|YUNUSOVA, ROZA - North Dakota State University|
|NEVILLE, TAMMI - North Dakota State University|
|VONNAHME, KIMBERLY - North Dakota State University|
|HAMMER, CAROLYN - North Dakota State University|
|REED, JAKE - North Dakota State University|
|Taylor, Joshua - Bret|
|REDMER, DALE - North Dakota State University|
|REYNOLDS, LAWRENCE - North Dakota State University|
|CATON, JOEL - North Dakota State University|
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/17/2013
Publication Date: 5/1/2013
Citation: Yunusova, R., Neville, T.L., Vonnahme, K.A., Hammer, C., Reed, J., Taylor, J.B., Redmer, D.A., Reynolds, L.P., Caton, J.S. 2013. Impacts of maternal selenium supply and nutritional plane on visceral tissues and intestinal biology in 180-day-old offspring in sheep. Journal of Animal Science. 91:2229-2242.
Interpretive Summary: Recently, we have demonstrated the advantages of feeding diets naturally rich in selenium to ruminant livestock. Critics have expressed concern about the potential for selenium toxicity at the dietary levels of selenium that we have proposed in the past. These results clearly demonstrate that selenium, from natural selenium-rich feeds, fed at 10-fold the recommended requirement is safe and nutritious for the pregnant ewe and developing fetus.
Technical Abstract: Objectives were to investigate the effects of maternal Se supply and nutritional plane during gestation on offspring visceral tissues and indices of intestinal growth, vascularity, and function at 180 d of age. Rambouillet ewe lambs (n = 82, approximately 240 d of age; 52 ± 0.8 kg BW at breeding) were allocated to a 2 × 3 factorial arrangement of treatments. Treatments included dietary Se (adequate Se [ASe, 9.5 µg/kg BW] or high 31 Se [HSe, 81.8 µg/kg BW]) initiated at breeding and nutritional plane (60% [restricted, RES], 100% [control, CON], and 140% [ high, HI] of requirements) initiated at d 50 of gestation. Ewes were fed pelleted diets and housed individually indoors. At parturition, lambs were immediately removed and fed artificial colostrum for the first 20 h followed by ad libitum access to milk replacer. At 180 ± 2 d of age, lambs were euthanized and 36 tissues harvested. Birth weight was affected by nutritional treatments (P < 0.001) with decreased birth weight in RES and HI compared with CON. Offspring from RES and HI ewes had decreased (P = 0.07) blood volume compared to CON, and those born to HSe ewes had increased (P < 0.04) total visceral adiposity. Within offspring from CON ewes, 40 those from HSe ewes had greater (P < 0.02) intestinal mass compared with ASe ewes. Within offspring from HSe ewes, both RES and HI had reduced (P = 0.05) intestinal mass compared with CON. Jejunal capillary area density was greater (P = 0.08) in offspring from ewes fed HSe compared with ASe. In addition, area per capillary was 44 greater (P = 0.09) in CON compared with RES. Maternal nutritional plane tended (P = 0.11) to alter total small intestinal vascularity, with lambs from CON being greater than RES. Expression of most mRNA for measured angiogenic factors and receptors was not altered (P = 0.13) by maternal treatments; however expression of glucagon like peptide -2 (GLP-2) was lower (P = 0.07) in offspring from RES compared with CON ewes. Offspring from ewes fed HI diets had increased (P = 0.08) jejunal mucosal maltase activity. In conclusion, maternal Se supply and nutritional plane during gestation resulted in measurable changes in offspring visceral tissues and intestinal biology including 52 perirenal fat, blood volume, intestinal mass, total jejunal crypt cell proliferation, area per capillary in jejunal villi, GLP-2 mRNA expression, and maltase activity at 180 d. Additional work is needed to determine impacts on intestinal function and nutrient uptake.