Tissue Glycogen and Blood Glucose and Fructose Levels in the Pig Fetus during the Second Half of Gestation

Abstract

Tissue glycogen levels in the liver, cardiac ventricle, lung, thigh muscle, kidney and placenta were determined in pig fetuses of 60–112 days gestational age. Liver glycogen levels increased earlier in gestation than suggested by previous reports although the maximum rate of deposition occurred between 100 and 107 days. The time of deposition of muscle glycogen was similar to that of the liver. Lung glycogen levels peaked between 70 and 90 days but then fell rapidly in late gestation. Cardiac levels were similar at all ages studied. Blood fructose levels were high in younger fetuses but levels were lower in older fetuses and were falling rapidly between 107 and 112 days. Maternal blood contained only traces of fructose. Fetal blood glucose levels were lower than maternal levels and appeared to be more closely related to maternal levels than to the gestational age of the fetuses.

Effects of meal intake on materno-foetal exchanges of energetic substrates in the pig

“…In agreement with earlier reports in sows [1,47] and ewes [51], fructose was not detected in significant amounts (< 0.1 mmol . L -1 ) in maternal blood at any sampling times.…”

“…L -1 and 12.3%, respectively). This is in keeping with the data obtained in foetuses from anaesthetised sows [1,9,47,48] or before meal intake [44]. As a consequence of the hyperglycaemia induced by meal intake in the sow, we observed an elevation of foetal glycaemia, since the placental transfer of glucose depends on the concentration difference of glucose between the mother and the foetus [3].…”

“…Fasting plasma levels of glucose in the maternal artery were within the same range as those previously reported in sows [1,10,18,20,44,47,48], cows [16,17], ewes [7,36], and rabbits [24]. The arterio-venous difference of glucose across the uterus was within the range of those reported earlier in conscious gilts at a similar stage of pregnancy after an overnight fast [1,10,18,44].…”

“…Measurements of blood substrate levels in pig foetuses were made either from the umbilical blood during a caesarean operation in anaesthetised animals [1,9,35,[46][47][48][49]59], or from foetuses with catheters implanted in the jugular vein or in the carotid artery [20,44,45]. An attempt of measuring substrate balances across the foetoplacental unit was also performed in the gilt [10].…”

Effect of the Frequency of Feeding Pregnant Sows on Carcass Composition and Thermostability of the Neonatal Pig

“…Recently, an intravenous infusion of lipid to the mother during delivery has increased the levels of FFA in human babies (Rubaltelli et al 1978 Smith (1975 by Atinmo et al (1974). Randall and L'Ecuyer (1976) (Silver et al 1973) (Edson et al 1975) and direct incorporation of maternal FFA into the lipid of the fetus has since been demonstrated (Hudson et al 19'77 (Seerley et al 1914). Other reports, particularly for supplements given during the latter stages of gestation, concerning the use ofcornstarch and corn oil (Friend 1974;Maxwell 1975;' Seerley et al 1978b), sucrose and tallow (Okai et al 197'7) and tallow and cornstarch (Seerley et (Feaster et al 1966 (Randall and L'Ecuyer 1916;Okai 1977) but are lower than those reported by Mersmann (1914).…”