Mahan D C, Vallet J L
Department of Animal Sciences, Ohio State University, Columbus 43210-1095, USA.
J Anim Sci. 1997 Oct;75(10):2731-8. doi: 10.2527/1997.75102731x.
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.
在怀孕期间，母猪在某些时间段对特定维生素和矿物质的需求可能会暂时增加。已发现有将视黄醇和铁转运至发育中的仔猪胎儿的蛋白质，而其他维生素和矿物质的转运机制可能存在但尚未被识别。母猪的身体组织可作为多种微量营养素的储存库，但尚不清楚这些储备在胎儿关键发育阶段能否提供足够的量。即使给妊娠动物饲喂的日粮中维生素E浓度很高，其向胎儿的胎盘转运量也很低，但当给母猪饲喂这种营养素时，初乳和乳汁中的浓度会增加。如果母体日粮中钙或磷不足，发育中胎儿和乳汁中这些元素的浓度不会受到影响。因此，在日粮钙和磷不足的情况下，母猪会出现骨质脱矿。其他营养素（如硒）在经过几胎后会从母猪组织储存库中耗尽，导致为哺乳仔猪提供的乳汁中含量较低。关于为提高母猪受孕率和胚胎存活率而提供充足维生素和矿物质营养以实现最佳胎儿和产后仔猪发育的科学信息，目前仍处于起步阶段。
