Influence of regrouping strategy on performance, behaviour and carcass parameters in pigs

One thousand two hundred pigs were weaned at 4 weeks of age and mixed to form groups of ten animals that were balanced for gender. The groups consisted of uniform weight groups (i.e. separate groups of small, medium or large pigs), or mixed weight groups (i.e. groups containing small, medium and large pigs). Half of the groups were retained from weaning until slaughter at 21 weeks of age, and half were regrouped at the start of the finishing period at 10 weeks of age. In this regrouping, uniform weight groups were regrouped to form mixed weight groups, and mixed weight groups were regrouped to form uniform weight groups. In addition, some mixed weight groups were regrouped to form mixed weight groups in order to assess the effect of regrouping at 10 weeks of age on performance and aggressive behaviour.

Effect of target slaughter weight on production efficiency, carcass traits and behaviour of restrictively-fed gilts and intact male finisher pigs

The effect of 3 slaughter weights (85.95 or 105 kg) on performance and carcass traits of 481 pigs in single-gender groups of 13 (18 groups of gilts and 19 groups of intact males) was evaluated. Pigs (39.5 +/- 3.3 kg) were fed a liquid diet 3 times daily in a long trough. The behaviour of pigs slaughtered at 105 kg was recorded at 50, 60 and 70 days after the start of the experiment (5 groups of gilts and 4 groups of intact males). Behaviour (active, inactive, feeding) and posture (standing, lying, dog-sitting) of all pigs was recorded at 5-min intervals for 30 min prior to and 1 h after each feeding event. Slaughtering pigs at 95 kg and 105 kg delayed production by 7 and 16 days, respectively, compared to slaughtering at 85 kg (P0.05). Muscle depth increased with increasing slaughter weight (P

Active immunisation of lambs with a monoclonal antibody against clenbuterol

An experiment was undertaken with 50 Texel x Suffolk-Cheviot lambs (54+/-8.8 days of age) to investigate the effects of active immunisation with a murine monoclonal antibody against clenburerol on growth and carcass characteristics. Animals on treatments 1 and 2 each received 0.1 mg of clenbuterol antibody while animals on treatments 3 and 4 received 0.1 mg of antibody encapsulated within a synthetic polymer. Diethylaminoethyl (DEAE)-dextran was used as the adjuvant in treatments 1 and 3 and saponin in treatments 2 and 4. Control animals were immunised with saponin only. Four immunisations were given at 4-week intervals. Animals were slaughtered 3 weeks after the final immunisation. Each vaccine evoked a similar level of antibody response while the control group showed no titres. Lamb growth rate did not vary significantly between the vaccinated and control groups. Dressing proportion was higher (P

OBSERVATIONS ON THE EFFECTS OF LONG-TERM WITHDRAWAL ON CARCASS COMPOSITION AND RESIDUE CONCENTRATIONS IN CLENBUTEROL-MEDICATED CATTLE

The detection of the illegal use of clenbuterol (CBL) as a growth promoter has relied on detecting residual concentrations of the drug in body fluids or tissues. Analysis of retinal extracts has recently been shown to considerably extend the detection period following withdrawal. The withdrawal periods required to eliminate residues from the liver and retina were investigated by medicating 20 cattle with CBL for 30 days; 6 control animals remained unmedicated. Residual concentrations were monitored throughout this period and for the subsequent 140 days. Concurrent changes in muscle areas and backfat thicknesses were recorded by ultrasound.

High Percentage Inorganic Arsenic Content of Mining Impacted and Nonimpacted Chinese Rice

Two approaches were undertaken to characterize the arsenic (As) content of Chinese rice. First, a national market basket survey (n = 240) was conducted in provincial capitals, sourcing grain from China's premier rice production areas. Second, to reflect rural diets, paddy rice (n = 195) directly from farmers fields were collected from three regions in Hunan, a key rice producing province located in southern China. Two of the sites were within mining and smeltery districts, and the third was devoid of large-scale metal processing industries. Arsenic levels were determined in all the samples while a subset (n = 33) were characterized for As species, using a new simple and rapid extraction method suitable for use with Hamilton PRP-X100 anion exchange columns and HPLC-ICP-MS. The vast majority (85%) of the market rice grains possessed total As levels <150 ng g(-1). The rice collected from mine-impacted regions, however, were found to be highly enriched in As, reaching concentrations of up to 624 ng g(-1). Inorganic As (As(i)) was the predominant species detected in all of the speciated grain, with As(i) levels in some samples exceeding 300 ng g(-1). The As(i) concentration in polished and unpolished Chinese rice was successfully predicted from total As levels. The mean baseline concentrations for As(i) in Chinese market rice based on this survey were estimated to be 96 ng g(-1) while levels in mine-impacted areas were higher with ca. 50% of the rice in one region predicted to fail the national standard.

The distribution of arsenic in the body tissues of wood mice and bank voles

Arsenic is accumulated by free-living small mammals, but there is little information on the resultant concentrations in different tissues other than liver and kidney. Such information is important because the severity of toxicological effects may be related to the amount of arsenic accumulated in specific organs, and the availability of arsenic to predators is, in part, dependent on which tissues accumulate arsenic. The objective of this study was to quantify the arsenic concentrations and the percentage of the total body burden (%TBB) accumulated in different body tissues of free-living small mammals and to determine how these factors varied with severity of habitat contamination. Arsenic concentrations were measured in various tissues of wood mice (Apodemus sylvaticus) and bank voles (Clethrionomys glareolus) from a range of arsenic-contaminated sites in southwest Britain. Arsenic concentrations in the gastrointestinal (GI) tract (including contents), liver, kidneys, spleen, lung, femur, and fur of both species varied significantly between sites and were higher in mice and voles from heavily contaminated areas. Heart and brain arsenic concentrations did not vary with degree of environmental contamination. The GI tract and excised carcass contained roughly equal amounts of arsenic and, in sum, comprised 75-85% of the TBB on uncontaminated sites and 90-99% on contaminated sites. Although the excised carcass contains about half of the TBB, its importance in food-chain transfer of arsenic to predators may depend on the bioavailability of arsenic sequestered in fur. In contrast, the GI tract and its contents, provided that it is consumed, will always be a major transfer pathway for arsenic to predators, regardless of the severity of habitat contamination.

Dressing Plasmons in Particle-in-Cavity Architectures

Placing metallic nanoparticles inside cavities, rather than in dimers, greatly improves their plasmonic response. Such particle-in-cavity (PIC) hybrid architectures are shown to produce extremely strong field enhancement at the particle cavity junctions, arising from the cascaded focusing of large optical cross sections into small gaps. These simply constructed PIC structures produce the strongest field enhancement for coupled nanoparticles, up to 90% stronger than for a dimer. The coupling is found to follow a universal power law with particle surface separation, both for field enhancements and resonant wavelength shifts. Significantly enhanced Raman signals are experimentally observed for molecules adsorbed in such PIC structures, in quantitive agreement with theoretical calculations. PIC architectures may have important implications in many applications, such as reliable single molecule sensing and light harvesting in plasmonic photovoltaic devices.

Effects of scalding and dehairing of pig carcasses at abattoirs on the visibility of welfare-related lesions

There is increasing interest in developing abattoir-based welfare measures for pigs.The primary aim of this study was to determine the most appropriate place on theslaughter line to conduct assessments of welfare-related lesions, namely apparentaggression-related skin lesions (hereafter referred to as 'skin lesions'), loin bruising andapparent tail biting damage. The study also lent itself to an assessment of theprevalence of these lesions, and the extent to which they were linked with productionparameters. Finishing pigs processed at two abattoirs on the Island of Ireland (n =1950 in abattoir A, and n = 1939 in abattoir B) were used. Data were collected over 6days in each abattoir in July 2014. Lesion scoring took place at two points on theslaughter line: (1) at exsanguination (Slaughter Stage 1 [SS1]), and (2) followingscalding and dehairing of carcasses (Slaughter Stage 2 [SS2]). At both points, eachcarcass was assigned a skin and tail lesion score ranging from 0 (lesion absent) to 3 or4 (severe lesions), respectively. Loin bruising was recorded as present or absent.Differences in the percentage of pigs with observable lesions of each type werecompared between SS1 and SS2 using McNemar/McNemar-Bowker tests. Theassociations between each lesion type, and both cold carcass weight andcondemnations, were examined at batch level using Pearson's correlations. Batch wasdefined as the group of animals with a particular farm identification code on a givenday. The overall percentage of pigs with a visible skin lesion (i.e. score > 0) decreasedbetween SS1 and SS2 (P<0.001). However, the percentage of pigs with a severe skinlesion increased numerically from SS1 to SS2. The percentage of pigs with a visible taillesion and with loin bruising also increased between SS1 and SS2 (P<0.001). Therewas a positive correlation between the percentage of carcasses that were partiallycondemned, and the percentage of pigs with skin lesions, tail lesions and loin bruising(P<0.05). Additionally, as the batch-level frequency of each lesion type increased,average cold carcass weight decreased (P<0.001). These findings suggest that severeskin lesions, tail lesions and loin bruising are more visible on pig carcasses after theyhave been scalded and dehaired, and that this is when abattoir-based lesion scoringshould take place. The high prevalence of all three lesion types, and the links witheconomically important production parameters, suggests more research into identifying key risk factors is warranted.