|
|
Tebbich Sabine, Griffin Andrea S., Peschl Markus F., & Sterelny Kim. (2016). From mechanisms to function: an integrated framework of animal innovation. Philos Trans R Soc Lond B Biol Sci, 371(1690), 20150195.
Abstract: Animal innovations range from the discovery of novel food types to the invention of completely novel behaviours. Innovations can give access to new opportunities, and thus enable innovating agents to invade and create novel niches. This in turn can pave the way for morphological adaptation and adaptive radiation. The mechanisms that make innovations possible are probably as diverse as the innovations themselves. So too are their evolutionary consequences. Perhaps because of this diversity, we lack a unifying framework that links mechanism to function. We propose a framework for animal innovation that describes the interactions between mechanism, fitness benefit and evolutionary significance, and which suggests an expanded range of experimental approaches. In doing so, we split innovation into factors (components and phases) that can be manipulated systematically, and which can be investigated both experimentally and with correlational studies. We apply this framework to a selection of cases, showing how it helps us ask more precise questions and design more revealing experiments.
|
|
|
|
Leliveld, L. M. C., Düpjan, S., Tuchscherer, A., & Puppe, B. (2016). Behavioural and physiological measures indicate subtle variations in the emotional valence of young pigs. Physiol. Behav., 157, 116–124.
Abstract: Abstract In the study of animal emotions, emotional valence has been found to be difficult to measure. Many studies of farm animals' emotions have therefore focussed on the identification of indicators of strong, mainly negative, emotions. However, subtle variations in emotional valence, such as those caused by rather moderate differences in husbandry conditions, may also affect animals' mood and welfare when such variations occur consistently. In this study, we investigated whether repeated moderate aversive or rewarding events could lead to measurable differences in emotional valence in young, weaned pigs. We conditioned 105 female pigs in a test arena to either a repeated startling procedure (sudden noises or appearances of objects) or a repeated rewarding procedure (applesauce, toy and straw) over 11 sessions. Control pigs were also regularly exposed to the same test arena but without conditioning. Before and after conditioning, we measured heart rate and its variability as well as the behavioural reactions of the subjects in the test arena, with a special focus on detailed acoustic analyses of their vocalisations. The behavioural and heart rate measures were analysed as changes compared to the baseline values before conditioning. A limited number of the putative indicators of emotional valence were affected by the conditioning. We found that the negatively conditioned pigs showed changes that were significantly different from those in control pigs, namely a decrease in locomotion and an increase in standing. The positively conditioned pigs, however, showed a stronger increase in heart rate and a smaller decrease in SDNN (a heart rate variability parameter indicating changes in autonomic regulation) compared to the controls. Compared to the negatively conditioned pigs, the positively conditioned pigs produced fewer vocalisations overall as well as fewer low-frequency grunts but more high-frequency grunts. The low-frequency grunts of the negatively conditioned pigs also showed lower frequency parameters (bandwidth, maximum frequency, 25% and 50% quartiles) compared to those of the positively conditioned pigs. In any of the statistically significant results, the conditioning accounted for 1.5–11.9% of variability in the outcome variable. Hence, we conclude that repeated moderate aversive and rewarding events have weak but measurable effects on some aspects of behaviour and physiology in young pigs, possibly indicating changes in emotional valence, which could ultimately affect their welfare. The combination of ethophysiological indicators, i.e., the concurrent examination of heart rate measures, behavioural responses and especially vocalisation patterns, as used in the current study, might be a useful way of examining subtle effects on emotional valence in further studies.
|
|
|
|
Elfers, K., Marr, I., Wilkens, M. R., Breves, G., Langeheine, M., Brehm, R., et al. (2016). Expression of Tight Junction Proteins and Cadherin 17 in the Small Intestine of Young Goats Offered a Reduced N and/or Ca Diet. PLoS ONE, 11(4), e0154311.
Abstract: <p>Diets fed to ruminants should contain nitrogen (N) as low as possible to reduce feed costs and environmental pollution. Though possessing effective N-recycling mechanisms to maintain the N supply for rumen microbial protein synthesis and hence protein supply for the host, an N reduction caused substantial changes in calcium (Ca) and phosphate homeostasis in young goats including decreased intestinal transepithelial Ca absorption as reported for monogastric species. In contrast to the transcellular component of transepithelial Ca transport, the paracellular route has not been investigated in young goats. Therefore, the aim of the present study was to characterise the effects of dietary N and/or Ca reduction on paracellular transport mechanisms in young goats. Electrophysiological properties of intestinal epithelia were investigated by Ussing chamber experiments. The expression of tight junction (TJ) and adherens junction (AJ) proteins in intestinal epithelia were examined on mRNA level by <italic>q</italic>PCR and on protein level by western blot analysis. Dietary N reduction led to a segment specific increase in tissue conductances in the proximal jejunum which might be linked to concomitantly decreased expression of cadherin 17 mRNA. Expression of occludin (OCLN) and zonula occludens protein 1 was increased in mid jejunal epithelia of N reduced fed goats on mRNA and partly on protein level. Reduced dietary Ca supply resulted in a segment specific increase in claudin 2 and claudin 12 expression and decreased the expression of OCLN which might have been mediated at least in part by calcitriol. These data show that dietary N as well as Ca reduction affected expression of TJ and AJ proteins in a segment specific manner in young goats and may thus be involved in modulation of paracellular Ca permeability.</p>
|
|
|
|
Chapron, G., & Treves, A. (2016). Blood does not buy goodwill: allowing culling increases poaching of a large carnivore. Proc. R. Soc. Lond. B, 283(1830).
Abstract: Quantifying environmental crime and the effectiveness of policy interventions is difficult because perpetrators typically conceal evidence. To prevent illegal uses of natural resources, such as poaching endangered species, governments have advocated granting policy flexibility to local authorities by liberalizing culling or hunting of large carnivores. We present the first quantitative evaluation of the hypothesis that liberalizing culling will reduce poaching and improve population status of an endangered carnivore. We show that allowing wolf (Canis lupus) culling was substantially more likely to increase poaching than reduce it. Replicated, quasi-experimental changes in wolf policies in Wisconsin and Michigan, USA, revealed that a repeated policy signal to allow state culling triggered repeated slowdowns in wolf population growth, irrespective of the policy implementation measured as the number of wolves killed. The most likely explanation for these slowdowns was poaching and alternative explanations found no support. When the government kills a protected species, the perceived value of each individual of that species may decline; so liberalizing wolf culling may have sent a negative message about the value of wolves or acceptability of poaching. Our results suggest that granting management flexibility for endangered species to address illegal behaviour may instead promote such behaviour.
|
|
|
|
Palm, A. - K. E., Wattle, O., Lundström, T., & Wattrang, E. (2016). Secretory immunoglobulin A and immunoglobulin G in horse saliva. Vet. Immunol. Immunolpathol., 180, 59–65.
Abstract: This study aimed to increase the knowledge on salivary antibodies in the horse since these constitute an important part of the immune defence of the oral cavity. For that purpose assays to detect horse immunoglobulin A (IgA) including secretory IgA (SIgA) were set up and the molecular weights of different components of the horse IgA system were estimated. Moreover, samples from 51 clinically healthy horses were tested for total SIgA and IgG amounts in saliva and relative IgG3/5 (IgG(T)) and IgG4/7 (IgGb) content were tested in serum and saliva. Results showed a mean concentration of 74μg SIgA/ml horse saliva and that there was a large inter-individual variation in salivary SIgA concentration. For total IgG the mean concentration was approx. 5 times lower than that of SIgA, i.e. 20μg IgG/ml saliva and the inter-individual variation was lower than that observed for SIgA. The saliva-serum ratio for IgG isotypes IgG3/5 and IgG4/7 was also assessed in the sampled horses and this analysis showed that the saliva-serum ratio of IgG4/7 was in general approximately 4 times higher than that of IgG3/5. The large inter-individual variation in salivary SIgA levels observed for the normal healthy horses in the present study emphasises the need for a large number of observations when studying this parameter especially in a clinical setting. Moreover, our results also indicated that some of the salivary IgG does not originate from serum but may be produced locally. Thus, these results provide novel insight, and a base for further research, into salivary antibody responses of horses.
|
|
|
|
Hölker, S. (2016). Typologie der deutschen Pferdehaltung – Eine empirische Studie mittels Two-Step-Clusteranalyse. Z. Agrarpolit. Landwirtsch., 94(3).
Abstract: In der deutschen Pferdebranche besteht u. a. hinsichtlich der Ausrichtung, Lage, Größe und ökonomischen Zielsetzung von Pferdehaltern eine große Heterogenität, gleichzeitig sind die Strukturen in diesem Sektor bislang kaum wissenschaftlich erfasst. Aus diesem Grund wird im vorliegenden Beitrag die Vielzahl unterschiedlicher Erscheinungsformen in der Pferdehaltung mittels einer empirisch gestützten Typologie systematisch beschrieben. Mittels einer standardisierten Onlinebefragung wurden 1.110 private, landwirtschaftliche und gewerbliche Pferdehalter sowie pferdehaltende Vereine befragt. Abgefragt wurden neben der Organisationsform, Bestandsgröße und der Ausrichtung auch Aspekte wie u. a. die Ausstattung der Anlage, die angewandten Haltungssysteme für die Pferde sowie Angaben zur zukünftige Entwicklung und den wahrgenommenen aktuellen sowie zukünftigen Herausforderungen in der Pferdehaltung. Mittels einer Clusteranalyse konnten sechs Typen herausgearbeitet werden: ländliche Hobbypferdehaltung, stadtorientierte Hobbypferdehaltung, Hobby-Zuchtpferdehaltung, Zuchtpferdehaltung, Pensionspferdehaltung und diversifizierte Pferdehaltung. Dabei sind die drei erstgenannten Typen der Liebhaberei zuzuordnen und die drei letztgenannten Typen werden mit Gewinnerzielungsabsicht betrieben. Die ermittelten Typen unterscheiden sich teilweise signifikant u. a. hinsichtlich ihrer Größe, den angewandten Haltungssystemen, der Anzahl an Betriebszweigen oder auch ihren zukünftig geplanten Entwicklungen. Die vorliegende Studie zeigt somit, dass beispielsweise bei der Entwicklung politischer Maßnahmen im Bereich der Pferdehaltung die Auswirkungen für einzelne Pferdehalter sehr unterschiedlich ausfallen können und es daher notwendig ist, die unterschiedlichen, real existierenden Betriebstypen zu berücksichtigen.
|
|
