Piglets' acute responses to local anesthetic injection and surgical castration: Effects of the injection method and interval between injection and castration.

Although applied in some countries, efficacy of local anesthetics based on procaine to mitigate acute responses to piglet castration remains questioned. This paper presents results from a factorial study examining the effects of two methods of injection of a procaine-based drug (intra-funicular, IF, vs. intra-testicular, IT), and four intervals between drug injection and castration (2.

Piglets' acute responses to procaine-based local anesthetic injection and surgical castration: Effects of two volumes of anesthetic.

Surgical castration of piglets is painful, but practiced routinely in commercial pig production. Procaine-based local anesthetics are used to mitigate piglet pain during castration in some countries. Yet, effects of the volume of anesthetic injected remain under-studied.

Exploratory behaviour towards novel objects is associated with enhanced learning in young horses.

The mechanisms underlying individual variation in learning are key to understanding the development of cognitive abilities. In humans and primates, curiosity has been suggested as an important intrinsic factor that enhances learning, whereas in domesticated species research has primarily identified factors with a negative effect on cognitive abilities, such as stress and fearfulness. This study presents the first evidence of a link between object-directed curiosity and learning performance in young horses in two very different learning tasks (visual discrimination and pressure-release).

Maternal temperament modulates curiosity and cortisol responses in farmed mink.

Early life events can shape the development of individual behavior and stress sensitivity. This study explored whether the temperament of the mother modulates curiosity, fear, and Hypothalamic-Pituitary-Adrenal (HPA)-axis hormones in different lines of mink. We designed a study with all combinations of cross-mating between males and females from lines of Confident (C) and Fearful (F) mink.

Selection for temperament has no negative consequences on important production traits in farmed mink1.

Danish and European legislation recommend mink breeding programs that include selection for "confidence," defined as exploratory activity in a standardized behavioral test. Although this recommendation may improve mink welfare, farmers may consider this criterion risky due to possible negative consequences on other traits. The overall objectives of this study were to estimate the heritability of exploratory/fearful behavior and to identify genetic correlations with other traits of major economic importance in mink fur production.

Development of vocalization and hearing in American mink (Neovison vison).

American mink (Neovison vison) kits are born altricial and fully dependent on maternal care, for which the kits' vocalizations appear essential. We used auditory brainstem responses (ABRs) to determine: (1) hearing sensitivity of adult females from two breeding lines known to differ in maternal behaviour and (2) development of hearing in kits 8-52 days of age. We also studied sound production in 20 kits throughout postnatal days 1 to 44.

Responses of mink to auditory stimuli: prerequisites for applying the 'cognitive bias' approach.

The aim of the study was to determine and validate prerequisites for applying a cognitive (judgement) bias approach to assessing welfare in farmed mink (Neovison vison). We investigated discrimination ability and associative learning ability using auditory cues. The mink (n=15 females) were divided into two groups (High, n=8; Low, n=7, representing the frequency of the tone they were habituated to, 18 and 2 kHz respectively) and were tested using a habituation-dishabituation procedure in experiment 1.

Hippocampal neurogenesis increase with stereotypic behavior in mink (Neovison vison).

Unlabelled: We investigated the hypothesis that performance of abnormal behavior is a stress response concurrent with reduced cell formation in the hippocampal region of the brain, using groups of adult female American mink with high occurrence of stereotypic behavior (STEREO, n=12), high occurrence of fur-chewing behavior (FURCHEW, n=12), or without abnormal behavior (CONTROL, n=12). Following repeated injections of Bromodeoxyuridine (BrdU) as a marker of dividing cells, animals were sacrificed and brain tissue fixated. After brain sectioning and a mink-adapted free-floating BrdU/NeuN doublestaining protocol, we counted the number of cells formed in the subgranular zone (SGZ) and the granular cell layer (GCL) of the dentate gyrus (DG) in the mink hippocampus.

Exploration of the hypothalamic-pituitary-adrenal function as a tool to evaluate animal welfare.

Measuring HPA axis activity is the standard approach to the study of stress and welfare in farm animals. Although the reference technique is the use of blood plasma to measure glucocorticoid hormones (cortisol or corticosterone), several alternative methods such as the measurement of corticosteroids in saliva, urine or faeces have been developed to overcome the stress induced by blood sampling itself. In chronic stress situations, as is frequently the case in studies about farm animal welfare, hormonal secretions are usually unchanged but dynamic testing allows the demonstration of functional changes at several levels of the system, including the sensitization of the adrenal cortex to ACTH and the resistance of the axis to feedback inhibition by corticosteroids (dexamethasone suppression test).

Effect of the serotonin agonist buspirone on behaviour and hypothalamic-pituitary-adrenal axis in confident and fearful mink.

Behavioural and hypothalamic-pituitary-adrenal (HPA) axis responses were investigated in farm mink (Mustela vison) selected for either confident or fearful behaviour for nine generations. Two groups of 2-year-old confident (n=12) and fearful (n=12) female mink were given the serotonin (5-HT) 1A receptor agonist buspirone (1.25 mg/kg/day), whereas two other groups of 2-year-old confident (n=12) and fearful (n=12) female mink were given saline, continuously for 5 weeks via osmotic minipumps.