Location: Reproduction ResearchTitle: Glucosamine supplementation during late gestation alters placental development and increases litter size
Submitted to: Journal of Animal Science and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/11/2017
Publication Date: 9/1/2017
Publication URL: http://handle.nal.usda.gov/10113/5798451
Citation: Vallet, J.L., Miles, J.R., Freking, B.A., Meyer, S. 2017. Glucosamine supplementation during late gestation alters placental development and increases litter size. JOURNAL OF ANIMAL SCIENCE AND BIOTECHNOLOGY. 8:68. https://doi.org/10.1186/s40104-017-0198-9.
Interpretive Summary: The number of piglets born alive and piglet birth weights are both limited by the delivery of nutrients by the pig placenta to the developing fetus. Within the placenta, nutrient transport occurs across the fetal-maternal interface, which is highly folded. The depth of the folds contributes to nutrient transport by increasing the interacting surface between the sow and fetus; this depth is limited in placenta associated with small fetuses. We hypothesized that glucosamine supplementation during late gestation would promote greater depth of the folded fetal-maternal interface and improve litter size and/or piglet birth weights. In the first experiment, the effects of glucosamine supplementation during late gestation on fetal-maternal interface fold development, litter size, and fetal and placental weights were tested in young females. Depth of the folds in the fetal-maternal interface and overall thickness of the placenta was increased after glucosamine supplementation, and these changes occurred in association with an increase in litter size. In a second experiment, the effects of glucosamine supplementation on litter size and piglet birth weights were tested in commercial sows that had delivered from 1 to 7 previous litters of piglets. Glucosamine supplementation did not alter litter size or birth weights of piglets but did increase stillbirths in animals that had previously delivered 6 or 7 litters of piglets. Because the commercial sows in the second experiment were larger than the gilts in the first experiment, we repeated the second experiment with a greater dose (20 g per day) of glucosamine in a third experiment on commercial sows. Glucosamine supplementation resulted in +1.3 piglets per litter without affecting birth or weaning weights or preweaning survival, resulting in more weaned piglets. We conclude that glucosamine supplementation increased fetal-maternal interface fold development and litter size in young females and increased litter size in commercial sows without reducing birth or weaning weights or increasing preweaning mortality. Glucosamine supplementation during late gestation should be very useful to swine producers to improve reproductive efficiency.
Technical Abstract: Background: During late gestation the placental epithelial interface becomes highly folded, which involves changes in stromal hyaluronan. Hyaluronan is composed of glucoronate and N-acetyl-glucosamine. We hypothesized that supplementing gestating dams with glucosamine during this time would support placental folded-epithelial-bilayer development and increase litter size. In Exp. 1, gilts were unilaterally hysterectomized-ovariectomized (UHO). UHO gilts were mated and then supplemented daily with 10 g glucosamine (n = 16) or glucose (control, n = 17) from d 85 of gestation until slaughter (d 105). At slaughter, the number of live fetuses was recorded and each live fetus and its placenta was weighed. Uterine wall samples adjacent to the largest and smallest fetuses within each litter were processed for histology. In Exp. 2, pregnant sows in a commercial sow farm were supplemented with either 10 g glucosamine or glucose daily from d 85 of gestation to farrowing. Total piglets born and born alive were recorded for each litter. In Exp. 3, the same commercial farm and same protocol were used except that the dose of glucosamine and glucose was doubled to 20 g/d. Results: In Exp. 1, the number of live fetuses tended to be greater in glucosamine-treated UHO gilts (P = 0.098). Placental morphometry indicated that the width of the folded bilayer was greater (P = 0.05) in glucosamine-treated gilts. In Exp. 2, litter size did not differ between glucosamine- and glucose-treated sows. However in Exp. 3, the increased dose of glucosamine resulted in a significant treatment by parity interaction (P = 0.01), in which total piglets born and born alive were greater in glucosamine treated sows of later parity (5 and 6). Conclusions: These results indicated that glucosamine supplementation increased the width of the folds of the placental bilayer and increased litter size in later parity, intact pregnant commercial sows.