Littérature scientifique sur le sujet « Thermoregulation feeding behaviour »

Two trials were conducted to determine whether the effects of morning (1000) vs. evening (2000) feed delivery on the frequency and duration of feedbunk visits, thermoregulatory physiology and growth performance of feedlot steers were modified by ambient winter temperatures. Night-time feeding behaviours were more pronounced for evening-fed than for morning-fed cattle during both the forage-based backgrounding and concentrate-based finishing periods. Evening feeding also led to increased core body temperatures during the coldest part of the day during the backgrounding period but had little effect during the finishing period. Although ambient temperatures were similar in both trials, evening feeding improved growth rate and efficiency during the coldest part of the backgrounding period in Trial 1 but not in Trial 2. Feeding time did not affect feedlot performance during the finishing period of either trial. Evening feeding successfully altered feeding behaviours and appeared to improve thermoregulatory status during the coldest part of the backgrounding period, but did not improve growth performance or efficiency. Key words: Beef cattle, thermoregulation, evening feeding, feeding behaviour

The activity patterns of marked hyrax in the Mountain Zebra National Park were quantified by direct observations. Extended periods are spent on basking during winter (6,8 h) and summer (5,3 h) respectively. At least 80 % of each day is spent in an inactive phase. The more extended time spent on movement and time spent within refuges during summer (0,4 and 2,7 h), compared to winter (0,2 and 0,9 h), can possibly be interpreted in terms of behavioural thermoregulation. Distinct differences between the feeding behaviour of juveniles (< 6 months) and older hyrax were observed. Foraging of juveniles was limited to a distance of 40 m or less from refuges and took place under the surveilance of adults. Foraging of older hyrax frequently occurred for extended distances (up to 500 m) from refuges. These hyrax frequently visited riparian thickets. Foraging excursions of individual hyrax lasted for 0,5 - 8 h. The reported early and late afternoon group feeding sessions for hyrax older than 5 months could not be confirmed.

AbstractOstrich welfare on farms of is great importance, particularly because little is known about appropriate husbandry conditions for these birds in a northern European environment. Rain has been shown to influence the pattern of behaviour during the spring months. This study examined the effects of four different climatic conditions (raining, dull but overcast, bright but overcast and sunny) on the behaviour of ostriches during the winter. Compared with dry conditions, there was a significantly higher rate of sitting during rainy periods — apparently at the expense of foraging (from pasture) and pacing (around the perimeter). The rate of sitting was much lower than that reported for the same birds during rain in the spring. During all climatic conditions, feeding (on concentrate feed provided) and foraging were the most dominant behaviours. Feeding was not significantly affected by rain but the frequency of foraging was reduced. Standing was a common behaviour. There were significant gender differences for standing (males > females) and foraging (females > males). These results show that winter conditions require ostriches to feed and forage at higher rates than during the spring or summer, presumably to consume more energy for thermoregulation. Gender differences in pacing and feeding behaviours previously observed in breeding birds were absent in non-breeding ostriches (presumably because males were not defending territories); although non-breeding males appeared to be more vigilant than females and needed to consume more food. Improvements in ostrich husbandry should take into account the need to provide both adequate shelter and more concentrate rations during the cold weather of winter. Energy requirements will be higher at this time, yet the ability of the birds to forage will be diminished. Without such considerations, ostrich welfare during the winter in northern Europe will be compromised.

The combined behaviours of individuals within insect societies determine the survival and development of the colony. For the western honey bee (Apis mellifera), individual behaviours include nest building, foraging, storing and ripening food, nursing the brood, temperature regulation, hygiene and defence. However, the various behaviours inside the colony, especially within the cells, are hidden from sight, and until recently, were primarily described through texts and line drawings, which lack the dynamics of moving images. In this study, we provide a comprehensive source of online video material that offers a view of honey bee behaviour within comb cells, thereby providing a new mode of observation for the scientific community and the general public. We analysed long-term video recordings from longitudinally truncated cells, which allowed us to see sideways into the cells in the middle of a colony. Our qualitative study provides insight into worker behaviours, including the use of wax scales and existing nest material to remodel combs, storing pollen and nectar in cells, brood care and thermoregulation, and hygienic practices, such as cannibalism, grooming and surface cleaning. We reveal unique processes that have not been previously published, such as the rare mouth-to-mouth feeding by nurses to larvae as well as thermoregulation within cells containing the developing brood. With our unique video method, we are able to bring the processes of a fully functioning social insect colony into classrooms and homes, facilitating ecological awareness in modern times. We provide new details and images that will help scientists test their hypotheses on social behaviours. In addition, we encourage the non-commercial use of our material to educate beekeepers, the media and the public and, in turn, call attention to the general decline of insect biomass and diversity.

This study supports the hypothesis that well-fed cod (Gadus morhua) seek higher temperatures to increase growth rate, and poorly fed cod select lower temperatures to save metabolic energy. Depth and temperature of free-ranging adult cod (44–79 cm) were studied with data storage tags as part of a ranching project in an Icelandic fjord. Forage fish were regularly provided at four feeding stations where cod formed distinct “herds” (herd cod) that did not mingle much with the rest of the unconditioned cod in the fjord (wild cod). Several parameters (stomach fullness, liver index (fat reserves), condition factor, and growth rate) indicated that food intake was much greater in herd cod than in wild cod. In August, when the thermocline was well established, the herd cod remained in shallow (15–35 m) and warm water (8–10 °C), whereas the wild cod stayed in deep (80–90 m) and cold water (3–4 °C), but occasionally both groups explored depths and temperatures outside their preferred range. After vertical mixing in autumn when thermoregulation was not possible, the depth difference between the two groups decreased significantly.

Metabolism links organisms to their environment through its effects on thermoregulation, feeding behaviour and energetics. Genes involved in metabolic processes have known pleiotropic effects on some melanic colour traits. Understanding links between physiology and melanic colour is critical for understanding the role of, and potential constraints on, colour production. Despite considerable variation in metabolic rates and presumed ancestral melanic coloration in vertebrates, few studies have looked at a potential relationship between these two systems in a comparative framework. Here, we test the hypothesis that changes in melanosome shape in integumentary structures track metabolic rate variation across amniotes. Using multivariate comparative analyses and incorporating both extant and fossil taxa, we find significantly faster rates of melanosome shape evolution in taxa with high metabolic rates, as well as both colour- and clade-specific differences in the relationship between metabolic rate and melanosome shape. Phylogenetic tests recover an expansion in melanosome morphospace in maniraptoran dinosaurs, as well as rate shifts within birds (in songbirds) and mammals. These findings indicate another core phenotype influenced by metabolic changes in vertebrates. They also provide a framework for testing clade-specific gene expression patterns in the melanocortin system and may improve colour reconstructions in extinct taxa.

Although ambient temperature has diverse effects on disease dynamics, few studies have examined how temperature alters pathogen transmission by changing host physiology or behaviour. Here, we test whether reducing ambient temperature alters host foraging, pathology and the potential for fomite transmission of the bacterial pathogen Mycoplasma gallisepticum (MG), which causes seasonal outbreaks of severe conjunctivitis in house finches ( Haemorhous mexicanus ). We housed finches at temperatures within or below the thermoneutral zone to manipulate food intake by altering energetic requirements of thermoregulation. We predicted that pathogen deposition on bird feeders would increase with temperature-driven increases in food intake and with conjunctival pathology. As expected, housing birds below the thermoneutral zone increased food consumption. Despite this difference, pathogen deposition on feeders did not vary across temperature treatments. However, pathogen deposition increased with conjunctival pathology, independently of temperature and pathogen load, suggesting that MG could enhance its transmission by increasing virulence. Our results suggest that in this system, host physiological responses are more important for transmission potential than temperature-dependent alterations in feeding. Understanding such behavioural and physiological contributions to disease transmission is critical to linking individual responses to climate with population-level disease dynamics.

Larvae of the arctic moth Gynaephora groenlandica stop feeding and spin silk hibernacula before the peak of summer season in the Canadian High Arctic Archipelago. This study examines the function of these hibernacula in relation to the biotic and abiotic mortality factors of parasitism and temperature. Winter mortality of 10% among larvae in cages on the tundra was compared with previous results on parasitism (56% mortality). Prior to winter, the cages were used to record larval behaviour and the location of hibernacula. The majority of the larvae (81%) spun hibernacula, most of which were concealed between the stems of arctic heather, Cassiope tetragona. Fewer hibernacula were found on the primary host plant, arctic willow, Salix arctica, than on C. tetragona or Dryas integrifolia, which formed the dominant plant cover. Nearly one-half of all the larvae that spun hibernacula made joint hibernacula with other larvae. Frequency of larvae sharing hibernacula declined with increasing numbers of larvae per cage. At low population density about half of the larvae occupied communal hibernacula, whereas only one-quarter of the larvae at high density shared hibernacula. In most cases only 2 larvae spun a common hibernaculum, 3 larvae shared hibernacula less frequently, and greater numbers of larvae were rarely found in a single hibernaculum. Unlike the high excess body temperatures usually achieved through thermoregulation by feeding larvae and pupae, temperatures within hibernacula were nearly identical with those of the surrounding substrate over 18 h and rose < 5 °C during the afternoon. This study suggests that larval hibernacula lower summer and winter mortality of G. groenlandica larvae. Hibernacula are an effective barrier to parasitism, which is the primary mortality factor. Furthermore, the behavioural shift from feeding to spinning hibernacula may prevent energy depletion by inducing metabolic depression during mid to late summer, which may be essential for winter survival.

The roosting and breeding behaviour of a pair of Tawny Frogmouths Podargus strigoides was observed on the central Queensland coast over a period of 4 years (2018–2021). The study was conducted in a subtropical climate near Rockhampton, and provides data from a different geographical and climatic area compared with previous studies that were conducted in temperate southern Australia (New England Tablelands, Moree, and Sydney, New South Wales, and the Australian Capital Territory). Breeding data matched other studies: breeding in November–December, incubation of 28–30 days, fledging at 27–31 days, care of fledglings from 1–3 months, nests located in a horizontal fork of a tree on the edge of a clearing. Breeding success was high at 80% (8 of 10 nestlings survived). Roost sites were generally in tree species with a fibrous dark bark that provided camouflage, and were mostly within the leafy canopy (average height 9.11 m above ground), which provided protection from high daytime temperatures in both winter and summer. Only early in the morning on very cool days in winter did Frogmouths seek lower perches where sun exposure was greatest. These findings are consistent with other studies identifying thermoregulation and camouflage as important determinants of roost selection, although the need for greater sun exposure in winter was much lower in this study, reflecting the generally warm winter days. Fidelity to roost trees was high (90% of roosts were in four trees) and Frogmouths nested in a different tree each year. Both roosts and nests were confined to a home range of 1.6 ha. The frequency of feeding increased with nestling age, and was higher during the early part of the night. Overall, these findings advance understanding of the breeding biology of the Tawny Frogmouth in subtropical Australia.

Background Precision Livestock Farming (PLF) is a promising approach to minimize the conflicts between socio-economic activities and landscape conservation. However, its application on extensive systems of livestock production can be challenging. The main difficulties arise because animals graze on large natural pastures where they are exposed to competition with wild herbivores for heterogeneous and scarce resources, predation risk, adverse weather, and complex topography. Considering that the 91% of the world’s surface devoted to livestock production is composed of extensive systems (i.e., rangelands), our general aim was to develop a PLF methodology that quantifies: (i) detailed behavioural patterns, (ii) feeding rate, and (iii) costs associated with different behaviours and landscape traits. Methods For this, we used Merino sheep in Patagonian rangelands as a case study. We combined data from an animal-attached multi-sensor tag (tri-axial acceleration, tri-axial magnetometry, temperature sensor and Global Positioning System) with landscape layers from a Geographical Information System to acquire data. Then, we used high accuracy decision trees, dead reckoning methods and spatial data processing techniques to show how this combination of tools could be used to assess energy balance, predation risk and competition experienced by livestock through time and space. Results The combination of methods proposed here are a useful tool to assess livestock behaviour and the different factors that influence extensive livestock production, such as topography, environmental temperature, predation risk and competition for heterogeneous resources. We were able to quantify feeding rate continuously through time and space with high accuracy and show how it could be used to estimate animal production and the intensity of grazing on the landscape. We also assessed the effects of resource heterogeneity (inferred through search times), and the potential costs associated with predation risk, competition, thermoregulation and movement on complex topography. Discussion The quantification of feeding rate and behavioural costs provided by our approach could be used to estimate energy balance and to predict individual growth, survival and reproduction. Finally, we discussed how the information provided by this combination of methods can be used to develop wildlife-friendly strategies that also maximize animal welfare, quality and environmental sustainability.

Avec l'augmentation de la température mondiale et des vagues de chaleur plus fréquentes, le stress thermique réduit la production porcine dans de nombreux pays. La diminution de la croissance est principalement liée à une réduction de la consommation alimentaire mais d'autres aspects du stress thermique chez les porcs sont apparus au cours des dernières années. La thèse vise à contribuer aux connaissances actuelles avec les objectifs suivants : 1) étudier l'effet d'un stress thermique prénatal chronique sur la tolérance des porcs à la chaleur, 2) confirmer les effets directs et indirects de l'exposition à la chaleur, 3) évaluer les stratégies d'alimentation qui peuvent aider les porcs pendant le stress thermique, et 4) explorer l'idée que le maintien de l’équilibre thermique est un processus dynamique qui varie tout au long de la journée. Ce projet de thèse a montré qu'un déséquilibre entre la production et la perte de chaleur (charge thermique) et la capacité de perte de chaleur entraîne une réduction des performances, non seulement une croissance réduite, mais également une altération du métabolisme énergétique, des réponses physiologiques et une composition corporelle exacerbée par une exposition au stress thermique pendant la période fœtale.De plus, l'amélioration de la tolérance à la chaleur des porcs est liée dans leur capacité à maintenir un équilibre dynamique entre la production et la perte de chaleur tout au long de la journée, en particulier pendant et après un repas en raison de la forte contribution du comportement alimentaire à la production de chaleur. Nos résultats ont également confirmé la tolérance à la chaleur est en partie déterminée par la capacité des animaux à perdre de la chaleur par la voie évaporative. Les stratégies nutritionnelles liées à un comportement alimentaire modifié ont été évaluée. La supplémentation en levures vivantes a amélioré la sensibilité à l'insuline et l'efficacité de la perte de chaleur qui a aidé les porcs à faire face au stress thermique en modifiant le comportement alimentaire avec des effets positifs sur l'efficacité énergétique lors d'un défi thermique
Heat stress remains to be one of the major limiting factors in swine production in many countries and this concern will rise in the future especially with increasing global temperature and more frequent heat waves due to warming climate. While decreased growth is mainly related to a reduction in feed intake, other aspects of heat stress in growing pigs have emerged in the recent decades. The thesis thus aims to contribute to the current knowledge with the following objectives: 1) to investigate effect of a chronic prenatal heat challenge on pig’s heat tolerance, 2) to confirm direct and indirect effects of heat exposure on pig performance, 3) to evaluate feeding practices that can help pigs cope to a heat challenge, and 4) to explore the idea of maintaining thermal balance as a dynamic process that varies throughout the day. This thesis project has demonstrated that an imbalance between heat production and loss (heat load) results in reduced growth and in altered energy metabolism, physiological responses, and body composition. This later effect is exacerbated in pigs exposed to a chronic prenatal heat challenge. Improved heat tolerance in pigs was found to depend on their ability to maintain dynamic equilibrium between heat production and losses within a day, especially during and after a meal. Our results also confirmed the importance of water intake in improving evaporative heat losses in the ability of pigs to cope with heat stress. Nutritional management practices linked to modified feeding behavior were evaluated. Live yeast supplementation improved insulin sensitivity, increased heat loss efficiency under heat stress, and modified feeding behavior with positive effects on energy efficiency and protein deposition during a heat challenge

Abstract This chapter provides information on body care of animals on the following: types of body care behaviour; organization of body care; grooming, feeding, dust bathing; thermoregulation; and defacation.