The aquaporins (AQPs) are a family of small integral membrane proteins 28-35kDa in size, sub classified into 2 groups; those selectively permeated by water (the aquaporins; AQP0, AQP1, AQP2, AQP4, AQP5, AQP6 and AQP8) or by water and small organic osmolytes such as glycerol and urea (the aquaglyceroporins; AQP3, AQP7, AQP9 and AQP10). AQPs are expressed in a variety of epithelial tissues where they are responsible for rapid water movement driven by osmotic gradients. The mammary gland produces and secretes milk which consists of water, lipids, electrolytes, vitamins, sugars and specific milk proteins. However, little is known about AQP expression, distribution and function in mammary tissue or about the process of water transport across the mammary epithelium. The only information available relates to the identification of AQP1 and AQP3 in capillary endothelia and epithelial cells of mouse mammary glands respectively (Matsuzaki et al., 2005). Since water delivery to the mammary gland is critical for milk production, which is of major economic importance to the dairy industry, it is necessary to understand the underlying physiology involved. The aim of this study was to determine the expression and distribution of AQPs within the bovine mammary gland.

Methods that detect QTL within commercial populations circumvent the need for expensive experimental populations and facilitate direct application of results through marker assisted selection. Variance component analysis (VCA) uses phenotypic, pedigree and marker information within a mixed linear model to simultaneously detect QTL and estimate breeding values. The inclusion of non-additive effects has potential for greater accuracy of selection and understanding of underlying mechanisms. The linear model can be extended to include higher order effects such as dominance, however, there is little information on empirical power. Here VCA was applied to real and simulated commercial broiler data to detect additive and dominant QTL effects.

Quantitative trait loci (QTL) associated with physical and chemical body composition of the pig are of substantial economic interest. Previous studies have reported QTL for physical body composition such as lean and fat tissue traits (Roehe et al., 2003). In contrast, QTL associated with chemical body composition and for the change in deposition of such components during growth have only been reported in one previous study (Mohrmann et al., 2006). Knowledge of the genomic regulation of body composition during growth is important to accurately estimate nutritional requirements, optimise the entire production system, characterise the population of interest, and to optimise food intake capacity by breeding.

Exceptionally high prolificacy in the Cambridge and Belclare breeds has been shown to be attributable to point mutations in genes (BMP15 and GDF9) that code for oocyte derived growth factors which have profound effects on ovarian follicle development. The BMP15 gene is X linked while GDF9 is autosomal (chromosome 5). Two different BMP15 mutations are present in the Belclare population (FecXG and FecXB) but only one of these (FecXG) was found in the Cambridge while the GDF9 mutation (FecGH) was common to both breeds. The Inverdale and Hanna mutations in NZ Romney sheep (Davis et al. 2001) are point mutations in BMP15 but involve different codons from those involved in Cambridge and Belclare. It is of interest to know whether the mutations common to Cambridge and Belclare are likely to have had a common ancestral source or arose independently. The Lleyn breed was a common source of genetic material in the genesis of both breeds. Thus, the foundation ewes for the Cambridge included three Lleyn ewes (Owen,1976) while a set of 13 Lleyn sheep selected for high litter size was a major contributor to the Belclare breed (accounted for 50% of the genetic material at one stage; subsequently diluted to about 25%). The hypothesis is that the Lleyn was the likely source of the two mutations common to Belclare and Cambridge.

Modern cattle management systems involve animals’ separation from penmates for procedures such as weighing, measuring and blood-sampling. This separation can result in distress in some individuals. Environmental and genetic factors are known to control the variability observed in behavioural responses of different individuals. We carried out a genome scan in a Holstein x Charolais cross population to identify QTL influencing temperament-related traits. One of these tests was the social separation test (SS test), which was designed to measure animals’ fearfulness to social separation (Ball et al., 2002). We present here the results obtained for the traits scored in the SS test performed in the heifers of the second-generation of this population.

Quantitative trait loci (QTL) are chromosome regions which are significantly associated with the expression of a phenotypic trait in a particular population. Detection of a QTL is carried out using association with a genetic marker, such as a single nucleotide polymorphism (SNP), which is in linkage disequilibrium (LD) with the QTL. The two main categories of association studies are linkage analyses (LA), which consider LD within families and linkage disequilibrium methods, which make use of LD across an entire population. The recent reduction in genotyping costs has allowed for testing individuals for a large number of SNP. This substantial increase in genotypic data has lead to denser marker distributions on the bovine genome thus potentially increasing the power of QTL detection studies. The objective of this study was to scan the bovine genome to detect QTL for 305 day lactation milk yield (MY), 305 day lactation fat yield (FY), 305 day lactation protein yield (PY), herd life (HL), somatic cell score (SCS), interval from calving to first service in cows (CTFS) and age at first service in heifers (AFS). HL is a measure of longevity measured in the number of lactations a cow stays in the herd. SCS refers to the amount of somatic cells a cow has in her milk and is an important indicator trait for mastitis. CTFS is the period from parturition to first insemination in days and AFS is the age in days at which a heifer was artificially inseminated for the first time. Fertility traits, such as CTFS and AFS, are indicators of reproductive efficiency.

Beta-Lacto globulin (BLG) is a major protein in the milk of ruminants. Bovine BLG gene is located on the chromosome 11q28 and has two common genetic variants, ‘A’ and ‘B’ (Gene-Bank X14710). These variants are different in amino acids at positions 64 and 118, where allele ‘A’ has Asp and Val and allele ‘B’ has Gly and Ala, respectively. Difference at position 118 can be detected by PCR-RFLP (Medrano and Agiular-Cordova 1990). It is reported that allele ‘A’ is associated with milk production (Strzalkowska et al. 2002) and allele ‘B’ has a positive effect on fat percentage (Tsiaras et al. 2005). The aim of our study was to estimate the allelic frequency in polymorphic site of exon IV (allele ‘A’ or HaeIII (-)) of BLG gene in Holstein dairy cattle of Iran and also to find any association of total milk production (first lactation) with BLG genotypes.

Osteoarthritis (OA) and Osteochondritis Dissecans (OCD) are osteoarticular disorders that cause leg weakness, lameness, pain and suffering in companion animals, some farm animals and humans. OA is one of the most common age-related osteoarticular disorders in humans and dogs. In pigs, both OA and OCD are thought to arise from changes in the articular cartilage and growth plates within the synovial joints causing structural damage to joint tissues. Since these changes are not observed in the slow maturing wild boar, they are suggested to be a result of the modern intensive pig production industry which has very successfully selected pigs for rapid growth rates, large muscle mass and efficient feed conversion placing increased weight and mechanical stress on growth plates. The aim of this study was to establish canine and porcine articular cartilage explant models which are essentially tissue culture techniques for isolating and maintaining cartilage tissue ex vivo for subsequent assessment of potentially beneficial effects of specific phytonutrients. Bacterial lipopolysaccharide (LPS) was used as a catabolic mediator to create a culture model of joint inflammation mimicking the events that occur in late stages of OA and OCD. We then performed assays to determine if the dietary phytochemical ‘curcumin’ (derived from Curcuma longa) and the polyphenolic phytoalexin stilbene ‘resveratrol’ (found in red grapes, red wine, peanuts and some berries) are able to counteract the catabolic effects of LPS by inhibiting LPS stimulated release of cartilage matrix glycosaminoglycans (GAGs).

The health benefits of consuming sufficient very long chain n-3 polyunsaturated fatty acids (VLC n-3 PUFA) such as EPA (C20:5) and DHA (C22:6) are well established. A key supplier of these fatty acids is oil-rich fish, however a recent study relating to UK adults indicated that only 27% of the population consume oil-rich fish and current intakes of VLC n-3 PUFA are substantially sub-optimal (Givens and Gibbs, 2006). There is also evidence to indicate that in vivo conversion of alpha linolenic acid (C18:3 n-3) to EPA and DHA is limited and highlights the need for an increased supply of preformed EPA and DHA in the diet. The role of animal-derived foods in the supply of VLC n-3 PUFA has been identified and emphasis has been placed on the need to enrich foods such as poultry meat which are widely consumed in order to make a valuable contribution to the supply of EPA and DHA to those with low or zero oil-rich fish consumption. However the effect of age and gender on intakes remained unclear. The objective of this study was to investigate the effect of age and gender on oil-rich fish consumption.

While meat from ruminants (beef and lamb) has been shown to have high levels of saturated and low levels of polyunsaturated fatty acids (PUFA) (Wood et al 1999), the beneficial properties of beef include the lower n-6:n-3 ratio, particularly under grass-fed systems, relative to pork or poultry and the presence of appreciable quantities of α linolenic acid, eicosapentaenoic and docosapentaenoic acid. The latter have been shown to reduce the incidence of cardio-vascular disease in humans. While feeding whole linseed has been shown to enhance the fatty acid composition of muscle (Scollan et al 2001), whole linseed is subject to significant levels of biohydrogenation in the rumen. Extruded linseed (Valomega) is promoted as increasing conjugated linoleic acid and α linolenic acid in meat through improving the efficiency of fatty acid metabolism in the rumen and intestine. The objective of the current study was to evaluate the effect of level of inclusion of extruded linseed in diets of dairy bulls on fatty acid composition of meat and instrumental meat quality.

Some studies have shown a synergistic effect of supplementing dairy cow diets with a blend of fish and soya oil on the concentration of conjugated linoleic acid (CLA) in milk. This is apparently due to increased accumulation of ruminal and tissue concentrations of vaccenic acid (VA), the main substrate for ∆-9 desaturase catalysed, de novo tissue synthesis of the cis 9, trans 11 isomer of CLA. Furthermore, recent in vitro studies suggest that the dietary ratio of linoleic acid to the omega-3 polyunsaturated fatty acids (ω-3 PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may be an important mediator of this synergism (AbuGhazaleh and Jenkins, 2004). Additionally, dietary supplementation with ω-3 PUFA can shorten the shelf life of meat. The objectives of the current study were to examine level and duration of dietary PUFA supplementation on tissue fatty acid concentrations and on lipid oxidative stability of beef cattle.

Supplementation of cattle diets with a blend of oils rich in omega-3 polyunsaturated fatty acids (ω-3 PUFA) and linoleic acid have a synergistic effect on the accumulation of ruminal and tissue concentrations of vaccenic acid (VA), the main substrate for ∆-9 desaturase catalysed de novo tissue synthesis of the cis 9, trans 11 isomer of conjugated linoleic acid (CLA). This dietary strategy translates into increases in milk concentrations of CLA in dairy cows, however, CLA concentrations in the muscle of beef animals have not always been increased (Kenny et al., 2007). Studies with in-vitro mammary cell lines (Keating et al., 2006) and mice (Ntambi et al., 1999) suggest that ω-3 PUFA may inhibit expression of ∆-9 desaturase. Furthermore, the promoter regions of the bovine ∆-9 desaturase gene have been shown to contain a conserved PUFA response region (Keating et al., 2005) and this has been suggested as a mechanism through which ω-3 PUFA may modulate ∆-9 desaturase expression in bovine muscle. Currently there is no evidence to support this hypothesis. The objective of this study, therefore, was to determine the influence of ω-3 PUFA dietary supplementation on the expression of ∆-9 desaturase gene in bovine muscle.

Compared with conventional indoor rations, consumption of grazed grass by cattle improved the fatty acid profile of beef, by increasing the polyunsaturated fatty acid (PUFA) and conjugated linoleic acid (CLA) concentrations and decreasing the n-6:n-3 PUFA ratio (French et al., 2000). Supplementation of grazing cattle with sunflower oil (S), increased the concentration of CLA in muscle but also increased the n-6: n-3 PUFA ratio (Noci et al., 2006). Supplementation with fishoil (F), a source of long-chain n-3 PUFA might decrease this ratio while enhancing CLA synthesis. However, increasing the concentration of PUFA, particularly the long-chain PUFA, may predispose muscle lipids and pigments to oxidation, with consequent impairment of lipid and colour stability. The objectives were to determine the effect of supplementation of grazing cattle with S and F on (i) tissue n-3 PUFA and CLA concentrations and (ii) the colour and lipid stability of beef.

Nutritional approaches are the most important strategy for altering the fatty acid composition of muscle lipids (Scollan et al., 2006). Grass relative to concentrate feeding increases the content of n-3 polyunsaturated fatty acids (PUFA) resulting in a low n-6:n-3 PUFA ratio. Ruminally protected plant lipids enhance PUFA content very significantly resulting in beneficial P:S and n-6:n-3 ratios (Scollan et al., 2006). This study considered the effects of finishing steers (1) outdoors on grass ± concentrate versus (2) indoors on straw/concentrate ± a protected lipid supplement with one of two levels of vitamin E on the fatty acid composition of the m. longissimus thoracis et lumborum.

Proportions of polyunsaturated fatty acid (PUFA) in ruminant tissues are generally low as dietary PUFA including linoleic acid (LA) and α-linolenic acid (ALA) undergo biohydrogenation to stearic acid in the rumen. Conjugated linoleic acid (CLA) is formed during biohydrogenation as an intermediate metabolite. Feeding PUFA-rich sources can enhance deposition in the tissues of ruminants (Bolte et al, 2002), but the degree of lipid hydrogenation may depend on the source form and the ruminant species (Rowell-Schäffer et al, 2001). Bolte et al, (2002) showed that oilseed-fed sheep had higher PUFA proportions in their tissues than sheep fed a beet pulp-based diet but Rowell-Schäffer et al (2001) found in deer tissues higher PUFA proportions than in those of sheep. Possible effects of the form of the lipid source and the ruminant species on the fatty acids deposited were tested.

The benefits to human health from consuming the very long chain n-3 polyunsaturated fatty acids (VLC n-3 PUFA) 20:5 (EPA) and 22:6 (DHA) are well known. In the human diet, oil-rich fish is a key source of VLC n-3 PUFA but fish consumption is so low that VLC n-3 PUFA intake is well below the minimum recommended. Other vehicles for increasing dietary supply have been explored and chicken meat is a potentially important contributor to human intakes if it is enriched with VLC n-3 PUFA, as it is responsive to dietary manipulation and is widely consumed. Enrichment of chicken meat can be achieved by supplementing the diets of growing birds with fish oil. However, reliance upon fish oil for this purpose is potentially unsustainable and the meat that is produced is more susceptible to constraints associated with its oxidative stability and organoleptic properties. Alternative sources of these fatty acids include marine algae (the primary producers of VLC n-3 PUFA) and fish oil encapsulated in a gelatin capsule. Both of these alternatives may increase the VLC n-3 PUFA content of the meat and also enhance its oxidative stability compared with meat that has been enriched by the inclusion of fish oil in the broiler diet. The objective of this study was to compare different sources of VLC n-3 PUFA in the broiler diet in relation to their effects on EPA and DHA concentration of the white and dark meat of the chicken.

Enriching chicken meat with the very long chain n-3 polyunsaturated fatty acids (VLC n-3 PUFA) 20:5 (EPA) and 22:6 (DHA) is a possible means of increasing the human consumption of these essential fatty acids as current levels of intake of these fatty acids are extremely low. However, a potential drawback of increasing the VLC n-3 PUFA content of chicken meat is that the oxidative stability of the meat is reduced. Chicken meat is enriched with VLC n-3 PUFA by the addition of fish oil to the chickens’ diet. It is possible that using alternative dietary sources of VLC n-3 PUFA may increase the oxidative stability of the meat (Mooney et al., 1998). The objective of this experiment was to determine what the source of VLC n-3 PUFA in broilers’ diets had on the oxidative stability of their edible tissues.

Enriching chicken meat with the very long chain n-3 polyunsaturated fatty acids (VLC n-3 PUFA) 20:5 (EPA) and 22:6 (DHA) is a possible means of increasing the human consumption of these essential fatty acids as current levels of intake of these fatty acids are extremely low. However, a potential drawback of increasing the VLC n-3 PUFA content of chicken meat is that the oxidative stability of the meat is reduced. PUFA are more oxidatively unstable than monounsaturated or saturated fatty acids, and the aldehydes produced by the n-3 PUFA during autoxidation have a lower taste threshold, and are much more unpalatable, than the aldehydes associated with autoxidation of the n-6 series of PUFA. The objective of this study was to determine what relationship there was between the fatty acid profiles of chicken meat that had been enriched (by dietary means) with VLC n-3 PUFA and the volatile aldehydes that were produced by the meat after it had been cooked.

Presently, indigenous pig farming is relatively growing in Thailand, because Thai consumers increasingly prefer the meat of indigenous pigs. Generally, indigenous pigs tend to store more fat in their carcass than pigs of commercial breeds. The nature of the dietary fat source may have an effect on fat deposition processes in indigenous pigs and subsequently on carcass and meat characteristics. For example, alpha-linolenic acid (ALA, C18:3, n-3) is an essential polyunsaturated fatty acid that is more preferentially oxidized in the body than linoleic acid (LA, C18:2, n-6) and other fatty acids. Therefore, the supplementation of ALA in pig diets should have a more beneficial effect on animal performance than LA supplementation. However, some adverse effects, e.g. meat characteristics, might result from a higher level of ALA supplementation as well. Thus, the aim of this study was to specify the effect of dietary supplementation of ALA versus LA on growth performance, carcass and meat characteristics of pigs.