One-carbon metabolite supplementation to nutrient-restricted beef heifers affects placental vascularity during early pregnancy

Authors: KANJANARUCH, CHUTIKUN - Khon Kaen University; BOCHANTIN, KERRI - North Dakota State University; DAVILA RUIZ, BETHANIA - North Dakota State University; SYRING, JESSICA - North Dakota State University; ENTZIE, YSSI - North Dakota State University; KING, LAYLA - North Dakota State University; BOROWICZ, PAWEL - North Dakota State University; Crouse, Matthew; CATON, JOEL - North Dakota State University; DAHLEN, CARL - North Dakota State University; WARD, ALISON - North Dakota State University; REYNOLDS, LAWRENCE - North Dakota State University

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/23/2024
Publication Date: 2/26/2024
Citation: Kanjanaruch, C., Bochantin, K.A., Davila Ruiz, B.J., Syring, J., Entzie, Y., King, L., Borowicz, P.P., Crouse, M.S., Caton, J.S., Dahlen, C.R., Ward, A.K., Reynolds, L.P. 2024. One-carbon metabolite supplementation to nutrient-restricted beef heifers affects placental vascularity during early pregnancy. Journal of Animal Science. 102. Article skae044. https://doi.org/10.1093/jas/skae044.
DOI: https://doi.org/10.1093/jas/skae044

Interpretive Summary: In cow-calf production, periods of poor forage availability or quality can result in nutrient restriction during pregnancy. Previous studies have shown that even moderate maternal feed restriction during pregnancy, including very early in pregnancy, has profound effects on fetal and placental development, potentially have lasting impacts on calf growth and body composition later in life. One-carbon metabolites (OCM) in the diet are biomolecules required for methylation reactions and participate in regulation of gene expression. Our objective was to evaluate the effects of nutrient restriction and OCM supplementation (specifically methionine, choline, folate, and vitamin B12) on placental vascular development during early pregnancy. Proper placental vascular development is necessary for healthy pregnancy outcomes, reflected by normal birth weight and healthy offspring. Our results indicated that maternal rate of gain and OCM supplementation affect placental vascularization, which could affect placental function and thereby fetal development throughout gestation. This study provides a better understanding of the role of restricted feeding and OCM on placental vascularization. Our findings contribute to understanding early pregnancy feeding strategies that could improve placental vascular development in beef cattle.

Technical Abstract: We hypothesized that restricted maternal nutrition and supplementation of one-carbon metabolites (OCM; methionine, folate, choline, and vitamin B12) would affect placental vascular development during early pregnancy. A total of 43 cows were bred, and 32 heifers successfully became pregnant with female calves, leading to the formation of four treatment groups: CON - OCM (n=8), CON + OCM (n=7), RES - OCM (n=9), and RES + OCM (n=8). The experimental design was a 2 × 2 factorial, with main factors of dietary intake affecting average daily gain: control (CON; 0.6 kg/d ADG) and restricted (RES; -0.23 kg/d ADG); and OCM supplementation (+ OCM) in which the heifers were supplemented with rumen-protected methionine (7.4 g/d) and choline (44.4 g/d) and received weekly injections of 320 mg of folate and 20 mg of vitamin B12, or received no supplementation (-OCM; corn carrier and saline injections). Heifers were individually fed and randomly assigned to treatment at breeding (d 0). Placentomes were collected on d 63 of gestation (0.225 of gestation). Fluorescent staining with CD31 and CD34 combined with image analysis was used to determine vascularity of the placenta. Images were analyzed for capillary area density (CAD) and capillary number density (CND). Areas evaluated included fetal placenta (cotyledon; COT), maternal placenta (caruncle; CAR), whole placentome (CAR + COT), intercotyledonary fetal membranes (ICOT, or chorioallantois), intercaruncular endometrium (ICAR), and endometrial glands (EG). Data were analyzed with the GLM procedure of SAS, with heifer as the experimental unit and significance at P 0.05 and P < 0.10. Though no gain × OCM interactions existed (P >/= 0.10), OCM supplementation increased (P = 0.01) CAD of EG, whereas nutrient restriction tended (P < 0.10) to increase CAD of ICOT and CND of COT. Additionally, there was a gain × OCM interaction (P < 0.05) for CAD within the placentome and ICAR, such that RES reduced and supplementation of RES with OCM restored CAD. These results indicate that maternal rate of gain and OCM supplementation affected placental vascularization (capillary area and number density), which could affect placental function and thus the efficiency of nutrient transfer to the fetus during early gestation.