Effects of maternal streptozotocin-diabetes on fetal growth, energy reserves and body composition of newborn pigs

Two doses of Streptozotocin (50 and 100 mg/kg body weight) were administered to two groups of pregnant gilts at d 80 of gestation to determine the influence of two levels of maternal diabetes on the gilts, their developing progenies and the body composition of the pigs. All the experimental animals received 1.82 kg of gestation diet/day throughout gestation. Serum glucose concentration increased to hyperglycemic levels in low-dose and high-dose groups; insulin concentrations decreased (P less than .01) in the high-dose, but not in the low-dose group (P greater than .05). Maternal free fatty acids (FFA) increased (P less than .05) in both treatment groups when compared with the control. However, birth weight of the litter and litter size were not affected. The liver weight increased (P less than .01) in the progeny of high-dose but not the low-dose group. Total liver DNA and RNA were not altered by the treatments, however; total liver protein and protein:DNA ratio increased (P less than .01) in the progeny of high-dose gilts. Pigs from high-dose and low-dose groups showed increases (P less than .01) in liver glycogen concentrations and percentage liver lipid. Body chemical composition data showed increases in percentage dry matter and percentage lipid (P less than .05 and P less than .01, respectively) in the progeny of high-dose but not in the low-dose group. It was concluded that streptozotocin administered to gestating gilts increased the maternal nutrient supply to the developing pigs, which resulted in higher energy status of the pigs at birth.     

Fructose utilization for nucleic acid synthesis in the fetal pig

Eight fetal pigs, in utero, were injected ip with 20 microCi/fetus [U14C]-fructose between d 55 and 65 pregnancy. The isotope was allowed to equilibrate between blood and tissues within injected fetuses for a period of 240 min. Fetal pigs were then sacrificed and nucleic acids were extracted from cold tissue homogenates of skeletal muscle and liver. Nuclide disintegrations per minute recovered in extracted DNA and RNA were used to calculate incorporation of labeled C from fructose. The recovery of labeled C per mmol of nucleic acids from skeletal muscle was greater (P less than .05) than that from liver. Relative incorporation of labeled C into skeletal muscle RNA (395.9 pmol/mmol) was greater (P less than .05) than for DNA (189.5 pmol/mmol). The same trend was observed for liver RNA (78.0 pmol/mmol) and DNA (55.6 pmol/mmol), but differences were nonsignificant. These data suggest that at least part of the high concentration of endogenous fructose measured in fetal pigs in utero is involved in synthesis of nucleic acids, thereby providing substrate for anabolic functions necessary for fetal growth and development.     

某猪场新生仔猪流行性腹泻的发生与防治

猪流行性腹泻病毒(PEDV)可以感染各个年龄段的猪只,但更易感染刚出生的仔猪.仔猪流行性腹泻是猪场一种较为普遍的疾病,具有较大的危害性.文章通过调查连云港某猪场新生仔猪(2019年4—5月期间56头母猪产下的全部641头活仔猪)发生腹泻及其死亡情况,结果发现哺乳期共死亡仔猪94头(其中疾病死亡共42头,约占45％),其...     

Adipose tissue development in the fetal pig examined using monoclonal antibodies

Two anti-adipocyte monoclonal antibodies (MAbs: AD-1 and AD-2) have been used to study the development of dorsal s.c. adipose tissue in fetuses from 50 to 110 d of gestation. Immunofluorescent staining of cryostat sections with each antibody revealed antigen-positive cells in fetal s.c. mesenchyme prior to lipid deposition. Lipid droplets as well as AD-1 and AD-2 positive cells were detected within the underlying muscle at 50 d. From 70 to 110 d of development, the AD-1 and AD-2 MAbs each detected all adipocytes examined, as well as capillaries associated with fat cell clusters in s.c. tissues. Reactivity toward both antibodies, as well as lipid deposition, also was detectable in the muscle underlying the s.c. mesenchyme from 70 d onward. Each MAb possessed a distinct pattern of reactivity. The AD-2 MAb stained arrector pili muscles and vessels in the s.c. mesenchyme and vessels in the underlying muscles, whereas the AD-1 did not. No reactivity using either MAb was detectable toward any other cell types within s.c. tissues. These results established the presence of cells expressing surface determinants found on mature adipocytes and associated capillaries prior to adipogenesis. A lineage relationship between adipocytes and capillary endothelial cells is suggested.     

Substrate utilization by fetal pig skeletal muscle

The ability of fetal pig skeletal muscle (biceps femoris) to metabolize glucose, fructose, lactate, acetate and palmitate in vitro was examined at 70, 90 and 110 d of gestation. Even though succinate dehydrogenase activity increased as fetal age increased (P less than .01), the rate of oxidation of glucose, fructose, acetate and palmitate to CO2 was not influenced by fetal age (P greater than .05), but each rate was dose-dependent (P less than .01). At higher concentration, lactate oxidation to CO2 proceeded at a faster rate in the muscle of 70-d fetuses when compared with 90- or 110-d fetuses. Muscle glycogen content increased (P less than .01) from 70 to 110 d of gestation. The rate of glucose incorporation into glycogen increased over this same time frame (P less than .06). Glucose-6-phosphate dehydrogenase activity did not change with age when activity was expressed per unit wet weight of muscle (P greater than .05). The ratio [1-14C]glucose/[6-14C]glucose oxidized to CO2 was independent of age and substrate concentration, and indicated significant pentose cycle activity in fetal muscle. Incorporation of lactate and palmitate into phospholipid was greatest at 70 d of gestation, a time period that coincides with establishment of mature muscle fiber number and fiber hypertrophy. The rate of palmitate incorporation into triacylglycerol was dependent on concentration of substrate (P less than .01) but not on age (P greater than .05). The rate of fructose oxidation to CO2 was lower than the rate for glucose, lactate and acetate when compared at similar concentrations. Acetate carbons were not incorporated into free fatty acids or lipid.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of colostral fat level on fat deposition and plasma metabolites in the newborn pig

The effects of colostral fat level on fat deposition and plasma concentrations of glucose, insulin, and free fatty acids (FFA) were determined in 28 newborn pigs during the first postnatal day. Soon after birth, pigs were allotted to four treatments groups. Group 1 was killed at birth. The remaining pigs were fed intragastrically sow colostrum that contained high (10.2%; HFC), normal (4.8%; NFC) or low (1.0%; LFC) levels of total fat at the rate of 15 to 18 g/kg birth weight at 65- to 70-min intervals. A total of 21 feedings was provided and pigs were killed 1 h after the last feeding. Body fat deposition increased linearly (P less than .01) with the amount of ingested fat by .32 (+/- .04) g per 1-g increase in fat intake. Fatty acid composition of the pigs changed toward that of the colostrum with increased fat in colostrum. More liver glycogen was lost (P less than .01) in pigs given LFC. Plasma concentrations of glucose and insulin were similar in pigs fed HFC and NFC. After the 11th feeding (14 h postnatal), LFC resulted in lower plasma glucose concentrations (P less than .05) than HFC or NFC. Plasma insulin concentrations also were lower in pigs fed LFC. Plasma FFA concentrations remained unchanged in pigs fed LFC but increased with both fat content in colostrum (P less than .05) and time (P less than .05) in the other two groups. Colostral fat plays a major role in the supply of energy and in glucose homeostasis in the neonatal pig.     

Changes in fetal and maternal blood at the end of pregnancy and during parturition in the pig

Fetal and maternal blood gas tensions, pH, packed cell volume and glucose, fructose and lactic acid concentrations were monitored during the last two days of gestation, during parturition and and the first hour after birth. Blood samples were taken by means of indwelling catheters (implanted seven to 14 days before parturition) from 12 fetuses in seven sows. All fetuses were liveborn at a mean gestational age of 113.1 days. The significant finding was that all variables in fetal blood were stable during labour and, although mild hypercapnia was present during the last three hours, no significant changes in mean values were seen until those of samples taken within 15 minutes of birth. In some fetuses, no changes were seen until after birth, while in others pH and pO2 values declined during the last hour of fetal life. Immediately after birth a rapid increase in pO2 and decrease in pCO2 followed the onset of respiration. Blood pH fell during the first 30 minutes after birth and this fall was accompanied by increasing blood lactic acid concentrations. Blood glucose concentrations rose rapidly in the first 15 minutes after birth and were maintained during the first hour despite separation of the piglets from the sow. There was a transient, but significant, increase in packed cell volume during the period from 15 minutes before to 15 minutes after birth. Maternal values for all variables measured remained virtually unchanged during delivery.