University Distinguished Professors

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Becoming a University Distinguished Professor (UDP) is the highest honor that can be awarded to a faculty member at North Dakota State University. Research from these individuals can be found here. More information about University Distinguished Professors can be found at https://www.ndsu.edu/president/honors/distinguished_professors/

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Now showing 1 - 9 of 9

Arginine Supplementation Strategies during Gestation: Impacts on Dams and Offspring
(North Dakota State University, 2015) Bjertness, Jena Lee
We hypothesize rumen-protected arginine supplementation during gestation will mitigate deleterious offspring effects caused by undernutrition. Experiment 1: non-pregnant ewes were supplemented with rumen-protected arginine at varying doses to assess effects on circulating amino acids and carotid hemodynamics. Arginine concentrations post-supplementation were greater in ewes supplemented with 180 vs. 90 mg/kg BW, and vascular resistance indices were lesser with 180 mg/kg BW; therefore, 180 mg/kg BW was used in experiment 2. Experiment 2: nutrient-restricted pregnant ewes were supplemented with rumen-protected arginine and maternal and offspring growth and physiological responses were measured. Arginine supplementation to nutrient restricted ewes improved offspring development compared to restricted ewes without supplementation. Circulating amino acids in offspring were efficiently metabolized, which may contribute to improved growth and development. There was no change in carotid hemodynamics in supplemented pregnant ewes. Further research should determine how arginine improves development, as this dietary supplement could rescue at-risk pregnancies.
Biological Evaluation of the Associations Between Animal Size, Feeding Behavior, Blood Metabolites and Feed Efficiency in Beef Cattle
(North Dakota State University, 2017) Portela Fontoura, Ananda Barbara
The biological variation in feed efficiency is regulated by multiple physiological mechanisms relevant to energy use in livestock species. The current study examined the associations between body composition, feeding behavior, linear body measurements and plasma metabolites with different measures of feed efficiency in growing heifers, finishing steers and mature pregnant cows. Our findings indicate that inclusion of body size measurements in prediction models of gain and intake improved the models’ accuracy and might account important differences related to eating capacity. Among the traits evaluated, feeding behavior possessed stronger associations with efficiency measures and displayed differences between efficient and inefficient animals. The associations between the traits studied herein varied across the efficiency measures used and beef cattle stage of production. Thus, selection criteria and performance evaluation based on efficiency measures should account for these traits, combined with animal’s stage of production and system’s outputs of interest.
Effects of Corn Condensed Distillers Solubles Supplementation on Intake, Performance, Rate and Site of Digestion, and Ruminal Fermentation in Cattle Consuming Forage-Based Diets
(North Dakota State University, 2015) Coupe, Lindsey Rebecca
Two studies were conducted to determine effect of feeding method and level of corn condensed distillers solubles supplementation on performance of beef cows fed forage-based diets and effects on digestibility and ruminal fermentation. Experiment 1 utilized 80 gestating crossbred cows in a randomized complete block design. Treatments were arranged in a 2 × 2 + 1 factorial design; main effects were feeding method (mixed vs. fed separately) and level of CCDS. All treatments were offered ad libitum forage. Experiment 2, utilized 5 ruminally and duodenally cannulated Holstein steers in a 5×5 Latin square to evaluate effects of CCDS supplementation on DM intake, site of digestion, and ruminal fermentation. Exp. 2 utilized similar treatments as experiment 1; and all treatments were offered ad libitum forage. Results of these studies suggest that CCDS supplementation increases intake, performance, and CP digestion and appears to be an effective supplement for cattle eating moderate-quality forages.
Effects of Maternal Nutrition on Fructose, Glucose, and Cationic Amino Acid Transporter Expression in Bovine Utero-Placental Tissues from Days 16 to 50 of Gestation
(North Dakota State University, 2016) Crouse, Matthew Scott Pennell
Poor Maternal nutrition has been implicated to reduce nutrient transport to the conceptus. Therefore, we hypothesized that maternal nutrition and day of gestation would impact mRNA expression of nutrient transporters GLUT1, GLUT3, GLUT5, GLUT14, CAT-1, CAT-2, and CAT-3 in beef heifers. Crossbred Angus heifers (n = 49) were bred via AI, assigned to nutritional treatment (CON = 100% of requirements for 0.45 kg/d gain and RES = 60% of CON) and ovariohysterectomized on d 16, 34, or 50 of gestation. Expression of CAT-2 was the only gene in any tissue to demonstrate a day × treatment interaction. Expression of nutrient transporters were not influence by nutritional treatment (P > 0.05); however, transporters were differentially expressed by day of gestation (P ≤ 0.05). We interpret these results to indicate that day, has a greater influence than a 40% global nutrient restriction on mRNA expression of nutrient transporters in bovine utero-placental tissues.
The Impact of Digestive Enzymes in the Ruminant Animal
(North Dakota State University, 2016) Keomanivong, Faithe Elizabeth
Understanding the enzymatic activity in ruminant digestive systems is essential for securing adequate growth, reproduction and overall metabolism. In order to evaluate the impact of various nutritional sources and dietary strategies on enzymatic activity, five experiments were designed. Experiment 1 examined the influence of nutrient restriction and melatonin supplementation on maternal and fetal pancreatic development. Experiment 2 explored various phases of the reproductive cycle and the impact of intravenous arginine infusion amid differing levels of feed intake. Experiment 3 determined the effectiveness of realimentation during advancing stages of gestation. Experiments 4 and 5 examined the impact of variable rations on ruminal pH, NH3, VFA, total gas and methane concentration and enzymatic activity in steers consuming rations of fine- vs coarse-rolled corn and 20% vs 40% DDGS (Experiment 4) and corn vs barley based diets with low- vs moderate-oil DDGS (Experiment 5). Overall, nutrient restriction caused reduced BW, pancreatic mass and pancreatic enzyme activity in mature animals. In Experiment 1, the addition of dietary melatonin diminished the impact of nutrient restriction on maternal pancreatic mass and α-amylase activity while reducing the secretion of insulin and size of insulin-containing cell clusters. Fetal pancreatic enzymes were unaffected by treatment, however, pancreatic morphology exhibited greater insulin-containing cell cluster size in fetuses from adequately fed dams. In Experiment 2, arginine infusion did not alter pancreatic exocrine or endocrine function during the various luteal stage phases. In Experiment 3, realimentation during different stages of gestation decreased the impact of reduced feed intake and, in some cases, allowed for compensatory gain of the exocrine pancreas. The maternal and fetal endocrine pancreas was unaffected. Mature animals had greater changes in pancreatic exocrine secretions whereas fetuses differed mainly in endocrine function as a result of improper nutritional status. Comparison of pancreatic tissue revealed a greater quantity, and larger size, of insulin-containing cell clusters in fetuses which appear to separate as the animal matures. Differences in rumen enzymatic activity was found in Experiments 4 and 5, however, despite changes in lag time of gas production or ruminal degradation rates, the concentration of greenhouse gases (CH4 or CO2) produced were unaffected.
Impacts of Beef Cow Nutrition on Conceptus Development
(North Dakota State University, 2013) Camacho, Leticia Elideth
Two experiments were conducted to determine the effect of maternal nutrient restriction followed by realimentation during early to mid-gestation on uterine blood flow (BF), maternal performance, and conceptus development in pregnant beef cows. In Experiment 1, effects of maternal nutrient restriction followed by realimentation during mid-gestation on uterine BF of lactating, multiparous cows were evaluated. Nutrient restriction from d 30 until 140 of gestation did not alter total uterine BF. However, upon realimentation (from d 140 to 198 of gestation), there was enhanced ipsilateral uterine BF. In Experiment 2, effects of maternal nutrient restriction followed by realimentation during early to mid-gestation on late gestation uterine BF, maternal performance, and conceptus development was evaluated using non-lactating, multiparous cows. Slaughters were performed at d 85, 140, and 254 of gestation. During late gestation when all cows were receiving similar nutrition (100% of the NRC requirements), ipsilateral uterine BF and total BF were increased in cows that were previously nutrient restricted from d 30 until d 85 of gestation and realimented until d 254 of gestation. Therefore, results from both experiments suggest that the bovine placenta may be programmed to function differently after a period of nutrient restriction. Duration of restriction or realimentation impacted maternal performance and organ weights. The dam might become more efficient in the utilization of nutrients after being realimented as gestation advances. Nutrient restriction during early pregnancy tended to increase fetal and placental size by d 85. However, when cows were restricted longer or when realimented, there were no observable differences in placental or fetal growth. The maternal system may adapt to allow for fetal catch up growth during later gestation by enhancing uteroplacental nutrient transport capacity or placental function. From the results obtained in these 2 experiments we can conclude that maternal nutrient restriction during early gestation enhances conceptus growth and uterine BF later in pregnancy. Perhaps, timely management strategies might result in enhanced conceptus development. Even though more research is necessary, opportunities to intervene appear to be available during times of poor nutrition in beef cow/calf systems.
Impacts of Supplemental Arginine on Ewe Reproductive Performance
(North Dakota State University, 2014) Crane, Alison Ryan
The objective of this study was to determine the effects of injectable and oral arginine (Arg) supplementation provided 14 d post-breeding on reproductive performance of fall lambing ewes. Upon estrus detection (d 0) ewes were randomly assigned to one of six treatments for a 14-d treatment period: injectable saline (CON; n = 25), injectable alanine (IVALA; n = 20), injectable arginine (IVARG; n = 23), oral rumen-protected Arg (RPARG; n = 20), oral soybean meal (SBM; n = 23), or oral fishmeal (FM; n = 24). Weaning rates were higher (P < 0.05) in Arg supplemented ewes. Plasma progesterone and serum Arg concentrations exhibited a treatment and day effect (P < 0.05), but no treatment × day interaction was observed (P > 0.05). In contrast to previous research, supplemental Arg during the first 14 d of pregnancy did not improve pregnancy or lambing rates, however, IVARG positively impacted weaning rates.
Influence of Maternal Nutrient Intake on Placental Vascular Function in Pregnant Beef Cows
(North Dakota State University, 2014) Reyaz, Arshi
We hypothesized that global maternal nutrient restriction during early and mid-gestation followed by realimentation in pregnant beef cows would alter placental arterial vascular function. We tested changes in placental caruncular (CAR) and cotyledonary (COT) arterial sensitivity to bradykinin (BK), a potent vasodilator. Cows were randomly assigned to be nutrient restricted for 55 or 110 during early to mid pregnancy. On d 85, 140, and 254 cows were euthanized and CAR and COT arteries were isolated. Maternal nutrient restriction during early and mid-gestation allowed for placental compensation to overcome the loss of nutrients while realimentation returned placental arterial vosoactivity similar to control cows in response to BK. Further, CAR and COT placental arteries may respond to BK induced vasodilation through different pathways which is important when considering possible therapeutics for compromised pregnancies.
Maternal Nutritional Plane and Endogenous Retroviral Gene Elements, Pregnancy Hormones, and Placental Vascularity and Angiogenic Factors during the Establishment of Pregnancy in Beef Cattle
(North Dakota State University, 2016) McLean, Kyle James
In order to meet the projected food demands by 2050, animal agriculture must increase production of animal products on the same or decreased land area through increased efficiency. Early gestation is one area to increase efficiency in beef production in a twofold manner 1) by increasing the number of calves born due to decreased early embryonic loss and 2) by minimizing detrimental effects due to fetal programming which may decrease offspring growth or reproductive efficiency. Both of which will result in more pounds of beef produced by the same number of cows. Recently, endogenous retroviral elements (ERV), which make up a significant portion of mammalian genomes, have been implicated in vital steps during placentation. The placenta is the source of nutrient, gas, and waste exchange between maternal and fetal circulation which is necessary to support fetal growth. Maternal nutrition influences fetal growth and placental development. Therefore, we hypothesized that ERV envelope genes, syncytin-Rum1 and BERV-K1, as well as pregnancy specific hormones, PSP-B, and IFN-τ will be differentially expressed during critical time points of early pregnancy and maternal nutrition restriction will alter mRNA expression at critical time points. We developed a technique to ovariohysterectomized beef heifers which provides a large animal model to acquire uteroplacental tissues. In year 1, we established basal expression patterns for syncytin-Rum1 and BERV-K1, PSP-B, and IFN-τ within utero-placental tissues during the first 50 d of gestation. In year 2, we determined the effects of 40% global nutrient restriction on the mRNA expression of syncytin-Rum1 and BERV-K1, PSP-B, and IFN-τ on d 16, 34, and 50 of gestation in uteroplacental tissues. These data provide novel evidence of differential expression of endogenous retroviruses (syncytin-Rum1 and BERV-K1), PSP-B, and IFN-τ during early gestation but 40% maternal nutrient restriction had little influence of mRNA expression. However, further work needs to be completed to elucidate functions, mechanisms, and interactions of these genes during early gestation and their importance to the successful establishment of pregnancy.

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