Morfología de la Piel y Producción de Lana en Cruzamiento Absorbente con Merino Multipropósito / Skin Morphology and Wool Production on Merino Multipurpose from Absorbent Crosses

Las tendencias del mercado de fibras textiles muestran que las lanas finas son las que se adaptan a las preferencias de la industria textil. En Argentina, la producción de lanas finas es insignificante y esto representa una limitante para el crecimiento lanero del país. La necesidad de desarrollar una alternativa de producción ovina lleva a considerar al Merino Multipropósito como una opción interesante. En la provincia de Corrientes, se iniciaron cruzamientos con estos animales, pero existen inquietudes con respecto a lograr una disminución en el diámetro de la fibra y que repercuta en el peso del vellón. El objetivo del trabajo fue evaluar el efecto del cruzamiento de ovejas Corriedale con machos MPM, sobre las características de la piel y la producción y calidad de lana. Los parámetros evaluados fueron diámetro de fibra, densidad de folículos y relación S/P. Para el recuento de folículos primarios y secundarios se realizaron biopsias de piel con auxilio de un sacabocado. Las características en relación con la producción y calidad de lana se consideraron entre borregas contemporáneas. La comparación realizada en este trabajo permitiría atribuir la disminución del diámetro de fibra, al cruzamiento con MPM. La densidad de folículos en las madres Corriedale, en las borregas Corriedale y en la F1 (Corriedale x MPM) fueron diferente significativamente. La relación S/P fue 9,08 ± 2,32, 9,46 ± 1,57, y 11,93± 2,18, respectivamente. El peso del vellón en borregas de la F1 (Corriedale x MPM) fue inferior y significativamente diferente de sus contemporáneas Corriedale. El rinde al lavado en las borregas Corriedale fue superior al de las borregas nacidas del cruzamiento con MPM. Las diferencias fueron significativas en el largo de mecha entre borregas Corriedale y Corriedale x MPM. En las condiciones realizadas no se pudo comprobar todas las expectativas esperadas con el cruzamiento. Nuevas experiencias serán necesarias para respaldar morfológica y productivamente la posible inversión.

Textile market trends show that fine wools are more suitable to reach the preferences of textile industry. Production of fine wool in Argentina are insignificant, which is a limitation on the development of the country. The need to develop new alternatives of production leads us consider the Multipurpose Merinos as an option. Crossbreeding with these animals began at Corrientes state in order to achieve a reduction in the diameter of fiber and an impact on the weight of the fleece. These crossbreedings with Corriedale sheep were carried out with the objective of analyzing changes on wool production, quality and skin characteristics. Evaluation parameters were fiber diameter, density of follicles and Secondary/Primary relation. Follicle count primary and secondary were made from skin biopsies and were performed with the aid of a punch. Features regarding the production and quality of wool from sheep were considered in contemporary animals, evaluating fleece weight and clean dirty, length of strands, washing yields, coefficient variation of fiber and W / D3. The comparison made in this paper would attribute the decrease in fiber diameter to the crossing with MPM. The follicle density on Corriedale ewes, Corriedale ewe lambs in and the F1 (Corriedale x MPM) were significantly different. The S / P was 9,08 ± 2,32 ; 9.46 ± 1.57 and 11,93 ± 2,18 respectively. The fleece weight in the F1 ewe lambs (Corriedale x MPM) was lower and significantly different from its Corriedale contemporaries. The yield on wash fleece at Corriedale ewe lambs was higher than ewe lambs crossbred with MPM. The differences were significant in length of strands between Corriedale and Corriedale sheep x MPM. Expected results from the crossbreeding could not be substantiated under the conditions realized. Additional studies will be needed to support possible morphological and productive investment.

Avaliação da densidade folicular em ovários de fetos humanos / Follicular density evaluation in ovaries of human fetuses

OBJETIVO: avaliar a variação da população de folículos ovarianos ao longo do desenvolvimento fetal e acrescentar dados aos escassos, incompletos e, algumas vezes, divergentes dados descritos na literatura. MÉTODOS: doze ovários de fetos necropsiados foram estudados, sendo nove de fetos e três de neonatos. As idades dos fetos foram determinadas pela cronologia e por ultra-sonografia, enquanto os neonatos nascidos na 39ª semana de gravidez faleceram nas primeiras horas de vida. As peças foram fixadas com formaldeído e incluídas em parafina. Foram realizados cortes seriados com espessura de 7 mm e a cada 50 cortes, o material foi corado com HE e analisado com microscópio com aumento de 400 vezes. Foram contados os folículos em dez diferentes regiões do córtex ovariano, cada região com uma área de 625 mm². O número total de folículos em 1 mm³ foi calculado usando-se a fórmula: Nt=(No x St x t)/do, onde Nt é o número de folículos, No é a média de folículos observados em 1 mm², St é o total de cortes em 1 mm³ do ovário, t é a espessura do corte e do é o diâmetro médio do núcleo. RESULTADOS: a idade dos fetos variou de 24 a 39 semanas. O número de folículos por 0,25 mm² variou de 10,9 ± 4,8 em um neonato até 34,7 ± 10,6 também em um neonato. Entre os fetos, tivemos o menor valor com 36 semanas (11,1 ± 6,2) e o maior valor com 28 semanas (25,3 ± 9,6). O número de cortes observados por ovário variou de seis a 13, correspondendo à contagem de folículos em áreas que variaram de 15 a 32,5 mm². O total de folículos estimado variou de 500.000, na idade de 22 semanas, a mais de 1.000.000, na idade de 39 semanas. CONCLUSÕES: nossos resultados demonstram as diferentes densidades de folículos ovarianos durante o período gestacional, contribuindo para o escasso conhecimento existente na literatura até o momento.

PURPOSE: to determine the variation of the number of ovarian follicles during fetal life. METHODS: twelve ovaries donated for research were included in our study, nine from fetuses and three from newborn babies who died in the first hour after being delivered with 39 weeks of pregnancy. Fetal age was confirmed both by the last menstrual period of the woman and by ultrasonography. Ovaries were fixed in formaldehyde, included in paraffin and serially sliced at 7 mm. At every 50 cuts, the obtained material was haematoxilin-eosin stained and evaluated with an optical microscope (400 X). The follicles were counted in ten different regions of the ovarian cortex, each region with an area of 625 mm². The presence of a nucleus was considered the parameter for counting. Follicular density, per 1 mm³ was calculated using the formula Nt=(No x St x t)/do, where Nt is the number of follicles; No is the mean number of follicles in 1 mm²; St is the total number of slices in 1 mm³; t is the slice thickness and do is the nuclei mean diameter. RESULTS: the gestational age of fetuses ranged from 24 to 39 weeks. The number of follicles per 0.25 mm² ranged from 10.9 ± 4.8 in a newborn to 34.7 ± 10.6 in another newborn. Among the fetuses, the least value was obtained in a 36 week-old fetus (11.1 ± 6.2) and the highest in a 28 week-old fetus (25.3 ± 9.6). The total number of slices per ovary ranged from six to 13, corresponding to follicles counted in areas from 15 to 32.5 mm². The total number of follicles ranged from 500,000 at the age of 22 weeks to > 1,000,000 at the age of 39 weeks. CONCLUSIONS: our results demonstrate different (increasing) densities of ovarian follicles along the gestational period, providing more knowledge about this still not well-known subject.