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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2006-6-26
pubmed:abstractText
Ultrasonographic fetal eye measures have been used to estimate gestational age of the fetus in light horse mares. However, fetal eye measures have not been published for smaller pony breeds. This study was conducted to develop reference ranges for ultrasonographic measures of fetal eyes in small ponies for the purpose of predicting days before parturition (DBP) when breeding or ovulation dates are unknown. Twenty-three Shetland-type pony mares were studied across one (n = 10) or two (n = 13) gestations in 2004 (18 pregnancies) and 2005 (18 pregnancies). Measurements of fetal eyes were obtained during transrectal ultrasound examination. Examinations were conducted once monthly in a field situation beginning in December (2003) or August (2004) until mares foaled (March through July). The length (from sclera to sclera) and width (from retina to cornea) of the vitreous body were measured. For the 273 examinations in which gestation age was greater than 2 months, eye measures were obtainable in 248 (91%). Mixed-effects linear regression modeling was used to account for serial growth measures within pregnancy, repeated measurements across mares, and unbalanced study design. Independent variables evaluated included vitreous body length, vitreous body width, the ratio of length to width, parity, and mare height at the withers at parturition. Eye length was the best single predictor of days before parturition, with almost no additional predictive value of the other variables considered. Our resulting regression equation is: days before parturition=265.16-0.21*(vitreous body length in mm)(2). This study suggests that measure of the fetal eye is a practical on-farm procedure for estimating days before parturition in small ponies.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0093-691X
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
66
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
331-7
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Real-time ultrasound measure of the fetal eye (vitreous body) for prediction of parturition date in small ponies.
pubmed:affiliation
Section of Reproductive Studies, University of Pennsylvania, School of Veterinary Medicine, New Bolton Center, 382 West Street Road, Kennett Square, 19348, USA. rmturner@vet.upenn.edu
pubmed:publicationType
Journal Article