| 1. |
- Alexander, Jan, et al.
(författare)
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Scientific Opinion on Hexabromocyclododecanes (HBCDDs) in Food
- 2011
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Ingår i: EFSA Journal. - 1831-4732. ; 9:7, s. 2296-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- EFSA was asked by the European Commission to deliver a scientific opinion on hexabromocyclododecanes (HBCDDs) in food. HBCDDs are additive flame retardants primarily used in expanded and extruded polystyrene applied as construction and packing materials, and in textiles. Technical HBCDD predominantly consists of three stereoisomers (α-, β- and γ-HBCDD). Also δ- and ε-HBCDD may be present but at very low concentrations. HBCDDs are present in the environment and likewise in biota and in food and feed. Data from the analysis of HBCDDs in 1,914 food samples were provided to EFSA by seven European countries, covering the period from 2000 to 2010. The Panel on Contaminants in the Food Chain (CONTAM Panel) selected α-, β- and γ-HBCDD to be of primary interest. Since all toxicity studies were carried out with technical HBCDD, a risk assessment of individual stereoisomers was not possible. Main targets were the liver, thyroid hormone homeostasis and the reproductive, nervous and immune systems. HBCDDs are not genotoxic. The CONTAM Panel identified neurodevelopmental effects on behaviour as the critical endpoint, and derived a benchmark dose lower confidence limit for a benchmark response of 10 % (BMDL10) of 0.79 mg/kg body weight. Due to the limitations and uncertainties in the current data base, the CONTAM Panel concluded that it was inappropriate to use this BMDL to establish a health based guidance value, and instead used a margin of exposure (MOE) approach for the health risk assessment of HBCDDs. Since elimination characteristics of HBCDDs in animals and humans differ, the Panel used the body burden as starting point for the MOE approach. The CONTAM Panel concluded that current dietary exposure to HBCDDs in the European Union does not raise a health concern. Also additional exposure, particularly of young children, to HBCDDs from house dust is unlikely to raise a health concern
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| 2. |
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| 3. |
- Alexander, Jan, et al.
(författare)
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Scientific Opinion on Tetrabromobisphenol A (TBBPA) and its derivatives in food : EFSA Panel on Contaminants in the Food Chain (CONTAM)
- 2011
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Ingår i: EFSA Journal. - : Wiley. - 1831-4732. ; 9:12, s. 2477-
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Tidskriftsartikel (refereegranskat)abstract
- EFSA was asked by the European Commission to deliver a scientific opinion on tetrabromobisphenol A (TBBPA) and its derivatives in food. TBBPA and its derivatives are widely used as flame retardants. TBBPA is primarily used as reactive flame retardant covalently bound to epoxy and polycarbonate resins. TBBPA derivatives are used as either reactive or additive intermediates in polymer manufacture. Data from the analysis of TBBPA in 344 food samples were submitted to EFSA by two European countries (Norway and Spain), covering the period from 2007 to 2010. All samples were in the food group “Fish and other seafood”, and all analytical results were reported as less than the limit of quantification (LOQ) (about 1 ng/g wet weight). Toxicological studies with TBBPA have been carried out using different experimental designs with single or repeated administration during gestation, postnatally or in adulthood. The main target is thyroid hormone homeostasis. TBBPA is not genotoxic. There are no indications that TBBPA might be carcinogenic. The Panel on Contaminants in the Food Chain (CONTAM Panel) identified a lower confidence limit for a benchmark response of 10 % (BMDL10) of 16 mg/kg b.w. reported for changes in thyroid hormones as the critical reference point. Due to the limitations and uncertainties in the database, the CONTAM Panel concluded that it was inappropriate to use this BMDL to establish a health based guidance value, and therefore used a margin of exposure (MOE) approach for the health risk assessment of TBBPA. In view of the large MOEs, the CONTAM Panel concluded that current dietary exposure to TBBPA in the European Union does not raise a health concern. Also exposure of infants via human milk does not raise a health concern. Additional exposure, particularly of young children, to TBBPA from house dust is unlikely to raise a health concern.
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| 4. |
- Algers, Bo, et al.
(författare)
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Animal health safety of fresh meat derived from pigs vaccinated against classic swine fever
- 2009
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Ingår i: EFSA Journal. - : Wiley. - 1831-4732.
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Tidskriftsartikel (refereegranskat)abstract
- Classical swine fever (CSF) is a disease that has been causing major socio-economic damages in the EU during the last decades. Although considerable progress has been made in the eradication and prevention of the disease, the threat for an epidemic still exists. The measures to control and eradicate CSF are laid down in Community legislation (Council Directive 2001/89/EC and Commission Decision 2002/106/EC) and are based on stamping-out when CSF is confirmed on pig holdings. Emergency vaccination with 'conventional' live attenuated vaccine or marker vaccine can be used as an additional tool to control and eradicate the disease. In order to support and to improve the control and eradication measures as regards CSF in domestic pigs, EFSA was requested by the Commission to provide scientific advice on the safety of fresh meat (freedom from field virus) derived from vaccinated pigs. Specifically, two terms of reference were given: a) what is the risk that wild-type CSF virus is present in fresh meat obtained from pigs vaccinated in an emergency situation during an outbreak?; and b) what are the sampling schemes and testing procedures needed to detect field virus in fresh meat derived from such vaccinated pigs? Two types of vaccines are currently authorised in the EU for CSF: - A modified live vaccine (MLV, C-strain), which is safe and efficacious, inducing early protection; - An E2 subunit vaccine (E2subV, marker), safe, allowing serological DIVA, but with lower efficacy than MLV. The usefulness of emergency vaccination in order to limit disease spread and avoid excessive culling and economic damages remains to be evaluated. Very limited data related to the presence of CSFV in fresh meat have been generated after the implementation of a non-vaccination strategy. Therefore, a simulation modelling approach was developed to assess the risk of emergency vaccination on the safety of meat compared to the current control of CSF in domestic pigs without vaccination. CSFV is relatively stable in fresh meat and resists the maturation process in meat. Depending on the strain virulence, the age and breed, infected pigs die rapidly or may recover or can develop chronic infections. Viraemia is variable in duration and degree but it is always linked to the spread of virus to other body tissues including skeletal muscles (meat). The risk scenario includes two events that must happen before an infected animal is slaughtered and infected meat released: an infected herd has to escape clinical diagnosis before lifting of restrictions and during the final screening such a herd is not detected due to sample selection or false negative laboratory tests. Three scenarios were evaluated through the model: 1. Stamping-out of CSF detected as infected herds, standstill and pre-emptive culling. 2. Stamping-out of CSF detected as infected herds, standstill and emergency vaccination assuming a rapid protection. 3. Same as 2 but assuming a slower protection and DIVA property. It was concluded from the model that none of the strategies could reduce the risk to absolute zero. Lifting of restrictions can only occur after a certain time span (longer than the viraemic period of infected animals) after the last outbreak, thus the number of virus-positive animals in vaccinated infected herds at lifting will be very small. The model indicated that there is a lower risk of virus in fresh meat after emergency vaccination around outbreaks compared to the conventional strategy including pre-emptive culling, provided that control measures are adjusted to the applied vaccine and test systems. Adjustments may for instance include size of vaccination area, sampling schemes and timing of lift-up of restrictions. Any non-compliance of control measures will increase the risk of infectious animals remaining after lift-up. Chronically infected pigs are a potential hazard for fresh meat. However, in the risk assessment it was assumed that chronically infected pigs will be identified either by clinical signs and/or laboratory tests. Clinical diagnosis is unreliable and laboratory confirmation is needed. Highly sensitive and specific diagnostic assays are available to diagnose CSF. Agent detection tests are more suitable during early stages of infection. A positive rRT-PCR diagnosis indicates that an animal has been infected with the wild type or MLV virus but it is not necessarly still infectious. Antibody detection tests are mainly suitable for monitoring and surveillance purposes, but not for early diagnosis of suspect cases. Concerning the efficiency of the monitoring scheme, it is directly related to the diagnostic systems applied (organ sample, sensitivity, specificity) and to the number of samples taken. In case of selecting samples for rRT-PCR based on fever measurement in vaccinated animals, the sample size should be corrected. In terms of overall efficiency, rRT-PCR for virus detection and ELISA-systems for antibody investigation are the tests of choice. Vaccinated animals, that at an appropriate lift-up time are tested rRT-PCR negative for the wild type virus, can be considered as “zero risk” animals. If only a few animals become infected in a herd, which is possible especially when vaccination is applied, sampling and testing only a proportion of the animals may result in not detecting such an outbreak
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| 5. |
- Algers, Bo, et al.
(författare)
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Control and eradication of classic swine fever in wild boar
- 2009
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Ingår i: EFSA Journal. - : Wiley. - 1831-4732.
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Tidskriftsartikel (refereegranskat)abstract
- Classical swine fever (CSF) is a disease that has been causing major socio-economic damages in the EU during the last decades. Although considerable progress has been made in the eradication and prevention of the disease, the threat for an epidemic still exists. The virus is endemic in the wild boar population of several member states (MS). Wild boar cannot be managed as domestic pigs. Hunting and vaccination have been tentatively used in order to stop transmission by reducing the number of susceptibles. Oral vaccination of wild boar with modified live vaccine based on the C-strain (the only suitable) is used; this vaccine does not allow serological differentiation between vaccinated and infected animals. The aim of the control measures for CSF in wild boar is to reduce the risk of transmission to domestic pigs, to prevent an “endemic phase evolution” or to reduce the endemic phase duration. In order to support and to improve the control and eradication measures as regards CSF in wild boar, EFSA was requested by the Commission to provide scientific advice on the efficacy of the available surveillance, hunting and vaccination measures to control and eradicate CSF in feral pig populations (wild boar), considering the possible use of new diagnostic tests and vaccines. In order to reply to the mandate data were collected from MS through two questionnaires (CSF vaccines, hunting practices and CSF vaccination in wild boar). Data were also extracted from the EU CSF wild boar data base, after requesting permission from the participating MS. Considering that the data received were rather limited and not comparable, the WG decided to use a model in order to fill the gaps in the available knowledge. For the evaluation of the efficacy of CSF control in wild boar a continuous metapopulation compartmental model developed in an EU research project (FP6-5015599-CSFVACCINE&WILDBOAR) was applied. Although the disease manifests in the same manner in both domestic pig and wild boar it is more difficult to identify in wild boar because clinical monitoring of these is hardly possible. Wild boar found dead constitutes the main alert sign of CSF. Hunters and gamekeepers should be instructed to report the finding of each dead wild boar to the competent authority at all times. In case of high-risk situations, a passive surveillance should be complemented by an active serological surveillance. The active sampling of wild boar is not as efficient as in domestic pigs considering that hunting is the sole practical system to obtain samples and that the aim of hunting is quite different. Consequently, the sample size is not controlled by authorities and fits rarely the aim of the survey in terms of detecting the presence of disease at a certain level. In addition, the interpretation of serological results is confounded by maternal derived antibodies (until the 6th month of age), vaccination and the sampling quality. There is no definition at EU level of spatial and temporal units for surveillance, neither for criteria defining a disease free wild boar population. The sample size is not the only factor that dictates the overall sensitivity of surveillance systems. Indeed, wild boar habitat, hunting patterns, and disease distribution should be included when assessing surveillance system sensitivity. After a vaccination campaign, PCR positive animals can be due to modified live vaccines (MLV) but these MLV-vaccinated animals can be cross-checked for wild type CSF virus (genetic DIVA – discriminatory PCR). A positive PCR diagnosis should be considered to indicate that an animal is or has been infected with the wild type or MLV virus but it is not necessarly still infectious. According to previous field experience and to model simulations of a CSF epidemic in a wild boar population and the possible outcomes regarding vaccination: the disease will fade out without any additional control measures in small populations (between 1000 and 1500); hunting is not efficient for CSF control and should not exceed the normal 45% per year. Hunting is currently needed for sampling; vaccination: increases population immunity progressively. The maximum population immunity is only reached after three double campaigns; by one isolated campaign cannot increase population immunity adequately to control CSF and might even aggravate the persistence of CSF; mainly prevents the spread of the infection in neighbouring vaccinated patches; promotes long-term eradication through a progressive reduction of virus transmission to neighbouring areas; always reduces the epidemic peak (number of infected animals/time). Endemic evolution of infection may occur when a low rate of vaccination is achieved; in both infected and not yet infected areas, reaching a minimum target of 40 % of susceptible animals is necessary to obtain a positive control effect, below 20% - will increase probability of endemic stability, above 60% - will always eradicate the infection
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| 6. |
- Algers, Bo, et al.
(författare)
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Scientific opinion on the overall effects of farming systems on dairy cow welfare and disease
- 2009
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Ingår i: EFSA Journal. - : Wiley. - 1831-4732.
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Tidskriftsartikel (refereegranskat)abstract
- Following a request from the European Commission, the AHAW Panel was asked to deliver a Scientific Opinion on the welfare of dairy cows, considering whether current farming and husbandry systems comply with the requirements of and welfare of dairy cows from the pathological, zootechnical, physiological and behavioural points of view. Due to the great diversity of topics and the huge amount of scientific data, it was proposed that separate scientific opinions on different welfare subjects would be more adequate and effective. Therefore, it was agreed that a scientific report, an overall scientific opinion and four risk assessments on: i) metabolic and reproductive disorders, ii) udder disorders, iii) leg and locomotion problems and iv) behavioural disorders, fear and pain would be produced. This overall scientific opinion integrates conclusions and recommendations from the scientific report with the outcomes from the four separate risk assessments. In the resulting list of outcomes, conclusions and recommendations considered to have a high priority are evidenced. This scientific opinion on the overall effects of farming systems on dairy cow welfare and disease was adopted by the AHAW Panel on 05 June 2009. In considering the welfare of dairy cattle, some of the most important consequences of poor welfare are the occurrence of disease conditions, in particular foot and leg disorders and mastitis. Reproductive, metabolic and behavioural problems are also relevant indicators of poor welfare. European dairy production is based mainly from specialized intensive farming but there is considerable diversity in how cows are housed and managed. Systems range from grazing all of the year to remaining in a building with zero-grazing. The farming system by itself is a major factor determining the health problems of dairy cattle and other aspects of their welfare, partly through housing and equipment and partly through management and handling practices. Long term genetic selection for high milk yield is the major factor causing poor welfare, in particular health problems, in dairy cows. The milk yield of dairy cows has risen steadily over the last thirty years in Europe with approximately 50 % of this increase estimated to be attributable to genetic selection for milk production efficiency. This selection has also changed the form and size of dairy cows and hence demands on their behaviour and other adaptive mechanisms. The spatial requirements of the dairy cow have increased as well as its vulnerability for mechanical impacts and wounds on the exterior parts of the body, the skin, limbs and claws. The genetic component underlying milk yield has also been found to be positively correlated with the incidence of lameness, mastitis, reproductive disorders and metabolic disorders. In order to improve dairy cow welfare there is an urgent need to promote changes in the criteria used for genetic selection in the dairy industry. Higher weight should be given to fitness and welfare traits when these may conflict with selection for milk yield. Genetic selection for improved fertility, health and longevity is likely to improve welfare and lead to greater profit for the farmer. Whilst issues concerning genetic selection are common to different systems, when comparing different farming systems, hazards associated with housing and management variables have the greatest effects on dairy cattle welfare. The following are the major conclusions and recommendations when systems are compared. Since the body size of cows has increased during the last 20 years, where cubicles are used, they should be wide enough to minimise any movement difficulties or teat trampling. Cubicles and tie-stalls should be designed in such a way that the forward movement of the body of the cow is not thwarted when changing position from lying to standing. The risk assessment exercise confirmed that poor cubicle design and lack of space are the highest ranked hazards, respectively in cubicle houses and tie stalls, in the development of the most common problems in dairy cows. A total space allowance of less than 8.6 m² in cubicle houses negatively affects welfare. Cubicle width should be at least 1.8 times cow hip width. In cubicle houses there should be at least as many cubicles as there are cows in the house. A lying area of at least 2.7 m² / heifer (up to 400 kg) is necessary to avoid negative impact on welfare and production. In loose-housed cows, the area around each feeding place is a location where much aggression can occur. Therefore, the feeding area should be designed in such a way and with sufficient space that all cows can feed with minimal aggression or other interference. Since leg disorders are the major welfare problem for dairy cattle and leg disorders are a problem also in well managed cubicle houses, alternatives to cubicles e.g. straw yards and improvements to cubicle house design should be considered. When possible, dairy cows and heifers should be given access to well managed pasture or other suitable outdoor conditions, at least during summer time or dry weather. Tie-stalls restrict the voluntary movement and social behaviour of dairy cows. When periods of exercise are possible some of the adverse effects are reduced. Therefore, systems of husbandry and management should involve a minimum time of restricted movement in order that all dairy cows are able to meet their need to show certain behaviours such as grooming, social interaction and exercise. While tie-stall use continues, cows should have daily exercise that involves walking freely inside or outside (except where there are adverse climatic conditions) and also the freedom to carry out other behaviours. A minority opinion on the use of tie-stalls was expressed by some Panel members. All dairy cattle should be fed a diet that provides sufficient energy, nutrients and dietary fibre to meet the metabolic requirements in a way that is consistent with digestion. When diet is changed there should be carefully controlled transition feeding in order to prevent poor welfare in the cattle. Feeding systems should allow every individual cow to meet her needs for quantity and quality of feed. Dairy cows should be provided with drinking water whatever their diet. This water should be in sufficient quantity to prevent any dehydration and should be: free from repellent odour and taste, harmful infectious agents, toxic substances and contaminants that can accumulate in body tissue or be excreted in milk. Both indoors as well as outdoors, continuous access to water should be provided. Automatically regulated troughs and drinker bowls should be installed in the animal houses and farmyards. There should be systems for monitoring the prevalence of lameness by scoring locomotion and foot lesions every 3 to 6 months in all dairy herds. Because of the high risk of lameness in dairy cattle all dairy farmers should implement a lameness prevention programme. On farms with a high prevalence of recognisable locomotor difficulties, e.g. approaching 10%, there should be improvement of housing conditions, genetic strain and management practices. In addition to improved methods for genetic selection, the prevalence of mastitis should be reduced also through: treatment of clinical and subclinical disease, dry cow therapy, identification and elimination of carrier cows, prevention of transmission of infection from cow to cow or through the environment, and improvement of the immune system by minimising stress factors and by a controlled and nutritionally-balanced feed intake. Pain management should be part of the treatment of severe lameness and clinical mastitis. Farmers should be well trained in recognizing signs of disease at early stages and veterinary advice should be sought at an early stage of disease in dairy cattle. Recommendations in this opinion for disease prevention and management should be followed. The body of research on dairy cattle welfare should be incorporated into codes of practice and monitoring protocols that address potential hazards and incorporate animal-based measures of welfare outcomes
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| 7. |
- Algers, Bo
(författare)
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Scientific Opinion on the welfare of cattle kept for beef production and the welfare in intensive calf farming systems
- 2012
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Ingår i: EFSA Journal. - : Wiley. - 1831-4732. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Information given in previous Opinions "Welfare of cattle kept for beef production" (SCAHAW, 2001) and "The risks of poor welfare in intensive calf farming systems" (EFSA, 2006) is updated and recent scientific evidence on the topics reviewed. Risks of poor welfare are identified using a structured analysis, and issues not identified in the SCAHAW (2001) beef Opinion, especially effects of housing and management on enteric and respiratory diseases are reviewed. The Opinion covers all systems of beef production, although the welfare of suckler cows or breeding bulls is not considered. The Chapter on beef cattle presents new evidence and recommendations in relation to heat and cold stress, mutilations and pain management, digestive disorders linked to high concentrate feeds and respiratory disorders linked to overstocking, inadequate ventilation, mixing of animals and failure of early diagnosis and treatment. Major welfare problems in cattle kept for beef production, as identified by risk assessment, were respiratory diseases linked to overstocking, inadequate ventilation, mixing of animals and failure of early diagnosis and treatment, digestive disorders linked to intensive concentrate feeding, lack of physically effective fibre in the diet, and behavioural disorders linked to inadequate floor space, and co-mingling in the feedlot. Major hazards for white veal calves were considered to be iron-deficiency anaemia, a direct consequence of dietary iron restriction, enteric diseases linked to high intakes of liquid feed and inadequate intake of physically effective fibre, discomfort and behavioural disorders linked to inadequate floors and floor space.
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| 8. |
- Algers, Bo, et al.
(författare)
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Scientific opinion on welfare of dairy cows in relation to behaviour, fear and pain based on a risk assessment with special reference to the impact of housing, feeding, management and genetic selection
- 2009
-
Ingår i: EFSA Journal. - : Wiley. - 1831-4732.
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Tidskriftsartikel (refereegranskat)abstract
- Following a request from the European Commission, the AHAW Panel was asked to deliver a Scientific Opinion on the welfare of dairy cows, considering whether current farming and husbandry systems comply with the requirements of and welfare of dairy cows from the pathological, zootechnical, physiological and behavioural points of view. Due to the great diversity of topics and the huge amount of scientific data, it was proposed that separate scientific opinions on different welfare subjects would be more adequate and effective. Therefore, it was agreed to subdivide the risk assessment process into four different subjects: i) metabolic and reproductive disorders, ii) udder disorders, iii) leg and locomotion problems and iiii) behaviour, fear and pain. A fifth scientific opinion integrates conclusions and recommendations from the scientific report with the outcomes from the four separate risk assessments. The scientific opinion on welfare of dairy cows in relation to behaviour, fear and pain, based on a risk assessment with special reference to the impact of housing, feeding, management and genetic selection, was adopted by the AHAW Panel on 05 June 2009. In the risk assessment four different farming scenarios were considered: 1) cubicle houses; 2) tie-stalls; 3) straw yards; 4) pasture. Identified hazards were classified under (a) housing, (b) nutrition and feeding, (c) management and (d) genetics. The risk assessment outcomes for each of these four classes of hazards were determined and the four different farming scenarios compared. When comparing the different farming systems it can be concluded that the risk of suffering behaviour problems, fear and pain can be dependent of the farming systems. In the risk assessment, the risk estimates for behavioural problems, fear and pain associated with housing were generally higher than the risk estimates observed for the other categories of hazards. The risk estimates for behavioural problems, fear and pain associated with housing were highest for tie-stalls and lowest for cows at pasture, and were lower in straw yards than in cubicle housing. According to the scoring system used in this analysis, among the highest ranked hazards in terms of risk estimate in relation to the housing were design of stalls and inadequate bedding in both tie-stalls and cubicle housing. In cubicle houses, inappropriate flooring where cows walk posed the largest risk estimate for behavioural problems whereas having fewer cubicles than cows was the hazard with the largest magnitude of the adverse effect, but the risk estimate was relatively low. Poor air quality was rated as a hazard with a large magnitude of the adverse effect in all types of indoor housing. However, the degree of exposure was low, resulting in low risks for behavioural problems. For cows at pasture, hazards associated with housing have much lower magnitude of the adverse effect than for cows housed indoors. For cows at pasture, the largest risk estimates for behavioural problems were associated with inappropriate temperature and humidity, lack of handling facilities and problems with the milking parlour and waiting areas. The highest ranked hazards associated with straw yards were inadequate bedding, lack of space, zero grazing and inadequate flooring where cows walk. Finally, zero-grazing was rated as a hazard with a large magnitude of the adverse effect on cow behaviour, fear and pain in tie-stalls, straw yards and cubicle housing, but the risk estimate was relatively low. In relation to the use of tie stalls, Panel members concluded that tie-stalls restrict the voluntary movement and social behaviour of dairy cows. When periods of exercise are possible some of the adverse effects are reduced. Therefore, systems of husbandry and management should involve a minimum time of restricted movement in order that all dairy cows are able to meet their need to show certain behaviours such as grooming, social interaction and exercise. While tie-stall use continues, cows should have daily exercise that involves walking freely inside or outside (except where there are adverse climatic conditions) and also the freedom to carry out other behaviours. A minority opinion on the use of tie-stalls was expressed by some Panel members. The risk assessment showed that nutrition and feeding hazards have a lower risk of causing behavioural problems compared with other factors. The risk estimates and magnitudes of the adverse effects of behavioural problems associated with nutrition and feeding were quite similar for cubicle housing, tie-stalls and straw yards; however there were fewer hazards identified for pasture. The highest risk estimate for behavioural problems due to nutrition and feeding was associated with improper ration composition and underfeeding in cubicle houses, tie-stalls and straw yards. However, the magnitudes of the adverse effects were highest for poor feed quality of the roughage, improper ration composition, underfeeding, and improper sensory quality of the water source. As regards the management aspects for dairy cows, the maintenance of stable groups ensures that long-lasting affiliative relationships can continue, reducing the overall stress level in cows. In the risk assessment, the hazard with the highest or second highest magnitude of the adverse effect in the three systems where animals are kept loose was mixing animals from different groups. Husbandry practices should avoid regrouping of dairy cows in order to facilitate continuation of long-lasting social bonds, avoid frequent disruption and provide social stability. If social mixing of dairy cows is unavoidable, stress should be reduced by providing larger space allowance during grouping in buildings or on pasture. Regrouping or mixing on pasture is ideal as it offers space and good flooring. Appropriate management, together with larger space allowance, can minimize social agonistic interactions in the herd in general. When cows have to calve in groups indoors, this may cause disturbance for the cow. An individual calving pen with some visual and auditory contact with other cows gives the cow the best possibility to show normal behaviour and calve without problems. Dairy cows allowed to stay with their calf after birth and separated within 24 h show a mild stress reaction after separation. After the mother-young bond has been established, i.e. 2 days or more, the cow shows a stronger reaction after separation, and this reaction becomes stronger the longer the time that they stay together. Some infectious diseases may be transmitted from the cow to the calf at birth, and then an important measure for reducing disease transmission is to separate the calf very shortly after birth. If the cow is placed out of hearing and sight of the calf, the stress reaction of the cow is lower. When cow and calf have been together for prolonged suckling, e.g. 6-12 weeks, weaning plates placed on the calves reduce the stress reaction in the cow after separation. In the risk assessment, genetic selection for high milk yield with insufficient emphasis on other traits relating to fitness showed a very low risk of causing behavioural problems compared with other factors and no differences were observed among the different housing systems analysed. The magnitude of the adverse effect and the risk estimate for behavioural problems was highest for cows with high genetic potential for production due to selection ignoring other traits when the housing, nutrition and management are not optimized
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| 9. |
- Algers, Bo, et al.
(författare)
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Scientific opinion on welfare of dairy cows in relation to leg and locomotion problems based on a risk assessment with special reference to the impact of housing, feeding, management and genetic selection
- 2009
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Ingår i: EFSA Journal. - : Wiley. - 1831-4732.
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Tidskriftsartikel (refereegranskat)abstract
- Following a request from the European Commission, the AHAW Panel was asked to deliver a Scientific Opinion on the welfare of dairy cows, considering whether current farming and husbandry systems comply with the requirements of and welfare of dairy cows from the pathological, zootechnical, physiological and behavioural points of view. Due to the great diversity of topics and the huge amount of scientific data, it was proposed that separate scientific opinions on different welfare subjects would be more adequate and effective. Therefore, it was agreed to subdivide the risk assessment process into four different subjects: i) metabolic and reproductive disorders, ii) udder disorders, iii) leg and locomotion problems and iiii) behaviour, fear and pain. A fifth scientific opinion integrates conclusions and recommendations from the scientific report with the outcomes from the four separate risk assessments. The scientific opinion on the welfare of dairy cows in relation to leg and locomotion problems, based on a risk assessment with special reference to the impact of housing, feeding, management and genetic selection was adopted by the AHAW Panel on 05 June 2009. In the risk assessment four different farming scenarios were considered: 1) cubicle houses; 2) tie-stalls; 3) straw yards; 4) pasture. Identified hazards were classified under (a) housing, (b) nutrition and feeding, (c) management and (d) genetics. The risk assessment outcomes for each of these four classes of hazards were determined and the four different farming scenarios compared. When comparing the different farming systems it is concluded that the farming system has a major influence on leg and locomotion problems defined both in terms of magnitude of the adverse effect and risk estimate. Hazards associated with housing and management rank much higher, in terms of risk estimate, than those associated with nutrition and genetics. Magnitudes of the adverse effects and risk estimates in housing are much greater in systems involving cubicle housing or tie-stalls, than in straw yards or at pasture. Hazards attributable to management and genetic selection for high yields are similar for all farming systems, however risk estimates are higher in cubicles and tie-stalls than in straw yards or at pasture. In general, concrete flooring has a higher risk of claw disorders than pasture and straw-yards, since standing and walking for prolonged periods on concrete floors, or floors that are wet or covered in slurry cause severe foot disorders. According to the scoring system used in this analysis, the most important hazard in relation to the housing was the lack of space in tie-stalls. Larger space allowance, in the walking area as well as the lying area, is beneficial for the welfare of cows with respect to decreased aggression, injuries, and occurrence of lameness. Tied cattle have more lameness than those free to move with good flooring and resting facilities. In cubicles the most important magnitudes of the adverse effect and risk estimates are associated with inadequate floor in the walking area, poor cubicle design and inadequate bedding. Dairy cows have a strong motivation for lying, and lie down for 7-15 hours per day. The lying time varies between housing systems and can be affected by housing design. Altered patterns of lying down can be a sign of lameness, injury or poor housing design. When dairy cattle are kept in cubicle houses, foot and leg disorders are substantially more frequent than they are in straw yards. Since leg and foot disorders are the major welfare problem for dairy cattle and leg and foot disorders are a problem even in well-managed cubicle houses, alternatives to cubicles, e.g. straw yards, are needed and in the short-term improvements to cubicle house design should be made. In the case of nutrition and feeding the most important hazards are inadequacies in transition feeding and imbalanced diets. The greatest risk estimate is related to transition feeding. However the probability of risks attributable to nutrition and feeding systems are low relative to those attributable to housing and management. As regards the management measures for dairy cows, the risk assessment showed that the most important management hazards causing leg and locomotion problems are those related to inadequate care and monitoring of foot health and hygiene, and these are similar across all housing systems considered. However the risk estimate and magnitude of the adverse effect are exacerbated by hazards in the housing category and are approximately twice as great in cubicle systems and tie-stalls as in straw yards or at pasture. Most lame cows are in pain and have greater difficulty in coping with their living conditions than non-lame cows because of the effects of the foot or leg disorder on walking, lying comfort, standing up and avoidance behaviour. Lame cows are more likely to become subordinate, lose body condition and are more prone to show reduced fertility and to develop mastitis and metabolic disease. Weekly attention to foot hygiene in dairy cattle leads to reduction of infectious conditions of the foot. When the prevalence of recognisable locomotor difficulties in dairy cattle is above 10%, this indicates that the prevention programme is inadequate. Because of the high risk of lameness in dairy cattle all dairy farmers should implement a lameness prevention programme. Well-executed hoof-trimming can reduce the likelihood of lameness and improve cow welfare but poorly executed hoof-trimming can cause lameness. The genetic selection has changed the form and size of dairy cows and hence demands on their behaviour and other adaptive mechanisms. The spatial requirements of the dairy cow have increased, as well as its vulnerability for mechanical impacts and wounds on the exterior parts of the body, the skin, limbs and claws. Udder shape and volume are of specific concern, with respect to normal locomotion, prevention of lameness and comfort during resting in the most common housing types. The risk assessment confirmed that genetic selection for high milk yield with insufficient emphasis on other traits relating to fitness increases the risk of suffering from leg and locomotion problems. This risk is greater when housing, nutrition and management are unable to compensate for the adverse effects of genetic selection. A general conclusion is that leg and locomotion problems in dairy cows are multifactorial in origin, so that the magnitudes of the adverse effect in individual animals and the risk estimates, measured in terms of herd prevalence, can usually be attributed to a combination of hazards associated with housing, feeding and nutrition, management and genetics. However the most important hazards and risks are those associated with inadequate provisions for lying, standing and walking in cubicle houses and tie-stalls, and management failures relating to locomotion monitoring and foot care
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- Algers, Bo, et al.
(författare)
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Scientific opinion on welfare of dairy cows in relation to metabolic and reproductive problems based on a risk assessment with special reference to the impact of housing, feeding, management and genetic selection
- 2009
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Ingår i: EFSA Journal. - : Wiley. - 1831-4732.
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Tidskriftsartikel (refereegranskat)abstract
- Following a request from the European Commission, the AHAW Panel was asked to deliver a Scientific Opinion on the welfare of dairy cows, considering whether current farming and husbandry systems comply with the requirements of and welfare of dairy cows from the pathological, zootechnical, physiological and behavioural points of view. Due to the great diversity of topics and the huge amount of scientific data, it was proposed that separate scientific opinions on different welfare subjects would be more adequate and effective. Therefore, it was agreed to subdivide the risk assessment process into four different subjects: i) metabolic and reproductive disorders, ii) udder disorders, iii) leg and locomotion problems and iiii) behaviour, fear and pain. A fifth scientific opinion integrates conclusions and recommendations from the scientific report with the outcomes from the four separate risk assessments. The scientific opinion on welfare of dairy cows in relation to metabolic and reproductive problems, based on a risk assessment with special reference to the impact of housing, feeding, management and genetic selection, was adopted by the AHAW Panel on 05 June 2009. In the risk assessment four different farming scenarios were considered: 1) cubicle houses; 2) tie-stalls; 3) straw yards; 4) pasture. Identified hazards were classified under (a) housing, (b) nutrition and feeding, (c) management and (d) genetics. The risk assessment outcomes for each of these four classes of hazards were determined and the four different farming scenarios compared. When comparing the different farming systems it can be concluded that the risk of suffering metabolic and reproductive disorders is independent of the housing system; however, lower risk estimate values were observed for animals kept at pasture, which may indicate that they are less likely to have metabolic and reproductive problems and therefore poor welfare. According to the scoring system used in this analysis, the most important hazards in relation to the housing were poor cubicle design and lack of space in cubicle houses and tie-stalls, respectively, with high risk estimate values. Inadequate ventilation, temperature and humidity were the highest ranked hazard in straw yards. However, the risk estimate and magnitude values in straw yards were much lowers than in cubicles and tie-stalls. Nutrition and feeding related hazards have a major influence on metabolic and reproductive problems defined both in terms of magnitude of the adverse effect and risk estimate. An inadequate transition feeding was the hazard with the highest risk estimates in the three indoor farming systems. Cows are in negative energy balance during early lactation, when functional body tissues may be metabolised to excess, causing poor welfare. This risk is particularly severe in high-producing genetic strains. A transition period feeding that sustains dry matter intake while maintaining optimal body condition at calving reduces this risk. Also, the risk of cow over/under feeding was very high ranked, as well as the risk of an unbalanced diet. Cattle require a diet that is adequate in fibre otherwise the anatomy and physiology of the rumen are impaired and there is increased risk of ruminal acidosis and other related disorders. Unbalanced diet is the major cause of sub-acute ruminal acidosis. Ruminal acidosis (acute and subacute) and parturient paresis (milk fever) can cause very poor welfare in dairy cows. When concentrate dispensers are used, appropriate control is necessary to avoid over/underfeeding and reduce the risk of acute ruminal acidosis. Concentrate feeding facilities on dairy farms should be adequately maintained and diets carefully balanced so as to maintain optimal ruminal fermentation and to minimise negative energy balance. Reproductive disorders can reflect prolonged or short-term poor welfare, such as lack of oestrus, embryonic loss or early abortion due to stress during parturition and in early lactation, and can also cause poor welfare directly, particularly dystocia and genital infections associated with pain or inflammatory reactions. Among the hazards related to the management of dairy cows, inadequate biosecurity was the highest ranked hazard in all husbandry systems. The magnitude of the adverse effect was the same but in the case of pasture the risk estimate value was lower than on the other three systems. Good hygiene should be provided at calving to reduce risk of genital infections. Improper management was also highly ranked in all farming systems. Recent research shows that a reproductive management strategy with extended calving intervals of 15 months or more seems to offer significant advantages for the welfare of high yielding dairy cows, without reducing overall milk production. To reduce risk of dystocia particularly at first calving, heifers should be inseminated after they reach the mature weight for the breed and only sires known to have low incidence of dystocia should be used to breed heifers. Genetic selection for high milk yield with insufficient emphasis on other traits relating to fitness increases the risk of suffering from metabolic and reproductive problems. This risk is greater when housing, nutrition and management are unable to compensate for the adverse effects of genetic selection. The increased inbreeding of recent years may lead to, or be associated with, increased reproductive problems, reduced lifetime milk production and a reduction in breeding performance if it continues. Excessive or prolonged negative energy balance in dairy cows is more likely to occur in the highest producing animals and has been found to be associated with reduced fertility, digestive, metabolic and infectious disease, especially mastitis
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