La época del año y el plano nutricional y su influencia sobre la morfología espermática en carneros Corriedale en pastoreo

espanolSe comunica por primera vez la Cardiomiopatia congenita asociada al pelaje crespo en terneros Polled Hereford de Uruguay. La enfermedad se diagnostico en una cabana Polled Hereford de Cerro Largo (70 vacas) y en un predio comercial de Lavalleja (80 vacas). Ambos predios usaban toros Polled Hereford de pedigri de diferentes lineas de sangre. Cuatro terneros afectados nacieron en 1996 en la cabana (5,71%) y 3 en el predio comercial en 2009 (3,75%). Al nacer los terneros presentaban un pelaje denso, rizado, muy distintivo, y mostraban signos clinicos de depresion e intolerancia al ejercicio. La mayoria murieron dentro de los 7 dias de nacidos. La necropsia en 4 terneros sacrificados mostro marcada cardiomegalia con aumento patologico del peso cardiaco (media de 391,3 ± 60 g) y de la razon peso cardiaco/peso al nacer (1,178% ± 0,131). Todos los terneros presentaban una hipertrofia concentrica global con severa reduccion de volumen en ambas camaras ventriculares. Microscopicamente, habia hipertrofia de cardiomiocitos, desorganizacion en la arquitectura de las fibras miocardicas y fibrosis intersticial leve. En la piel, los foliculos pilosos estaban distorsionados, la vaina radicular interna era anormal, y los bulbos pilosos eran helicoidales con forma de gancho. Se concluye que la Cardiomiopatia asociada al pelaje crespo tiene una incidencia relativamente alta en la raza Polled Hereford de Uruguay. La enfermedad es patologicamente unica, diferente a los sindromes cardiocutaneos humanos (enfermedades de Naxos y Carvajal) y de los ratones mutantes waved 3. EnglishA cardiomyopathy associated with a woolly hair coat (CWH) in calves of the Polled Hereford breed is described for the first time in Uruguay. The disease was diagnosed in a stud farm (70 cows) and in a commercial farm (80 cows), both with purebred Polled Hereford cows. A pedigree Polled Hereford bull, of different blood lines, was used in both farms. Four affected calves were born in 1996 in the stud-farm (5,71%) and 3 in the commercial farm in 2009 (3.75%). Analysis of the pedigrees in the stud-farm demonstrated common ancestors for all sires and dams of affected calves. CWH calves presented at birth a tight, curly hair coat and showed clinical signs of depression and exercise intolerance. Most calves died within 7 days of birth. Postmortem examination in 4 euthanized calves showed a marked cardiomegaly characterized by increased cardiac weight (mean 391.3 g ± 60 SEM) and cardiac weight / birth weight ratio (mean 1.178% ± 0.131). All calves had massive bi-ventricular and septum hypertrophy with severe reduction in ventricular chamber volume. Microscopically, there was myocyte hypertrophy, haphazard disarray of bundles of myocytes, and slight interstitial fibrosis. The woolly skin had severe follicular dysplasia with distorted hair follicles, abnormal inner root sheet, and hook shaped hair bulbs. It is concluded that CWH occurs with relatively high incidence in the Polled Hereford breed in Uruguay. CWH phenotype is unique, pathologically different to human (Naxos and Carvajal diseases) and murine (waved 3) cardiocutaneous syndromes.