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Author Arnold, W.; Ruf, T.; Kuntz, R. doi  openurl
  Title Seasonal adjustment of energy budget in a large wild mammal, the Przewalski horse (Equus ferus przewalskii) II. Energy expenditure Type Journal Article
  Year 2006 Publication The Journal of experimental biology Abbreviated Journal J Exp Biol  
  Volume 209 Issue Pt 22 Pages 4566-4573  
  Keywords Animals; Animals, Wild/*physiology; Body Temperature; Body Temperature Regulation; Eating; *Energy Metabolism; Female; Heart Rate; Horses/*physiology; Male; Motor Activity; Pregnancy; Reproduction; *Seasons  
  Abstract Many large mammals show pronounced seasonal fluctuations of metabolic rate (MR). It has been argued, based on studies in ruminants, that this variation merely results from different levels of locomotor activity (LA), and heat increment of feeding (HI). However, a recent study in red deer (Cervus elaphus) identified a previously unknown mechanism in ungulates--nocturnal hypometabolism--that contributed significantly to reduced energy expenditure, mainly during late winter. The relative contribution of these different mechanisms to seasonal adjustments of MR is still unknown, however. Therefore, in the study presented here we quantified for the first time the independent contribution of thermoregulation, LA and HI to heart rate (f(H)) as a measure of MR in a free-roaming large ungulate, the Przewalski horse or Takhi (Equus ferus przewalskii Poljakow). f(H) varied periodically throughout the year with a twofold increase from a mean of 44 beats min(-1) during December and January to a spring peak of 89 beats min(-1) at the beginning of May. LA increased from 23% per day during December and January to a mean level of 53% per day during May, and declined again thereafter. Daily mean subcutaneous body temperature (T(s)) declined continuously during winter and reached a nadir at the beginning of April (annual range was 5.8 degrees C), well after the annual low of air temperature and LA. Lower T(s) during winter contributed considerably to the reduction in f(H). In addition to thermoregulation, f(H) was affected by reproduction, LA, HI and unexplained seasonal variation, presumably reflecting to some degree changes in organ mass. The observed phase relations of seasonal changes indicate that energy expenditure was not a consequence of energy uptake but is under endogenous control, preparing the organism well in advance of seasonal energetic demands.  
  Address Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Savoyenstrasse 1, 1160 Vienna, Austria. walter.arnold@vu-wien.ac.at  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-0949 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:17079726 Approved no  
  Call Number Serial 1782  
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Author Keiper, R.; Houpt, K. openurl 
  Title Reproduction in feral horses: an eight-year study Type Journal Article
  Year 1984 Publication American journal of veterinary research Abbreviated Journal Am J Vet Res  
  Volume 45 Issue 5 Pages 991-995  
  Keywords Abortion, Veterinary/epidemiology; Anestrus; Animal Population Groups/*physiology; Animals; Animals, Wild/*physiology; Birth Rate; Female; Fertility; Horse Diseases/epidemiology; Horses/*physiology; Lactation; Male; Maryland; Pregnancy; *Reproduction; Seasons; Sex Ratio; Virginia  
  Abstract The reproductive rate and foal survival of the free-ranging ponies on Assateague Island National Seashore were studied for 8 years, 1975 to 1982. Most (52%) of the 86 foals were born in May, 13% were born in April, 22.6% in June, 10.4% in July, and less than 1% in August and September. The mean foaling rate was 57.1 +/- 3.9% and the survival rate was 88.3 +/- 3.6%. Forty-eight colts and 55 fillies were born (sex ratio 53% female). Mares less than 3 years old did not foal and the foaling rate of 3-year-old mares was only 23%, that of 4-year-old mares was 46%, that of 5-year-old mares was 53%, and 6-year-old mares was 69%. The relatively poor reproduction rate was believed to be a consequence of the stress of lactating while carrying a foal when forage quality on the island was low. The hypothesis was supported by the higher reproductive rate (74.4 +/- 2.4%) of the ponies in the Chincoteague National Wildlife Refuge on the southern part of the island. Their foals are weaned and sold in July each year. Despite the low reproductive rate on Assateague Island National Seashore , the number of ponies increased from 43 to 80, a 90% increase in the 8-year period or greater than 10%/yr. There were 24 deaths and 8 dispersals from the study area.  
  Address  
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  Language English Summary Language Original Title  
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  ISSN 0002-9645 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:6732036 Approved no  
  Call Number refbase @ user @ Serial 665  
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Author Kirkpatrick, J.F.; Turner, A. doi  openurl
  Title Absence of effects from immunocontraception on seasonal birth patterns and foal survival among barrier island wild horses Type Journal Article
  Year 2003 Publication Journal of applied animal welfare science : JAAWS Abbreviated Journal J Appl Anim Welf Sci  
  Volume 6 Issue 4 Pages 301-308  
  Keywords Animals; Animals, Newborn; Animals, Wild/*physiology; Birth Rate; Case-Control Studies; Contraception, Immunologic/methods/*veterinary; Egg Proteins/administration & dosage; Female; Horses/*physiology; Maryland/epidemiology; Membrane Glycoproteins/administration & dosage; Population Control; Pregnancy; *Receptors, Cell Surface; *Reproduction; Seasons; Vaccines, Contraceptive/administration & dosage  
  Abstract Despite a large body of safety data, concern exists that porcine zonae pellucidae (PZP) immunocontraception--used to manage wild horse populations--may cause out-of-season births with resulting foal mortality. Our study at Assateague, Maryland indicated the effects of immunocontraception on season of birth and foal survival between 1990 and 2002 on wild horses from Assateague Island. Among 91 mares never treated, 69 (75.8%) of foals were born in April, May, and June (in season). Among 77 treated mares, 50 (64.9%) were born in season. Of 29 mares foaling within 1 year after treatment (contraceptive failures), 20 (68.9%) were born in season. Of 48 mares treated for greater than 2 years then withdrawn from treatment, 30 (62.5%) of 48 foals were born in season. There were no significant differences (p <.05) between either treatment group or untreated mares. Survival did not differ significantly among foals born in or out of season or among foals born to treated or untreated mares. Data indicate a lack of effect of PZP contraception on season of birth or foal survival on barrier island habitats.  
  Address Science and Conservation Center Zoo Montana, Billings, Montana 59106, USA. jkirkpatrick@montana.net  
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  Language English Summary Language Original Title  
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  ISSN 1088-8705 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:14965784 Approved no  
  Call Number refbase @ user @ Serial 140  
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Author Lucas, Z.; Raeside, J.I.; Betteridge, K.J. openurl 
  Title Non-invasive assessment of the incidences of pregnancy and pregnancy loss in the feral horses of Sable Island Type Journal Article
  Year 1991 Publication Journal of Reproduction and Fertility. Supplement Abbreviated Journal J Reprod Fertil Suppl  
  Volume 44 Issue Pages 479-488  
  Keywords Abortion, Veterinary/*epidemiology; Animals; Animals, Wild/*physiology; Atlantic Islands; Estrogens/analysis; Feces/chemistry; Female; Fertilization; Gestational Age; Horse Diseases/*epidemiology; Horses; Incidence; Pregnancy; *Pregnancy, Animal  
  Abstract Field observations of 400 totally unmanaged feral horses on Sable Island, Nova Scotia, were complemented by oestrogen determinations in faecal samples from 154 identified females over a 4-year period (454 mare-years). Of mares that were sampled throughout the year and subsequently produced foals, 92.1% exhibited elevated faecal oestrogens between 15 October and 30 March. The results confirm that faecal oestrogens are a useful indicator of pregnancy after approximately 120 days gestation. Distribution of foaling resembled that seen in other feral populations, with 95% of births occurring from April through July. The foaling rate for mares aged 3 years or older was 62.0%, with 50.7% of mares foaling in 3 or 4 years. Foaling rates were low (4.1%) in mares bred as yearlings and rose with age to 70.8% in those bred as 4-year-olds. Fetal loss after Day 120 was deduced from faecal oestrogens to be 26.0% overall, with marked variation from year to year (9.6-37.3%) and with age (70.0% in those bred as yearlings, decreasing to 5.6% in those bred as 4-year-olds). Of 58 mares aged 2 years or older that were sampled every year, about half (49.6%) the barren years were attributable to fetal loss after 120 days gestation. All mares conceived in at least 2 of the 4 years, suggesting that pregnancy loss, even after Day 120, is as important as failure to conceive in causing barren years.  
  Address Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Canada  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0449-3087 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:1795292 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2247  
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