Responses in carcass lean pH at 24 hours post-mortem in lines of Large White pigs selected for growth rate on a fixed ration over a set time

A restricted maximum likelihood analysis applied to an animal model showed no significant differences (P > 0.05) in pH value of the longissimus dorsi measured at 24 h post-mortem (pH24) between high and low lines of Large White pigs selected over 4 years for post-weaning growth rate on restricted feeding. Genetic and phenotypic correlations between pH24 and production and carcass traits were estimated using all performance testing records combined with the pH24 measurements (5.05-7.02) on slaughtered animals. The estimate of heritability for pH24 was moderate (0.29 ± 0.18). Genetic correlations between pH24 and production or carcass composition traits, except for ultrasonic backfat (UBF), were not significantly different from zero. UBF had a moderate, positive genetic correlation with pH24 (0.24 ± 0.33). These estimates of genetic correlations affirmed that selection for increased growth rate on restricted feeding is likely to result in limited changes in pH24 and pork quality since the selection does not put a high emphasis on reduced fatness.

Migration of feral pigs (Sus scrofa) in rainforests of north Queensland: fact or fiction?

The Wet Tropics bioregion of north Queensland has been identified as an area of global significance. The world-heritage-listed rainforests have been invaded by feral pigs (Sus scrofa) that are perceived to cause substantial environmental damage. A community perception exists of an annual altitudinal migration of the feral-pig population. The present study describes the movements of 29 feral pigs in relation to altitudinal migration (highland, transitional and lowland areas). Feral pigs were sedentary and stayed within their home range throughout a 4-year study period. No altitudinal migration was detected; pigs moved no more than a mean distance of 1.0 km from the centre of their calculated home ranges. There was no significant difference between the mean (+/- 95% confidence interval) aggregate home ranges for males (8.7 +/- 4.3 km², n = 15) and females (7.2 +/- 1.8 km², n = 14). No difference in home range was detected among the three altitudinal areas: 7.2 +/- 2.4 km² for highland, 6.2 +/- 3.9 km² for transitional and 9.9 +/- 5.3 km² for lowland areas. The aggregate mean home range for all pigs in the present study was 8.0 +/- 2.4 km². The study also assessed the influence seasons had on the home range of eight feral pigs on the rainforest boundary; home ranges did not significantly vary in size between the tropical wet and dry seasons, although the mean home range in the dry season (7.7 +/- 6.9 km²) was more than twice the home range in the wet season (2.9 +/- 0.8 km²). Heavier pigs tended to have larger home ranges. The results of the present study suggest that feral pigs are sedentary throughout the year so broad-scale control techniques need to be applied over sufficient areas to encompass individual home ranges. Control strategies need a coordinated approach if a long-term reduction in the pig population is to be achieved.

Efficacy of exclusion fencing to protect ephemeral floodplain lagoon habitats from feral pigs (Sus scrofa)

Foraging by feral pigs can strongly affect wetland vegetation assemblages and so too wider ecological processes, although their effects on freshwater ecosystems have seldom been tudied. We assessed the ecological effects of pig foraging in replicate fenced and unfenced ephemeral floodplain lagoons in tropical north-eastern Australia. Pig foraging activities in unfenced lagoons caused major changes to aquatic macrophyte communities and as a consequence, to the proportional amounts of open water and bare ground. The destruction of macrophyte communities and upheaval of wetland sediments significantly affected wetland turbidity, and caused prolonged anoxia and pH imbalances in the unfenced treatments. Whilst fencing of floodplain lagoons will protect against feral pig foraging activities, our repeated measures of many biological, physical and chemical parameters inferred that natural seasonal (i.e. temporal) effects had a greater influence on these variables than did pigs. To validate this observation requires measuring how these effects are influenced by the seemingly greater annual disturbance regime of variable flooding and drying in this tropical climate.

A Review of Transport Practices and Mortalities in pigs in Australia

The closure of abattoirs in Australia dictates that pigs will be transported over greater distances resulting in increased costs and reduced margins for producers. Factors contributing to reduced margins could include increased freight costs, reduced scale weight as a result of reduced killing out percentage and condemnations (due to injuries) plus possible increased deaths in transport. More information is needed in Australia on transport practices and mortalities to address knowledge deficiencies in our understanding of the welfare implications of road transport.

Forage Legumes for supplementing village pigs in Lao PDR

Potential for forage legumes as a feed ingredient for pig nutrition.

Evidence of bat origin for Menangle virus, a zoonotic paramyxovirus first isolated from diseased pigs

Menangle virus (MenPV) is a zoonotic paramyxovirus capable of causing disease in pigs and humans. It was first isolated in 1997 from stillborn piglets at a commercial piggery in New South Wales, Australia, where an outbreak of reproductive disease occurred. Neutralizing antibodies to MenPV were detected in various pteropid bat species in Australia and fruit bats were suspected to be the source of the virus responsible for the outbreak in pigs. However, previous attempts to isolate MenPV from various fruit bat species proved fruitless. Here, we report the isolation of MenPV from urine samples of the black flying fox, Pteropus alecto, using a combination of improved procedures and newly established bat cell lines. The nucleotide sequence of the bat isolate is 94% identical to the pig isolate. This finding provides strong evidence supporting the hypothesis that the MenPV outbreak in pigs originated from viruses in bats roosting near the piggery. © 2012 Printed in Great Britain.

Detection of a putative hemolysin operon, hhdBA, of Haemophilus parasuis from pigs with Glasser disease

The aim of the current study was to investigate whether polymerase chain reaction amplification of 16S ribosomal (r)RNA and a putative hemolysin gene operon, hhdBA, can be used to monitor live pigs for the presence of Haemophilus parasuis and predict the virulence of the strains present. Nasal cavity swabs were taken from 30 live, healthy, 1- to 8-week-old pigs on a weekly cycle from a commercial Thai nursery pig herd. A total of 27 of these pigs (90%) tested positive for H. parasuis as early as week 1 of age. None of the H. parasuis-positive samples from healthy pigs was positive for the hhdBA genes. At the same pig nursery, swab samples from nasal cavity, tonsil, trachea, and lung, and exudate samples from pleural/peritoneal cavity were taken from 30 dead pigs displaying typical pathological lesions consistent with Glasser disease. Twenty-two of 140 samples (15.7%) taken from 30 diseased pigs yielded a positive result for H. parasuis. Samples from the exudate (27%) yielded the most positive results, followed by lung, tracheal swab, tonsil, and nasal swab, respectively. Out of 22 positive samples, 12 samples (54.5%) harbored hhdA and/or hhdB genes. Detection rates of hhdA were higher than hhdB. None of the H. parasuis-positive samples taken from nasal cavity of diseased pigs tested positive for hhdBA genes. More work is required to determine if the detection of hhdBA genes is useful for identifying the virulence potential of H. parasuis field isolates.

An exploratory study to assess the activity of the acarine growth inhibitor, fluazuron, against Sarcoptes scabei infestation in pigs

Background: The most common treatments for scabies in human and veterinary settings are topical 5% permethrin or systemic treatment with ivermectin. However, these treatments have very little activity against arthropod eggs, and therefore repeated treatment is frequently required. In-vitro, biochemical and molecular studies have demonstrated that human mites are becoming increasingly resistant to both acaricides. To identify alternate acaricides, we undertook a pilot study of the in vivo activity of the benzoylphenyl urea inhibitor of chitin synthesis, fluazuron, in pigs with sarcoptic mange. Findings: Pigs (n = 5) were infested with S. scabei var suis, and randomised to treatment at the start of peak infestation with fluazuron at a dose of 10 mg/kg/day per os for 7 days (n = 3) or no treatment (n = 2). Clinical scores, skin scrapings for mite counts and blood sampling for pharmacokinetic analysis were undertaken. Fluazuron was well absorbed in treated pigs with measureable blood levels up to 4 weeks post treatment. No adverse effects were observed. Modest acaricidal activity of the compound was observed, with a reduction in severity of skin lesions in treated pigs, as well as a reduction in number of scabies mite's early life stages. Conclusions: The moderate efficacy of fluazuron against scabies mites indicates a lead to the development of alternate treatments for scabies, such as combination therapies that maybe applicable for human use in the future.

A dynamic programming model for optimising feeding and slaughter decisions regarding fattening pigs

Costs of purchasing new piglets and of feeding them until slaughter are the main variable expenditures in pig fattening. They both depend on slaughter intensity, the nature of feeding patterns and the technological constraints of pig fattening, such as genotype. Therefore, it is of interest to examine the effect of production technology and changes in input and output prices on feeding and slaughter decisions. This study examines the problem by using a dynamic programming model that links genetic characteristics of a pig to feeding decisions and the timing of slaughter and takes into account how these jointly affect the quality-adjusted value of a carcass. The model simulates the growth mechanism of a pig under optional feeding and slaughter patterns and then solves the optimal feeding and slaughter decisions recursively. The state of nature and the genotype of a pig are known in the analysis. The main contribution of this study is the dynamic approach that explicitly takes into account carcass quality while simultaneously optimising feeding and slaughter decisions. The method maximises the internal rate of return to the capacity unit. Hence, the results can have vital impact on competitiveness of pig production, which is known to be quite capital-intensive. The results suggest that producer can significantly benefit from improvements in the pig's genotype, because they improve efficiency of pig production. The annual benefits from obtaining pigs of improved genotype can be more than €20 per capacity unit. The annual net benefits of animal breeding to pig farms can also be considerable. Animals of improved genotype can reach optimal slaughter maturity quicker and produce leaner meat than animals of poor genotype. In order to fully utilise the benefits of animal breeding, the producer must adjust feeding and slaughter patterns on the basis of genotype. The results suggest that the producer can benefit from flexible feeding technology. The flexible feeding technology segregates pigs into groups according to their weight, carcass leanness, genotype and sex and thereafter optimises feeding and slaughter decisions separately for these groups. Typically, such a technology provides incentives to feed piglets with protein-rich feed such that the genetic potential to produce leaner meat is fully utilised. When the pig approaches slaughter maturity, the share of protein-rich feed in the diet gradually decreases and the amount of energy-rich feed increases. Generally, the optimal slaughter weight is within the weight range that pays the highest price per kilogram of pig meat. The optimal feeding pattern and the optimal timing of slaughter depend on price ratios. Particularly, an increase in the price of pig meat provides incentives to increase the growth rates up to the pig's biological maximum by increasing the amount of energy in the feed. Price changes and changes in slaughter premium can also have large income effects. Key words: barley, carcass composition, dynamic programming, feeding, genotypes, lean, pig fattening, precision agriculture, productivity, slaughter weight, soybeans

Impacts and management of wild pigs Sus scrofa in Australia

Globally, wild or feral pigs Sus scrofa are a widespread and important pest. Mitigation of their impacts requires a sound understanding of those impacts and the benefits and limitations of different management approaches. Here, we review published and unpublished studies to provide a synopsis of contemporary understanding of wild pig impacts and management in Australia, and to identify important shortcomings. Wild pigs can have important impacts on biodiversity values, ecosystem functioning and agricultural production. However, many of these impacts remain poorly described, and therefore, difficult to manage effectively. Many impacts are highly variable, and innovative experimental and analytical approaches may be necessary to elucidate them. Most contemporary management programmes use lethal techniques to attempt to reduce pig densities, but it is often unclear how effective they are at reducing damage. We conclude that greater integration of experimental approaches into wild pig management programmes is necessary to improve our understanding of wild pig impacts, and our ability to manage those impacts effectively and efficiently.

Impacts on nontarget avian species from aerial meat baiting for feral pigs

Bait containing sodium fluoroacetate (1080) is widely used for the routine control of feral pigs in Australia. In Queensland, meat baits are popular in western and northern pastoral areas where they are readily accepted by feral pigs and can be distributed aerially. Field studies have indicated some levels of interference and consumption of baits by nontarget species and, based on toxicity data and the 1080 content of baits, many nontarget species (particularly birds and varanids) are potentially at risk through primary poisoning. While occasional deaths of species have been recorded, it remains unclear whether the level of mortality is sufficient to threaten the viability or ecological function of species. A series of field trials at Culgoa National Park in south-western Queensland was conducted to determine the effect of broadscale aerial baiting (1.7 baits per km2) on the density of nontarget avian species that may consume baits. Counts of susceptible bird species were conducted prior to and following aerial baiting, and on three nearby unbaited properties, in May and November 2011, and May 2012. A sample of baits was monitored with remote cameras in the November 2011 and May 2012 trials. Over the three baiting campaigns, there was no evidence of a population-level decline among the seven avian nontarget species that were monitored. Thirty per cent and 15% of baits monitored by remote cameras in the November 2011 and May 2012 trials were sampled by birds, varanids or other reptiles. These results support the continued use of 1080 meat baits for feral pig management in western Queensland and similar environs.

Effect of rabbit antiserum to ovine LH on reproductive organs in male hamsters and guinea-pigs

Administration of rabbit antiserum to ovine luteinizing hormone to immature hamsters and guinea-pigs resulted in a significant decrease in the weights of testes, seminal vesicle and ventral prostate. The author wishes to thank Prof. N.R. Moudgal for his interest and Family Planning Foundation for financial assistance.

Transfer of Dietary Plant Natural Flavor Compounds From Essential Oils to Maternal Fluids in Pigs

Fetal flavor conditioning during the perinatal stage could be essential at the time of the weaning to reduce the stress and improve the feed intake in pigs. The transfer of flavor compounds from maternal diet to amniotic fluid and milk has been shown in behavioral experiments, but not through analytical procedures such as gas chromatography–mass spectrometry (GC–MS). The aim of the experiment was to trace the principal essential oils compounds supplied in the diet in maternal fluids. Twenty Large White sows around their 104th gestational day were allocated to individual farrowing crates. Two groups of 10 sows were fed either a standard gestation diet or the same diet supplemented with a mix of 8 essential oils at a rate of 1kg/ton during the last 10 days of gestation. At approximately the 113th gestational day, animals were individually treated with 10mg of Lutalyse IM was to induce farrowing. Fresh amniotic fluid was collected during the farrowing in 100-mL glass bottles and immediately stored at −20 °C freezer. During the second lactation day, 10–20 IU of Oxytocin IM was administered to each sow to facilitate collection of milk samples in 20-mL glass bottles. The samples were stored at −20 °C until analyzed by GC–MS. The presence of significant amounts of principal components of all the essential oils except one were found in the milk and amniotic fluid samples of the treated sows relative to the control sows. Our data prove the transfer of selected dietary flavors to maternal fluids and sets the scenario for further trials to manipulate postweaning behavior in piglets.

Consumption of crops by feral pigs (Sus scrofa) in a fragmented agricultural landscape

Feral pigs (Sus scrofa) consume and damage crops and impact the environment through predation, competition and habitat disturbance, although supporting dietary data are lacking in agricultural landscapes. This study was undertaken to determine the relative importance of food items in the diet of feral pigs in a fragmented agricultural landscape, particularly to assist in predicting the breadth of likely impacts. Diet composition was assessed from the stomach contents of 196 feral pigs from agricultural properties in southern Queensland. Feral pigs were herbivorous, with plant matter comprising >99% of biomass consumed. Crops were consumed more frequently than non-crop species, and comprised >60% of dietary biomass, indicating a clear potential for direct economic losses. Consumption of pasture and forage species also suggests potential competition for pasture with domestic stock. There is little evidence of direct predation on native fauna, but feral pig feeding activities may impact environmental values. Seasonal differences in consumption of crop, pasture or animal food groups probably reflect the changing availability of food items. We recommend that future dietary studies examine food availability to determine any dietary preferences to assist in determining the foods most susceptible to damage. The outcomes of this study are important for developing techniques for monitoring the impacts of feral pigs, essential for developing management options to reduce feral pig damage on agricultural lands.