New Applications for Health and Innovation in Veterinary Medicine

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Throughout the history of livestock production, infectious diseases have been a problem. One of the greatest impediments to the economics of livestock production today is the loss due to infectious disease. In addition to the current endemic diseases that plague livestock production, the emergence of new diseases or re-emergence of diseases to which populations are totally susceptible is especially worrisome. In the last 30 years, there have been approximately 30 newly emerged or re-emerged diseases, many of which can infect multiple species. There is clearly a need for novel, more effective control and treatment methods to ensure the viability of the livestock industry. Currently, the 3 available methods to control infectious disease include antimicrobials, vaccines, and immunomodulators. Recent advantages in our understanding of the interactions between disease causing organisms and the host, combined with techniques to identify protective antigens are providing novel approaches to developing more effective vaccines. Furthermore, by combining methods to stimulate the host’s own defences (innate immune responses), we can induce early protection from a broad-spectrum of infections, in the case of accidental introduction of a disease. These approaches should reduce animal suffering and add significant economic benefits to the producers, as well as improve food safety for the consumer

Silencing of natural interferon producing cell activation by porcine circovirus type 2 DNA

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Porcine circovirus type 2 (PCV2) infection of natural interferon producing
cells (NIPCs) impairs the induction of interferon (IFN)-a and
tumour necrosis factor (TNF)-a by cytosine-phosphorothioate-guanine
(CpG) oligodeoxynucleotides (ODNs), thereby preventing both their autocrine
maturation and the paracrine maturation of myeloid dendritic cells
(DCs). The present study shows that the PCV2-mediated inhibition of
NIPCs was mediated by viral DNA, although it was independent of virus
replication. The inhibitory effect of PCV2 DNA was more diversified than
if it had simply targeted CpG-ODN-induced cytokines (IFN-a, TNF-a,
interleukin-6, IL-12). A broad spectrum inhibition was noted, affecting
responses induced by toll-like receptor (TLR)-7 and TLR9 agonists, as
well as viruses including pseudorabies virus, transmissible gastroenteritis
virus and classical swine fever virus. From these results, it would appear
that PCV2 DNA can induce a dominant negative signal influencing independent
pattern recognition receptor-induced activation cascades. Despite
a concomitant internalization of PCV2 DNA and CpG-ODNs, no colocalization
was observed, indicating that PCV2 DNA and CPG-ODNs may not
target the same receptor. This study describes a novel modulation of the
innate immune response, which would render the host more susceptible
to secondary or concomitant microbial infections.

Comparison of scratching behaviour of growing pigs with sarcoptic mange before and after treatment, employing two distinct approaches

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Sarcoptic mange in pig breeding and finishing farms is a major economic problem. The economic losses by mange are caused by the costs of treatment and damage to piggery fixtures through permanent rubbing, reduced feed conversion efficiency, increased return rates, and piglet mortalities (Davies, 1995). Horst (2004) estimated that the loss due to reduced feed conversion efficacy and increased piglet mortalities at €66 per mangy sow and year. Kirchner (1998) reported a mortality of 11.5% in piglet as a consequence of frequent unrest (pruritus) in untreated mangy sows, in contrast to 3.7% in treated sows. Damriyasa et al. (2004) examined 11 breeding farms with a total of 2754 sows and estimated the mean economic loss due to Sarcoptes scabiei infestation at €4200 per affected farm and year. Based on these economic losses and the animal welfare issues, there is a need to eradicate and prevent sarcoptic mange and to establish mange-free pig farms. To achieve a mange-free status and certification a reliable management and control program, and sensitive and specific diagnostic methods are required as complementary tools. The enzyme-linked immunosorbent assay (ELISA), skin scraping, clinical score, papular dermatitis score and scratching index are tools with differing specificities and sensitivities. Of these, the scratching index using different limiting values is often used and has been recommended by various authors as an additional method for the diagnosis of sarcoptic mange. The aim of the present study was to observe the scratching behaviour of growing pigs suffering from sarcoptic mange in a closed herd before and after treatment, to calculate scratching indices using different methods and to critically evaluate the results obtained employing recommended limiting values. In a closed pig breeding and finishing herd suffering from sarcoptic mange, two selected groups of pigs were filmed during a period of 10 days before and after treatment. The observation always commenced each hour and lasted for 15 min. Before treatment, observations was done round the clock, after treatment from 8:00 to 22:15. Before treatment the pens were stocked with 11 (pen A) and 10 (pen B) growing pigs (Large White x Landrace sows; 5 months old) with an average weight of ~70 kg examined for sarcoptic mange by skin scrapings and ELISA. The animals had never been treated with an acaricide or endectocide before. After 10 days, the pigs were treated twice (18 days interval) with Dectomax® 1% solution for pigs (Pfizer, Austria) at a dose of 0.3 mg Doramectin i.m./kg body weight. After treatment, seven pigs were observed in both pens. Most scratching actions both before (83.1%) and after (94.5%) treatment were of one to 10s. After treatment, the 10s scratching episodes decreased by 67.3% (from 21.2 to 6.9 mean SRE/pig), and the scratching actions of longer than 10s by 91.7% (from 4.3 to 0.4 mean SRE/pig), such that the latter could be observed only occasionally after treatment. A distinct increase in scratching activity both before and after treatment could be observed primarily between 10:00 and 15:00. Significant differences of scratching and rubbing activity between before and after treatment could also be seen at midday. Depending on the methods used and the limiting values set, 6.7–34.6% of the observations before and 2.0–17.3% of the observations after treatment revealed a ‘‘strong evidence of mange’’ or a ‘‘suspicion of mange’’. All other observations indicated that the pigs were free from mange.

CpG oligodinucleotides induce strong humoral and cellular responses to swine streptococcic septicemia vaccine in piglets in vivo

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An investigation into the effect of floor colour on the behaviour of the horse

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Hesitation and alarm reactions of horses to visual features on the ground can be problematic in training and management. The reaction of riding horses to eight different coloured mats presented either on the ground or on the wall in an alleyway was recorded in order to assess the effect of the visual feature, colour, on horse behaviour. Horses had to walk over mats on the ground and walk past mats on the wall. Each colour and position combination was presented two times so that the effect of previous experience could be examined. The time taken to walk through the alleyway and the horses’ reactions to the colour were both related to the position of the colour and whether the horse had previous experience with that colour/position combination. The highest percentage of adverse reactions was observed during the initial presentation of colours on the ground. The colours yellow, white, black and blue, when encountered for the first time on the ground, caused more adverse reactions and an increase in time taken to walk through the alleyway than the colours green, red, brown and grey. During the second presentation of coloured mats on the ground, behavioural differences in response to colour were observed, but no difference in the time taken to walk through the alleyway was noted. No effects of colour were found when the mats were presented against the wall. The results of this study indicate that the colour of flooring can be controlled in order to minimize adverse behavioural reactions of horses, particularly during initial training.

Porcine Reproductive and Respiratory Syndrome Virus (PRRSV): A Ring Test Performed in Germany to Assess RT-PCR Detection Methods

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Porcine reproductive and respiratory syndrome virus (PRRSV) is a major pathogen of swine. Due to genetic variation between the European and the US genotype as well as within both genotypes detection of PRRSV is a diagnostic challenge. This paper reports on a ring test to compare different
established reverse transcriptase polymerase chain reaction methods applied routinely in 16 different laboratories in Germany. Three different sets of samples were sent to the laboratories which were to be analysed as follows: (i) basis package: detection of PRRS (yes/no); (ii) differentiation
package I: differentiation of EU and US genotypes; and (iii) differentiation package II: differentiation of EU field isolates and EU vaccine strain. A total of 80% of the samples of the
basic package were analysed correctly, the analysis of the differentiation package I revealed 61.82% correctly tested samples and the two laboratories that analysed the differentiation package II showed only one correct result. The ring test showed that the majority of incorrect diagnoses were falsenegative results.

Influence of different types of environmental enrichment on the behaviour of finishing pigs in two different housing systems 1. Hanging toy versus rootable substrate

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Studies have suggested that environmental enrichment can improve the welfare of growing pigs through the provision of substrates for exploratory and manipulatory behaviour (Beattie et al., 2000; Petersen et al., 1995; Arey, 1993). EU Directive 2001/93/ EU states that pigs must have permanent access to materials such as straw, hay, wood, sawdust, mushroom compost and peat to enable proper investigation and manipulation. This extends the previous Directive 91/630/EEC which stated that: ‘‘ . . .all pigs . . .shall have access to straw or other material or object suitable to satisfy those [behavioural] needs’’. However, the suitability of different forms of enrichment is still the subject of debate. Straw can offer advantages for animal welfare due to its use as a recreational stimulus, a nutritional substrate and as bedding (Fraser et al., 1991). In barren rearing environments, the highly motivated oral activities of rooting and chewing tend to become re-directed towards penmates (e.g. Lyons et al., 1995;Kelly et al., 2000) and pen hardware (e.g. Lyons et al., 1995; Guy et al., 2002). Despite this, a recent review of housing systems in current use within the EU shows that the majority of finishing pigs are kept in buildings with slatted floors (Hendriks et al., 1998), with no access to straw for either bedding or occupation. The use of rooting materials, such as straw, in slatted systems can cause difficulties for slurry management and it is therefore important to establish whether alternative forms of environmental enrichment, such as hanging objects, can be equally effective. This study aimed to assess the effects of environmental enrichment with either hanging manipulable toys or rootable substrates on the behaviour of finishing pigs in two contrasting housing systems. Thousand one hundred and twenty four (Large White x Landrace) x Large White pigs were housed contemporarily in either a straw-based (ST) or fully slatted (FS) building from 35 kg to slaughter at 104 kg liveweight. In each building, half the pens received additional enrichment in the form of a hanging plastic toy (Bite-Rite). In the ST house only the straw bedding enriched the remaining pens. The remaining pens in the FS house were provided with hoppers containing shreds of unmolassed sugar beet pulp. The level of Bite-Rite manipulation was significantly higher in the FS system than in the ST system (P < 0.05). Within the FS system, the sugar beet pulp occupied the pigs for more time than the Bite-Rite object (P < 0.05). Neither object provided a level of occupation close to that of straw bedding in the ST system. In the absence of straw, more investigatory behaviours were directed towards pen components (P < 0.001); however, no significant differences in pig-directed behaviours were observed. Further study is required to identify functional forms of environmental enrichment for pigs in unbedded systems.

Immunopathological effects of porcine circovirus type 2 (PCV2) on swine alveolar macrophages by in vitro inoculation

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A note on the preference of naïve horses for different water bowls.

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The objective of this study was to determine the preference of naïve horses for different types of water bowls. Four different bowls were tested: two float valve and two push valve models were tested. Water consumption was measured in two groups of horses (n=8 and n=11) and three individual horses. The push valve water bowls were hardly used. There appeared to be a slight preference for one model of the float valve over the other when the horses came to drink as a group. This difference was significant when individual horses were studied. The preferred float valve bowl had a larger, more open bowl, which could hold a greater volume of water that remained in the bowl due to the float valve. Therefore, there was not a tendency for frequent refilling of the bowl, which could startle the horses, and could have led to less preference for the other types of water bowls.

Welfare Index and Reproductive Performance in the Sow

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Actions promoting production animal welfare are often seen as investments without reward. By definition, high welfare is characterized by low levels of stress (Broom and Johnson 1993). As stress is shown to have adverse effects on reproduction (Dobson and Smith 2000), a low level of welfare may be suspected to have similar output. Many effects of management on pig reproduction are basically understood. These factors influence the wellbeing of animals, and when combined they can be used to assess welfare. There are probably no studies published on effects of animal welfare on productivity, if welfare is considered a state comprised of several contributing factors as housing, stockmanship etc. Poor health or productivity in animals can be used as an indicator of poor welfare. Good health and especially productivity can, however, not be taken as conclusive evidence of good welfare (Scientific Veterinary Committee
1997). Detrimental effects on reproductive performance are to be expected only when welfare is considerably compromised, because coping systems of animals have evolved to minimize effects of stress on reproduction (Dobson and Smith 2000). The Scientific Veterinary Committee states that ‘If there are differences between systems, even a small effect on reproduction may indicate considerable welfare problems’ (Scientific Veterinary Committee 1997). The Animal Needs Index TGI 35L (Tiergerechtheitsindex) is a scoring method developed to certify the level of pig, cattle and lying hen welfare on farms (Bartussek 1999). Points are assigned to easily identifiable attributes of the housing system. Management, health and behaviour parameters are noticed superficially. Based on knowledge of the needs of the animals more points are given for favourable circumstances. All points are summed for a final score that judges the prerequisites for animal welfare. The assessment of welfare by TGI 35L is classified as indirect, because most aspects are environment-based (Johnsen et al. 2001). Objectives of the study were to investigate the relationship between different parameters describing on-farm sow welfare and reproductive performance. Welfare was assessed using a modified TGI 35L–Animal Needs Index. The modified index had a maximal total score of 100. It was comprised of six categories: ‘locomotion’ (maximal score 21 for dry sows and 11 for lactating sows), ‘social interaction’ (12/8), ‘floor quality’ (16/9), ‘stable climate’ (16/21), ‘feeding’ (16/23) and ‘health and stockmanship’ (19/29). Index scorings were performed separately in farrowing, breeding and gestation units on 28 representative Finnish sow farms. One-year production parameters were collected. Multiple linear regression was used for statistical analysis. Total ANI-points varied between 36.5–68.0 for lactating and 39.5–86.0 for dry sows. Litter size increased with increasing scores for ‘feeding’ in the dry sow unit. Controlling for breed, high scores for ‘health and stockmanship’ and ‘floor quality’ shortened the reproductive cycle, probably because of good leg health. The number of weaned piglets per sow per year (PSY) increased with increasing scores for dry sow ‘health and stockmanship’, ‘floor quality’ and an interaction of ‘feeding’ in the farrowing and mating units. PSY increased with decreasing scores for farrowing pen ‘climate’. It was concluded that high-quality floors and stockmanship appear to correlate positively with reproductive performance in the sow; however, the effects of a welfare-promoting feeding strategy on reproduction are contradictory.