A study of the prolificity and viability, at the weaning stage, of Large White and Pietrain pigs

Abstract

In a trial with pigs, being reared intensively, with 60 Large White breeding females and one male Pietrain, the prolificity and viability of their piglets was kept under observation, on weaning, during the first five litters. It has been possible to prove that the age of the sow, shown by the number of litters, influences significantly the number of piglets which are born. This influence was also found in pure breed Large White pigs (Terra and col. 1974a). The average viability of Large White Pietrain piglets, on weaning, was 80.55 p. 100 and no appreciable variation was observed between the number of weaned piglets belonging to different litters; this was possibly due to the distribution of the newly born piglets, designed to produce homogeneous litters and thus to make the task of rearing them easier. We have found a highly significant variation between the characteristics of prolificity and viability, on weaning (P<0"O01). In the 4th and 5th litters, a positive and significant correlation was assessed between the number of piglets born and the number weaned. The average of the piglets which there were at birth and at the weaning stage was 10.451 ±0.524 and 8.419±0.137, respectively.En una explotación porcina, de régimen intensivo, con 60 reproductoras Large White y 1 verraco Pietrain se ha controlado la prolificidad y viabilidad de sus lechones al destete (45 días) durante los 5 primeros partos. Se ha podido comprobar que la edad de la cerda, representada por su numero de partos, influye significativamente sobre el número de lechones al nacimiento. Esta influencia también se encontró en cerdos de pura rata Large White (Tena y col. 1974 a). La viabilidad media de los lechones Large White X Pietrain, al destete, fue del 80"55 p. 100, sin que se observe variación sensible entre el número de lechones destetados que proceden de camadas diferentes; posiblemente debido a la distribución de los lechones recién nacidos para formar camadas homogéneas, y así facilitar su cría. Hemos hallado variación altamente significativa entre los caracteres de prolificidad y viabilidad, al destete (Pr 0"001). En los partos 4.° y 5.° se aprecia correlación positiva y significativa entre el numero de lechones paridos y destetados. El promedio de lechones habidos al nacimiento y al destete fue de 10"451±0"524 y 8"419±0"137, respectivamente