VARIABLES RELATED TO THE PROGRESS OF PARTURITION AND PROBABILITY OF STILLBIRTH IN SWINE

Sow and piglet variables related to probability of stillbirth and to v iability score were analyzed in litters from 98 multiparous Yorkshire sows. Immediately after the birth of each piglet, viability was scored using Randall's method. Sow variables related to the probability of s tillbirth were average birth weight of the litter (p = 0.0001), sow ag e (p = 0.001), sow condition score (p = 0.003), length of gestation (p = 0.005), and number of piglets in the litter (p = 0.01). Sow variabl es related to average viability score were average birth weight of the litter (p = 0.001), standard deviation in birth weight in the litter (p = 0.02), sow age (p = 0.03), sow condition score (p = 0.03), and le ngth of gestation (p = 0.03). Piglet variables related to probability of stillbirth were piglet hemoglobin (p = 0.0001), position in the bir th order (p = 0.0001), broken umbilical cord (p = 0.0004), and precedi ng birth interval (p = 0.0004). Piglet variables related to viability score were piglet hemoglobin (p = 0.0001), position in the birth order (p = 0.0001), broken umbilical cord (p = 0.0001), preceding birth int erval (p = 0.0001), and birth weight (p = 0.004). Preceding birth inte rval was related to whether the piglet was live or stillborn (p = 0.00 01), to position in the birth order (p = 0.003), and to the sex of the piglet (p = 0.03). The results demonstrated that sow and piglet varia bles were highly correlated to probability of stillbirth and to viabil ity score. In addition it was also found that the probability of still birth was not associated with the duration of farrowing but with the n umber of piglets in the litter and piglet hemoglobin level. This study also found that lower weight piglets tend to have poor viability, but are not more prone to stillbirth as commonly suggested. These low via bility piglets may survive if the necessary care is given during the f arrowing process.