Maternal ingestion of locoweed

The effect of Ipomoea carnea on maternal reproductive outcomes and fetal and postnatal development in rats

Ipomoea carnea is a toxic plant found in Brazil and other tropical countries. The plant contains the alkaloids calystegines and swainsonine, which inhibit key cellular enzymes and cause systematic cell death. It is known that swainsonine is excreted in the amniotic fluid of dams exposed to the plant. Thus, the aim of this study was to verify whether the toxic effect of I. carnea on fetuses is due to exclusively the passage of the active principle of the plant through the placenta, or if the placentotoxic effect of swainsonine could collaborate in the adverse effects observed in the fetus. The teratogenic effects of exposure to the toxic principles of I. carnea were evaluated not only using the conventional protocol but also at later stages in the postnatal developmental period. Females were treated, from gestation day (GD) 6 until GD19, with 0.0, 1.0, 3.0 or 7.0 g/kg body weight of I. carnea dry leaves. The plant did not induce changes in reproductive performance or biochemical profile of the dams. Dams that received the highest dose of I. carnea showed cytoplasmic vacuolization in the liver, kidney and placental tissue. I. carnea promoted different lectin binding patterns in different areas of placental tissue. No fetal skeletal or visceral malformations was observed. The postnatal evaluation revealed a lower litter weight and a lower pup body weight one day after birth in the group that received the highest dose of I. carnea. Physical milestones were unaffected by the treatments. Female pups from all experimental groups exhibited a delay in achieving a negative geotaxis response. The results show that the toxic principle of I. carnea produces injury in utero in mothers and fetuses, but these deleterious effects were better demonstrated using postnatal evaluation.

Maternal Ingestion of Ipomoea carnea: Effects on Goat-Kid Bonding and Behavior

Ipomoea carnea is a toxic plant found in Brazil and other tropical and subtropical countries and often causes poisoning of livestock. The plant contains the alkaloids swainsonine and calystegines, which inhibit key cellular enzymes and cause systematic cell death. This study evaluated the behavioral effects of prenatal ingestion of this plant on dams and their kids. Twenty-four pregnant goats were randomly allocated into four treatment groups and received the following doses (g/kg BW) of fresh I. carnea: 0 (control group), 1.0 (IC1), 3.0 (IC3), and 5.0 (IC5) from day 27 of gestation until parturition. Dam and kid bonding and behavior were evaluated by several tests, immediately after birth until six weeks of age. Dams from IC3 and IC5 groups spent less time paying attention to the newborn. There was a lack of maternal-infant bonding due to I. carnea intoxication. Kids from treated dams had difficulty in standing, suckling, and in recognizing their mother hours after birth. I. carnea can also compromise the kids’ ability to learn and to retain spatial memory. We suggest that kids from pregnant goats given I. carnea during gestation have significant behavioral alterations and developmental delays that may compromise their survival.

A study on embryonic death in goats due to Nicotiana glauca ingestion

Numerous plants are known to be teratogenic in livestock. In addition to causing malformations, several plants can also cause embryonic death. These losses decrease the reproductive efficiency of animals exposed to these plants. The aim of this study was to determine if teratogenic plants such as lupines or tobaccos cause embryonic losses. A goat model using the plant Nicotiana glauca was used in this study, as this model has been used to characterize the mechanism of Lupinus, Conium, and Nicotiana-induced terata. Four groups of goats were dosed from gestational day 1-10, 11-20, 21-30, and 31-40. Goats were evaluated via ultrasound imaging for pregnancy after completion of the dosing regimen and kids were evaluated for malformations at the time of parturition. Overall, there was no evidence from this study that N. glauca (anabasine) at this dose (2 g/kg/day) would cause embryonic losses in goats. However, the dose of N. glauca used in this study was at the lower threshold that would be expected to produce terata. Therefore it is possible that higher doses of anabasine could cause embryonic loss. Further work is also needed to characterize the kinetic profile of anabasine, and other teratogenic alkaloids, in the fetal compartments.

Sire effects on neonatal lamb vigour and following-behaviour

The ability of the lamb to maintain contact with the ewe as she moves away from the birth site is critical to the lamb’s subsequent survival. If this contact is compromised then lamb loss is likely to occur due to starvation/mismothering. This study uses sires from the Sheep CRC Information Nucleus Flock to compare the effect of selection of sires within the Merino breed for high or low losses due to starvation/mismothering on neonatal lamb vigour. Lamb vigour was measured using conventional measures of time to perform early neonatal behaviours, early physiological measures (rectal temperatures and blood glucose), and performance in a modified barrier test while under physiological stress from cold exposure. Lambs were exposed to cold at a time (4–6 h after birth) when the ewe is likely to be moving away from the birth site and therefore when losses due to starvation/mismothering are likely to begin. Progeny from the high-loss sires were significantly (P < 0.05) slower to attempt to stand, and to stand, than progeny from the no-loss sires and tended to be slower to reach the udder and suckle (P = 0.07). Lambs from the no-loss group also had a significantly (P < 0.01) higher vigour score than the high-loss group. There was no effect of sire group on the performance of lambs in the modified barrier test; however, cold-treated lambs performed poorly in the test compared with control lambs. It was concluded that sire can have an effect on lamb vigour, but it does not necessarily translate into effects on later following-behaviour while under stressful conditions.

The immunomodulatory effects of Ipomoea carnea in rats vary depending on life stage

Ipomoea carnea Jacq. ssp. fistulosa (Mart. Ex Choisy; Convolvulaceae; I. carnea) possesses a toxic component: an indolizidine alkaloid swainsonine (SW) that has immunomodulatory effects due to its inhibition of glycoprotein metabolism. It is also known that SW is excreted into both the amniotic fluid and milk of female rats exposed to I. carnea. Thus, the aim of this study was to determine whether SW exposure, either in utero or from the milk of dams treated with I. carnea, modulates offspring immune function into adulthood. In addition, adult (70 days old) and juvenile rats (21 days old) were exposed to I. carnea in order to evaluate several other immune parameters: lymphoid organs relative weight and cellularity, humoral and cellular immune responses. Offspring exposed to I. carnea during lactation developed rheumatoid arthritis (RA) in adulthood after an immunogenic challenge. In addition, both adult and juvenile rats exposed to I. carnea showed discrepancies in several immune parameters, but did not exhibit any decrease in humoral immune response, which was enhanced at both ages. These findings indicate that SW modulates immune function in adult rats exposed to SW during lactation and in juvenile and adult rats exposed to SW as juveniles and adults, respectively.

Clinical and Morphologic Changes in Ewes and Fetuses Poisoned by Ipomoea Carnea Subspecies Fistulosa

Intoxication with Ipomoea carnea has been reported in goats, sheep, and cattle in tropical regions worldwide. The disease has been characterized only in goats; therefore, the present study was conducted in sheep. Nine animals were fed feed rations that contained 3 different concentrations of Ipomoea carnea subsp. fistulosa. Individual intake varied between 10.5 and 135.2 g of fresh plant per kilogram of body weight (BW) per day. Animals first showed clinical signs between day 43 and day 63. The maximum survival time was 133 days. Sheep presented with weight loss and neurologic abnormalities. Neurologic signs were dominated by marked depression, abnormal behavior, and musculoskeletal weakness, with poorly defined motor and proprioceptive deficits. In mature animals, cytoplasmic vacuolation, consistent with accumulation of secondary lysosomes, affected neurons, astrocytes, exocrine pancreatic acinar epithelia, hepatocytes and Kupffer cells, renal tubular epithelia, thyroid follicular epithelia, cortical adrenal epithelia, endothelia and perivascular cells, and macrophages in lymph nodes and spleen. In the central nervous system, there was axonal degeneration and astrogliosis. Abortion was observed as early as day 22 of the trial. In fetal tissues and placenta of chronically poisoned ewes, cytoplasmic vacuolation was histologically detected in neurons, exocrine pancreatic acinar epithelia, hepatocytes, renal tubular epithelia, and thyroid follicular epithelia. All the sheep developed a glycoprotein storage disease, with lysosomal accumulation of N-glycosidically linked oligosaccharides, which was indistinguishable from that induced by the alkaloid swainsonine alone.