Effects of sow nutrition during gestation on within-litter birth weight variation: a review

Abstract

The increasing demand for efficiency in pork production requires great specialization of all sectors involved in this activity. In this context, the development of strategies that could reduce undesirable traits related with negative effects on piglet survival and postnatal growth and development are essential for the pig industry. Currently, special attention is given to variation in birth weight, as some evidences suggest an increased within-litter birth weight variation in modern sows. This variation has been shown to be associated with preweaning mortality, variable weights at weaning and deteriorated growth performance, which results in economic losses and lower efficiency. Therefore, understanding the factors that can influence the events that occur during gestation and that have an impact on the fetal growth and development are important to achieve better efficiency and also to develop strategies that can be used to achieve increased within-litter uniformity of piglet birth weight. This study concludes that even at a given placental size, fetal growth may vary because of differences in placental vascularization and efficiency. Feeding extra feed or energy during late gestation only marginally improves birth weight, and positive effects are not consistent between different studies. The detrimental effects of protein restriction on fetal growth during early gestation may be due to altered placental and endometrial angiogenesis and growth, which leads to a reduction in placental-fetal blood flow, nutrient supply from mother to the fetuses and ultimately to fetal growth retardation. The number of studies that attempted to influence within-litter birth weight variation by means of sow nutrition during gestation is limited. Therefore, more research concerning sow nutrition during gestation associated with the provision of balanced diets to meet requirements of the sows and fetuses are still required. This knowledge may subsequently provide starting points for the design of nutritional strategies that can influence within-litter birth variation.

Invited review: Aspects of gastrointestinal tract growth and maturation in the pre- and postweaning period of pigs

“…Furthermore, intrauterine growth retardation (IUGR), which increases the risk of death of the fetus and the newborn in the perinatal period and can modify/inhibit normal growth and development thereafter, has negative effects on GIT growth and development (e.g., Xu et al, 1994;Wang et al, 2005;D'Inca et al, 2010D'Inca et al, , 2011. The importance of IUGR to neonatal growth, development, welfare, and survival has received increasing attention of late given the larger litter sizes being produced with hyperprolific sow lines (Campos et al, 2012).…”

Compensatory growth feeding strategy does not overcome negative effects on growth and carcass composition of low birth weight pigs

“…Over the last decade sow's prolificacy markedly increased and as a consequence average birth weight decreased and displayed greater variability within litter (Quesnel et al, 2008;Campos et al, 2012). Responsible for this outcome are gestational factors such as intrauterine crowding and impaired placental development resulting in insufficient nutrient supply and therefore impaired foetuses development (Foxcroft et al, 2006;Wu et al, 2006).…”

“…Responsible for this outcome are gestational factors such as intrauterine crowding and impaired placental development resulting in insufficient nutrient supply and therefore impaired foetuses development (Foxcroft et al, 2006;Wu et al, 2006). Because piglet's survival rate during lactation is closely related to their birth weight (Quiniou et al, 2002) and the percentage of piglets weighing < 1 kg increases with increasing litter size (Bérard et al, 2008;Campos et al, 2012), overall reproduction efficiency in terms of number of weaned piglets and total weaning weight might be compromised in high prolific sows. In case that low birth weight pigs survive the lactation period and reach the weaning age, there is compelling evidence that impaired foetal development negatively affects postnatal development (Bérard et al, 2008;Beaulieu et al, 2010).…”

Glutamate–glutamine cycle and exchange in the placenta–fetus unit during late pregnancy

“…The placenta is the organ responsible for the exchange of nutrients, gases, metabolic waste and biologically active substances between the maternal and the fetal system. Thus, placenta by supporting the required blood flow plays a central role in the growth and development of the fetus (Campos et al 2012). The fetus exerts an acquisitive demand for nutrients, which is satisfied through morphological and functional adaptations of the placenta (Larque et al 2013).…”