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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Nutrition, Growth and Physiology » Research » Publications at this Location » Publication #297176

Title: Effects of maternal nutrient restriction followed by realimentation during midgestation on uterine blood flow in beef cows

Author
item CAMACHO, L - North Dakota State University
item LEMLEY, C - North Dakota State University
item PREZOTTO, L - North Dakota State University
item BAUER, M - North Dakota State University
item Freetly, Harvey
item SWANSON, K - North Dakota State University
item VONNAHME, K - North Dakota State University

Submitted to: Theriogenology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/7/2014
Publication Date: 6/20/2014
Publication URL: http://handle.nal.usda.gov/10113/58732
Citation: Camacho, L.E., Lemley, C.O., Prezotto, L.D., Bauer, M.L., Freetly, H.C., Swanson, K.C., Vonnahme, K.A. 2014. Effects of maternal nutrient restriction followed by realimentation during midgestation on uterine blood flow in beef cows. Theriogenology. 81(9):1248-1256.

Interpretive Summary: Beef cows are commonly managed in grazing systems where the quality of forage can negatively impact the nutritional and physiological status of the dam resulting in underdevelopment of their offspring at birth. Giving proper supplemental nutrition can mitigate the underdevelopment; however, there is a scarcity of information on how the timing of realimentation impacts placental and fetal development. Researchers at North Dakota State University and the U.S. Meat Animal Research Center determined that blood flow to the uterus during early gestation in cows that received a nutrient restriction did not differ from cows fed to meet nutrient requirements. However, when restricted cows received additional nutrients during late pregnancy, the blood flow to the portion of the uterus that contained the fetus increased above that of the control cows. These findings suggest that the placenta may be programmed to function differently after a period of nutrient restriction.

Technical Abstract: The objective was to examine the effect of maternal nutrient restriction followed by realimentation during mid-gestation on uterine blood flow (BF). On Day 30 of pregnancy, lactating, multiparous Simmental beef cows were assigned randomly to treatments: control (CON; 100% National Research Council; n = 6) and nutrient restriction (RES; 60% of CON; n= 4) from Day 30 to 140 (Period 1) and, thereafter, realimented to CON until Day 198 of gestation (Period 2). Uterine BF, pulsatility index (PI), and resistance index (RI) were obtained from both the ipsilateral and contralateral uterine arteries via Doppler ultrasonography. Generalized least squares analysis was performed. Ipsilateral uterine BF in both groups increased quadratically (P < 0.01) during period 1 and linearly (P < 0.01) during period 2. There was a treatment (P = 0.05) effect during period 2; where RES cows had greater ipsilateral BF versus CON. Ipsilateral uterine PI and RI decreased linearly (P