To assess this study, weaned piglets (at 28 days) received three dietary treatments until 39 days of age: (1) 12,5 mg alpha tocopheryl acetate/kg feed (2) 6,75 mg/l d-alpha tocopherol in drinking water (ratio 1:2) (3) 4,5 mg/l d-alpha tocopherol in drinking water (ratio 1:3). Alpha- Tocoferol accumulation was not significantly affected in any of the tissues analysed which would indicate a more efficient absorption of natural vitamin E in drinking water than the synthetic source in feed. Moreover, the lowest supplementation in drinking water (group 1:3) led to similar concentrations of vitamin E in tissues than the group supplemented with higher concentration (group 1:2). Consequently, when weaned piglets are fed under the minimum established requirements the minimum natural vitamin E supplementation to produce an equivalent tissues vitamin E concentration would be establish at 1:3 (water:feed).

A new group of RNA virus was described in 1988 by Pereira. This group of viruses has only two segments of RNA; it was called Picobinavirus (PBV). Since then, it has been reported in animals and humans in several countries, but not in Mexico. In this paper the finding of these viruses in Merida, Mexico is reported. Faecal specimens were obtained from two hundred and eighty nine pigs with diarrhoea during their first month of life. Stools were analyzed by polyacrylamide gel elelctrophoresis (PAGE). Seventy four pigs showed electrophoretic pattern for rotavirus, whereas only three showed a typical electrophoretic pattern for PBV. Characterization of the strains showed segment sizes which ranged from 2600-1600 bp. The nucleic acid was shown double-stranded RNA by nuclease digestion. This pattern resembles PBV. These findings suggest that PBV could be a new group of virus associated with gastroenteritis in pigs | En 1988, en Brasil, Pereira describio un nuevo grupo de virus con genoma bisegmentado de acido ribonucleico (ARN), al que nombro picobirnavirus (PBV), desde entonces este se ha localizado en animales y en humanos de todo el mundo. En Mexico no existe ningun dato sobre este virus, por lo que al encontrar patrones electroforeticos semejantes a los mencionados en tres muestras de heces de lechones con diarrea infecciosa aguda (DIA), se decidio identificar este hallazgo de dos segmentos de ARN encontrado por medio de la tecnica de electroforesis en geles de poliacrilamida (PAGE) con tincion de nitrato de plata. De las muestras analizadas, 74 presentaron un patron electroforetico de 11 segmentos de ARN caracteristico de los rotavirus (RV) y en 3 muestras se observaron unicamente 2 bandas con distribucion diferente a los RV. A estas 3 muestras se les realizo digestion enzimatica con DNAsa I y RNAsa A, encontrandose que corresponden a segmentos de ARN de doble cadena de aproximadamente 2600-1600 pares de bases, semejante a lo que se ha informado para los "picobirnavirus"; por lo que estos hallazgos sugieren la existencia de un virus con dos segmentos de doble cadena de ARN, que son particulas representativas de un nuevo virus intestinal, asociado con gastroenteritis en lechones, aunque no se conoce el papel que desempena en ellas