-feed antimicrobial growth promoters (AGPs) is expected to place pigs at greater risk of post weaning enteric disorders (PWED), and accentuate the need for alternative, non-pharmaceutical, strategies for disease prevention. Evidence in the literature suggest that appropriate non-starch polysaccharides (NSPs) may be added to weaner diets in order to improve gut health and reduce the incidence of PWED (Bolduan et al., 1988). NSP solubility may be an important factor in such potential health benefits with soluble NSPs that lead to high digesta viscosity actually increasing the occurrence and severity of PWED (Hopwood et al., 2004). The objective of this experiment was to investigate effects of NSP solubility and inclusion rate on gut health and development, growth performance and the risk of PWED in the absence of effects on digesta viscosity.

Analysing egg and weight traits together may provide a new procedure to express the maternal effects in poultry. Maternal effects in poultry are atypical from those of mammals as any maternal effects on chicks, incubated artificially, must be the residual effect of dam reflected in egg characteristics at laying. Possible relationships between W (weekly body weight) and reproduction, including the existence of maternal effects, might be used to improve both meat and egg production. The aims of this study were to analyse the genetic parameters of liveweights and egg traits, and their relationship with maternal effects for a one-to-one sire and dam pedigree recorded and artificially incubated Japanese quail population.

The common methodology for the genetic evaluation of the egg production in poultry is to use cumulative data. However, the source and the scale of variation in egg laying are not constant during the whole period and thus, longitudinal models might offer more accurate predictions. Random Regression Models (RRMs) allow for differences in the phenotypic trajectory within a population and for these to be decomposed for each individual into genetic and environmental components. A similar approach is widely used in dairy cattle, where RRMs have underpinned the development of test day models for genetic evaluation. The objective of this study was to investigate the application of RRMs in the egg production of turkeys.

Mapping quantitative trait loci (QTL) within commercial populations circumvents the need to verify segregation of QTL detected under experimental crosses. Variance component (VC) mapping combines information from all relationships within a pedigree to provide a breeding value for the animal and QTL with immediate potential for marker assisted selection. Variance components are estimated by modelling the covariance structure between relatives sharing alleles identical by descent (IBD). Commercial poultry data and simulation will be used as a model to explore how VC methodology behaves under varying population structures. Data is available from the Cobb Vantress broiler population to evaluate extensions to the additive QTL model. Computer simulation will be used to test models including additive, dominance, epistatic and imprinting effects over a range of pedigree structures including family sizes and number of generations.

The concentrations of the long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) eicosapentaenoic acid (C20:5, EPA) and docosahexaenoic acid (C22:6, DHA) in poultry meat can be increased (to some extent) by enriching poultry diets with these two acids. However, this relies almost entirely on the use of fish oil as there are no terrestrial sources of these acids. This raises the issue of both the sustainability of such an approach and also the consumer acceptability of such a reliance on fish oil in poultry diets. The conversion of α-linolenic acid (LNA) to EPA and DHA, though limited, is done by birds and so an alternative approach would be to enrich poultry diets with the more abundantly available LNA as a means of increasing the EPA and DHA content of poultry meat. The objective of this study was to investigate whether there was any effect of poultry species and breed on the enrichment of poultry meat with EPA and DHA in response to increased dietary concentrations of LNA.

High ambient temperature reduces feed intake, live weight gain, and feed efficiency (Siegel, 1995), thus negatively influencing the performance of broilers. Heat stress has also been shown to suppress immune responses of broiler. Chromium is an essential nutrient required to promote the action of insulin in body tissues so that the body can use sugars, proteins and fats. Cr deficiency can disrupt carbohydrate and protein metabolism, reduce insulin sensitivity in peripheral tissues and impair growth rate (Vincent, 2000).Chromium is important in altering the immune response by immunostimulatory or immunosuppressive processes as shown by its effects on T and B lymphocytes, macrophages and cytokine production. Dietary chromium supplementation has been reported to have a positive effect on growth rate and feed efficiency of growing poultry under stress conditions (Sahin et al., 2002). Another reason for supplementing chromium is due to the fact that chromium is excreted excessively during stress (Anderson, 1994). Also the dietary requirement of livestock for chromium has not been defined yet (NRC, 1997). This study was to investigate the effects of different levels of Cr nicotinate on the growth performance and antibody titres against Newcastle and Influenza disease in broilers.

The potential to increase the n-3 polyunsaturated fatty acid (PUFA) content of poultry meat by enriching the poultry diet with n-3 PUFA is well established. However, the responsiveness to different fatty acids is variable (Rymer and Givens, 2005) and there is little information on the effect of species and breed of poultry. The objective of this study was to investigate the effect of poultry species and breed on the response to increased dietary concentrations of the n-3 PUFA α-linolenic acid (C18:3, LNA), eicosapentaenoic acid (C20:5, EPA) and docosahexaenoic acid (C22:6, DHA) in terms of the increased concentrations of these fatty acids in white and dark poultry meat.

In sire referencing schemes (SRS) genetic links are formed among flocks by the mutual use of some rams (reference sires). These connections allow for across-flock genetic evaluations offering a larger pool of candidates for selection. Where SRS have been established in hill breeds, their guidelines have been adopted from terminal sire breeds. Hill flocks, however, are typically much larger in size than other pure breeds with more candidates to select among within individual flocks. Guidelines from other breeds may therefore be inappropriate. Using stochastic simulation, the objective of this study was to explore the effect of number and method [artificial insemination (AI) vs. natural service (NS)] of use of reference sires (RS) on genetic gain, inbreeding and connectedness for a lamb trait (weaning weight) in SRS tailored to characteristics of hill breeds.

In order to increase farm incomes, hill sheep farmers must improve the productivity and quality of their flocks. Recent changes to farm support schemes have focused attention on a number of options, including a change of ewe breed, genetic improvement of the flock, the use of crossbred ewes, or crossbred lamb production from native hill breeds. A switch to crossbred lamb production could lead to an immediate increase in the quality of production from hill ewes whilst maintaining a dam that is adapted to the hill environment. The aim of this work was to evaluate the performance of crossbred lambs from Welsh Mountain ewes.