Vitamin and mineral transfer during fetal development and the early postnatal period in pigs.

Abstract

There are periods during pregnancy when sows may have a temporally high requirement for certain vitamins and minerals. Proteins transferring retinol and Fe to the developing pig fetus have been discovered, whereas transport mechanisms for other vitamins and minerals are probably present but have not yet been identified. Sow body tissues can serve as a reservoir for many micronutrients, but it is not known whether these reserves can supply an adequate quantity during critical fetal developmental periods. There is a low placental transfer of vitamin E to the fetus even if the dietary concentration fed to a gestating animal is high, but colostrum and milk concentrations can be increased when the nutrient is fed to sows. If the dam's diet contains inadequate Ca or P, the concentration of these elements in the developing fetus and milk will not be affected. Consequently, sow bone demineralization will occur under conditions of dietary inadequacy of Ca and P. Other nutrients can be depleted from sow tissue reservoirs over several parities (e.g., Se), resulting in low quantities being provided in the milk for nursing pigs. Scientific information involving adequate vitamin and mineral nutrition for female pigs to improve conception rate and embryonal survival that will result in optimum fetal and postnatal pig development can be considered to be in its infancy.

Bone cortical compactness in ‘tree sloths’ reflects convergent evolution

“…It is therefore not expected that the increased secondary bone remodeling is a response to mineral demands. Cases of special mineral need that can lead to increased mobilization of these are gestation and lactation in mammals (Mahan & Vallet, ), and development of temporary mineralized structures, such as antlers or eggshells in vertebrates (Francillon‐Vieillot et al. ; Mitchell, ).…”

Influence of phytase added to a vegetarian diet on bone metabolism in pregnant and lactating sows

“…This must be because of the fact that although these groups received lower P contents with the diet, the homeostatic mechanisms reacted in the same way as in the other groups. It has been stated in another study (Mahan and Vallet, 1997), that if sows received inadequate Ca or P concentrations with the diet, the concentrations of these elements are not affected in the foetus or the milk, but bone demineralization in the sow will occur. This is in contrast with the present study, as neither differences between bone formation or bone resorption markers between the groups were observed nor differences in the milk concentrations were obvious.…”

“…Especially during gestation and lactation, large calcium (Ca) and P quantities are needed. During gestation, it is important to provide an adequate development of the foetus, especially during the latter trimester (Hansard et al., 1966; Mahan and Vallet, 1997; Giesemann et al., 1998), and during lactation mineral requirements are increased because of milk production (Mahan and Fetter, 1982; Kemme et al., 1997). It has been described that body reservoirs of Ca and P such as bone are depleted during these stages of reproduction (Mahan and Fetter, 1982; Giesemann et al., 1998).…”

Evaluating the impact of maternal vitamin D supplementation on sow performance: II. Subsequent growth performance and carcass characteristics of growing pigs1,2

“…Mahan and Vallet (1997) concluded that the understanding of vitamin and mineral transport in utero was still very much in its infancy almost 2 decades ago. Research specifically focused on vitamin D's transport and function in utero has been more prolific than research on some other vitamins and trace minerals.…”