PRRSV-eradication: an option for pig herds in Germany?

The problem of successfully controling PRRS with traditional methods has led to a growing interest in eradication. This review summarizes the current literature on topics of PRRS-eradication, including the relevant routine diagnostic procedures, routes of virus transmission between pig herds (as i.e. pig movement, semen, aerosols, insects, fomites, transport vehicles) and eradication by close&rollover and test&removal, respectively. On the basis of this knowledge and experiences it can be concluded that PRRS eradication in Germany with its intensive pig production and remarkably high pig density in several regions may only be possible through a national eradication program. The lack of potent marker vaccines that reduce the virus spread significantly, combined with the lack of differentiating diagnostic tests for routine laboratory use leads to the recommendation not to launch a national eradication program under the given circumstances. For the future it should be taken into account that the situation after reintroduction of PRRSV in a free region could only be managed by stamping-out which is generally poorly accepted by the majority of pig producers.     

Risk factors for foot-and-mouth disease in Zambia, 1981–2012

The aim of this study was to describe the spatial distribution of foot-and-mouth disease (FMD) outbreaks in Zambia for the period January 1981–December 2012 and to quantify the association between geographical features (proximity to roads, national parks, wetland areas) and the spatial distribution of FMD using a Poisson point process model.     

Estriolum Treatment in the Bitch: A Risk for Uterine Infection?

Purulent vaginal discharge in a bitch in which ovariohysterectomy has been performed is often caused by inflammation of the uterine stump. The inflammation is due to either cystic endometrial hyperplasia (CEH) induced primarily by progesterone from remnant ovarian tissue or exogenous progestagens, or it is due to the presence of unabsorbed suture material. This report describes a 9-year-old Irish setter with hemopurulent vaginal discharge and non-pruritic symmetrical alopecia, which had undergone ovariohysterectomy 3.5 years ago and which had been treated with estriolum daily for the past 2.5 years because of urinary incontinence. Vaginoscopy revealed hemopurulent discharge throughout the vagina and vestibule. Cytological examination of ultrasound-guided fine-needle aspiration biopsies of a large mass in the hypogastricum, which appeared to be the uterine cervical stump, revealed septic purulent inflammation. The concentration of plasma progesterone was low and the concentration of plasma 17-ß oestradiol did not increase after gonadotrophin-releasing hormone administration. No remnant ovarian tissue was found by abdominal ultrasonography, laparotomy, or histological examination of mesovarian pedicles. Laparotomy revealed uterine stump empyema. Histological examination of the surgically removed mass excluded both CEH and unabsorbed suture material as the cause of the stump empyema. Instead, it is hypothesized that the long-term treatment with estriolum was a causative factor. This suggests that bitches treated with estriolum should be examined regularly.     

Risk factors for superficial digital flexor tendinopathy in Thoroughbred racehorses in steeplechase starts in the United Kingdom (2001–2009)

The objective of this study was to identify risk factors for superficial digital flexor (SDF) tendinopathy in Thoroughbred horses in steeplechase races in the United Kingdom. Potential risk factors for SDF tendinopathy were studied between 1st January 2001 and 31st December 2009 using a cohort study design with 648 injuries sustained in 102,894 starts. Potential risk factors were screened using univariable logistic regression prior to multivariable model building.In the final multivariable model, 12 statistically significant risk factors were identified. Variables that increased the odds of SDF tendinopathy included firmer going, increased horse age, and racing in the summer compared to other seasons. Variables that decreased the odds included having a higher official rating and the number of starts in the preceding days.Fewer and different risk factors were identified than in an equivalent model of SDF tendinopathy in hurdle racing, highlighting potential differences between these disciplines. Further collection of training and racecourse information would be beneficial and may help to explain further some of the associations identified in this study. The results will facilitate the development of strategies to improve overall safety of horses in UK steeplechase racing.     

Cultural and Immunological Detection Methods for Salmonella spp. in Animal Feeds – A Review

Food-borne salmonellosis continues to be a major public health concern, and contamination with Salmonella spp. in pre-harvest animal production is considered a primary contributor to this problem. Animal feeds can easily become contaminated during primary production, feed mixing and processing as well as during feeding. Consequently, monitoring and surveillance of feeds and feed ingredients for Salmonella spp. contamination may be useful or necessary in the prevention and control of this organism. Cultural and immunological detection methods for salmonellae have been used or suggested as possible approaches for use in animal feeds. Cultural methods remain advantageous owing to their ability to detect viable bacterial cells, while immunological methods have the capability of detecting nonculturable bacterial cells. Advancements and improvements in both methodologies offer opportunities for eventual routine use of these detection technologies in animal feed assays.     

Usefulness of molecular-based methods for estimating effective population size in livestock assessed using data from the endangered black-coated Asturcón pony

Empirical evidence of the usefulness of different molecular-based methods to estimate the effective population size (N(e)) for conservation purposes in endangered livestock populations is reported. The black-coated Asturcón pony pedigree (1,981 individuals) was available. Additionally, a total of 267 Asturcón individuals born in 1998, 2002, and 2008 were typed for 15 microsatellites. These yearly cohorts (cohort(1998, 2002, 2008)) included almost all individuals kept for reproduction at the end of the corresponding foaling season. The genealogical realized N(e) was estimated for each cohort by using the individual increase in inbreeding. Molecular N(e) was computed by using 1) linkage disequilibrium [N(e)(()(D)())], 2) a temporal method based on F-statistics [N(e)(()(T)())], 3) an unbiased temporal method [N(e)(()(JR)())], and 4) a Bayesian temporal method [N(e)(()(B)())]. Estimates of increased from cohort(1998) (18.8 ± 5.1) to cohort(2008) (24.9 ± 5.2), illustrating the history of the population and its breeding policy of avoiding matings between close relatives. The estimates of N(e)(()(D)()) were highly biased upward, with the maximum N(e)(()(D)()) value obtained for cohort(2002) (137.0). The estimates of N(e)(()(T)()), N(e)(()(JR)()), and N(e)(()(B)()) showed similar performance. However, N(e)(()(JR)()) estimates were very consistent across cohorts, varying from 14.9 to 15.5 after correcting for the effect of overlapping generations. When the drift signal was not strong (pair cohort(1998)-cohort(2002)), estimates of N(e)(()(T)()) and N(e)(()(B)()) were not realistic. Estimates of N(e)(()(B)()) tended to be biased downward (being 9.0 or below for the sampling pairs including cohort(2008)). Results of N(e)(()(D)()) are more likely to be estimates of the effective number of breeders producing the sample, rather than the effective size for a generation. The temporal methods were strongly affected by a weak drift signal, particularly when samplings were not spaced a sufficient number of generations or a sufficient time apart. The use of molecular-based estimates of N(e) is not straightforward, and their use in livestock conservation programs should be carried out with caution. Sampling strategies (including sampling sizes, sampling periods, and the age structure of the sampled individuals) must be carefully planned to ensure that robust estimates of N(e) are obtained.     

On farm observations to increase genetic gain in breeding schemes for village poultry production – A simulation study

To improve genetic gain of breeding programs for village poultry production, breeding schemes with observations obtained in village production systems using individual (VIO) and group recording (VGO) were examined under different levels of genotype-by-environment-interactions (GxE). GxE was modeled by varying the correlation between traits measured in the breeding station and village environments for bodyweight (r_{g_BW}) and egg production (r_{g_EP}). Relative and absolute genetic gains obtained from VIO and VGO were used for comparison between the schemes. Results showed that village observations significantly improved genetic gains compared to the scheme without birds tested in the village. The improvement was only slightly larger with individual observations than with group observations. Higher r_{g_BW} and r_{g_EP} led to lower relative genetic gain, but a higher absolute gain of VIO and VGO. It is recommended to apply a breeding scheme using group recording of village performance when strong GxE in breeding for village poultry is expected.     

Intervertebral disc disease in dogs – Part 1: A new histological grading scheme for classification of intervertebral disc degeneration in dogs

Intervertebral disc (IVD) degeneration is common in dogs and can lead to serious disorders. Current treatments can relieve clinical signs of disease, but do not restore IVD function. The development of regenerative strategies for IVD dysfunction requires detailed knowledge of the pathogenesis of IVD degeneration and its underlying mechanisms. Histological examination of IVDs at different stages of degeneration might provide this knowledge, but as there is currently no histological grading scheme for canine IVD degeneration, the aim of this study, which is the first of a two-part series, was to design and validate an appropriate scheme.Three independent observers evaluated 35 IVDs at different stages of degeneration using the scheme. Glycosaminoglycan contents of the nucleus pulposus and macroscopic grading according to Thompson, which are considered ‘gold standards’ for IVD degeneration, were used to validate the scheme. Reproducibility was assessed by analysing the inter-observer reliability of all individual variables of the grading scheme, using a weighted κ analysis. Significant correlations were found between Thompson grading and total histological score (r = 0.94; P < 0.01) and between glycosaminoglycan content and total histological score (r = ?0.72; P < 0.01). Most individual histological variables showed ‘moderate’ to ‘almost perfect’ inter-observer reliability. The high correlation with the gold standards in combination with the high reproducibility indicates that the proposed histological grading scheme is reliable and objective for classification of IVD degeneration in both chondrodystrophic and non-chondrodystrophic dog breeds.     

Prediction precision for lean meat percentage in Norwegian pig carcasses using ‘Hennessy grading probe 7’: Evaluation of methods emphasized at exploiting additional information from computed tomography

The present study aims at improving the prediction of lean meat percentage (LMP) for pig carcasses based on on-line measurements from the slaughterhouses using the ‘Hennessy Grading Probe 7’ (HGP7) and auxiliary information such as gender and breed. The prediction performance is evaluated using an empirical Bayes method capable of utilizing information from a surrogate variable, that is, LMP from computed tomography. HGP7 measures thicknesses of fat and meat layers. The HGP7 measurements of subcutaneous fat, sirloin height and interior fat layer should be included as predictor variables together with gender. For efficiency at the slaughter-line gender might be omitted. The empirical Bayes method improved prediction precision only marginally compared with the standard ordinary least-squares method when applied to the full set of data. However, simulations show that the empirical Bayes method enables a considerable reduction of the data sample size without appreciable loss of prediction precision.     

A stochastic model accommodating the FAMACHA© system for estimating worm burdens and associated risk factors in sheep naturally infected with Haemonchus contortus

A previously developed multiple regression algorithm was used as the basis of a stochastic model to simulate worm burdens in sheep naturally infected with Haemonchus contortus over five consecutive Haemonchus seasons (November to January/February) on a farm in the summer rainfall region in South Africa, although only one season is discussed. The algorithm associates haemoglobin levels with worm counts in individual animals. Variables were represented by distributions based on FAMACHA(?) scores and body weights of sheep, and Monte Carlo sampling was used to simulate worm burdens. Under conditions of high disease risk, defined as the sampling event during the worm season with the lowest relative mean haemoglobin level for a class of sheep, the model provided a distribution function for mean class H. contortus burdens and the probability of these occurring. A mean H. contortus burden for ewes (n=130 per sample) of approximately 1000 (range 51-28,768) and 2933 (range 78-44,175) for rams (n=120 per sample) was predicted under these conditions. At the beginning of the worm season when the risk of disease was lowest (i.e. when both classes had their highest estimated mean haemoglobin levels), a mean worm burden of 525 (range 39-4910) for ewes and 651 (range 37-17,260) for rams was predicted. Model indications were that despite being selectively drenched according to FAMACHA(?) evaluation, 72% of the ewes would maintain their mean worm burden below an arbitrarily selected threshold of 1000 even when risk of disease was at its highest. In contrast, far fewer rams (27%) remained below this threshold, especially towards the end of the worm season. The model was most sensitive to changes in haemoglobin value, and thus by extrapolation, the haematocrit, which is used as the gold standard for validating the FAMACHA(?) system. The mean class haemoglobin level at which there was a 50% probability of worm burdens being ≤ 1000 worms was 7.05 g/dl in ewes and 7.92 g/dl in rams.     

Improving the accuracy of genomic prediction for meat quality traits using whole genome sequence data in pigsOA

Background Pork quality can directly affect customer purchase tendency and meat quality traits have become valuable in modern pork production. However, genetic improvement has been slow due to high phenotyping costs. In this study, whole genome sequence(WGS) data was used to evaluate the prediction accuracy of genomic best linear unbiased prediction(GBLUP) for meat quality in large-scale crossbred commercial pigs.Results We produced WGS data(18,695,907 SNPs and 2,106,902 INDELs exceed quality co...     

A ten years (2007–2016) retrospective serological survey for <Emphasis Type="Italic">Seneca Valley virus</Emphasis> infection in major pig producing states of Brazil

Seneca Valley virus (SVV) is the etiological agent of vesicular disease in pigs, clinically indistinguishable of classical viral vesicular infections, including foot-and-mouth disease. The first outbreaks of SVV infection in Brazil were reported in 2014. However, it was not known whether the virus was circulating in Brazilian pig herds before this year. This study is a retrospective serological investigation of porcine health status to SVV in Brazil. Serum samples (n = 594) were grouped in before (2007–2013, n = 347) and after (2014–2016, n = 247) SVV outbreaks in Brazil. Twenty-three pig herds were analyzed, of which 19 and 4 were sampled before and after the beginning of SVV outbreaks, respectively. Two herds sampled after 2014 presented animals with SVV-associated clinical manifestations, while the other two housed asymptomatic pigs. Anti-SVV antibodies were evaluated by virus neutralization test. The results demonstrated that pig herds of different Brazilian geographical regions and distinct pig categories were negative to anti-SVV antibodies in sera obtained before 2014. Antibodies to SVV were detected only in serum samples obtained after 2014, particularly in herds with the presence of pigs with SVV-clinical signs. These results present robust serological evidence that the SVV was not present in the major Brazilian pig producing regions prior to 2014.     

Technical note: A novel method for routine genotyping of the G allele of β-casein (CSN2) and T allele of κ-casein (CSN3) in a sheep population using LightCycler

The goal of this work was to develop a protocol for rapid genotyping of A and G variants at the CSN2 locus and genotyping of T and C variants at the CSN3 locus in sheep breeds (Sumava and Valachian) by means of PCR and LightCycler analysis. The LightCycler technique combines rapid and efficient in vitro amplification of DNA in glass capillaries with melting curve analysis based on fluorescence resonance energy transfer for the sensitive detection of point mutation. The A variant had a greater frequency (Sumava, 0.778; Valachian, 0.835) than did variant G (Sumava, 0.222; Valachian, 0.165) in both sheep breeds. The CSN3 locus was found to be monomorphic, with no polymorphism identified in either population.