M.B.M. Bracke

Aggregation of measures to produce an overall assessment of animal welfare. Part 1: a review of existing methods.

Several systems have been proposed for the overall assessment of animal welfare at the farm level for the purpose of advising farmers or assisting public decision-making. They are generally based on several measures compounded into a single evaluation, using different rules to assemble the information. Here we discuss the different methods used to aggregate welfare measures and their applicability to certification schemes involving welfare. Data obtained on a farm can be (i) analysed by an expert who draws an overall conclusion; (ii) compared with minimal requirements set for each measure; (iii) converted into ranks, which are then summed; or (iv) converted into values or scores compounded in a weighted sum (e.g. TGI35L) or using ad hoc rules. Existing methods used at present (at least when used exclusively) may be insufficiently sensitive or not routinely applicable, or may not reflect the multidimensional nature of welfare and the relative importance of various welfare measures. It is concluded that different methods may be used at different stages of the construction of an overall assessment of animal welfare, depending on the constraints imposed on the aggregation process.

Welfare of ducks in European duck husbandry systems

European duck meat production is based on the use of Pekin, Muscovy and Mule duck genotypes that vary in their behavioural and physiological characteristics. Furthermore, large differences exist in their housing and management conditions. The aim of this review is to discuss the welfare of these different genotypes in typical husbandry systems, focusing on ducks kept for meat production. Firstly, factors that can affect duck welfare, such as stocking density and group size, access to straw, an outdoor run, or open water, are described. Secondly, welfare problems such as feather pecking, fear and stress, and health problems are assessed. Thirdly, the various systems used in Europe are described for these aspects. Giving ducks access to straw, an outdoor run, or open water increases the behavioural opportunities of the ducks (foraging, preening, bathing, and swimming), but can also lead to poor hygiene and increased health- and food safety risks. Therefore, practical solutions that allow expression of natural behaviour, but do not lead to hygiene or health problems have to be found and some practical suggestions are provided.

Characteristics of biter and victim piglets apparent before a tail-biting outbreak

Little is known about the characteristics of biters and victims before the appearance of a tail-biting outbreak in groups of pigs. This study aimed to characterise biters and victims (according to gender and performance) and to quantify their behavioural development during the 6 days preceding the tail-biting outbreak. The hypotheses tested were: (a) biters are more often female, are the lighter pigs in the group, are more restless and perform more aggressive behaviour; and (b) victims are more often male, heavier and less active. Using video recordings we carried out a detailed study of 14 pens with a tail-biting outbreak among the weaned piglets. All piglets were individually marked and we observed the behaviour of biters, victims and control piglets (piglet types). In every pen, each piglet type was observed every other day from 6 days before (D-6) to the day of the first visible tail damage (i.e. day of tail biting outbreak; D0). While the number of male biters (6 of the 14 biters) and male victims (11 of the 14 victims) was not significantly different (P = 0.13), this numerical contrast was considerable. The start weight of victims was significantly (P = 0.03) higher (8.6 kg) than those of biters (7.5 kg) and control piglets (8.0 kg). Biters tended (P = 0.08) to spend longer sitting/kneeling (3.1 min/h) than controls (1.7 min/h), but no differences were seen in the time spent lying or standing. Victims tended (P = 0.07) to change posture more often (restlessness) than controls and chased penmates more (P = 0.04) than biters. Victims also performed more (P = 0.04) aggressive behaviour than biters and controls. In contrast, biters tended (P = 0.08) to be chased by penmates more often and tended (P = 0.06) to receive more aggressive behaviour than controls. Furthermore, biters spent longer manipulating the enrichment device (P = 0.01) and the posterior/tail (P = 0.02) of their penmates than controls and tended (P = 0.06) to perform more tail bites than victims. Victims received more posterior/tail manipulation (P = 0.02) and tail bites (P = 0.04) than controls. It was also noticed that, independent of piglet type, restlessness (P = 0.03) increased and the frequency of performed tail bites tended (P = 0.08) to increase in the 6 days preceding a tail-biting outbreak. These findings may contribute to the early identification of biters or victims and support the development of strategies to minimise the occurrence of tail biting.

Individual piglets' contribution to the development of tail biting.

Conflicting hypotheses exist about the contribution of individual pigs to the development of a tail-biting outbreak, but there is limited quantitative information to support or dismiss them. This study aims to quantify the development of tail-biting behaviour at pen and individual piglet level, before and after the first visible tail damage. Video recordings of 14 pens with tail-biting outbreaks and individually marked weaned piglets were used to observe tail-biting incidents (TBIs; piglet biting a penmates tail). When visible tail damage was first observed in a pen (i.e. day of tail biting outbreak; D0), the video recordings of the previous 6 (till D-6) and the following 6 days (till D6) were analysed every other day for TBIs and the identities of the biter and bitten piglet were recorded. The average TBIs per individual piglet (within each pen) per observation day were analysed to quantify the development of tail-biting behaviour and to identify pronounced biters and/or bitten piglets. The (absence of) coherence for TBIs in a pen was used to test whether biters preferred a specific penmate. There was an exponential increase in the intensity (linear on log scale) of the TBIs from an average of 0.7 bites/h at D-6 to 2.3 bites/h at D6. An additional negative quadratic component suggests that a plateau for tail-biting behaviour was reached by the end of the observation period. Before any visible tail damage was observed (i.e. before D0), 82% of the piglets performed and 96% of them received tail bites. After D0, the figures were 99% and 100%, respectively. One or a few pronounced biters could be identified in almost all pens. These biters already showed more tail biting at D-6 than their penmates. Furthermore, these biters showed a greater increase in tail-biting behaviour during the observation period than the average scores of their penmates. In contrast, there was no apparent increase in the receipt of bites among the piglets that had already been bitten more than their penmates at D-6. Finally, there was no significant coherence between biters and bitten piglets, indicating that biters showed no preference for biting particular penmates, even when some of them had a damaged tail. These results show that, by using observations of TBIs, possible biters or bitten piglets can already be identified 6 days before tail damage is first apparent in a pen.

Chains as proper enrichment for intensively-farmed pigs?

Abstract This chapter primarily compiles work in which the author (Marc Bracke) has been involved with providing science-based decision support on the question of what is proper enrichment material for intensively-farmed pigs as required by EC Directive 2001/93/EC. Proper manipulable material should primarily provide occupation (i.e., reduce boredom), and preferably reduce tail biting. The RICHPIG model was built expressing enrichment value as a score on a scale from 0 to 10. Metal objects like short metal chains had the lowest score. Subsequently, the Dutch government banned the use of metal chains and most Dutch pig farmers attached a hard plastic ball or pipe to the prevalent, short metal chain. Unfortunately, our on-farm observations repeatedly suggested that this ‘enrichment’ may have reduced pig welfare, rather than improving it as intended by the Directive. So-called AMI (animal–material interaction) sensors can be used to (semi-)automatically record object manipulation by attaching a motion sensor to hanging objects. AMI sensors may provide objective, flexible and feasible registration tools of enrichment value, but their application is still rather demanding. Exploratory data are presented to demonstrate the utility of AMI sensors. The enrichment value of short metal chains can be improved upon, e.g., by providing branched chains. This entails making chains longer, preferably reaching until the floor, and making them more readily available in a pig pen. To facilitate the process towards proper enrichment the principle of intelligent natural design (IND) is proposed. IND entails organising a repeated selection process of the (currently) best-available enrichment material so as to gradually reduce pig boredom and enhance the opportunities for the rearing of pigs with intact tails. IND should start with basically all pig farmers implementing promising enrichment like the branched-chain design on their farms as soon as possible, followed by conducting small-scale on-farm experiments to compare and improve enrichment through sharing of available knowledge. Suggestions are given as to how and why this novel approach can be implemented to solve persistent animal welfare problems like providing proper enrichment for intensively-farmed pigs.

Electrophysiological and behavioural responses of turbot (Scophthalmus maximus) cooled in ice water

Behavioural, neural and physiological aspects related to pre-slaughter cooling of turbot habituated to two environmental temperatures (18.7 and 12.0°C) were investigated. Six fish in both treatments were immersed in ice water for 75 min. For control, four fish were immersed in water under their habituated environmental temperature. Turbot did not show a quick reduction of overall power in the EEG (electroencephalogram) to less than 10%, nor did the turbot show a shift in brain wave predominance from high to low frequency waves. At 15 min after immersion in ice water at least 7 out of 12 fish still showed total power values over 10% of pre-immersion values. Significant reductions in responsiveness to needle scratches and reduced breathing after immersion in ice water were observed, but none of these parameters had dropped to 0 even after 75 min in ice water. A significant reduction in gill score was found at 2 and 5 min after immersion in ice water compared to the control fish (p<0.05). Heart rates significantly increased immediately after immersion in ice water and then decreased to a low basal value 30 min after immersion. The heart beat did not show major changes in regularity over time. Finally, at 15 and 75 min the turbot in ice water were significantly more responsive to vibration than to needle scratches. From these results we conclude that immersion in ice water may not induce unconsciousness, however, the brain activity does decrease to a lower level. The implication of this low brain activity with respect to welfare is not clear. Increased heart rates and maintained low brain activity and response to needle scratches during early immersion in ice water are indicative of a stress response appearing to affect welfare negatively.

Reply to Diggles et al. (2011): Ecology and welfare of aquatic animals in wild capture fisheries

In their recent review, Diggles et al. advocate the use of ‘‘function-based’’ and ‘‘nature-based’’ welfare approaches instead of the ‘‘feelings-based’’ approach regarding aquatic animals in wild capture fisheries. We disagree with key premises and conclusions in their paper and have a few remarks as to what welfare is and what it is not. The basis for the interest in animal welfare is man’s capacity for empathy and the assumption or suspicion that animals have an experience of life. The term welfare, however it is measured, should be restricted to addressing the quality of the lives of animals that are able to experience it. Since it is commonly accepted that e.g., plants and fungi have no sentient experience of life, the terms ‘‘plant welfare’’ and ‘‘fungus welfare’’ do not exist—they would have no meaning. Still, in order to produce healthy plant crops, offering the plants conditions and care that meet function-based ‘‘welfare’’ criteria is generally a good strategy, as it will ensure healthy, growing plants. As this care is instrumental in the production of plant crops, making a semantic detour via constructed welfare terms is not necessary to justify such practices. Feelings are partially concealed to anyone but the subject itself. However, verbal creatures, like neighbors, friends and family, can talk about their experience of life, and this will often reflect how they feel. Non-verbal communication can be at least as effective in expressing welfare. The welfare of sentient animals and human beings with limited verbal capacities (such as very young children and mentally impaired individuals) can be assessed, more or less directly using emotional expressions (e.g., vocalisations) and tests [e.g., cognitive bias test (Harding et al. 2004)]. In addition, we may check whether they appear fit and agile and with a healthy appetite, i.e., how they function. The reason why the function-based animal welfare approach exists is that it makes welfare measurable under the assumption that an animal that does not function properly, does not or will not have good welfare, provided that it has the capacity for having an experience of life. Function is therefore a welfare indicator; a useful proxy for current and future welfare, but not welfare in itself. The T. Torgersen (&) T. S. Kristiansen Animal Welfare Research Group, Institute of Marine Research, Matre Research Station, 5984 Matredal, Norway e-mail: thomast@imr.no

A 'meta-analysis' of effects of post-hatch food and water deprivation on development, performance and welfare of chickens

A ‘meta-analysis’ was performed to determine effects of post-hatch food and water deprivation (PHFWD) on chicken development, performance and welfare (including health). Two types of meta-analysis were performed on peer-reviewed scientific publications: a quantitative ‘meta-analysis’ (MA) and a qualitative analysis (QA). Previously reported effects of PHFWD were quantified in the MA, for variables related to performance, mortality and relative yolk sac weight. The QA counted the number of studies reporting (non-)significant effects when five or more records were available in the data set (i.e. relative heart, liver and pancreas weight; plasma T3, T4 and glucose concentrations; relative duodenum, jejunum and ileum weight; duodenum, jejunum and ileum length; and villus height and crypt depth in duodenum, jejunum and ileum). MA results indicated that 24 hours of PHFWD (i.e. ≥12–36 hours) or more resulted in significantly lower body weights compared to early-fed chickens up to six weeks of age. Body weights and food intake were more reduced as durations of PHFWD (24, 48, 72, ≥84 hours) increased. Feed conversion rate increased in chickens up to 21 and 42 days of age after ≥84 hours PHFWD in comparison with chickens fed earlier. Total mortality at day 42 was higher in chickens after 48 hours PHFWD compared to early fed chickens or chickens after 24 hours PHFWD. First week mortality was higher in chickens after ≥84 hours PHFWD than in early fed chickens. The MA for relative yolk sac weight was inconclusive for PHFWD. The QA for plasma T3, T4 and glucose concentrations indicated mainly short-term decreases in T3 and glucose in PHFWD chickens compared to early fed chickens, and no effects of PHFWD on T4 concentrations. Relative weights of liver, pancreas and heart were lower after PHFWD, but only in the first week of life. A retarded development of gut segments (duodenum, jejunum and ileum) was found in the first week of life, measured as shorter, lower relative weight, and lower villus height and crypt depth. It is concluded that 48 hours (≥36–60 hours) PHFWD leads to lower body weights and higher total mortality in chickens up to six weeks of age, the latter suggesting compromised chicken welfare, but effects of PHFWD on organ development and physiological status appear to be mainly short-term.

Exploration Feeding and Higher Space Allocation Improve Welfare of Growing-Finishing Pigs

Simple Summary A lack of exploration materials in pig pens can result in damaging behavior towards pen mates. The objective of our study was to reduce skin and tail lesions by frequently providing small amounts of feed on the floor and by providing more space per pig. Both the so-called “exploration feeding” and the additional space resulted in fewer skin lesions. Finally, this can lead to a more welfare-friendly pig husbandry. Abstract Lack of environmental enrichment and high stocking densities in growing-finishing pigs can lead to adverse social behaviors directed to pen mates, resulting in skin lesions, lameness, and tail biting. The objective of the study was to improve animal welfare and prevent biting behavior in an experiment with a 2 × 2 × 2 factorial design on exploration feeding, stocking density, and sex. We kept 550 pigs in 69 pens from 63 days to 171 days of life. Pigs were supplemented with or without exploration feeding, kept in groups of seven (1.0 m2/pig) or nine animals (0.8 m2/pig) and separated per sex. Exploration feeding provided small amounts of feed periodically on the solid floor. Skin lesion scores were significantly lower in pens with exploration feeding (p = 0.028, p < 0.001, p < 0.001 for front, middle, and hind body), in pens with high compared to low space allowance (p = 0.005, p = 0.006, p < 0.001 for front, middle and hind body), and in pens with females compared to males (p < 0.001, p = 0.005, p < 0.001 for front, middle and hind body). Males with exploration feeding had fewer front skin lesions than females with exploration feeding (p = 0.022). Pigs with 1.0 m2 compared to 0.8 m2 per pig had a higher daily gain of 27 g per pig per day (p = 0.04) and males compared to females had a higher daily gain of 39 g per pig per day (p = 0.01). These results indicate that exploration feeding might contribute to the development of a more welfare-friendly pig husbandry with intact tails in the near future.

Killing wild geese with carbon dioxide or a mixture of carbon dioxide and argon

The killing of animals is the subject of societal and political debate. Wild geese are caught and killed on a regular basis for fauna conservation and damage control. Killing geese with carbon dioxide (CO2) is commonly practiced, but not listed in legislation on the protection of flora and fauna, and societal concerns have been raised against this method. In this study, an experiment was carried out killing 30 wild-caught geese using either CO2 or a mixture of CO2 and argon (Ar). Brain function (EEG) and heart function (ECG) were measured to determine loss of consciousness and onset of death. The stage of unconsciousness was reached on average within one minute in both treatments (56 s for CO2 and 50 s for CO2 and Ar). States of minimal brain activity and ineffective heart beat were reached more quickly using CO2 compared to CO2 and Ar (112 versus 178 s for minimal brain activity and 312 versus 394 s for ineffective heart beat for CO2 and the mixture of CO2 and Ar, respectively). The mixture of carbon dioxide and argon did not significantly reduce time to loss of consciousness or death. Further studies on behaviour and stress physiology are needed to determine conclusively whether CO2 alone is a satisfactory agent to kill wild-caught geese as the lower CO2 concentration in the CO2-Ar treatment may act as a sedative and reduce the aversiveness of the animals during exposure to lethal gas concentrations.