<i>Campylobacter, Salmonella</i>and <i>Escherichia coli</i>Food Contamination Risk in Free-Range Poultry Production System

Livestock such as poultry is consumed as food worldwide and it constitutes one of the main protein sources for diners, as well as an important source of revenue generation for farmers. Poultry meat production chain identifies a significant role of the farm to folk. Most often, the systems used in poultry production can result in a higher prevalence of Campylobacter, Salmonella, and Escherichia coli contamination, leading to adverse health effects with detrimental consequences. The method of poultry keeping plays a significant role in the poultry meats’ outcome and its food safety standards. Farmers attempt to develop new poultry operations, however, there are two main possibilities;to operate within the present vertically integrated system which is incredibly good for disease prevention and to develop independently, or a smaller operation that is more animal friendly. This article reviews the available research on the impact of free-range poultry production systems on food safety, most importantly the prevalence and control of Campylobacter, Salmonella and Escherichia coli in free-range production systems. The results suggest a conflicting view when bacterial loads of poultry meat from conventional and free-range systems are compared. Studies have shown increased bacterial loads in a free-range production system.

An Evaluation of the Infection Status and Source of Subgroup J Avian Leukosis Virus in Cloned Free-Range Layers

In recent years, subgroup J avian leukosis virus （ALV-J） has been found to frequently infect layers in China. This virus is responsible for economic losses due to both mortality and decreased performance in chickens. In this study, 45-d-old cloned flee-range layers were suspected to be infected with ALV and other immunosuppressive diseases because their feathers were unkempt and their growth rate was impaired. To estimate the infection status and determine the source of ALV-J in the flock, 30 cloacal swabs were randomly collected to measure the p27 antigen level by enzyme-linked immunosorbent assay （ELISA）. Among the birds that were tested, 87% （26/30） were positive. In addition, 6 anticoagulant blood samples were aseptically collected at random from the flock when the layers were 60 d old. These samples were centrifuged to obtain the leukocytes, which were then used to inoculate chicken embryo fibroblast （CEF） cells for the identification of ALV-J by indirect immunofluorescence （IFA）. Of the samples tested, 100% （6/6） were positive. The flock＇s production performance was also investigated, and 10 layers were necropsied to evaluate pathological changes at 115 d of age. The flock never laid eggs even though they reached the age of the first laying （110 d）. Furthermore, there were pathological changes present, including atrophy of the thymus and bursa of Fabricius, undeveloped ovaries, glandular stomach haemorrhage, and hepatosplenomegaly. Paraffin-embedded sections of intumescent liver and spleen were prepared for antigen localisation using IFA. Positive signals were prevalent in paraffin-embedded sections of the intumescent liver and spleen. Furthermore, provirus DNA was extracted from 4 cloned flee-range layers, and 2 patemal parents （HR native cocks）, and the gp85 gene of ALV-J was amplified by PCR to analyse the genetic variation. The results of the autogenous variation analysis showed that the 6 strains were 98.5-99.7% homologous. This study indicated that there was persistent infection with ALV-J by dynamic inspection, which seriously reduced the production performance of the flock. In addition, the genetic variation analysis showed that ALV-J in the flock was more likely to have originated from the paternal parent, the HR native cock.

Comparative Analysis of Slaughter Performance and Meat Flavor Traits of Quality Chicken under Cage Rearing and Free-range Farming Conditions

[Objective]The paper was to compare the slaughter performance and meat flavor of quality chicken under cage rearing and free-range farming conditions.[Method]A total of 4001-day-old cocks,S07 line cultivated by Sichuan Dahen Poultry Breeding Co.,Ltd.(bred for 4 succes-sive generations),were kept in cages until the end of 5 weeks of age,which were then divided into cage rearing and free-range farming groups.All cocks were fed with the same diet,and slaughter tests and meat quality analysis were carried out at the end of 10 and 22 weeks of age,respectively.[Result]The live weight,carcass weight and abdominal fat percentage in cage rearing group were significantly higher than those in free-range farming group(P<0.01),and the percentage of half-eviscerated yield and percentage of eviscerated yield in cage rearing group were significantly higher than those in free-range farming group(P<0.05),but there were no significant differences in dressing percentage,percentage of leg muscle and per-centage of breast muscle.The intramuscular fat(IMF)content and muscle fiber density of chicken in cage rearing group were significantly higher than those in free-range farming group(P<0.01),but there was no significant difference in inosinic acid(IMP)content.The content of IMF and IMF increased with the increase of feeding age,but the deposition rate of intramuscular fat was higher than that of IMF in late feeding period.[Conclusion]The study will provide reliable guidance for production and market consumption of high quality chicken.

Technical Measures for High Quality and High Yield of Free-range Sows in Rural Areas

Today,with the rapid development of modern and large-scale pig industry,free-range pig farming is still an important part of the breeding industry.Different from large-scale pig farms,there are many shortcomings in feeding management,pig disease prevention and control and so on for small-scale farmers.In the long-term clinical diagnosis and production practice,it is found that sows raised by small-scale farmers often have some problems,such as non-estrus,repeated infertility and"false pregnancy",weak farrowing,stillbirth,and postpartum piglet death.This paper makes a comprehensive analysis on the performance and etiology of the above-mentioned free-range sows,and puts forward the corresponding prevention and control measures,in order to provide a theoretical basis for the feeding and management of rural free-range sows.

Free-range chicken eggs as a bioindicator of dioxin contamination in Vietnam,including long-term Agent Orange impact

PCDD/Fs contamination of free-range chicken eggs and soils from private Vietnam households was studied.The possibility of using free-range eggs as bio-indicators of dioxin contamination was considered as the soil-chicken-egg exposure pathway is considered to be the most sensitive exposure pathway of dioxins in soils to humans.A large territory from Dong Nai province in the south to Lao Cai province in the north was covered by the research.All analyses were performed by HRGC-HRMS method.PCDD/Fs levels in eggs from the majority of southern households exceeded the EC limit for eggs and egg products(2.5 pg WHO-TEQ2005 g^-1 lipid).Total TEQs ranged from 0.4 to 361 pg WHO-TEQ2005 g^-1 lipid in eggs and from 0.1 to 1272 pg WHO-TEQ2005/g in soil.2,3,7,8-TCDD contribution was statistically significantly higher in both eggs and soils in sprayed with Agent Orange areas,indicating its long-term impact.In order to assess within site variation,a total of 62 individual eggs from 14 private households were analyzed.Mean relative standard deviation of total TEQ values in individual eggs within the separate households was 27%.Rather good correlation of PCDD/Fs concentration in eggs and respective soils was observed for all dioxin congeners and for hexa-and hepta-furans(except for 1,2,3,7,8,9-HxCDF).Higher bioaccumulation for lower chlorinated congeners was confirmed.The current study of using eggs as bioindicators for large POPs contaminated sites may be suggested as a policy approach to evaluate human exposure to dioxin/POPs contaminated sites for known or suspected contaminated areas.

Free-ranging dogs match a human’s preference in a foraging task

Social learning is a mechanism used by many species to effciently gain information about their environment.Although many animals live in an environment where members of other species are present,little is known about interspecifc social learning.Domesticated and urbanized species provide the opportunity to investigate whether nonhuman animals can learn from heterospecifcs such as humans,who are integral parts of their social landscape.Although domestic dogs Canis familiaris have been intensively researched for their ability to learn from humans,most studies have focused on dogs living as pets.However,free-ranging dogs represent the majority of the world’s dog population,they live alongside humans,scavenge on human refuse,and are subject to natural and sexual selection.Thus,free-ranging dogs with extensive exposure to humans and their artifacts provide the opportunity to investigate interspecifc social learning in a naturalistic setting,where learning from humans might be a beneft for them.Here we tested individual free-ranging dogs in a between-subject design:Dogs in the control group could spontaneously choose between two novel and differently patterned food-delivering boxes.In the experimental group,instead,dogs could frst observe an unfamiliar human approaching and eating from 1 of the 2 boxes.We provide the frst evidence that free-ranging dogs match the choice of an unfamiliar human.These results show that at least simple forms of interspecifc social learning might be involved in dogs’success in living alongside humans in a complex urbanized environment.

Spy out to Protect: Sensing Devices for Wildlife Virtual Fencing

To avoid wildlife-human conflict several solutions are used, like electrical fences, the most expensive solution. Nowadays, technology enables alternative and cheaper approaches for conservation projects. A technological device was developed to detect elephants, moving on their habitat, and predict and react by avoiding confrontation with man. The devices were tested in field experiments, and proved to be efficient in capturing floor vibration, and air-sound signals. Collected data also enabled the estimation of the vibration-source by calculus (using triangulation), revealing the importance of the methodology for real-time location and tracking of high mass animals (e.g. elephants). Building up a mesh of devices, separated 25 m from each other, is estimated as possible to monitor and identify different animals (by discriminating patterns) in an area, like a virtual fencing system. Though the devices may be effective for animal behaviour research, or even animal communication analysis, or other Biology field, other applications outside Biology are possible for them, like monitoring of: rock-falling, micro seismic railway, infrastructures, and people movements.