Grassland Management and Animal Product Quality

The expectations of consumers ultimately determine the specification of product quality; and grassland systems produce a wide range of animal-based products. Therefore, to provide focus, this paper deals only with food products that are destined for markets that exhibit strong discretionary choice. Quality expectations of consumers have traditionally been based on product attributes such as taste, freshness, nutritional value and appearance, but customer expectations are expanding to encompass food safety, environmental care, animal welfare and biotechnologies. Grassland forages and their management influence the intrinsic sensory properties of food. A dairy products case study is presented, indicating that pasture species and their interaction with local environmental factors, and the methods of forage conservation, can influence the chemical composition of milk, its ability to be processed into butter or cheese, and the final sensory characteristics of the product. These effects may result directly from compounds originating in the forage (e.g. carotenoids, aromatic terpenes) or indirectly through forage-related changes in animal physiology and enzyme production. Knowledge of these influences and the strict control of the determining factors are key elements in the granting of Protected Denomination of Origin (DMO) status and the benefits that accrue from marketing strategies that depend on this status. Animal feeding regimes also influence the attributes of meat. Pasture-grazed animals have harder and yellower carcass fat than grain-fed animals. The daily energy intake of pasture-grazed animals is also generally lower; therefore there is less intra-muscular marbling. In addition, glycogen levels tend to be more marginal, which can negatively interact with psychological stress to produce a greater incidence of high ultimate pH carcasses. High pH levels (\u3e 5.8) result in reduced tenderness, dark muscle and reduced shelf-life of fresh and chilled meats. Early identification of product quality variation is key to placing meat into the correct supply chain, and maximising the total value of the carcass. The positive and negative aspects of fatty acid profiles, phenol and indole compounds, and antioxidants originating from forages are discussed in respect of meat flavour and animal health. Tight planning and management protocols for both plants and animals are crucial to achieving quality raw material from grassland systems. Unlike feedlot and barn-based enterprises, variation in forage quantity and quality can severely impact on animal performance, timeliness of supply and raw product constituents. Control of a forage-based system requires the setting of performance targets and on-going monitoring. Such measures can signal when the tactical use of specialist forages, or of high-quality supplements, will be of most value in maintaining target performance and animal health. Consistently supplying products with desired attributes, attending to animal welfare expectations and caring for environmental integrity will all be required if the credibility of ‘natural’ grassland products is to be sustained in the market-place. Controlled grazing of animals will be invaluable in meeting these multiple market demands

Zooming into plant-flower visitor networks: an individual trait-based approach

Understanding how ecological communities are structured is a major goal in ecology. Ecological networks representing interaction patterns among species have become a powerful tool to capture the mechanisms underlying plant-animal assemblages. However, these networks largely do not account for inter-individual variability and thus may be limiting our development of a clear mechanistic understanding of community structure. In this study, we develop a new individual-trait based approach to examine the importance of individual plant and pollinator functional size traits (pollinator thorax width and plant nectar holder depth) in mutualistic networks. We performed hierarchical cluster analyses to group interacting individuals into classes, according to their similarity in functional size. We then compared the structure of bee-flower networks where nodes represented either species identity or trait sets. The individual trait-based network was almost twice as nested as its species-based equivalent and it had a more symmetric linkage pattern resulting from of a high degree of size-matching. In conclusion, we show that by constructing individual trait-based networks we can reveal important patterns otherwise difficult to observe in species-based networks and thus improve our understanding of community structure. We therefore recommend using both trait-based and species-based approaches together to develop a clearer understanding of the properties of ecological networks

Vicariance in a generalist fish parasite driven by climate and salinity tolerance of hosts

Acanthocephalans are parasites with complex lifecycles that are important components of aquatic systems and are often model species for parasite-mediated host manipulation. Genetic characterization has recently resurrected Pomphorhynchus tereticollis as a distinct species from Pomphorhynchus laevis, with potential implications for fisheries management and host manipulation research. Morphological and molecular examinations of parasites from 7 English rivers across 9 fish species revealed that P. tereticollis was the only Pomphorhynchus parasite present in Britain, rather than P. laevis as previously recorded. Molecular analyses included two non-overlapping regions of the mitochondrial gene – cytochrome oxidase and generated 62 sequences for the shorter fragment (295 bp) and 74 for the larger fragment (583 bp). These were combined with 61 and 13 sequences respectively, from Genbank. A phylogenetic analysis using the two genetic regions and all the DNA sequences available for P. tereticollis identified two distinct genetic lineages in Britain. One lineage, possibly associated with cold water tolerant fish, potentially spread to the northern parts of Britain from the Baltic region via a northern route across the estuarine area of what is now the North Sea during the last Glaciation. The other lineage, associated with temperate freshwater fish, may have arrived later via the Rhine/Thames fluvial connection during the last glaciation or early Holocene when sea levels were low. These results raise important questions on this generalist parasite and its variously environmentally adapted hosts, and especially in relation to the consequences for parasite vicariance

Reproductive ecology and diet of a persistent Ameiurus melas (Rafinesque, 1820) population in the UK

The black bullhead Ameiurus melas was introduced to Europe from North America in the early 20th Century and invasive populations are now present in many European countries (Novomesk a et al., 2013). Their invasion is assisted by their traits of high reproductive output, parental care, omnivory, aggressive behaviour and tolerance to environmental parameters (e.g. Leunda et al., 2008; Novomesk a et al., 2013). In the UK, however, they are not invasive, with only a single, persistent wild population believed to be present (Britton et al., 2010). The lag phase – the time period between the introduction of a species and an invasion developing – can be considerable for non-native fishes. For many species, its cessation requires a change in environmental conditions and/or the provision of a new dispersal opportunity (Fausch, 2007). The aim of this study was to assess the reproductive ecology and diet of A. melas in UK conditions through assessment of this persistent population. As there was only one population available, the plasticity of their traits in UK conditions could not be assessed; however, the study results are compared with their populations elsewhere. An assessment is then made to identify whether these aspects of their ecology are inhibiting their invasion of UK freshwaters. Note that Novomesk a et al. (2013) recently concluded that morphological plasticity was not a factor affecting their invasive ability and so is not considered here.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1439-04262016-01-31hb201

Volatile compounds in the perirenal fat from calves finished on semiextensive or intensive systems with special emphasis on terpenoids

Grazing ruminants and their production systems have been associated with lower environmental impact and higher animal welfare, along with distinctive meat quality characteristics when compared to intensively reared animals. Recent studies have been aimed at finding compounds in ruminant meat and fat which could be used as tracers of herbage feeding. This study determined and compared the volatile composition of the perirenal fat from Tudanca-breed calves reared on semi-extensive (SE; n=8) or intensive (I; n=8) systems. The volatile compounds of perirenal fat were analyzed using simultaneous distillation-extraction and gas chromatography coupled with mass spectrometry (GC/MS) with the mass spectra detector operating in full scan mode. Terpenes were also determined using solid-phase micro-extraction and GC/MS operating in the selective ion monitoring mode. The SE system resulted in decreased levels of octanal, 2-octenal and 2,4-decadienal, and increased levels of 2,3-octanedione and skatole. The levels of α-pinene, aromadendrene, α-phellandrene, eucalyptol and α-gurjunene were higher for the SE system. Fenchene, eucalyptol and α-gurjunene have not been reported in previous studies on beef volatiles. The study showed the possibility of using several terpenes of perirenal fat as indicators of pasture-feeding in Tudanca calves.<br><br>La producción de rumiantes en pastoreo puede suponer un menor impacto ambiental y un mayor bienestar animal, y considerarse como una característica de calidad diferenciada de la carne generada, con respecto a los animales producidos de forma intensiva. En estudios recientes se ha investigado sobre la presencia de compuestos en la carne o grasa de rumiantes que puedan ser utilizados como marcadores de alimentación a base de pasto. En el presente estudio se ha determinado y comparado la composición volátil de la grasa perirrenal de terneros de raza Tudanca criados mediante un sistema semi-extensivo (SE; n=8) o intensivo (I; n=8). Los compuestos volátiles de grasa perirrenal fueron analizados utilizando un método de extracción-destilación simultánea seguido por cromatografía de gases acoplada a un detector de espectro de masas (CG/EM), operando en modo de barrido completo. Por otra parte, se determinaron de forma específica los terpenoides utilizando la técnica de microextracción en fase solida seguida por CG/EM, operando en modo de barrido selectivo de iones. La grasa del sistema SE mostró menores niveles de octanal, 2-octenal y 2,4-decadienal y mayores niveles de 2,3-octanodiona y escatol que el sistema I. Además, los niveles de α-pineno, aromadendreno, α-felandreno, eucaliptol, α-gurjuneno fueron más altos en el sistema SE. La presencia de fencheno, eucaliptol y α-gurjuneno no ha sido descrita en estudios previos en compuestos volátiles en carne o grasa de bovino. Este estudio muestra la posibilidad de utilizar varios terpenos presentes la grasa perirrenal como indicadores de alimentación en pastoreo en terneros Tudancos