Proportion of the litter farrowed, litter size, and progesterone and estradiol effects on piglet birth intervals and stillbirths

Abstract

Stillbirth in swine ranges from 2 to 9%, resulting in a significant loss of piglets. Previous studies clearly indicate a relationship between prolonged birth intervals and stillbirth, but factors influencing birth intervals are not fully known. To characterize birth intervals and stillbirth, farrowing was recorded during three farrowing seasons. Blood samples were collected on d 110 and d 113 of gestation, and were assayed for progesterone and estrogen. Relationships between estrumate (cloprostenol sodium, an analogue of prostaglandin F(2alpha)) usage, litter size, proportion of the litter farrowed, progesterone and estrogen concentrations, birth intervals, and stillbirth were analyzed using regression analysis. A clear relationship between birth intervals and stillbirth was observed. Stillbirth rate was unaffected by birth intervals of <1 h, and increased (P < 0.01) for birth intervals >1 h. A significant negative association between litter size and birth intervals was observed (P < 0.01). Birth intervals were unaffected by proportion of the litter farrowed until the last piglet in the litter, whose birth interval increased dramatically (1.5-fold; P < 0.01). Stillbirth rates increased as proportion of the litter farrowed increased, and a dramatic increase in stillbirth occurred for the last piglet in the litter. Neither d 110 nor 113 plasma progesterone concentrations were associated with litter size, birth intervals, or stillbirth rates. Curvilinear relationships were present between d 110 or 113 plasma estradiol concentrations and litter size. However, neither d 110 nor 113 estradiol concentrations were associated with birth intervals or stillbirth rates. These results indicate that (1) birth intervals greater than 1 h are associated with increased stillbirth; (2) larger litter size reduces birth intervals; (3) the last piglet in the litter has both a prolonged birth interval and increased risk of stillbirth; (4) plasma progesterone before farrowing does not influence birth intervals or stillbirth; and (5) plasma estradiol does not influence birth interval or stillbirth, despite a positive relationship between litter size and plasma estradiol. An understanding of the effects of litter size and proportion of the litter farrowed on birth intervals might be exploited to decrease stillbirth in piglets.

Animal welfare in the newborn piglet: a review

“…Vallet et al (2010) assessed the expulsion intervals and concentrations of steroids in newborn piglets and their relation to stillborns and concluded that (1) birth intervals greater than 1 h are associated with an increased number of stillbirths; (2) larger litter size reduces birth intervals; (3) the last piglet in the litter has both a prolonged birth interval and an increased risk of stillbirth; (4) plasma progesterone before farrowing does not influence birth intervals or stillbirths; and, (5) plasma estradiol does not influence birth interval or stillbirths, despite its positive relation to litter size. The authors concluded that a better understanding of the effects of litter size and the proportion of the litter that is farrowed on birth intervals could be used in the future to decrease stillbirths in piglets.…”

“…Neonatal mortality is a serious problem for the pork industry worldwide where 2% to 9% of stillborns result from perinatal asphyxia (Vallet et al 2010). The proportion of live born and stillborn piglets often impact on the economic outcome of the farm (Houska et al 2010).…”

Farrowing response and piglet viability following Cloprostenol-induced farrowing in Duroc sows with prolonged gestation

“…Long piglet birth intervals may result anoxia and poorer viability that predisposes to piglet neonatal mortality. Vallet et al (2010) observed a significant negative association (P < 0.01) between litter size and birth intervals and stillbirth rate was increased (P < 0.01) for birth intervals of more than one hour. Interestingly, Oliviero et al (2013) established that sows with longer duration of farrowing have higher repeat breeding rate at first insemination after weaning.…”

Analysis of the Course of Birth and the Early Postpartal Period in Pigs After Hormonal Partus Induction with Special Consideration of Complication Rate

“…As in all mammals, the peripartal period must be regarded as a particularly critical time of the reproduction cycle also in the sow. Within this relatively short period, increased physical stress originating from the last third of gestation due to enforced fetal growth add to extreme metabolic, endocrine and psychological stress, which occurs within a time span of only 24 hours, and which reaches its climax intra partum [8,24,25,15]. This stress is potentiated by initiation of lactation which starts directly post partum and also by behavioural changes (maternal behaviour).…”