Prématurité de la mise bas chez la truie et signification du poids à la naissance du porcelet

Abstract

Summary. Premature farrowing in the sow and significance of piglet birth weight. fig. 3) when pregnancy lasted less than 112 days (2.53 and 1.45 per litter for herds I and II). Survival rate was minimum for animals born before 111 days (table 3).At 35 days, less than 2 animals remained out of 3 born alive in the following weight classes of herd I : less 900 g, less than 1 000 g for those born before 117 days, and less than 1 100 g up to 112 days. In herd II, only animals weighing less than 900 g born before 117 days and those weighing less than 1 000 g before 113 days were truly premature. Prematurity seemed to vary in swine not only with the duration of gestation and with birth weight, but also with managemental and environmental (nutrition, microclimate, quality and intensity of care at birth) conditions. Introduction.

Induction of parturition in the sow and incidence of splayleg syndrome in the newborn piglet

“…However, our study indicates that there exists a negative within-breed correlation of -0.22 between litter size at birth and gestation length as far as natural farrowings are concerned. This negative correlation was previously reported in several pig breeds [3,13,21,33]. It may therefore be hypothesized that the effect of litter size on incidence of splayleg partly operates through gestation length.…”

Mortality in premature mice at birth and during neonatal development

“…Even when additional factors affecting morbidity are present, mortality data related to both birth weight and gestation age are essential for determining the chances of survival of the premature infant (Lubchenco et al, 1972 ;Papiernik, 1977). These results are comparable to those obtained in premature monkey (Digiacomo and Shaughnessy, 1972 ;Price et al, 1972 ;Hird et al, 1975 ;Shaughnessy et al, 1978) and premature piglet (Aumaitre et al, 1979 (Dalle et al, 1978 (Loctin, 1980). al., 1980).…”

“…al., 1980). In swine, the number of stillborn piglets is significantly higher when gestation lasts less than 112 days, although maturity is reached at 113-116 days (Aumaitre et al, 1979). The birth weight in full-term newborn sheep varies between 1 500 and 5 000 g ; survival rate is 70 % for birth weights between 1 500 and 2 000 g and only 10 % for those of less than 1 500 g (Houssin and Brelurut, 1980 (Loctin, 1980 (Loctin, 1980 …”