Peter C. Schön

Agonistic interactions and physiological reactions of top- and bottom-ranking pigs confronted with a familiar and an unfamiliar group: Preliminary results

Abstract Four trials were carried out, where in each trial during a selection test two groups of growing pigs (12 weeks old) with nine animals each were randomly formed. After a week, the top (TR) and bottom (BR) ranking pig from each group was isolated and kept under single housing conditions. At the age of 15 to 16 weeks, the test animals were confronted once with the familiar and once with the unfamiliar group. During the 10-h social confrontation test, agonistic behaviour (agonistic interactions, individual dominance values) and physiological stress reactions (epinephrine, norepinephrine, cortisol, heart rate) were investigated simultaneously. The social confrontation of a pig with a familiar or an unfamiliar group caused very frequent agonistic interactions during the first 30 min. This behaviour was accompanied by a rapid increase of the heart rate and the plasma catecholamine concentrations and a delayed increase of cortisol. TR pigs elicited more agonistic interactions during the first 30 min and displayed higher plasma catecholamine concentrations. Additionally, TR animals showed significantly higher dominance values during the 10-h testing situation compared to the BR pigs. The confrontation of an animal with the unfamiliar group resulted in a more pronounced adrenocortical reaction compared to the confrontation with the familiar group. In particular, the TR animals showed a distinct increase of plasma cortisol during the first hour and a later bradycardia when they were confronted with the unfamiliar group. The preliminary results presented in this paper indicate that pigs show different, but inconsistent behavioural and physiological reactions when they are confronted with a social group. The agonistic behaviour and the physiological stress reactions during a social confrontation test are still influenced by the former rank of the animal, even when the animal was isolated under single housing conditions in the meantime for 2 to 3 weeks.

Physiological and behavioral effects of different success during social confrontation in pigs with prior dominance experience

The impact of a 10-h social confrontation on behavior, plasma adrenaline, noradrenaline and cortisol was studied in 14 domestic pigs (eight castrated males and six females) with prior dominance experience. Prior to the experiments, animal groups, each consisting of nine growing pigs (12 weeks old) from different litters, were composed randomly. After 5 days, the pig with the highest rank from each group was removed, provided with a jugular vein catheter and kept in single housing for 2-3 weeks. After this period, each test animal was returned into its familiar group for a 10-h social confrontation. The reintroduction of the test animals into the familiar groups caused frequent agonistic interactions during the first 30 min. Seven animals succeeded to win most of their encounters during the confrontation test and were classified as High Success (HS) animals, whereas seven other animals lost most of their encounters and were classified as Low Success (LS) animals. The reintroduction of the test animals into the groups provoked also marked changes in behavioral and physiological measures. The frequent fighting behavior during the first 30 min was accompanied by a rapid increase of plasma catecholamines and a delayed increase of cortisol. Immediately after introduction, LS pigs tended to show higher plasma adrenaline and noradrenaline concentrations than HS pigs. There was also a tendency for a sustained increase of noradrenaline/adrenaline ratios in HS pigs, whereas the ratios of LS pigs remained nearly unchanged. No significant differences between both groups were found in cortisol levels and in the frequency of agonistic interactions. However, LS animals showed less locomotion, more lying and spent less time exploring the pen or other animals. These results show that during a social confrontation the experience of defeats for formerly high-ranking pigs is accompanied by increased submissive or passive behavior and a higher sympathoneural and adrenomedullary reaction, which may indicate more emotional distress and fear compared to successful animals.

Short-term feed intake is regulated by macronutrient oxidation in lactating Holstein cows

In addition to plasma metabolites and hormones participating as humoral signals in the control of feed intake, oxidative metabolic processes in peripheral organs also generate signals to terminate feeding. Although the degree of oxidation over longer periods is relatively constant, recent work suggests that the periprandial pattern of fuel oxidation is involved in regulating feeding behavior in the bovine. However, the association between periprandial oxidative metabolism and feed intake of dairy cows has not yet been studied. Therefore, the aim of this study was to elucidate possible associations existing between single feed intake events and whole-body net fat and net carbohydrate oxidation as well as their relation to plasma metabolite concentrations. To this end, 4 late-lactating cows equipped with jugular catheters were kept in respiratory chambers with continuous and simultaneous recording of gas exchange and feed intake. Animals were fed ad libitum (AL) for 24h and then feed restricted (RE) to 50% of the previous AL intake for a further 24h. Blood samples were collected hourly to analyze β-hydroxybutyrate (BHBA), glucose, nonesterified fatty acids (NEFA), insulin, and acylated ghrelin concentrations. Cross-correlation analysis revealed an offset ranging between 30 and 42 min between the maximum of a feed intake event and the lowest level of postprandial net fat oxidation (FOX(net)) and the maximum level of postprandial net carbohydrate oxidation (COX(net)), respectively. During the AL period, FOX(net) did not increase above -0.2g/min, whereas COX(net) did not decrease below 6g/min before the start of the next feed intake event. A strong inverse cross-correlation was obtained between COX(net) and plasma glucose concentration. Direct cross-correlations were observed between COXnet and insulin, between heat production and BHBA, between insulin and glucose, and between BHBA and ghrelin. We found no cross-correlation between FOX(net) and NEFA. During RE, FOX(net) increased with an exponential slope, exceeded the threshold of -0.2g/min as indicated by increasing plasma NEFA concentrations, and approached a maximum rate of 0.1g/min, whereas COX(net) decayed in an exponential manner, approaching a minimal COX(net) rate of about 2.5 g/min in all cows. Our novel findings suggest that, in late-lactating cows, postprandial increases in metabolic oxidative processes seem to signal suppression of feed intake, whereas preprandially an accelerated FOX(net) rate and a decelerated COX(net) rate initiate feed intake.

Acetylcholine injection into the amygdala elicits vocalization in domestic pigs (Sus scrofa)

In a pilot study we have injected the amygdala of five female pigs (age 8 weeks) with acetylcholine (ACh, 5.5muM/20mul) and recorded short latency utterances. The evoked vocalizations displayed the characteristics of natural screams in sonagram appearance and hearing impression. Quantitative analyses, too, revealed the similarity of the ACh-evoked vocalizations with natural screaming. The results demonstrate for the first time that aversive vocalizations can be triggered by cholinergic amygdala stimulation.

Towards qualitative and quantitative prediction and detection of parturition onset in sows using light barriers

A single light barrier can be used for the prediction and detection of parturition.A validated classification performance close to 90% was achieved.Approaches for measuring the parturition related activity increase were compared.A method for a quantitative prediction of the duration until parturition was tested. Piglet mortality can be a large economic and animal welfare issue in breeding facilities. A system that predicts the parturition can help the breeder in economically organising staff assignments in order to achieve an optimal workload levelling. In the current study, light barriers at the head and torso region of a sow were used to measure and classify the activity increase of 34 sows related to their near parturition. Based on this data, 4 different activity frequency and activity duration based qualitative predictors for the near onset of parturition were developed retrospectively, utilising cumulative sum techniques and a global threshold approach. The threshold optimisation for the qualitative prediction was performed using a random set of 17 sows and validated with the remaining sows. The best performing qualitative prediction yielded a validated sensitivity of 88% at a precision of 88%. This prediction generated parturition alerts with a 25th percentile of 13h and a 75th percentile of 20h before the parturition started. Based on this indicator, a quantitative prediction of the time remaining until the onset of parturition could be developed. This prediction exhibited a mean prediction error of 0.5h?2.6h (SD) for 88% of the sows over a period of 13-24h before the onset of parturition. At the same time 12% of the predictions were unusable with a mean prediction error of 12.5h?6.9h (SD). In addition, a method for detecting the parturition onset with an accuracy of ?4h, a sensitivity of 88% and a precision of 97% for the head sensor could be obtained. With data from the torso sensor, the performance of the various indicators was generally lower and optimality was achieved with different thresholds. The present study follows other studies showing the general detectability of the parturition related increase in activity using video, light barriers and ultrasonic distance sensors. It is also closely based on earlier studies using accelerometers for individual qualitative parturition detection, with the explicit intent to reproduce these results using light barriers.

Anticipation and frequency of feeding affect heart reactions in domestic pigs

Measuring heart reactions has become a widely used method for the assessment of emotions. Heart rate and its variability, which can quite easily be noninvasively recorded, reflect the inputs of the sympathetic and parasympathetic branches of the autonomous nervous system. We tested the hypothesis that frequent anticipation of a positive event results in an increased state of welfare in pigs, expressed as positive arousal in anticipation of announced feeding as well as lowered heart rate and augmented heart rate variability during resting periods. We used a controlled paradigm with 3 groups of young domestic pigs (Sus scrofa domestica). We compared frequent acoustic announcement of feed delivery (group 1: 3 feedings between 0730 h and 1030 h plus 3 feedings between 1200 h and 1530 h) with the same number of feedings as in group 1 but without a temporal relation to the sound (group 2) and with a fixed-schedule feeding (group 3: 2 feedings at 0600 h and 1500 h). Specific cardiac and behavioral reactions indicated short-term (1 min) anticipation in the conditioned group. In this group, heart rate increased (P < 0.001) mainly through vagal withdraw and behavior became more active (P < 0.001). Only the conditioned group displayed changing heart rate characteristics during the sound. Pigs in the frequent unpredictable feed group reacted to feed delivery with increased heart rates (P < 0.001), whereas the heart-rate characteristics of pigs with the fixed schedule were unchanged during the sound and while the other 2 treatment groups were feeding. Clear evidence for long-term anticipation (over the course of hours) was not present in the data. Comparisons between the 3 treatment groups suggested that in housing conditions where pigs cannot obtain feed by their actions but must wait for feed delivery, feeding at 2 fixed times would be preferred. Animals in this treatment group presented lower resting heart rates at the end of the experiment than animals in the other 2 groups (P < 0.01). Therefore, merely announcing a positive stimulus without giving control to its access is apparently not suitable for increasing welfare.

Interference of stress with the somatotropic axis in pigs – lights on new biomarkers

The acceptance of animal products is increasingly associated with standardized animal welfare, which relates to appropriate animal husbandry from birth to slaughter. In particular, shipment to the slaughterhouse is considered as a critical process exposing the animals to a number of, in part severe, stressors. New biomarkers may be useful for the assessment of animal welfare. The IGF-system has been assessed in a commercial pig transport in conjunction with established markers of stress response. Furthermore, the effect of repeated restraint as an experimental model for repeated acute stress was investigated. During shipment from farm to slaughterhouse, plasma concentrations of IGFBP-3 and IGFBP-2 were significantly reduced (p < 0.01). After shipment, the plasma concentrations of IGFBP-5, glucocorticoids and IL-2 increased but decreased after lairage (p < 0.05) whereas IGF-1 decreased after shipment (p < 0.01). Repeated acute stress increased concentrations of IGFBP-3 and IGF-1 in exsanguination blood (p < 0.05). Differential IGF- signatures can indicate altered endocrine or metabolic control and thus contain complex animal-related information. The somatotropic axis may be of particular interest when established biomarkers such as cortisol, glucose, or lactate cannot be used for the assessment of animal stress or welfare.

Postpartum changes in the lying behavior of sows in farrowing crates

ABSTRACT The objective of the study was to compare the behavior of sows before and after farrowing with a focus on lying behavior and side preference in a lateral position. Collecting information on normal and deviant behaviors may consequently improve the care and welfare of animals and severe variations can indicate possible welfare issues. The study was conducted on a farrow‐to‐finish‐farm with 14 crossbred sows. For each sow, behavior was analyzed by video observation (continuous sampling) on 2 days, one before (3 or 4 days after transfer to the trial compartment) and one after farrowing (second day after farrowing). The duration and frequency of lying on the left side, lying on the right side, lying on the abdomen, standing, sitting, and lying down per sow and day were compared for these 2 days. The total time that sows spent lying increased significantly (P = 0.01) on the second day after farrowing compared with the analyzed day before farrowing. The time spent lying on the right side and facing the udder to the piglet nest also increased significantly (P = 0.02) after farrowing. For the other postures (i.e., lying on the left side, lying on the abdomen (P > 0.05), sitting, standing, lying down [P ≤ 0.03]), the duration as well as the sum of changes in posture decreased after farrowing. On the test day before farrowing, sows spent a total of 85% of the day in a lying position (35% on the left side, 39% on the right, and 11% on the abdomen). The total lying time increased to 96% per sow and day on the second day after farrowing (31% on the left side, 58% on the right, and 7% on the abdomen). After farrowing, the lying duration of sows increased, and they preferred to lie on the body side facing the piglet nest. The sows spent the most time in a lateral lying position, which is information that should be used to adjust farrowing crates to improve the welfare of sows.

ASSESSMENT OF CONTINUOUS VAGINAL LOGGER-BASED TEMPERATURE MONITORING IN FEVER-INDUCED GILTS

The aim of this study was to identify a low risk method to induce fever in gilts and to evaluate vaginal sensors for temperature monitoring. Therefore, a rhinitis atrophicans vaccine was used to induce fever to evaluate sensors and behavioral patterns. During 11 trials, two of four animals were injected with 2 mL of the vaccine Porcilis AR-T DF (Intervet) and the other two animals were treated with 2 mL of 0.9% NaCl as controls. A temperature logger (TRIX-8, LogTag Recorders, Auckland, New Zealand) was used to continuously monitor the vaginal temperature. Additionally, rectal temperatures were measured four times daily. The water consumption, food intake and locomotion behaviors of the animals were analysed one day before treatment and during the day of the treatment. The vaccine induced fever in all gilts, which occurred approximately 5.87 h after vaccination. The vaginal logger temperatures and the rectal temperatures showed a linear correlation in 21 vaccinated gilts (r = 0.86; p

Vocalization as an indicator of estrus climax in Holstein heifers during natural estrus and superovulation

The reliable detection of estrus is an important scientific and practical challenge in dairy cattle farming. Female vocalization may indicate reproductive status, and preliminary evidence suggests that this information can be used to detect estrus in dairy cattle. The aim of this study was to associate the changes in the vocalization rate of dairy heifers with behavioral estrus indicators as well as test the influence of the type of estrus (natural estrus vs. superovulation-induced estrus). We analyzed 6 predefined estrus-related behavior patterns (standing to be mounted, head-side mounting, active mounting, chin resting, being mounted while not standing, and active sniffing in the anogenital region) and vocalization rates in the peri-estrus period (day of estrus ± 1 d) of 12 German Holstein heifers using audio-visual recordings. Each heifer was observed under natural estrus and a consecutive superovulation induced by FSH and cloprostenol. Estrus was determined by behavioral patterns and confirmed by clinical examination (vaginoscopy and ultrasound imaging of the ovaries) as well as by the concentration of peripheral progesterone. Estrus behavior and vocalization rates were analyzed in 3-h intervals (an average of 19 intervals for each heifer), and an estrus score was calculated based on the 6 behaviors. The interval with the highest estrus score (I0) was considered the estrus climax. We demonstrated similar time courses for the estrus score and vocalization rate independent of estrus type. However, in natural estrus, the maximum vocalization rate (±SE) occurred in the interval before estrus climax (I-1; 42.58 ± 21.89) and was significantly higher than that in any other interval except estrus climax (I0; 27.58 ± 9.76). During natural estrus, the vocalization rate was significantly higher within the interval before estrus climax (I-1; 42.58 ± 21.89 vs. 11.58 ± 5.51) than under superovulation. The results underscore the potential use of vocalization rate as a suitable indicator of estrus climax in automated estrus detection devices. Further studies and technical development are required to record and process individual vocalization rates.