Effects of Maternal Nutrition and Rumen-Protected Arginine Supplementation on Pregnant and Non-Pregnant Ewe and Postnatal Lamb Serum Amino Acids

Tuesday, July 22, 2014: 3:30 PM
2103C (Kansas City Convention Center)
Jena L. Peine , North Dakota State University, Fargo, ND
Guangqiang Jia , North Dakota State University, Fargo, ND
Marsha Kapphahn , North Dakota State University, Fargo, ND
Stephen T O'Rourke , North Dakota State University, Fargo, ND
Allison M. Meyer , Division of Animal Sciences, University of Missouri, Columbia, MO
Lawrence P. Reynolds , North Dakota State University, Fargo, ND
Joel S. Caton , North Dakota State University, Fargo, ND
Abstract Text:

Our hypothesis was that rumen-protected arginine supplementation would increase levels of serum amino acids in both non-pregnant and pregnant ewes and their offspring, and thereby help overcome negative effects of nutrient restriction during the last two-thirds of gestation. To test this hypothesis, 2 studies were conducted with Rambouillet ewes penned individually in a temperature-controlled facility: Study 1 was a dose titration study to determine the most effective dose of rumen-protected arginine, and Study 2 tested our hypothesis in pregnant ewes and their lambs. Study 1 used non-pregnant primiparous ewes (n = 60) randomly assigned to 1 of 4 treatments: a control group receiving no supplement (0), and groups receiving 90mg/kg BW (90), 180mg/kg BW (180), or 360mg/kg BW of rumen-protected arginine supplement (360). After 15 d of supplementation, ewes receiving 180 had greater serum ornithine (P = 0.05) and arginine (P = 0.05), and tended to have greater aspartate (P = 0.08) than ewes receiving 90, and 180 were similar to 360 fed ewes (P ≥ 0.55). In study 2, multiparous ewes (n = 32) were allocated to 3 treatments at 54 ± 3.9 d of gestation: 100% of requirements (control, CON), 60% of control (restricted, RES), or RES plus a 180 mg/kg BW rumen-protected arginine supplement once daily (RES-ARG).  Ewes were maintained on treatments through parturition, when lambs were removed from dams and reared independently. At 128 d of gestation, CON ewes weighed more (P ≤ 0.001) than RES and RES-ARG ewes, and had greater (P ≤ 0.001) BCS. In addition, serum ornithine, citrulline, aspartate, arginine, and methionine were greater (P ≤ 0.03) in CON than RES and RES-ARG ewes, suggesting that arginine supplementation could not overcome differences in nutritional plane. Lambs from CON ewes had greater (P = 0.03) birth weights than RES, with lambs from RES-ARG ewes being intermediate and similar in weight to other treatments (P ≥ 0.08). At birth, lambs from RES-ARG ewes had greater serum arginine (P = 0.04) and lysine (P = 0.04) than those from RES ewes, suggesting effects on amino acid transport from dam to fetus. These results support our hypothesis that maternal rumen-protected arginine supplementation could increase serum levels of amino acids in offspring. Additionally, arginine supplementation of dams may be able to increase fetal circulating arginine without altering maternal circulating arginine.

Keywords: arginine, amino acids, developmental programming