Objective—To describe the health status of foals derived by use of somatic cell nuclear transfer (NT) at a university laboratory.
Design—Retrospective case series.
Animals—14 live-born NT-derived foals.
Procedures—Medical records from 2004 through 2008 were evaluated to identify all pregnancies resulting in live-born NT-derived foals. Information obtained included gestation length, birth weight, foaling complications, gross abnormalities of the fetal membranes, appearance of the umbilicus, mentation of the foal, limb deformities, and any other abnormalities detected in the neonatal period. Clinicopathologic data were also evaluated when available. Records of 4 recipient mares during gestation were included.
Results—Six foals were clinically normal for all evaluated variables. The most common abnormalities detected in the remaining 8 foals included maladjustment, enlarged umbilical remnant, and angular deformity of the forelimbs. Two foals died within 7 days after parturition; in the remaining foals, these conditions all resolved with medical or surgical management. Large offspring syndrome and gross abnormalities of the fetal membranes were not detected. The 12 surviving foals remained healthy.
Conclusions and Clinical Relevance—Associated problems of calves resulting from use of NT have been reported, but there are few data on the outcome of foals resulting from adult somatic cell NT in horses. Although this population of foals had a lower perinatal mortality rate than has been reported for NT-derived calves, some NT-derived foals required aggressive supportive care. Birth of foals derived from NT should take place at a center equipped to handle critical care of neonates.
Objective—To evaluate lateral ventricular size in clinically normal calves by use of computed tomography and to examine the relationships between ventricular height (Vh), ventricular area (VA), and ventricular volume (VV).
Animals—14 Holstein calves.
Procedures—14 calves underwent computed tomography of the head with transverse images acquired from the rostral aspect of the frontal lobe continuing caudally to the level of the foramen magnum. Hemispheric height, Vh, VA, and hemispheric area were measured on images obtained at the level of the interventricular foramen. Ventricular volume was calculated by multiplying the sum of VAs measured on each transverse image by the total slice thickness. The left Vh-to-right Vh ratio was calculated to determine the degree of ventricular asymmetry, which was categorized as normal (ie, symmetric) to minimally asymmetric, mildly asymmetric, or severely asymmetric.
Results—Mean ± SD values for Vh and the Vh-to-hemispheric height ratio were 4.96 ± 1.56 mm and 7.47%, respectively. The mean VA was 114.29 ± 47.68 mm2, and the mean VV was 2,443.50 ± 1,351.50 mm3. Normal to minimally asymmetric ventricles were identified in 13 calves, and mildly asymmetric ventricles were identified in 1 calf. Significant correlations were found between Vh and VA and between Vh and VV.
Conclusions and Clinical Relevance—These results establish reference values for ventricular size in clinically normal calves and suggest that Vh measurement may be a simple and useful technique for examining size of the cerebral ventricles in calves.
Objective—To evaluate the efficiency of foal production following intracytoplasmic sperm injection (ICSI) and blastocyst culture of oocytes from mares that died or were euthanized under field conditions.
Design—Prospective case series.
Animals—16 mares (age, 3 to 19 years) that died or were euthanized for various causes.
Procedures—Ovaries were collected immediately before euthanasia (n = 10) or after death (6). Ovaries were transported to the laboratory for oocyte recovery (15 mares), or oocytes were recovered at a remote location and shipped to the laboratory (1). Oocytes underwent ICSI, and presumptive zygotes were cultured for 7 to 10 days. Blastocysts were shipped to embryo transfer facilities for transcervical transfer to recipient mares.
Results—Ovaries were processed 30 minutes to 12 hours (mean ± SD, 4.6 ± 3.3 hours) after mares' deaths. A mean of 14.1 ± 8.6 oocytes/mare were cultured, and 110 of 225 (49%) matured. Twenty-one blastocysts developed after ICSI and were transferred to recipient mares. Thirteen pregnancies were established; 10 healthy foals were produced from 6 donor mares. The number of blastocysts produced per mare and number of live foals produced per mare were significantly correlated with the number of oocytes recovered.
Conclusions and Clinical Relevance—Foals were produced from mares after death or euthanasia under field conditions. Proportions of foals born overall (10 foals/16 mares) and mares from which ≥ 1 foal was produced (6/16) were greater than those reported following recovery and oviductal transfer of oocytes to inseminated recipients after death of donor mares under field conditions.