Pregnancy toxemia of ewes, does, and beef cows.

Pregnancy toxemia commonly affects pregnant ewes and does during late gestation. This metabolic disease is thought to result from disruption of the dam's glucose homeostatic mechanism in response to increased nutritional demands of the rapidly developing fetal placental unit. Commercial production systems are comprised of a variety of nutritional, metabolic, genetic, physiologic, environmental, economic, health, and management factors that singularly or as a group influence the clinical expression of pregnancy toxemia. Recognizing the role management plays in controlling these inputs is crucial to pregnancy toxemia prevention and treatment programs.

Use of a non-linear spline regression to model time-varying fluctuations in mammary-secretion element concentrations of periparturient mares in Michigan, USA.

A study was designed to model the fluctuations of nine specific element concentrations in mammary secretions from periparturient mares over time. During the 1992 foaling season, serial samples of mammary secretions were collected from all 18 pregnant Arabian mares at the Michigan State University equine teaching and research center. Non-linear regression techniques were used to model the relationship between element concentration in mammary secretions and days from foaling (which connected two separate sigmoid curves with a spline function); indicator variables were included for mare and mare parity. Element concentrations in mammary secretions varied significantly during the periparturient period in mares. Both time trends and individual variability explained a significant portion of the variation in these element concentrations. Multiparous mares had lower concentrations of K and Zn, but higher concentrations of Na. Substantial serial and spatial correlation were detected in spite of modeling efforts to avoid the problem. As a result, p-values obtained for parameter estimates were likely biased toward zero. Nonetheless, results of this analysis indicate that monitoring changes in mammary-secretion element concentrations might reasonably be used as a predictor of impending parturition in the mare. In addition, these results suggest that element concentrations warrant attention in the development of neonatal milk-replacement therapies. This study demonstrates that non-linear regression can be used successfully to model time-series data in animal-health management. This approach should be considered by investigators facing similar analytical challenges.

Multi-element assay of mammary secretions and sera from periparturient mares by inductively coupled argon plasma emission spectroscopy.

OBJECTIVE: To document and determine changes in the mineral profiles of sera and mammary secretions from a population of periparturient mares. ANIMALS: 18 clinically normal periparturient Arabian broodmares. PROCEDURE: Inductively coupled argon emission spectroscopy was used to measure Ca, Cu, Fe, K, Mg, Mn, Na, P, and Zn concentrations in sera and mammary secretions of periparturient mares. In addition, S was measured in mammary secretions. RESULTS: Serum concentrations of Ca, Cu, Fe, K, Mg, Na, P, and Zn remained constant throughout late pregnancy and the first 7 days of lactation. Compared with values on day 11 before foaling, mammary fluid concentrations of Ca, Cu, K, Mg, P, S, and Zn increased prior to parturition and all element concentrations, except Ca, decreased with the onset of lactation. In contrast, Na concentrations in mammary secretions decreased precipitously as parturition approached. Iron concentrations in mammary secretions remained relatively constant up to the time of parturition, decreased at parturition, and remained constant during lactation. CONCLUSIONS AND CLINICAL RELEVANCE: Prior to foaling, increasing concentrations of Ca, Cu, K, Mg, P, S, or Zn in mammary secretions in concert with precipitous decreases in Na concentrations may provide a predictive index of impending parturition in the mare and a means of assessing fetal readiness for birth.

Diagnosis and control of neonatal losses in sheep.

Perinatal mortality is affected by a variety of management factors and disease processes that create significant losses for the sheep industry. Annual production losses prior to weaning include roughly 15% to 20% of the lamb crop. The majority of these perinatal losses occur during the prenatal, natal, and early postnatal periods, with the predominant wave of mortality occurring during the first several days following birth. Causes of perinatal mortality may vary between flocks and between geographic areas; however, four dominant categories of lamb loss consistently surface: (1) abortions; (2) hypothermia, starvation, and exposure; (3) pneumonia; and (4) stillbirth and dystocia. They account for roughly 50% to 75% of all documented perinatal losses. Veterinarians and producers need to work together to document the type of losses that occur in a given flock and then design economic prevention programs that address these problems. In most cases, traditional prevention programs will need to be replaced by a comprehensive management scheme addressing nutrition, genetics, housing, marketing, lambing husbandry, and labor.

Multielement assay of perinatal lamb livers by inductively coupled argon plasma emission spectroscopy.

During the 1986 lambing season, 33 Michigan sheep producers submitted all lambs that had died before weaning to the Michigan State University Diagnostic Laboratory for necropsy. Inductively coupled argon plasma emission spectroscopy was used to measure 22 elements in the liver of 888 of the lambs submitted. Mean concentrations of each element were established and compared with literature values of established deficient, normal, and toxic concentrations. Mean values in milligrams per kilogram of wet weight were as follows: Al, 3.843; As, less than 1; Ba, 0.176; Ca, 128.2; Cr, 0.778; Cu, 56.82; Fe, 491.6; Hg, less than 2; K, 2,150; Mg, 138.4; Mn, 2.776; Mo, 0.489; Na, 1,384; P, 2,583; Pb, 1,453; Sb, less than 1; Tl, less than 5; Zn, 68.31. In only 11 lambs did the liver contain As, B, Cd, Co, Hg, Sb, Se, or Tl in detectable concentrations.

Use of fluorocarbon polymer and carbon fiber for restoration of facial contour in a horse.

A 10-year-old gelding was operated on for a depression fracture involving the frontal, lacrimal, and nasal bones. The fracture had been sustained 4 months prior to surgery and was healed. Fluorocarbon polymer and carbon fiber was implanted subperiosteally to reconstruct the defect, giving the animal a more cosmetic appearance.