Mohan Raj

Ad hoc method for the assessment on listing and categorisation of animal diseases within the framework of the Animal Health Law

Abstract The European Commission has requested EFSA to assess animal diseases according to the criteria as laid down in Articles 5, 7, 8 and Annex IV for the purpose of categorisation of diseases in accordance with Article 9 of the Regulation (EU) No 2016/429 (Animal Health Law). This scientific opinion addresses the ad hoc method developed for assessing any animal disease for the listing and categorisation of diseases within the Animal Health Law (AHL) framework. The assessment of individual diseases is addressed in distinct scientific opinions that are published separately. The assessment of Articles 5, 8 and 9 criteria is performed on the basis of the information collected according to Article 7 criteria. For that purpose, Article 7 criteria were structured into parameters and the information was collected at parameter level. The resulting fact sheets on the profile and impact of each disease were compiled by disease scientists. A mapping was developed to identify which parameters from Article 7 were needed to inform each Article 5, 8 and 9 criterion. Specifically, for Articles 5 and 9 criteria, a categorical assessment was performed, by applying an expert judgement procedure, based on the mapped information. The judgement was performed by EFSA Panel experts on Animal Health and Welfare in two rounds, individual and collective judgement. The output of the expert judgement on the criteria of Articles 5 and 9 for each disease is composed by the categorical answer, and for the questions where no consensus was reached, the different supporting views are reported.

Stunning methods for poultry

Electrical waterbath stunning is the most common method used to stun poultry under commercial conditions. The voltage supplied to a multiple bird waterbath stunner must be adequate to deliver the required minimum current to each bird. High frequency (> 300 Hz) electrical waterbath stunning needs further investigation to determine its efficiency. It should always be followed by a prompt neck cutting procedure where all the major blood vessels in the neck are severed. Irrespective of the waveform or frequency of the currents employed, constant current stunners should be installed under commercial conditions to ensure that the minimum currents are delivered to individual birds in waterbath stunners. Head only electrical stunning of poultry is being investigated in detail and there is scope for commercial development. Important features include (a) a constant current capable of delivering a preset current, (b) a bird restraining conveyor and head presentation devices enabling the stunning tongs to be accurately placed, (c) more effective electrical stunning tongs in terms of delivering necessary currents while using low voltages, and (d) induction of cardiac arrest immediately after stunning to eliminate wing flapping. Stunning/killing of poultry still in their transport containers using gas mixtures would appear to be the best future option as far as bird welfare is concerned. However, birds can also be stunned/killed on a conveyor using gas mixtures, thereby eliminating the stress associated with the shackling of live birds before electrical stunning. Under the conveyor system birds should be presented to the gas mixtures in a single layer. Within gas mixtures a minimum of 90% argon in air would appear to be the first choice. A mixture of 30% carbon dioxide and 60% argon in air is better than using a high concentration of carbon dioxide in air, and is therefore considered to be the second choice. A two stage system that involves firstly stunning broilers with a low concentration of carbon dioxide and then killing them with a high concentration of carbon dioxide can be used by those who wish to use this gas for economic reasons. The two stages should be distinctly separated so that the birds are stunned well before exposure to a high concentration of carbon dioxide in air. In comparison with carbon dioxide alone, a mixture of 30% oxygen and 40% carbon dioxide in air prolongs the induction of anaesthesia and the exposure time required to kill the birds. The addition of oxygen to carbon dioxide may therefore not have any benefit to bird welfare or the processors. Mechanical stunning of poultry using penetrating captive bolts or non-penetrating mushroom headed bolts has been developed. However, stunning with these devices results in very severe wing flapping and further research is necessary to find ways of alleviating this problem.

Determination of the aversion of farmed mink (Mustela vison) to carbon dioxide

High concentrations of carbon dioxide are commonly used to kill mink before their pelts are removed. The aversiveness of this procedure was investigated by using a passive avoidance technique. Eight mink were trained to obtain a reward (a novel object) by entering a chamber which could be filled with carbon dioxide, as under commercial conditions (over 80 per cent by volume). In the absence of carbon dioxide, mink entered the chamber within a mean (sd) of 16 (2.1) seconds and spent 45 (12) per cent of the next 10 minutes interacting with the novel object. When there was carbon dioxide in the test chamber, the mink would not enter it and coughed and recoiled from the chambers entrance instead. It was concluded that the mink detected and avoided high concentrations of carbon dioxide, and that if mink are to be killed humanely, less aversive techniques should be used.

Humane Killing of Nonhuman Animals for Disease Control Purposes

Reports and guidelines produced by international institutions such as the World Organization for Animal Health (OIE, 2005) describe various methods of killing nonhuman animals. Selection and implementation of a killing method may involve several factors. Preventing or minimizing risk to human health and safety may override animal welfare concerns if the disease has the potential to cause high mortality, for example, highly pathogenic avian influenza. Owing to the public health significance of this disease, the scope of this article presents only an overview of the welfare and practical aspects of large-scale killing of poultry on farms. Killing poultry in houses using a gas mixture eliminates the need for human contact with infective materials and birds. Several protocols for administering gas mixtures into poultry houses have been evaluated, mainly in Europe and North America. Overdose of anesthetics in feed and water has sedated birds kept under free-range or semi-intensive rearing systems. Containerized gas killing systems have proved successful on small-to-medium-size poultry farms. However, using nitrogen, a nonaversive gas, could greatly improve bird welfare.

Reaction of farmed mink (Mustela vison) to argon-induced hypoxia.

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Urgent request on avian influenza

Abstract Highly pathogenic avian influenza (HPAI) H5N8 is currently causing an epizootic in Europe, infecting many poultry holdings as well as captive and wild bird species in more than 10 countries. Given the clear clinical manifestation, passive surveillance is considered the most effective means of detecting infected wild and domestic birds. Testing samples from new species and non‐previously reported areas is key to determine the geographic spread of HPAIV H5N8 2016 in wild birds. Testing limited numbers of dead wild birds in previously reported areas is useful when it is relevant to know whether the virus is still present in the area or not, e.g. before restrictive measures in poultry are to be lifted. To prevent introduction of HPAIV from wild birds into poultry, strict biosecurity implemented and maintained by the poultry farmers is the most important measure. Providing holding‐specific biosecurity guidance is strongly recommended as it is expected to have a high impact on the achieved biosecurity level of the holding. This is preferably done during peace time to increase preparedness for future outbreaks. The location and size of control and in particular monitoring areas for poultry associated with positive wild bird findings are best based on knowledge of the wider habitat and flight distance of the affected wild bird species. It is recommended to increase awareness among poultry farmers in these established areas in order to enhance passive surveillance and to implement enhanced biosecurity measures including poultry confinement. There is no scientific evidence suggesting a different effectiveness of the protection measures on the introduction into poultry holdings and subsequent spread of HPAIV when applied to H5N8, H5N1 or other notifiable HPAI viruses.

Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): paratuberculosis

Abstract Paratuberculosis has been assessed according to the criteria of the Animal Health Law (AHL), in particular criteria of Article 7 on disease profile and impacts, Article 5 on the eligibility of paratuberculosis to be listed, Article 9 for the categorisation of paratuberculosis according to disease prevention and control rules as in Annex IV and Article 8 on the list of animal species related to paratuberculosis. The assessment has been performed following a methodology composed of information collection and compilation, expert judgement on each criterion at individual and, if no consensus was reached before, also at collective level. The output is composed of the categorical answer, and for the questions where no consensus was reached, the different supporting views are reported. Details on the methodology used for this assessment are explained in a separate opinion. According to the assessment performed, paratuberculosis can be considered eligible to be listed for Union intervention as laid down in Article 5(3) of the AHL. The disease would comply with the criteria in Sections 3, 4 and 5 of Annex IV of the AHL, for the application of the disease prevention and control rules referred to in points (c), (d) and (e) of Article 9(1). The animal species to be listed for paratuberculosis according to Article 8(3) criteria are several species of mammals and birds as susceptible species and some species of the families Bovidae, Cervidae and Leporidae as reservoirs.

Stunning and Slaughter

In most of the developed countries, excluding the United States of America, it is a statutory requirement that all animals including poultry slaughtered for human consumption are rendered immediately unconscious (stunning) and they remain so until death supervenes through blood loss (slaughter). The duration of unconsciousness induced by a stunning procedure must be longer than the sum of time that lapses between the end of stun and neck cutting and the time to onset of death following neck cutting. Since the effect of a stunning method is momentary, the onus of preventing resumption of consciousness thereafter relies on the efficiency of slaughter procedure (bleeding out); i.e. the prompt and accurate severance of blood vessels (neck cutting) supplying oxygenated blood to the brain. Some stunning procedures are therefore purposefully applied to induce humane death (e.g. killing with argon or nitrogen-induced anoxia), rather than mere unconsciousness, and other methods lead to death due to structural damage to the brain (e.g. penetrating captive bolts).

African swine fever in wild boar

Abstract The European Commission requested EFSA to compare the reliability of wild boar density estimates across the EU and to provide guidance to improve data collection methods. Currently, the only EU‐wide available data are hunting data. Their collection methods should be harmonised to be comparable and to improve predictive models for wild boar density. These models could be validated by more precise density data, collected at local level e.g. by camera trapping. Based on practical and theoretical considerations, it is currently not possible to establish wild boar density thresholds that do not allow sustaining African swine fever (ASF). There are many drivers determining if ASF can be sustained or not, including heterogeneous population structures and human‐mediated spread and there are still unknowns on the importance of different transmission modes in the epidemiology. Based on extensive literature reviews and observations from affected Member States, the efficacy of different wild boar population reduction and separation methods is evaluated. Different wild boar management strategies at different stages of the epidemic are suggested. Preventive measures to reduce and stabilise wild boar density, before ASF introduction, will be beneficial both in reducing the probability of exposure of the population to ASF and the efforts needed for potential emergency actions (i.e. less carcass removal) if an ASF incursion were to occur. Passive surveillance is the most effective and efficient method of surveillance for early detection of ASF in free areas. Following focal ASF introduction, the wild boar populations should be kept undisturbed for a short period (e.g. hunting ban on all species, leave crops unharvested to provide food and shelter within the affected area) and drastic reduction of the wild boar population may be performed only ahead of the ASF advance front, in the free populations. Following the decline in the epidemic, as demonstrated through passive surveillance, active population management should be reconsidered.

Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): infection with Brucella abortus, B. melitensis and B. suis

Abstract The infection with Brucella abortus, Brucella melitensis and Brucella suis has been assessed according to the criteria of the Animal Health Law (AHL), in particular criteria of Article 7 on disease profile and impacts, Article 5 on the eligibility of the infection with B. abortus, B. melitensis and B. suis to be listed, Article 9 for the categorisation of the infection with B. abortus, B. melitensis and B. suis according to disease prevention and control rules as in Annex IV and Article 8 on the list of animal species related to the infection with B. abortus, B. melitensis and B. suis. The assessment has been performed following a methodology composed of information collection and compilation, expert judgement on each criterion at individual and, if no consensus was reached before, also at collective level. The output is composed of the categorical answer, and for the questions where no consensus was reached, the different supporting views are reported. Details on the methodology used for this assessment are explained in a separate opinion. According to the assessment performed, the infection with B. abortus, B. melitensis and B. suis can be considered eligible to be listed for Union intervention as laid down in Article 5(3) of the AHL. The disease complies with the criteria as in Sections 2, 3, 4 and 5 of Annex IV of the AHL, for the application of the disease prevention and control rules referred to in points (b), (c), (d) and (e) of Article 9(1). The animal species to be listed for the infection with B. abortus, B. melitensis and B. suis according to Article 8(3) criteria are several mammal species, as indicated in the present opinion.