Lying, Feeding and Activity Preference of Weaned Piglets for LED-Illuminated vs. Dark Pen Compartments.

Little is known on the effect of light on pig behaviour. The choice behaviour of weaned piglets kept under two different light-emitting diode (LED) illuminance levels was investigated: 32 piglets (in two batches) were housed in a preference test room composed of two identical double pen units. One side of the pen unit was permanently illuminated with 600 lux, while the other was darkened to almost 0 lux (~0 lx); by using a passageway, piglets could move between the two sides. The "lying", "eating" and "activity" behaviours were evaluated during three days in the first, third and fifth experimental week based on video recordings and a 5-min time sampling method. At first, piglets preferred to stay in the 600 lux illuminated compartments. Then, this preference decreased for the "eating" and "activity" behaviours and reversed for the "lying" behaviour, with the darkened compartments being preferred. The results also show that pen soiling was higher under 600 lux, but feed consumption was not affected by the illuminance. Since pigs choose between the two illuminance levels to perform specific behaviours, illuminance could be used to divide the pens into functional areas and, thus, help in meeting pigs' behavioural needs.

Effects of edible environmental enrichments during the rearing and laying periods in a littered aviary-Part 1: integument condition in pullets and laying hens.

Severe feather pecking is a damaging allopecking behavior in pullets and laying hens which was found to be associated with multiple factors. The aim of this study was to investigate whether the occurrence of feather pecking could be reduced by additional environmental enrichment materials (EM; pecking stones and hard-pressed alfalfa bales) in a littered housing system. In total 4,000 pullets (2000 Lohmann Brown classic [LB] and 2000 Lohmann Selected Leghorn classic [LSL]) were reared in an aviary system until week 18, and 1,320 remaining laying hens were kept thereafter, from week 19 to 48. During rearing, half of the compartments were permanently supplied with enrichment materials, while the other half did not receive any EM. After transferring to the laying hens' stable, we examined the hens under four treatment variants: V1 - no EM over the entire study period; V2 - rearing period with and laying period without EM; V3 - rearing period without and laying period with EM; V4 - EM over the entire study period. The integument condition (i.e. beak protrusion, beak fissures, plumage condition, skin and toe injuries, and foot pad dermatitis) was scored in weeks 2, 4, 6, 10, 14, 18 (rearing) and 25, 30, 40, and 48 (laying period). At the end of the study (week 48), lower plumage damage was observed in the variants provided with EM during rearing (V2 and V4) compared to the other two variants (V1 and V3; P < 0.001). Skin injuries were less prevalent in week 40 in hens with access to EM during rearing (V2 and V4) than the other variants (V1 and V3) within LSL (P < 0.001), and in week 48 in the both strains (P < 0.001). The variants with access to EM during the laying period (V3 and V4) showed lesser protrusion of the beak tip in week 48 (P < 0.001). The observed beneficial effects of EM could be attributed to its impact on foraging behavior and beak-tip abrasion.

Effects of edible environmental enrichments during the rearing and laying periods in a littered aviary-Part 2: physical development of pullets and performance, egg quality, and carcass composition in laying hens.

Feather pecking and cannibalism are 2 major problems in laying hens' husbandry. Although additional environmental enrichment material (EM) supply is thought to lessen these problems, consistent evidences are lacking. This study examined the effects of EM supply (pecking stones and alfalfa bales) on biological performance, carcass composition, and animal losses in a littered housing system. 2,000 brown-egg and 2,000 white-egg layer hen pullets of the genetic strains Lohmann Brown classic and Lohmann Selected Leghorn classic, respectively, were reared separately in a 16-compartment aviary system until week 18. 1,320 remaining laying hens were then transferred to a 44-compartment laying stable (weeks 19-48). Both strains were tested under 4 treatment variants (n = 150-180 per strain and per variant): V1-no EM over the entire study period; V2-the rearing period with and the laying period without EM; V3-the rearing period without and the laying period with EM; V4-EM over the entire study period. Data on development, performance, egg quality, feed intake, EM consumption, animal losses, carcass composition, and economic traits were collected. Enrichment material supply during rearing (V2 and V4, both strains) was found to globally increase not only hens' relative gizzard mass (P = 0.036) but also the cracked eggs' percentage (compared with V3; P = 0.008) and to decrease the body mass in weeks 6 (P = 0.023) and 8 (P = 0.023) and the uniformity in week 16 (P = 0.011). Enrichment material provision during the laying period (V3 and V4, both strains) increased egg weights (P = 0.028) and the mean body mass (P = 0.036); however, continuous provision of EM (V4, both strains) increased the floor eggs' percentage (P = 0.019). The EM supply did not affect mortality, loss of production days, losses due to skin and toe cannibalism, or the income over feed costs. However, the income over feed and enrichment costs of V1 hens was higher by 0.55 €/hen than that of V4 hens (P = 0.022). Therefore, EM supply cannot be recommended as a measure to increase laying performance and reduce animal losses, but its positive effects on animal welfare should be considered.

Effects of litter and additional enrichment elements on the occurrence of feather pecking in pullets and laying hens - A focused review.

Severe feather pecking (SFP) is a serious problem in the egg production industry with regard to animal welfare and performance. The multifactorial causes of SFP are discussed in the areas of genetics, feeding, husbandry, stable climate and management. Several studies on the influence of manipulable material on the incidence of SFP in different environments and housing systems have been performed. This review presents current knowledge on the effects of litter and additional enrichment elements on the occurrence of SFP in pullets and laying hens. Because SFP is associated with foraging and feed intake behaviour, the provision of manipulable material in the husbandry environment is an approach that is intended to reduce the occurrence of SFP by adequate exercise of these behaviours. As shown in the literature, the positive effect of enrichment and litter substrate on SFP in a low-complexity cage environment is evident. On the other hand, consistent results have not been reported on the influence of additional enrichment material in housing systems with litter substrate, which represent the most common type of husbandry in Northwestern Europe. Thus, further research is recommended.

Feasibility of artificial light regimes to increase the vitamin D content in indoor-laid eggs.

Vitamin D insufficiency is prevalent worldwide. Recently, we showed that exposure of laying hens to sunlight or artificial ultraviolet B (UVB) light is an efficient strategy to increase the vitamin D content in eggs. In the current study, using 2 different chicken genotypes and stocking densities, we addressed the question of whether different UVB-emitting regimes work under real indoor housing conditions in a floor system or in furnished cages. Here, we found a 3.7-fold increase in the egg vitamin D content in Lohmann Selected Leghorn hens and a 4.2-fold increase in Lohmann Brown hens after UVB exposure for 6 h/d. The data further reveal that UVB exposure under high stocking density is equally effective compared to that at low stocking density. The different light regimes were not associated with changes in the behavior of these animals. To conclude, artificial UVB-emitting light regimes are a practical strategy to increase the vitamin D content in indoor-laid eggs.

Farm Animal Cognition-Linking Behavior, Welfare and Ethics.

Farm animal welfare is a major concern for society and food production. To more accurately evaluate animal farming in general and to avoid exposing farm animals to poor welfare situations, it is necessary to understand not only their behavioral but also their cognitive needs and capacities. Thus, general knowledge of how farm animals perceive and interact with their environment is of major importance for a range of stakeholders, from citizens to politicians to cognitive ethologists to philosophers. This review aims to outline the current state of farm animal cognition research and focuses on ungulate livestock species, such as cattle, horses, pigs and small ruminants, and reflects upon a defined set of cognitive capacities (physical cognition: categorization, numerical ability, object permanence, reasoning, tool use; social cognition: individual discrimination and recognition, communication with humans, social learning, attribution of attention, prosociality, fairness). We identify a lack of information on certain aspects of physico-cognitive capacities in most farm animal species, such as numerosity discrimination and object permanence. This leads to further questions on how livestock comprehend their physical environment and understand causal relationships. Increasing our knowledge in this area will facilitate efforts to adjust husbandry systems and enrichment items to meet the needs and preferences of farm animals. Research in the socio-cognitive domain indicates that ungulate livestock possess sophisticated mental capacities, such as the discrimination between, and recognition of, conspecifics as well as human handlers using multiple modalities. Livestock also react to very subtle behavioral cues of conspecifics and humans. These socio-cognitive capacities can impact human-animal interactions during management practices and introduce ethical considerations on how to treat livestock in general. We emphasize the importance of gaining a better understanding of how livestock species interact with their physical and social environments, as this information can improve housing and management conditions and can be used to evaluate the use and treatment of animals during production.

'Goats that stare at men'--revisited: do dwarf goats alter their behaviour in response to eye visibility and head direction of a human?

Being able to recognise when one is being observed by someone else is thought to be adaptive during cooperative or competitive events. In particular for prey species, this ability should be of use in the context of predation. A previous study reported that goats (Capra aegagrus hircus) alter their behaviour according to the body and head orientation of a human experimenter. During a food anticipation task, an experimenter remained in a particular posture for 30 s before delivering a reward, and the goats' active anticipation and standing alert behaviour were analysed. To further evaluate the specific mechanisms at work, we here present two additional test conditions. In particular, we investigated the effects of the eye visibility and head orientation of a human experimenter on the behaviour of the goats (N = 7). We found that the level of the subjects' active anticipatory behaviour was highest in the conditions where the experimenter was directing his head and body towards the goat ('Control' and 'Eyes closed' conditions), but the anticipatory behaviour was significantly decreased when the body ('Head only') or the head and body of the experimenter were directed away from the subject ('Back' condition). For standing alert, we found no significant differences between the three conditions in which the experimenter was directing his head towards the subject ('Control', 'Eyes closed' and 'Head only'). This lack of differences in the expression of standing alert suggests that goats evaluate the direction of a human's head as an important cue in their anticipatory behaviour. However, goats did not respond to the visibility of the experimenter's eyes alone.

Domestic pigs' (Sus scrofa domestica) use of direct and indirect visual and auditory cues in an object choice task.

Recently, foraging strategies have been linked to the ability to use indirect visual information. More selective feeders should express a higher aversion against losses compared to non-selective feeders and should therefore be more prone to avoid empty food locations. To extend these findings, in this study, we present a series of studies investigating the use of direct and indirect visual and auditory information by an omnivorous but selective feeder-the domestic pig. Subjects had to choose between two buckets, with only one containing a reward. Before making a choice, the subjects in Experiment 1 (N = 8) received full information regarding both the baited and non-baited location, either in a visual or auditory domain. In this experiment, the subjects were able to use visual but not auditory cues to infer the location of the reward spontaneously. Additionally, four individuals learned to use auditory cues after a period of training. In Experiment 2 (N = 8), the pigs were given different amounts of visual information about the content of the buckets-lifting either both of the buckets (full information), the baited bucket (direct information), the empty bucket (indirect information) or no bucket at all (no information). The subjects as a group were able to use direct and indirect visual cues. However, over the course of the experiment, the performance dropped to chance level when indirect information was provided. A final experiment (N = 3) provided preliminary results for pigs' use of indirect auditory information to infer the location of a reward. We conclude that pigs at a very young age are able to make decisions based on indirect information in the visual domain, whereas their performance in the use of indirect auditory information warrants further investigation.

Effect of temperature on the survival of Alaria alata mesocercariae.

Recent findings of Alaria alata mesocercariae in wild boars and other animals in Europe reinforced the concern about the public health risk posed by this parasite especially if the game meat is insufficiently heated during preparation. Cooking and freezing are effective methods for the inactivation of parasites in meat whereas refrigeration is considered as an essential part of the Good Hygiene Practice. Additionally, microwave dielectric heating may represent an equally effective tool for parasite inactivation. Therefore, isolated vital mesocercariae were examined with respect to their resilience against heating, refrigeration, freezing, and microwave heating. A. alata mesocercariae stored in Ringer's solution do not survive heating temperatures that exceed 60.0 °C. Similarly, exposure to microwave heating ensured an inactivation of all parasite developmental stages after 90 s of treatment. In contrast, the parasites' tolerance towards cold is far higher as the mesocercariae survived refrigeration temperatures (4.0 ± 2 °C) in Ringer's solution for up to 13 days. An effective inactivation by cold is therefore only guaranteed if the infested game meat is frozen to a core temperature of -13.7 °C for a minimum of 2 h at least. Game meat should be handled with the same or even higher caution than meat of husbandry animals since wild animals may be infected with parasites or other zoonotic agents that are not common in livestock. It is therefore of crucial importance that appropriate temperature time protocols are used for the reliable inactivation of these zoonotic agents.

'Goats that stare at men': dwarf goats alter their behaviour in response to human head orientation, but do not spontaneously use head direction as a cue in a food-related context.

Recently, comparative research on the mechanisms and species-specific adaptive values of attributing attentive states and using communicative cues has gained increased interest, particularly in non-human primates, birds, and dogs. Here, we investigate these phenomena in a farm animal species, the dwarf goat (Capra aegagrus hircus). In the first experiment, we investigated the effects of different human head and body orientations, as well as human experimenter presence/absence, on the behaviour of goats in a food-anticipating paradigm. Over a 30-s interval, the experimenter engaged in one of four different postures or behaviours (head and body towards the subject-'Control', head to the side, head and body away from the subject, or leaving the room) before delivering a reward. We found that the level of subjects' active anticipatory behaviour was highest in the control condition and decreased with a decreasing level of attention paid to the subject by the experimenter. Additionally, goats 'stared' (i.e. stood alert) at the experimental set-up for significantly more time when the experimenter was present but paid less attention to the subject ('Head' and 'Back' condition) than in the 'Control' and 'Out' conditions. In a second experiment, the experimenter provided different human-given cues that indicated the location of a hidden food reward in a two-way object choice task. Goats were able to use both 'Touch' and 'Point' cues to infer the correct location of the reward but did not perform above the level expected by chance in the 'Head only' condition. We conclude that goats are able to differentiate among different body postures of a human, including head orientation; however, despite their success at using multiple physical human cues, they fail to spontaneously use human head direction as a cue in a food-related context.

Effects of in vitro conditions on the survival of Alaria alata mesocercariae.

The aim of this study was to determine the effect of different concentrations of table salt (NaCl) and ethanol (v/v) solutions on the viability of Alaria alata mesocercariae. Furthermore, the survival of A. alata mesocercariae during simulated human gastric digestion was evaluated. For this purpose, A. alata mesocercariae migration technique (AMT) was used for the isolation of the parasite from high-positive A. alata mesocercariae meat from wild boar, raccoon, raccoon dog, and badger meat. In total, we have studied the behavior of 582 larvae under different conditions (NaCl, ethanol, and artificial gastric juice) in three independent in vitro experiments. The larvae survived at a NaCl concentration of up to 2.0% until day 21 with a median survival time of 11 days. At 3.0% NaCl concentration, the larvae lost their vitality after less than 24 h. In addition, it was found that ethanol concentrations from 8.0 to 70.0% were effective at reducing survival of A. alata mesocercariae within a short period of time (<1 min). Finally, our studies have revealed that it required 120 min to reliably inactivate all A. alata mesocercariae within HCl-pepsin digestion solution with a pH of 1.5-2.0 at 37°C. Consequently, the results showed that 3.0% is the minimum concentration of NaCl in meat products recommended for human consumption because at lower NaCl concentration the parasite survived for a substantial period of time. Finally, the common concentrations of ethanol used for the disinfection of surfaces in household and/or laboratory, are sufficient for the inactivation of A. alata mesocercariae.

Exclusion performance in dwarf goats (Capra aegagrus hircus) and sheep (Ovis orientalis aries).

Using a comparative approach, we investigated the ability of dwarf goats and sheep to use direct and indirect information about the location of a food reward in an object-choice task. Subjects had to choose between two cups with only one covering a reward. Before making a choice, subjects received information about the baited (direct information) or non-baited cup (indirect information). Both goats and sheep were able to use direct information (presence of food) in the object choice task. After controlling for local enhancement, we found that goats rather than sheep were able to use indirect information (i.e., the absence of food) to find a reward. The actual test setup could not clarify whether individual goats were able to inferentially reason about the content of the baited cup when only shown the content of the non-baited cup or if they simply avoided the empty cup in that situation. As browsing species, feral and wild goats exhibit highly selective feeding behaviour compared to the rather unselective grazing sheep. The potential influence of this species-specific foraging flexibility of goats and sheep for using direct and indirect information to find a food reward is discussed in relation to a higher aversion to losses in food acquisition in goats compared to sheep.

Tenacity of Alaria alata mesocercariae in homemade German meat products.

A renewed interest in the pathogenic potential of Alaria alata mesocercariae emerged over the last 10years as a result of increased findings of this parasite in feral pigs during official examination for Trichinella spp. Cases of food associated human alariosis in North America suggest that a risk associated with the consumption of traditional raw cured products from infected wild boar meat cannot be neglected because the commonly applied preservation techniques may not necessarily kill the mesocercariae. In addition, changes in consumer behavior and new preparation methods for game meat (e.g. pink roasting and grilling) may increase the risk for food-associated parasitic infections. Thus, there is a strong need for the evaluation of the tenacity of A. alata mesocercariae against different physical and chemical influences as pertaining to common preservation and preparation techniques. Against this backdrop the aim of our work was a sound analysis of the survivability of A. alata mesocercariae during curing, fermentation, cold smoking and drying in raw cured meat products. Eighty three samples of traditional German meat products were prepared from naturally infected game meat and partly spiked with additional vital mesocercariae to achieve an adequate dose of infection. The resultant products were examined chronologically for dead and viable A. alata mesocercariae with the Alaria mesocercariae migration technique. After 24h of production, vital A. alata mesocercariae were still found in raw type sausages but no vital parasites were detected in the final products. Based on these results a possible risk for the consumer for an infection with A. alata mesocercariae through the consumption of contaminated raw cured products can be largely ruled out if the respective food technological procedures are carried out properly. However, a risk for the consumer cannot be excluded in cases of very early consumption of these products.

Juvenile domestic pigs (Sus scrofa domestica) use human-given cues in an object choice task.

Research on the comprehension of human-given cues by domesticated as well as non-domesticated species has received considerable attention over the last decade. While several species seem to be capable of utilizing these cues, former work with domestic pigs (Sus scrofa domestica) has shown inconclusive results. In this study, we investigated the use of human-given cues in an object choice task by young domestic pigs (N = 17; 7 weeks of age) who had very limited human contact prior to the experiments. Subjects had to choose between two bowls of which only one was baited with a reward. Over the course of five experiments, pigs were able to use proximal and, with some constraints, also distal pointing cues presented in both a dynamic-sustained and in a momentary manner. When the experimenter was pointing from the incorrect bowl towards the correct one, most of the subjects had problems solving the task-indicating that some form of stimulus/local enhancement affected pigs' decision making. Interestingly, pigs were able to utilize the body and head orientation of a human experimenter to locate the hidden reward but failed to co-orient when head or body orientation of the experimenter was directed into distant space with no bowls present. Control trials ruled out the possibility that other factors (e.g. odour cues) affected subjects' choice behaviour. Learning during experiments played a minor role and only occurred in three out of twelve test conditions. We conclude that domestic pigs, even at a very young age, are skilful in utilizing various human-given cues in an object choice task-raising the question whether pigs only used stimulus/local enhancement and associative learning processes or whether they were able to comprehend the communicative nature of at least some of these cues.

Are juvenile domestic pigs (Sus scrofa domestica) sensitive to the attentive states of humans?--The impact of impulsivity on choice behaviour.

Previous studies have shown that apes, dogs and horses seem to be able to attribute attentive states to humans. Subjects had to choose between two persons: one who was able to see the animal and one who was not. Using a similar paradigm, we tested a species that does not rely strongly on visual cues, the domestic pig (Sus scrofa domestica). Subjects could choose between two unfamiliar persons, with only one showing attention, in three different conditions (body, head away, body turned - head front). Subjects (n=16) only showed a tendency towards the attentive human in the head away condition. However, by pooling those two conditions where the position of the human head was the only salient cue, we found a significant preference for the attentive person. Moreover, two approach styles could be distinguished - an impulsive style with short response times and a non-impulsive style where response times were relatively long. With the second approach style, pigs chose the attentive person significantly more often than expected by chance level, which was not the case when subjects chose impulsively. These first results suggest that pigs are able to use head cues to discriminate between different attentive states of humans.

Stress, behaviour and reproductive performance in female cattle and pigs.

Female farm animals are exposed to a great variety of environmental and management related stressors. As a consequence, their reproductive and maternal abilities may be compromised through mechanisms acting on the hypothalamic, pituitary, ovarian and uterine function. Responses to short- and long-term stressors may differ as short-term stressors often fail to affect reproduction or even may have stimulatory effects. Thus, the stress response induces diverse neuroendocrine reactions that can either increase or decrease the probability of an animal reproducing depending on the specific situation. The aim of the present review is to summarise the current knowledge on the stress concept and its implications on behaviour and reproductive performance in cows and female pigs as phenomena reported in laboratory animals are unable to explain all effects encountered in domesticated farm animals.

Heart rate variability as a measure of autonomic regulation of cardiac activity for assessing stress and welfare in farm animals -- a review.

Measurement of heart rate variability (HRV) is a non-invasive technique that can be used to investigate the functioning of the autonomic nervous system, especially the balance between sympathetic and vagal activity. It has been proven to be very useful in humans for both research and clinical studies concerned with cardiovascular diseases, diabetic autonomic dysfunction, hypertension and psychiatric and psychological disorders. Over the past decade, HRV has been used increasingly in animal research to analyse changes in sympathovagal balance related to diseases, psychological and environmental stressors or individual characteristics such as temperament and coping strategies. This paper discusses current and past HRV research in farm animals. First, it describes how cardiac activity is regulated and the relationships between HRV, sympathovagal balance and stress and animal welfare. Then it proceeds to outline the types of equipment and methodological approaches that have been adapted and developed to measure inter-beats intervals (IBI) and estimate HRV in farm animals. Finally, it discusses experiments and conclusions derived from the measurement of HRV in pigs, cattle, horses, sheep, goats and poultry. Emphasis has been placed on deriving recommendations for future research investigating HRV, including approaches for measuring and analysing IBI data. Data from earlier research demonstrate that HRV is a promising approach for evaluating stress and emotional states in animals. It has the potential to contribute much to our understanding and assessment of the underlying neurophysiological processes of stress responses and different welfare states in farm animals.