Periodontal disease in feral pigs (Sus scrofa) from Queensland, Australia

Periodontal lesions were present in 26 of 107 feral pigs (Sus scrofa) that were shot in southern Queensland. The severity of the lesions varied from gingivitis to extensive destruction of the alveolus and its contents. Examination of slaughtered domestic pigs revealed a similar prevalence of lesions (12 of 52). Only cheek teeth were affected, and molars were affected more frequently than premolars. In both feral and domestic pigs, prevalence of periodontal disease affecting bone increased with age. Although periodontal disease is recognized as a common and often serious problem in many mammalian species, both domestic and wild, it has rarely been recorded in the pig. It is considered that the most severe lesions would have interfered with mastication but that the contribution of the disease to mortality of feral pigs in Australia is probably not great.     

Characterization of a polymorphic IGLV gene in pigs (Sus scrofa)

Swine, unlike other artiodactyls, but similar to humans, utilize both lambda and kappa light chain isotypes almost equally in the generation of their antibody repertoire. The porcine antibody light chain loci have previously been characterized in a single Duroc sow in which was seen extensive allelic variation between light chain genes on homologous chromosomes. However, the extent of variation between individuals is completely unknown. Using deep sequencing of cDNA-derived amplicons from five pigs, we report the identification and characterization of an IGLV gene that is functional and highly expressed in some animals, yet completely absent in others. Our findings provide a possible rationale for the known individual-to-individual variation in antibody responses to vaccination, infectious challenge, and subsequent disease outcome.     

人与野猪冲突:现状、影响因素及管理建议

人与野猪冲突日趋严重,成为人们日益关注的问题.本文回顾了人与野猪冲突的类型、程度,分析了引发人与野猪冲突的原因和影响野猪危害的因素;综述了目前缓解人与野猪冲突的措施及其效果.在此基础上,总结了冲突管理中普遍存在的看法和问题,并针对人与野猪冲突管理中存在的一些问题,提出了相应的建议.     

Detection of hybrids between wild boars (Sus scrofa scrofa) and domestic pigs (Sus scrofa f. domestica) in Greece,using the PCR-RFLP method on melanocortin-1 receptor (MC1R) mutations

The melanocortin-1 receptor (MC1R) regulates melanogenesis in mammals within the mammalian melanocyte and the hair follicle. Common variations (polymorphisms) in the MC1R gene are associated with normal differences in skin and hair colour. So far, a unique MC1R allele (E+) has been identified in European wild boar (Sus scrofa scrofa), associated with the wild-type coat colour (variable shades of brown) that is not found in any of the domestic breeds. In addition, a series of alleles found in pigs, some of which observed only in particular breeds, have been proposed as markers in breed traceability systems. The current study is an attempt to detect possible hybrids between wild boars and domestic pig breeds as well as to identify races of pig that are not purebred. For this purpose, wild boars were analysed against Large White pigs, applying the PCR-restriction fragment length polymorphism (RFLP) method. A high percentage (16.7%) of hybrids was detected within a breeding station compared with the percentage of hybrids within the populations of free-ranging wild boar (5.0%). These results should be taken into consideration for future restocking operations to avoid the chance of outbreeding depression, which is more intense when local populations are introgressed by gene pools from domesticated, usually inbred, animals.     

Estimating body mass of wild pigs (Sus scrofa) using body morphometrics

Wild pigs (Sus scrofa) are invading many areas globally and impacting biodiversity and economies in their non‐native range. Thus, wild pigs are often targeted for eradication efforts. Age‐ and sex‐specific body measurements are important for informing these eradication efforts because they reflect body condition, resource availability, and fecundity, which are common indicators of population trajectory. However, body mass is often difficult to collect, especially on large individuals that require specialized equipment or multiple people to weigh. Measurements that can be rapidly taken by a single land or wildlife manager on any size wild pig without aid from specialized equipment would be beneficial if they accurately infer wild pig body mass. Our goals were to assess whether morphometric measurements could accurately predict wild pig body mass, and to provide tools to directly input these measures and estimate wild pig body mass. Using linear models, we quantified the relationship between body mass and morphometric measurements (i.e., body length, chest girth, ear length, eye to snout length, hindfoot length, shoulder length, and tail length) from a subset (n = 102) of wild pigs culled at the Mississippi Alluvial Valley, Mississippi, USA. We evaluated separate models for each individual morphometric measurement. We then used the model coefficients to develop equations to predict wild pig body mass. We validated these equations predicting body mass of 1592 individuals collected across eight areas in Australia, Guam, and the USA for cross‐validation. Each developed equation remained accurate when cross‐validated across regions. Body length, chest girth, and shoulder length were the morphometrics that best predicted wild pig body mass. Our analyses indicated it is possible to use the presented equations to infer wild pig body mass from simple metrics.     

Intrinsic rate of spermatogenesis in free-ranging feral pigs (Sus scrofa sp)

The aim of this research was to evaluate the intrinsic rate of spermatogenesis in adult free-ranging feral pigs. Twelve adult male free-ranging feral pigs were captured, sedated, and orchidectomized, and then were released and observed to complete recovery and return to their natural environment. Fragments of the testes were embedded in plastic resin and used to prepare slides for histometric analysis. Characteristics investigated included cell populations in the seminiferous epithelium in stage 1 of the cycle of the seminiferous epithelium, intrinsic rate of spermatogenesis and Sertoli cell index. The efficiency coefficient of spermatogonial mitosis was 7.59, the meiotic index was 3.03, the overall yield of spermatogenesis was 23.97 and the cell loss ratio during the meiotic prophase was 1.04. Each Sertoli cell supported an average of 0.92 type A spermatogonia, 7.01 primary spermatocytes in preleptotene/leptotene, 7.30 primary spermatocytes in pachytene and 22.16 round spermatids. In conclusion, the results of the present study indicate that the supporting capacity of Sertoli cells in free-ranging feral pigs is among the greatest values reported for most domestic animals, and the overall yield of spermatogenesis is comparable to that reported in wild boars.     

Sarcocystis miescheriana infection in domestic pigs (Sus scrofa) in the Philippines

Sarcocystis miescheriana sarcocysts were identified in skeletal muscles of 9 (27%) of 33 swine slaughtered for human consumption. Sarcocysts were 144-180 microm x 20-38 microm in size. Ultrastructurally, the cyst wall resembled the type 10 sarcocyst wall. The villar protrusions (VP) were 3-4.5 microm long and 0.6-1.2 microm wide and had prominent longitudinally arranged microtubules extending from the VP tips to the granular layer (=ground substance). The parasitophorous vacuolar membrane with its underlying electron-dense layer (EDL) measured 25 nm in thickness. The base of the VP exhibited minute (0.42-0.87 microm) bulblike inpocketings. Each VP had 80-90 microtubules situated underneath the EDL. The granular layer was 0.5-1.2 microm thick, and contained hairlike microtubules continuous with those of the VP core. This is the first report of S. miescheriana in Philippine domestic pigs Sus scrofa.     

Cryptosporidium suis n. sp. (Apicomplexa: Cryptosporidiidae) in pigs (Sus scrofa)

Molecular and biological characteristics of a new species of Cryptosporidium from the feces of pigs (Sus scrofa) is described. Oocysts are structurally indistinguishable from those of Cryptosporidium parvum; they are passed fully sporulated, lack sporocysts, and measure 4.9-4.4 microm (mean = 4.6 microm) x 4.0-4.3 microm (mean = 4.2 microm); length to width ratio 1.1 (n = 50). Cryptosporidium suis is not transmissible to nude mice and is poorly infectious for cattle. Molecular and phylogenetic analyses at the 18S ribosomal RNA, heat shock protein 70, and actin gene loci demonstrate C. suis to be genetically distinct from all known species and genotypes of Cryptosporidium, and thus is named as Cryptosporidium suis.     

Genetic diversity in wild (Sus scrofa scrofa) and domestic (Sus scrofa domestica) pigs and their hybrids based on polymorphism of a fragment of the D-loop region in the mitochondrial DNA

We examined the variation in mitochondrial DNA by sequencing the D-loop region in wild and domestic (large-white breed) pigs, in hybrids between domestic and wild pigs, and in Monteiro pigs. A D-loop fragment of approximately 330 bp was amplified by PCR. Sequencing of DNA amplicons identified haplotypes previously described as European and Asian types. Monteiro pigs and wild pigs had European haplotypes and domestic pigs had both European and Asian haplotypes.     

The impact of chronic environmental stressors on growing pigs, Sus scrofa (Part 2): social behaviour

The effects of common and concurrent environmental stressors on the social behaviour of farm animals are poorly understood. Here, we report the results of a multifactorial experiment designed specifically to examine the individual, additive or interactive effects of elevated ammonia, noise and low light (LL) levels on the social behaviour of growing pigs. Social behaviour was measured in terms of the nature, frequency and duration of both initiated and response behaviours for 4 weeks following mixing of the groups. General activity patterns, group cohesion and social discrimination were also examined as a function of the environmental treatments. Elevated concentrations of atmospheric ammonia (～20 v. <5 ppm) and LL intensity (～40 v. 200 lux) had the most pronounced effects, particularly on the nature of social interactions, with pigs under these conditions showing more aggression in the early stages of the experiment. In addition, pigs exposed to a high level of mechanical noise representative of artificial ventilation (～80 v. 40 dB [A]) were less submissive to aggressive acts, while pigs in ～20 ppm ammonia showed more reciprocated aggression when in coincident LL (<40 lux). The results indicate that atmospheric ammonia at commonly experienced concentrations may undermine social stability, particularly in the presence of low lighting, though the mechanisms are currently unknown. These findings have implications for the welfare of growing pigs and hence policy makers and farmers alike, with respect to the improvement of welfare in intensive pig farming.     

Comparative cytogenetic studies in Sus verrucosus,Sus celebensis and Sus scrofa vittatus (Suidae,Mammalia)

Chromosome studies on the Javan warty pig (Sus verrucosus), the Sulawesi warty pig (S. celebensis) and a subspecies of the wild boar, S. scrofa vittatus, have revealed diploid chromosome numbers of 38. The morphology and C-band size of chromosome 10 are different in S. verrucosus and the two other species. Both S. verrucosus and S. celebensis have a Y chromosome that is larger than the Y chromosome of domestic and wild S. scrofa, and is submetacentric rather than metacentric. There are differences between all three species in the G-banding pattern of the long arm of the Y chromosome. The presence of 2n=38 chromosomes in the Javan warty pig and the Sulawesi warty pig provides new strong evidence that the basic chromosome number in the genus Sus is 38. The differences in karyotype between these pigs (chromosome 10 and the Y chromosome) confirm that they are separate species.     

Wild pigs (Sus scrofa) mediate large-scale edge effects in a lowland tropical rainforest in Peninsular Malaysia

Edge-effects greatly extend the area of tropical forests degraded through human activities. At Pasoh, Peninsular Malaysia, it has been suggested that soil disturbance by highly abundant wild pigs (Sus scrofa), which feed in adjacent Oil Palm plantations, may have mediated the invasion of Clidemia hirta (Melastomataceae) into the diverse tropical lowland rain forest. To investigate this hypothesis, we established three 1 km transects from the forest/Oil Palm plantation boundary into the forest interior. We recorded the distribution of soil disturbance by wild pigs, C. hirta abundance, and environmental variables. These data were analyzed using a hierarchical Bayesian model that incorporated spatial auto-correlation in the environmental variables. As predicted, soil disturbance by wild pigs declined with distance from forest edge and C. hirta abundance was correlated with the level of soil disturbance. Importantly there was no effect of distance on C. hirta abundance, after controlling for the effect of soil disturbance. Clidemia hirta abundance was also correlated with the presence of canopy openings, but there was no significant association between the occurrence of canopy openings and distance from the edge. Increased levels of soil disturbance and C. hirta abundance were still detectable approximately 1 km from the edge, demonstrating the potential for exceptionally large-scale animal mediated edge effects.     

The contribution of social effects to heritable variation in finishing traits of domestic pigs (Sus scrofa)

Social interactions among individuals are ubiquitous both in animals and in plants, and in natural as well as domestic populations. These interactions affect both the direction and the magnitude of responses to selection and are a key factor in evolutionary success of species and in the design of breeding schemes in agriculture. At present, however, very little is known of the contribution of social effects to heritable variance in trait values. Here we present estimates of the direct and social genetic variance in growth rate, feed intake, back fat thickness, and muscle depth in a population of 14,032 domestic pigs with known pedigree. Results show that social effects contribute the vast majority of heritable variance in growth rate and feed intake in this population. Total heritable variance expressed relative to phenotypic variance was 71% for growth rate and 70% for feed intake. These values clearly exceed the usual range of heritability for those traits. Back fat thickness and muscle depth showed no heritable variance due to social effects. Our results suggest that genetic improvement in agriculture can be substantially advanced by redirecting breeding schemes, so as to capture heritable variance due to social effects.     

The feral pig (Sus scrofa,Suidae) in Cocos Island,Costa Rica: Rootings,soil alterations and erosion

Feral pigs (Sus scrofa) are of the most damaging exotic vertebrates, specially on oceanic island native communities. Feral pigs inhabit Cocos Island since 1793 and there are around 400-500 individuals. In order to quantify the impacts of the feral pigs at Cocos Island. I calculated the effect of the rooting activity and its influence on the natural erosion. During one year I walked, monthly, 15 km on trails estimating rooted area by transect and rooting recurrence. During eight months I compared erosion rates with and without rootings. I estimated the annual rooting rate between 10 and 20% of the total island surface. The rooted area was the only measured variable which correlated with the soil erosion rate. The erosion rate without rootings was 23.6 kg/ha/year and with rootings was 200.4 kg/ha/year (P < 0.01). The disturbances provoked by the rootings were not scattered homogeneously through the island. The rootings, together with the natural landslides, dominate the soil disturbance pattern at Cocos Island. This study suggests that the presence of feral pigs produces more erosion than the one that would naturally occur without feral pigs at Cocos Island.     

The foraging ball as a quick and easy enrichment device for pigs (Sus scrofa)

Providing research pigs with enrichment objects can encourage species-typical behavior such as rooting and foraging. The authors gave pigs hard plastic 'foraging balls' that resembled enrichment devices commonly used for nonhuman primates. Holes were custom-drilled into the balls, and animal caretakers filled them with palatable food items such as jellybeans, unsalted peanuts, cereal, Beggin' Strips, primate biscuits and dog biscuits. Staff members suspended the balls from chains in pigs' enclosures, ensuring that toys did not touch the floor. All pigs manipulated the balls and were able to obtain treats that were supplemental to their standard diet. The simple and effective enrichment device was easily incorporated into the daily routines of research facilities, with little disruption to schedules.     

Reproduction in a population of wild pigs (Sus scrofa) subjected to lethal control

The continued range expansion of wild pigs (Sus scrofa) in North America is an increasing cause for concern because of the numerous negative impacts that wild pigs have on ecosystem structure and function. Once populations are established, wild pigs have proven to be extremely difficult to control, and close to impossible to eradicate. If effective control and removal techniques are to be developed, we must determine if wild pig populations respond to reductions in density by increasing reproductive output. This study was designed to examine if reproductive parameters of female wild pigs display a density-dependent response following a concentrated removal effort. We compared reproductive parameters and condition of adult sows that were collected between a control area and a treatment area where lethal removal occurred. From August 2004 to May 2006, we focused a concentrated removal effort within the treatment area. Although the population density was more than 65% greater in the control area than the treatment area during the study, we did not detect differences between areas for condition, litter size, ovarian mass, corpus luteum mass, or corpora lutea number. Several years of heavy mast production during the study may have negated any effect on condition and subsequent reproduction between the 2 study areas. These data suggest that reproductive parameters of wild pigs do not exhibit density-dependence during periods when pig populations are in good condition. © 2012 The Wildlife Society.