| Records |
| Author |
Cameron, E.Z.; du Toit, J.T. |
| Title |
Winning by a neck: tall giraffes avoid competing with shorter browsers |
Type |
Journal Article |
| Year |
2007 |
Publication |
The American naturalist |
Abbreviated Journal |
Am Nat |
Volume  |
169 |
Issue |
1 |
Pages |
130-135 |
| Keywords |
Acacia/growth & development; Animals; Feeding Behavior/*physiology; Neck/*anatomy & histology; Plant Leaves/growth & development; Ruminants/*anatomy & histology/*physiology; South Africa |
| Abstract |
With their vertically elongated body form, giraffes generally feed above the level of other browsers within the savanna browsing guild, despite having access to foliage at lower levels. They ingest more leaf mass per bite when foraging high in the tree, perhaps because smaller, more selective browsers deplete shoots at lower levels or because trees differentially allocate resources to promote shoot growth in the upper canopy. We erected exclosures around individual Acacia nigrescens trees in the greater Kruger ecosystem, South Africa. After a complete growing season, we found no differences in leaf biomass per shoot across height zones in excluded trees but significant differences in control trees. We conclude that giraffes preferentially browse at high levels in the canopy to avoid competition with smaller browsers. Our findings are analogous with those from studies of grazing guilds and demonstrate that resource partitioning can be driven by competition when smaller foragers displace larger foragers from shared resources. This provides the first experimental support for the classic evolutionary hypothesis that vertical elongation of the giraffe body is an outcome of competition within the browsing ungulate guild. |
| Address |
Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa. ezcameron@zoology.up.ac.za |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Series Issue |
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Edition |
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| ISSN |
1537-5323 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:17206591 |
Approved |
no |
| Call Number |
refbase @ user @ |
Serial |
410 |
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| Author |
Robinson, H.C. |
| Title |
Equine interspecies aggression |
Type |
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| Year |
2007 |
Publication |
The Veterinary record |
Abbreviated Journal |
Vet. Rec. |
| Volume |
160 |
Issue |
7 |
Pages |
244 |
| Keywords |
*Aggression; Animals; Behavior, Animal; Equidae; Horses/*physiology/*psychology |
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Place of Publication |
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English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0042-4900 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:17308028 |
Approved |
no |
| Call Number |
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Serial |
1773 |
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| Author |
Franceschini, C.; Siutz, C.; Palme, R.; Millesi, E. |
| Title |
Seasonal changes in cortisol and progesterone secretion in Common hamsters |
Type |
Journal Article |
| Year |
2007 |
Publication |
General and Comparative Endocrinology |
Abbreviated Journal |
Gen Comp Endocrinol |
| Volume |
152 |
Issue |
1 |
Pages |
14-21 |
| Keywords |
Animals; Cortisone/*secretion; Cricetinae/*metabolism; Feces/chemistry; Female; Lactation/physiology; Male; Pregnancy; Progesterone/*secretion; Reproduction/physiology; *Seasons; Sexual Behavior, Animal/physiology |
| Abstract |
In this study, we investigated endocrine factors and behaviour in free-living Common hamsters (Cricetus cricetus) during reproductive and non-reproductive periods of the annual cycle. We applied a non-invasive method to gain information on seasonal changes in adrenocortical activity in male and female hamsters by analysing faecal glucocorticoid metabolite concentrations (FCM). In addition, plasma progesterone concentrations were monitored in females throughout the non-hibernation season. The animals were live-trapped from spring emergence until the onset of hibernation in autumn. Reproductive status was determined at capture and blood and faecal samples were collected. During behavioural observations, agonistic and sexual interactions were recorded. FCM concentrations were significantly higher in males than in females during the reproductive period. In males, a pronounced increase in FCM during the reproductive period coincided with high frequencies of intrasexual aggression. In females, FCM levels remained relatively constant. Aggressive behaviour in females increased during the reproductive period, but was much less frequent than in males. Females, which successfully raised a second litter after a postpartum oestrus and concurrent lactation and gestation had lower FCM levels than individuals, which lost their second litter after parturition. As expected, plasma progesterone concentrations were low before and after the reproductive period. During gestation, levels peaked and remained elevated during lactation. The results of this field study provide insight in critical periods associated with reproduction in male and female Common hamsters. |
| Address |
Department of Behavioural Biology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria. claudia.franceschini@univie.ac.ct |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0016-6480 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:17408667 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
4076 |
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| Author |
Sundaresan, S.R.; Fischhoff, I.R.; Dushoff, J.; Rubenstein, D.I. |
| Title |
Network metrics reveal differences in social organization between two fission-fusion species, Grevy's zebra and onager |
Type |
Journal Article |
| Year |
2007 |
Publication |
Oecologia |
Abbreviated Journal |
Oecologia |
| Volume |
151 |
Issue |
1 |
Pages |
140-149 |
| Keywords |
Analysis of Variance; Animals; Behavior, Animal/*physiology; *Environment; Equidae/*physiology; Female; India; Kenya; Male; *Models, Theoretical; *Social Behavior; *Social Environment |
| Abstract |
For species in which group membership frequently changes, it has been a challenge to characterize variation in individual interactions and social structure. Quantifying this variation is necessary to test hypotheses about ecological determinants of social patterns and to make predictions about how group dynamics affect the development of cooperative relationships and transmission processes. Network models have recently become popular for analyzing individual contacts within a population context. We use network metrics to compare populations of Grevy's zebra (Equus grevyi) and onagers (Equus hemionus khur). These closely related equids, previously described as having the same social system, inhabit environments differing in the distribution of food, water, and predators. Grevy's zebra and onagers are one example of many sets of coarsely similar fission-fusion species and populations, observed elsewhere in other ungulates, primates, and cetaceans. Our analysis of the population association networks reveals contrasts consistent with their distinctive environments. Grevy's zebra individuals are more selective in their association choices. Grevy's zebra form stable cliques, while onager associations are more fluid. We find evidence that females associate assortatively by reproductive state in Grevy's zebra but not in onagers. The current approach demonstrates the utility of network metrics for identifying fine-grained variation among individuals and populations in association patterns. From our analysis, we can make testable predictions about behavioral mechanisms underlying social structure and its effects on transmission processes. |
| Address |
Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA. ssundare@princeton.edu |
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English |
Summary Language |
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Original Title |
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Series Issue |
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Edition |
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| ISSN |
0029-8549 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:16964497 |
Approved |
no |
| Call Number |
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Serial |
1863 |
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| Author |
Li, C.; Jiang, Z.; Tang, S.; Zeng, Y. |
| Title |
Influence of enclosure size and animal density on fecal cortisol concentration and aggression in Pere David's deer stags |
Type |
Journal Article |
| Year |
2007 |
Publication |
General and Comparative Endocrinology |
Abbreviated Journal |
Gen Comp Endocrinol |
| Volume |
151 |
Issue |
2 |
Pages |
202-209 |
| Keywords |
*Aggression; Animals; *Deer; *Environment; Feces/*chemistry; Handling (Psychology); Housing, Animal; Hydrocortisone/*analysis; Male; Population Density |
| Abstract |
We investigated the impact of enclosure size and animal density on behavior and adrenocortical secretion in Pere David's deer in Dafeng Nature Reserve, China. From February 15 to April 16 in 2004, we conducted two experiments. First, we studied maintenance behavior and conflict behavior of Pere David's deer stags in a large enclosure (200 ha) with low animal density (0.66 deer/ha) and a small display pen (0.75 ha) with high animal density (25.33 deer/ha). The maintenance behavior we recorded included standing, locomotion, foraging and rest. During the behavioral observations, we collected fresh voided fecal samples from the stags periodically, and analyzed the fecal cortisol concentrations in those samples using radioimmunoassay technique. Second, we monitored the fecal cortisol concentrations of one group of stags (12 deer lived in an enclosure of 100 ha) before and after transferred into a small pen (0.5 ha). We found that in the first experiment: (1) there were significant differences in standing and rest whereas no significant differences of locomotion and foraging between the free-ranging group and the display group; (2) frequency of conflict behavior in the display group was significantly higher than those in the free-ranging group; and (3) fecal cortisol concentration of the display group (326.17+/-16.98 ng/g dry feces) was significantly higher than that of the free-ranging group (268.98+/-15.21 ng/g dry feces). In the second experiment, there was no significant difference of the fecal cortisol concentrations among sampling days, but the mean fecal cortisol concentration of the day after transferring (337.46+/-17.88 ng/g dry feces) was significantly higher than that of the day before transferring (248.44+/-7.99 ng/g dry feces). Comparison with published findings, our results indicated that enclosure size and animal density affect not only behaviors, but also adrenocortical secretion in Pere David's deer. Small living space with high animal density may impose physiological stress to captive Pere David's deer. Moreover, long-term physiological stress and increase of conflict behavior may subsequently affect survival and reproduction of the deer. |
| Address |
Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, China |
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English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0016-6480 |
ISBN |
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Medium |
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Conference |
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| Notes |
PMID:17324429 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
5475 |
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| Author |
Rapin, V.; Poncet, P.A.; Burger, D.; Mermod, C.; Richard, M.A. |
| Title |
[Measurement of the attention time in the horse] |
Type |
Journal Article |
| Year |
2007 |
Publication |
Schweizer Archiv fur Tierheilkunde |
Abbreviated Journal |
Schweiz Arch Tierheilkd |
| Volume |
149 |
Issue |
2 |
Pages |
77-83 |
| Keywords |
Age Factors; Animals; *Attention/physiology; Conditioning, Operant; Cross-Over Studies; Female; Horses/*physiology; Learning/*physiology; Male; Memory/*physiology; Time Factors |
| Abstract |
A study carried out on 49 horses showed that it is possible to measure the attention time by operant conditioning. After teaching horses an instrumental task using a signal, we were then able to test their attention time by asking them to prolong it increasingly while setting success and failure criteria. Two tests were performed 3 weeks apart. The 2nd test was feasible without relearning, a proof of memory, and was repeatable, a proof of consistency in the attention time. A significant difference was observed between the 3 age groups. Young horses often performed very well during the 1st test but their attention dropped in the 2nd test while older horses were more stable with respect to attention and even increased it slightly. The study shows that there are individual differences but it was not possible to prove a significant influence of breed, gender and paternal influence. Consequently, learning appears to be one of the most interesting approaches for evaluating the attention of horses and for observing their behaviour. |
| Address |
Laboratoire d'Ecoethologie, Universite de Neuchatel, Suisse. veronique.rapin@unine.ch |
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Place of Publication |
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| Language |
French |
Summary Language |
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Original Title |
Mesure de la duree d'attention chez le cheval |
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Series Title |
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Series Issue |
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Edition |
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| ISSN |
0036-7281 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:17343134 |
Approved |
no |
| Call Number |
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Serial |
1770 |
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| Author |
Stöwe, M. & Kotrschal, K. |
| Title |
Behavioural phenotypes may determine whether social context facilitates or delays novel object exploration in ravens. |
Type |
Journal Article |
| Year |
2007 |
Publication |
International Journal of Ornithology |
Abbreviated Journal |
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| Volume |
148 |
Issue |
Suppl 2 |
Pages |
179-184 |
| Keywords |
Corvus corax – Novel object exploration – Personality – Social facilitation |
| Abstract |
Individuals consistently differ in behavioural phenotypes. Here we examine the interaction between behavioural phenotype and response to social context during novel object exploration in a neophobic corvid species, the raven (Corvus corax). The presence of conspecifics tends to encourage object exploration and learning but may also delay or even inhibit exploratory behaviour. Factors such as individual differences in response to social context may determine whether the presence of a conspecific facilitates or inhibits approach to novel objects. We confronted eleven six-month-old hand-raised ravens with novel objects, both individually and in dyadic combinations. We defined individuals as “fast” and “slow” explorers on the basis of their approach latency to novel objects when tested individually. The presence of a conspecific delayed the approach of fast birds to novel objects. Slow birds, in contrast, approached the novel objects with lower latencies and spent more time close to them when in dyads with fast siblings than when alone. The individuals" approach behaviour seemed to determine whether social context facilitated or delayed exploratory behaviour. This may contribute to explaining ambiguous results concerning the effects of social context in previous studies. |
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Approved |
no |
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Equine Behaviour @ team @ |
Serial |
4507 |
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| Author |
Elfman, L.; Brannstrom, J.; Smedje, G. |
| Title |
Detection of Horse Allergen around a Stable |
Type |
Journal Article |
| Year |
2007 |
Publication |
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Abbreviated Journal |
Int Arch Allergy Immunol |
| Volume |
145 |
Issue |
4 |
Pages |
269-276 |
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| Abstract |
Background: Integrating horse stables with built-up areas may lead to conflicts. Dispersion of horse allergen may become a health risk for allergic people. The aim was to measure the dispersion of horse allergen around a stable, considering wind speed and direction and vegetation. The disturbance of staff at a workplace nearby a stable was investigated. Methods: Air sampling was performed around a stable (32 horses) at distances of 50-500 m in all directions. Sampling was done with a pump and an IOM sampler. Samples were collected at 50 points during all seasons. Horse allergen levels were determined using ELISA. Disturbance by horses was studied with a questionnaire handed to the employees in an office near the stable. Results: The median horse allergen level at the stable entrance was 316 U/m(3), in the horse fields 40 U/m(3) and in the whole source area 16 U/m(3), which declined to <2 U/m(3) at about 50 m from the source area. Downwind of the prevailing winds low levels of horse allergen (2-4 U/m(3)) could sometimes be detected at up to 500 m. The staff, including those allergic to horses, managed to tolerate horses close to the workplace. Conclusions: At low winds horse allergen spread in ambient air about 50 m from the stable and horse fields. At higher winds low allergen levels were sometimes found in open areas up to 500 m from the source area. These levels were similar to those found in the office after moving away from the stable area. The employees did not report more symptoms of allergy or asthma while working close to the stable compared to after the move. Copyright (c) 2007 S. Karger AG, Basel. |
| Address |
Department of Medical Sciences, Occupational and Environmental Medicine, Uppsala University Hospital, Uppsala, Sweden |
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English |
Summary Language |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
1423-0097 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:18025788 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
4357 |
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| Author |
Boissevain, I. |
| Title |
[Animal and human rights in installments] |
Type |
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| Year |
2007 |
Publication |
Tijdschrift Voor Diergeneeskunde |
Abbreviated Journal |
Tijdschr Diergeneeskd |
| Volume |
132 |
Issue |
4 |
Pages |
132 |
| Keywords |
Animals; Clinical Competence/*standards; Horse Diseases/*diagnosis; Horses; Humans; Netherlands; Time Factors; Veterinary Medicine/*methods/*standards |
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Dutch |
Summary Language |
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Original Title |
Dierenrechten en mensenrechten in termijnen |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0040-7453 |
ISBN |
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Medium |
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| Notes |
PMID:17366876 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
4018 |
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| Author |
Muller, C.E.; Uden, P. |
| Title |
Preference of horses for grass conserved as hay, haylage or silage |
Type |
Journal Article |
| Year |
2007 |
Publication |
Animal Feed Science and Technology |
Abbreviated Journal |
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| Volume |
132 |
Issue |
1-2 |
Pages |
66-78 |
| Keywords |
Horse; Preference; Silage; Haylage; Hay |
| Abstract |
The purpose of this experiment was to determine if different methods of forage conservation influenced horse preference for conserved forages. Silage, haylage with two different dry matter (DM) levels and hay was produced from the same grass crop at the same botanical maturity stage. Four horses were simultaneously offered the four forages (1 kg DM of each forage) once daily for four consecutive experimental periods, each period consisting of 5 days. On each experimental day, the horses were observed for 2 h and their first choice, eating time and forage consumption was registered for every forage. The number of times each horse depleted individual forages and the number of times each horse tasted or smelled a forage, but left it in favour of another forage, was also recorded. Silage had the highest rate of consumption (0.90 kg DM/day, S.D. 0.14) and longest eating time (28.4 min/day, S.D. 5.16). Hay had the lowest rate of consumption (0.23 kg DM/day, S.D. 0.14) and shortest eating time (6.8 min/day, S.D. 4.08), while the haylages were intermediate. Silage was the first choice 72 of 84 times (85%). Hay was never completely consumed and silage was never left in favour of another forage after smelling or tasting it. We conclude that the forage conservation methods had an impact on horse preference in favour of silage, even if the reason for silage preference remains to be explained. |
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no |
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Admin @ knut @ |
Serial |
4353 |
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