The Relationship Between Cortical Activation in Response to Anorectal Stimuli and Continence Behavior in Freely Behaving Rats Before and After Application of Sacral Nerve Stimulation.

BACKGROUND: Changes in anorectal sensation have been reported in patients with fecal incontinence, and there is limited evidence that sacral nerve stimulation can restore normal sensation. OBJECTIVE: The aims of the present study were to investigate changes in the transmission of sensory anorectal stimuli in a rodent model of fecal incontinence and to study the effects of sacral nerve stimulation on defecation behavior. DESIGN: An established model of fecal incontinence was utilized for this study. INTERVENTION: Pudendal nerve stretch and compression were used in 16 adult female Wistar rats and were monitored for 3 weeks: 6 rats received sacral nerve stimulation for 1 week by using an implantable neurostimulator and 10 rats had nonfunctioning "dummy" devices inserted. Five additional rats were sham operated. Anorectal cortical evoked potentials were used as a surrogate marker for anorectal sensory function. MAIN OUTCOME MEASURES: The primary outcomes measured were fecal incontinence index, evoked potential amplitude, and latency. RESULTS: Fifty percent of rats showed behavioral signs of fecal incontinence measured by the Fecal Incontinence Index (>0.20), calculated by using the pellet distribution outside the cage's latrine area. Anorectal evoked potential amplitude was reduced in rats with a Fecal Incontinence Index >0.20 (p = 0.019). The amplitude of forepaw evoked potentials recorded as a control was not different between groups. Chronic sacral nerve stimulation using the fully implantable device and custom rodent lead was safe and stable during this chronic prospective study. Incontinent rats (n = 3) that received sacral nerve stimulation showed an improvement of Fecal Incontinence Index and an increase of evoked potential amplitude to anorectal stimulation compared with the dummy implant controls (n = 5). LIMITATIONS: The main limitation is the small number of animals that received sacral nerve stimulation. CONCLUSIONS: Chronic sacral nerve stimulation is feasible in rats when miniature telemetric devices are used. Behavioral signs of fecal incontinence were positively correlated with the latency of anorectal evoked potentials. See Video Abstract at http://links.lww.com/DCR/B712.RELACIÓN ENTRE LA ACTIVACIÓN CORTICAL EN RESPUESTA A LOS ESTÍMULOS ANORRECTALES Y EL COMPORTAMIENTO DE CONTINENCIA EN RATAS QUE SE COMPORTAN LIBREMENTE ANTES Y DESPUÉS DE LA APLICACIÓN DE ESTIMULACIÓN DEL NERVIO SACRO. ANTECEDENTES: Se han informado cambios en la sensación anorrectal en pacientes con incontinencia fecal y hay evidencia limitada de que la estimulación del nervio sacro puede restaurar la sensación normal. OBJETIVO: Los objetivos del presente estudio fueron investigar los cambios en la transmisión de estímulos anorrectales sensoriales en un modelo de roedor de incontinencia fecal y estudiar los efectos de la estimulación del nervio sacro en la conducta de defecación. DISEO: Un modelo establecido de incontinencia fecal. INTERVENCIN: Se utilizó estiramiento y compresión del nervio pudendo en 16 ratas Wistar hembras adultas y se les realizó un seguimiento durante 3 semanas: seis ratas recibieron estimulación del nervio sacro durante 1 semana utilizando un neuroestimulador implantable y diez ratas tuvieron insertados dispositivos "ficticios" no funcionantes. Se operaron simuladamente cinco ratas adicionales. Los potenciales evocados corticales anorrectales se utilizaron como marcador subrogado de la función sensorial anorrectal. PRINCIPALES MEDIDAS DE RESULTADO: Índice de incontinencia fecal, amplitud de potenciales evocados y latencia. RESULTADOS: El cincuenta por ciento de las ratas mostró signos de comportamiento de incontinencia fecal medidos por el Índice de incontinencia fecal (> 0.20), calculado utilizando la distribución de heces fuera del área de la letrina de la jaula. La amplitud del potencial evocado anorrectal se redujo en ratas con un índice de incontinencia fecal >0.20 (p = 0.019). La amplitud de los potenciales evocados de la pata delantera registrados como control no fue diferente entre los grupos. La estimulación crónica del nervio sacro utilizando un dispositivo totalmente implantable y un cable de roedor personalizado fue segura y estable durante este estudio prospectivo crónico. Las ratas con incontinencia (N = 3) que recibieron estimulación del nervio sacro mostraron una mejora del índice de incontinencia fecal y un aumento de la amplitud del potencial evocado a la estimulación anorrectal en comparación con los controles de implante ficticio (N = 5). LIMITACIONES: La principal limitación es el pequeño número de animales que recibieron estimulación del nervio sacro. CONCLUSIONES: La estimulación crónica del nervio sacro es factible en ratas cuando se utilizan dispositivos telemétricos en miniatura. Los signos conductuales de incontinencia fecal se correlacionaron positivamente con la latencia de los potenciales evocados anorrectales. Consulte Video Resumen en http://links.lww.com/DCR/B712. (Traducción-Dr. Jorge Silva Velazco).

Vertical or Horizontal? Diagnosing and Treating Cats Who Urinate Outside the Box.

Feline elimination problems are commonly presented to general practitioners and behavioral medicine specialists. The correct diagnosis is often missed by veterinarians owing to individual variation and multifactorial cases. Three diagnostic umbrellas need to be considered: medical problems, toileting behavior outside of the litter box, and urine marking. The treatment plan for most cases, regardless of etiology, involves optimum litter box management, fulfilling cats' environmental needs, stress reduction, behavior therapy techniques, and trigger removal. Medical management with psychoactive medication might be necessary in cases where chronic stress, fear, and anxiety play a role in the feline patient's symptomatology.

Non-Invasive Genetic Mark-Recapture as a Means to Study Population Sizes and Marking Behaviour of the Elusive Eurasian Otter (Lutra lutra).

Quantifying population status is a key objective in many ecological studies, but is often difficult to achieve for cryptic or elusive species. Here, non-invasive genetic capture-mark-recapture (CMR) methods have become a very important tool to estimate population parameters, such as population size and sex ratio. The Eurasian otter (Lutra lutra) is such an elusive species of management concern and is increasingly studied using faecal-based genetic sampling. For unbiased sex ratios or population size estimates, the marking behaviour of otters has to be taken into account. Using 2132 otter faeces of a wild otter population in Upper Lusatia (Saxony, Germany) collected over six years (2006-2012), we studied the marking behaviour and applied closed population CMR models accounting for genetic misidentification to estimate population sizes and sex ratios. We detected a sex difference in the marking behaviour of otters with jelly samples being more often defecated by males and placed actively exposed on frequently used marking sites. Since jelly samples are of higher DNA quality, it is important to not only concentrate on this kind of samples or marking sites and to invest in sufficiently high numbers of repetitions of non-jelly samples to ensure an unbiased sex ratio. Furthermore, otters seemed to increase marking intensity due to the handling of their spraints, hence accounting for this behavioural response could be important. We provided the first precise population size estimate with confidence intervals for Upper Lusatia (for 2012: N = 20 ± 2.1, 95% CI = 16-25) and showed that spraint densities are not a reliable index for abundances. We further demonstrated that when minks live in sympatry with otters and have comparably high densities, a non-negligible number of supposed otter samples are actually of mink origin. This could severely bias results of otter monitoring if samples are not genetically identified.

Association between characteristics of cats and satisfaction of owners who adopted cats from an animal hospital in Japan.

A follow-up questionnaire survey was conducted with 29 cat owners who adopted cats from an animal hospital in Japan. Physical characteristics were found to be important factors for the owners when choosing a cat. There were significant differences between impression of the cat for the owners at present and images of their ideal cats, and the levels of aggression and activeness of the cats at present were rated higher than their ideal cats. A significant negative correlation was found between the degree of satisfaction with the cat and occurrence of house soiling; thus, some behavioral problems may deteriorate the relationship between the owner and the cat.

High novelty-seeking rats are resilient to negative physiological effects of the early life stress.

Exposure to early life stress dramatically impacts adult behavior, physiology, and neuroendocrine function. Using rats bred for novelty-seeking differences and known to display divergent anxiety, depression, and stress vulnerability, we examined the interaction between early life adversity and genetic predisposition for high- versus low-emotional reactivity. Thus, bred Low Novelty Responder (bLR) rats, which naturally exhibit high anxiety- and depression-like behavior, and bred High Novelty Responder (bHR) rats, which show low anxiety/depression together with elevated aggression, impulsivity, and addictive behavior, were subjected to daily 3 h maternal separation (MS) stress postnatal days 1-14. We hypothesized that MS stress would differentially impact adult bHR/bLR behavior, physiology (stress-induced defecation), and neuroendocrine reactivity. While MS stress did not impact bHR and bLR anxiety-like behavior in the open field test and elevated plus maze, it exacerbated bLRs' already high physiological response to stress - stress-induced defecation. In both tests, MS bLR adult offspring showed exaggerated stress-induced defecation compared to bLR controls while bHR offspring were unaffected. MS also selectively impacted bLRs' (but not bHRs') neuroendocrine stress reactivity, producing an exaggerated corticosterone acute stress response in MS bLR versus control bLR rats. These findings highlight how genetic predisposition shapes individuals' response to early life stress. Future work will explore neural mechanisms underlying the distinct behavioral and neuroendocrine consequences of MS in bHR/bLR animals.

Eliminative behavior of captive numbats, Myrmecobius fasciatus (Mammalia; Marsupialia): pattern and identification of fecal deposits.

This study examined the spatial defecation patterns of numbats within captivity and tested the efficacy of a food colorant as a fecal marker in this species. Rather than randomly distributing scats throughout their environment, the numbats aggregated their feces at specific sites forming latrines. It is unclear whether the strong inclination for latrine formation was due to this species' inherent behavior or is a direct result of captivity. Males were found to have a higher daily defecation rate, different defecation time, larger number of latrines, and greater number of scats per quadrant, as compared to females. In this study, the majority of scats were deposited along enclosure boundaries and for both sexes there was a higher probability of latrines being placed along enclosure fencing shared with a female neighbor. The high concentration of latrines along boundaries suggests that they may play a role in territorial defense. The results also indicated that captive numbats tend to choose defecation points away from food and refuge sites. Transit and total retention time of the marker through the GIT was ≤3 hr and between 24 and 27 hr, respectively. A marker dose of 3 gtts feed(-1) × 2 feeds day(-1) was required to reach a steady and detectable state of marker output, which enabled accurate identification of individual samples during the breeding season. Reliable labeling was obtained using blue and red colored food dye, and there was no evidence that incorporation of the marker into the diet had any negative effects on food intake.

Litter box preference in domestic cats: covered versus uncovered.

Feline inappropriate elimination (periuria and/or perichezia) remains a very common behavioral complaint of cat owners. Treatment recommendations often include improving the attractiveness of the litter boxes available to the cat. One frequent recommendation is to avoid covered litter boxes, although this has not previously been tested experimentally. The goal of this study was to assess whether, all else being equal, cats preferentially used uncovered litter boxes over covered litter boxes. Twenty-eight cats were enrolled in the study and offered the choice of a covered or uncovered box. Waste was scooped daily from each box, and the weight of waste in the different box styles was compared and evaluated using paired t-tests and χ(2) analyses. Overall, there was no significant difference between use of the two box styles. Eight individual cats did exhibit a preference (four for covered, four for uncovered), but individual preference results are not evenly distributed, with more cats than expected showing no preference between litter box types. We postulate that, if boxes are kept sufficiently clean (ie, once daily minimum cleaning), most cats will not show a preference for either box type. The observation that a minority of cats in the study exhibited a preference supports the recommendation of providing individual cats with a 'cafeteria' of litter box styles, including a covered box, to determine whether such a preference exists. These findings add to existing literature on the topic of feline inappropriate elimination and provide additional information for clinicians recommending treatment options for cats exhibiting this behavior.

Behavioural and cardiac responses towards conspecific distress calls in domestic pigs (Sus scrofa).

In domestic pigs, vocalisation can be an indicator of distress and negative emotional states. It might play a role in the transfer of emotion between individuals ('emotional contagion' or 'empathy'), which could result in impaired animal welfare on a group level based on the distress in an individual member of the group. The aim of this study was to characterise the responses of pigs to conspecific distress calls. We performed a playback experiment in an open arena with 24 juvenile German Landrace pigs, during which individual subjects were exposed to both conspecific distress calls and an artificial sine tone (control) on consecutive experimental days. Both behavioural (locomotion, vocalisation, elimination and distance to the speakers) and physiological responses (heart rate and heart rate variability) were measured for 2 min before, during and after the playback of the stimuli (distress calls/control). Subjects showed decreased locomotion and vocalisation rates during both stimuli, suggesting that the animals responded to both stimuli. Heart rates decreased at the onset of both stimuli due to an activation of the parasympathetic system, indicating an orientation response to sudden stimuli. However, heart rates decreased after the end of the distress calls but not after control stimuli, illustrating that conspecific calls and other sounds are evaluated differently. We conclude that pigs exposed to isolation are attentive to conspecific distress vocalisation and hence the information about threat possibly conveyed in it, but they do not share the distress of the caller. Therefore, we could not find direct effects of distress calls of unfamiliar conspecifics on the welfare of isolated juvenile pigs. However, the state of heightened attention elicited by conspecific distress calls may affect a pig's subsequent evaluation of its environment.

Using energy budget data to assess the most damaging life-stage of an agricultural pest Mocis latipes (Guenèe, 1982) (Lepidoptera--Noctuidae).

There is much evidence to support that Mocis latipes larvae (Guenèe, 1852) are the most dangerous pasture pest and usually cause large environmental losses. However, no studies have been carried out to identify the instars during which this moth causes the most damage to the environment. Here we calculate M. latipes larval energy budget to assess its consumption across all instars and estimate the consumption/amount of plant biomass required to complete its larval development. Assimilation, respiration, consumption, excretion, gross growth efficiency and net growth efficiency were calculated. Pearson correlations were used to identify the best predictors that influenced larval growth and weight. Across all instars consumption increased exponentially, especially during the last phase. M. latipes larvae consumed ca 13.8% of total food from the first to the fifth instar, whereas during the sixth instars these larvae consumed ca 72.6%. Results also show that the best gross growth and net growth efficiency were obtained when larvae reached the fifth instar. The results also show that one larva of Mocis latipes consumes 1.02 g (dry weight) of Paspalum maritimum (Trin) in 19 days. Overall, our results indentified the sixth instar as the most destructive instar of this insect. Thus, once we know the most destructive instars of this pest, measures can be taken to disable M. latipes larval development and consequently stop their increase in plant consumption, reducing ecological and economic damage. This knowledge may eventually lead to reduced agricultural damage and contribute to sustainable farming strategies.

Using energy budget data to assess the most damaging life-stage of an agricultural pest Mocis latipes (Guenèe, 1982) (Lepidoptera - Noctuidae) / Utilizando o balanço energético de Mocis latipes (Guenèe, 1982) (Lepidoptera - Noctuidae) para identificar o estágio do ciclo de vida mais perigoso de uma praga de pastos

There is much evidence to support that Mocis latipes larvae (Guenèe, 1852) are the most dangerous pasture pest and usually cause large environmental losses. However, no studies have been carried out to identify the instars during which this moth causes the most damage to the environment. Here we calculate M. latipes larval energy budget to assess its consumption across all instars and estimate the consumption/amount of plant biomass required to complete its larval development. Assimilation, respiration, consumption, excretion, gross growth efficiency and net growth efficiency were calculated. Pearson correlations were used to identify the best predictors that influenced larval growth and weight. Across all instars consumption increased exponentially, especially during the last phase. M. latipes larvae consumed ca 13.8 percent of total food from the first to the fifth instar, whereas during the sixth instars these larvae consumed ca 72.6 percent. Results also show that the best gross growth and net growth efficiency were obtained when larvae reached the fifth instar. The results also show that one larva of Mocis latipes consumes 1.02 g (dry weight) of Paspalum maritimum (Trin) in 19 days. Overall, our results indentified the sixth instar as the most destructive instar of this insect. Thus, once we know the most destructive instars of this pest, measures can be taken to disable M. latipes larval development and consequently stop their increase in plant consumption, reducing ecological and economic damage. This knowledge may eventually lead to reduced agricultural damage and contribute to sustainable farming strategies.

Inúmeras evidências indicam a larva de Mocis latipes (Guenèe, 1852) como uma das pragas de pastagem mais perigosas e que comumente causam grandes perdas ambientais. Entretanto, nenhum estudo foi feito para identificar qual a fase de desenvolvimento em que o dano ao ambiente é maior. Neste trabalho, nós calculamos o balanço energético larval de M. latipes para descobrir o consumo em cada instar e estimar o consumo requerido para completar o desenvolvimento larval. A assimilação, respiração, excreção, consumo e os coeficientes, bruto e líquido, do crescimento foram calculados. Correlações de Pearson foram usadas para identificar os preditores que mais influenciavam o crescimento da larva. Resultados indicaram que o consumo aumentou exponencialmente durante os instares, especialmente durante o último instar. Larvas de M. latipes consumiram aproximadamente 13,8 por cento do recurso alimentar total entre o primeiro e o quinto instar, enquanto que no sexto instar consumiram 72,6 por cento. Os resultados também indicaram que o consumo bruto e o consumo líquido foram maiores nos últimos instares. Também se verificou que apenas uma larva consumiu 1,02 g de Paspalum maritimum (Poaceae) em 19 dias. Em resumo, nossos resultados identificaram o sexto instar como o mais destrutivo. Uma vez que se conheça o instar mais destrutivo, medidas mais eficazes podem ser tomadas para inibir o desenvolvimento larval de M. Latipes e o crescimento significativo do seu consumo e, consequentemente, reduzir danos ao ambiente. Este conhecimento pode, eventualmente, contribuir para reduzir danos à agricultura e contribuir para seu desenvolvimento sustentável.

Effects of shade and sprinklers on performance, behavior, physiology, and the environment of heifers.

The objective was to measure effects of cooling technique (shade vs. water sprinklers) on performance, behavior, physiology, and the environmental effect of 40 Holstein heifers housed in drylot corrals during the hot summer months. The experiment was a replicated crossover design with four 21-d periods and 2 treatments: 1) shades installed in the front half of the pen or 2) sprinklers, which applied water to the pen surface at 2-h intervals from 1100 to 1900 h. Animal performance measures were dry matter intake, average daily gain, and feed efficiency (gain:feed). Behavioral measures, elimination patterns, and corral spatial distribution were measured in 5-min scan frequencies over four 24-h periods. Physiological measures were rectal temperature, respiration rate, urinary urea N, and blood urea N. Environmental measures were corral soil surface temperature and moisture, particulate matter, and surface NH(3) volatilization; meteorological measures were also collected. Shaded compared with sprinkled heifers had increased dry matter intake (3.4%), increased average daily gain (14%), and increased feed efficiency (11%). Heifers in shaded vs. sprinkler treatments had decreased respiration rates (13%). Behavioral differences between the treatments varied by time of day. Heifers spent most time in either the shaded or sprinkled areas of their corrals (65.9 and 64.2%, respectively). Elimination behavior occurred predominantly at the front of the corral in close proximity to the feed bunks and additionally at the water trough in sprinkled corrals. Sprinkler treatment had a 31.7% greater average corral surface moisture than the shaded treatment. Corral surface temperature varied based on areas of surface moisture, shade location, and elimination concentration within the corral. Sprinkled corrals had less particulate matter emissions than shaded (25%), but NH(3) emissions were 46% greater in sprinkler vs. shaded treatment. Overall, the use of shade in heifer corrals improved heifer performance and physiological measures, but sprinkler treatment had less PM [corrected] emissions from corral surfaces under heat stress conditions. Both cooling techniques affected spatial distribution and behaviors of the heifers, which affected pen usage and surface characteristics.

Rectal sac distention is induced by 20-hydroxyecdysone in the pupa of Bombyx mori.

Holometabolous insects do not excrete but store metabolic wastes during the pupal period. The waste is called meconium and is purged after adult emergence. Although the contents of meconium are well-studied, the developmental and physiological regulation of meconium accumulation is poorly understood. In Bombyx mori, meconium is accumulated in the rectal sac; thereby, the rectal sac distends at the late pupal stage. Here, we show that rectal sac distention occurs between 4 and 5 days after pupation. The distention is halted by brain-removal just after larval-pupal ecdysis but not by brain-removal 1 day after pupation. In the pupae, brain-removal just after ecdysis kept the hemolymph ecdysteroid titer low during early and mid-pupal stages. An injection of 20-hydroxyecdysone (20E) evoked the distention that was halted by brain-removal in a dose-dependent manner. Therefore, brain-removal caused the lack of ecdysteroid, and rectal sac distention did not appear in the brain-removed pupae because of the lack of ecdysteroid. We conclude that rectal sac distention is one of the developmental events regulated by 20E during the pupal period in B. mori.

Diagnosis and management of patients presenting with behavior problems.

Behavior problems are among the most common concerns for veterinary clients, and veterinarians need to be comfortable diagnosing and treating these conditions. Knowledge of animal behavior by veterinarians is critical for effective treatment of behavior problems, recognition and diagnosis of medical conditions for which behavior signs prevail, proper handling of veterinary patients, prevention of abandonment and euthanasia, preservation of the companion animal-human bond, and prevention of mental suffering. Successful patient management requires taking a thorough behavioral history, understanding the mechanisms underlying behavior changes, developing appropriate treatment interventions, and, in some cases, pharmacologic therapy.

Effect of an odor eliminator on feline litter box behavior.

Decreasing litter box odor may be an important treatment component in addressing feline inappropriate elimination. A three-phase study was conducted to determine if the use of Zero Odor litter box spray increases the preference of litter boxes to cats, presumably by its odor-eliminating quality. In the first phase, cats were given a litter box preference test between a litter box sprayed with Zero Odor and one without. In the second phase, the number of occurrences of behaviors indicative of a cat's dissatisfaction with the litter box (scratching at the sides of the box, floor or wall, hesitating when entering the litter box, balancing on the side of the box and eliminating outside of the litter box) was compared before and after the use of Zero Odor. Last, the frequency of eliminations that occurred outside the litter box was measured during a baseline phase and a test phase, in which Zero Odor was sprayed into all litter boxes in the home. Significantly fewer behaviors associated with feline litter box dissatisfaction and fewer undesirable eliminations were observed in phases 2 and 3, respectively. These findings suggest that use of Zero Odor litter box spray appears to decrease litter box odor and increases the attractiveness of litter box to cats.

Identified motoneurons involved in sexual and eliminative functions in the rat are powerfully excited by vasopressin and tachykinins.

The pudendal motor system is constituted by striated muscles of the pelvic floor and the spinal motoneurons that innervate them. It plays a role in eliminative functions of the bladder and intestine and in sexual function. Pudendal motoneurons are located in the ventral horn of the caudal lumbar spinal cord and send their axon into the pudendal nerve. In the rat, binding sites for vasopressin and tachykinin are present in the dorsomedial and dorsolateral pudendal nuclei, suggesting that these neuropeptides may affect pudendal motoneurons. The aim of the present study was to investigate possible effects of vasopressin and tachykinins on these motoneurons. Recordings were performed in spinal cord slices of young male rats using the whole-cell patch-clamp technique. Before recording, motoneurons were identified by 1,1'-dilinoleyl-3,3,3',3'-tetramethylindocarbocyanine, 4-chlorobenzenesulfonate retrograde labeling. The identification was confirmed, a posteriori, by choline acetyltransferase immunocytochemistry. Vasopressin and tachykinins caused a powerful excitation of pudendal motoneurons. The peptide-evoked depolarization, or the peptide-evoked inward current, persisted in the presence of tetrodotoxin, indicating that these effects were mainly postsynaptic. By using selective receptor agonists and antagonist, we determined that vasopressin acted via vasopressin 1a (V1a), but not V1b, V2, or oxytocin receptors, whereas tachykinins acted via neurokinin 1 (NK1), but not NK2 or NK3, receptors. Vasopressin acted by enhancing a nonselective cationic conductance; in some motoneurons, it also probably suppressed a resting K+ conductance. Our data show that vasopressin and tachykinins can excite pudendal motoneurons and thus influence the force of striated perineal muscles involved in eliminative and sexual functions.

Defecation behavior and ecology of insects.

Whereas foraging has been a major focus of ecological and entomological research, its obligate partner, defecation, has been comparatively neglected. Insects exhibit a range of intriguing behavioral and morphological adaptations related to waste disposal in a range of contexts, including predator-prey interactions, hygiene, habitat location, reproduction, feeding, and shelter construction. Some insects, for example, make use of their own excrement as a physical or chemical defense against natural enemies, while others actively distance themselves from their waste material. Internally feeding insects, fluid-feeders, and social insects face particular challenges because their feeding behavior and/or site fidelity makes them especially vulnerable to problems associated with waste accumulation. As is true for foraging, ecological interactions involving defecation may have far-reaching evolutionary consequences and merit further study.

Temporal characteristics of feeding behavior in the Munich miniature pig.

UNLABELLED: Correlations between meal size and inter-meal intervals as a characteristic of ingestive behavior are generally calculated utilizing Pearson's correlation coefficient. However, this commonly used method may exhibit disadvantages and methodological problems when dealing with dependent time series. Alternatively, a modified version of Pearson's r (r(diff)) or a nonparametric procedure, Pfanzagl's T combined with an expanded sampling theorem offer a statistical alternative for correlational analysis, robust to stochastic interdependencies between time series. In two studies, porcine self-initiated feeding behavior was observed in a closed economy setup, and a comparison of all three correlation coefficients was performed. STUDY 1: Twelve Munich mini-pigs were observed for 2 weeks. The rate of food ingestion was a stable characteristic of each individual pig, feeding and defecation behavior were temporally associated and light/dark cycle differences were seen for feeding. STUDY 2: Eight Munich mini-pigs were studied for 4 weeks. Kendall's Tau was utilized to test the stability of feeding behavior across weeks. Stability increased over time and feeding was more stable during the light period. Both correlation measures revealed a strong association between meal size and inter-meal intervals. CONCLUSION: Munich-miniature pigs exhibited a stable pattern of self-initiated ingestive and excretory behaviors. In both studies, Pfanzagl's T-values as well as r(diff)-values revealed a corresponding and consistent association between meal size and inter-meal intervals. In combination with the conventional Pearson's r, all three coefficients characterize different aspects of feeding behavior.